Similarly, when you call ftrace_return_to_handler(), pass it the frame pointer.
+HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+--------------------------------
+
+An arch may pass in a pointer to the return address on the stack. This
+prevents potential stack unwinding issues where the unwinder gets out of
+sync with ret_stack and the wrong addresses are reported by
+ftrace_graph_ret_addr().
+
+Adding support for it is easy: just define the macro in asm/ftrace.h and
+pass the return address pointer as the 'retp' argument to
+ftrace_push_return_trace().
HAVE_FTRACE_NMI_ENTER
---------------------
config CPU_NO_EFFICIENT_FFS
def_bool n
+config HAVE_ARCH_VMAP_STACK
+ def_bool n
+ help
+ An arch should select this symbol if it can support kernel stacks
+ in vmalloc space. This means:
+
+ - vmalloc space must be large enough to hold many kernel stacks.
+ This may rule out many 32-bit architectures.
+
+ - Stacks in vmalloc space need to work reliably. For example, if
+ vmap page tables are created on demand, either this mechanism
+ needs to work while the stack points to a virtual address with
+ unpopulated page tables or arch code (switch_to() and switch_mm(),
+ most likely) needs to ensure that the stack's page table entries
+ are populated before running on a possibly unpopulated stack.
+
+ - If the stack overflows into a guard page, something reasonable
+ should happen. The definition of "reasonable" is flexible, but
+ instantly rebooting without logging anything would be unfriendly.
+
+config VMAP_STACK
+ default y
+ bool "Use a virtually-mapped stack"
+ depends on HAVE_ARCH_VMAP_STACK && !KASAN
+ ---help---
+ Enable this if you want the use virtually-mapped kernel stacks
+ with guard pages. This causes kernel stack overflows to be
+ caught immediately rather than causing difficult-to-diagnose
+ corruption.
+
+ This is presently incompatible with KASAN because KASAN expects
+ the stack to map directly to the KASAN shadow map using a formula
+ that is incorrect if the stack is in vmalloc space.
+
source "kernel/gcov/Kconfig"
}
err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer);
+ frame_pointer, NULL);
if (err == -EBUSY) {
*parent = old;
return;
*
* Run ftrace_return_to_handler() before going back to parent.
* @fp is checked against the value passed by ftrace_graph_caller()
- * only when CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST is enabled.
+ * only when HAVE_FUNCTION_GRAPH_FP_TEST is enabled.
*/
ENTRY(return_to_handler)
save_return_regs
return;
err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer);
+ frame_pointer, NULL);
if (err == -EBUSY)
return;
else
r0 = sp; /* unsigned long *parent */
r1 = [sp]; /* unsigned long self_addr */
# endif
-# ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+# ifdef HAVE_FUNCTION_GRAPH_FP_TEST
r2 = fp; /* unsigned long frame_pointer */
# endif
r0 += 16; /* skip the 4 local regs on stack */
[--sp] = r1;
/* get original return address */
-# ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST
+# ifdef HAVE_FUNCTION_GRAPH_FP_TEST
r0 = fp; /* Blackfin is sane, so omit this */
# endif
call _ftrace_return_to_handler;
return;
if (ftrace_push_return_trace(*parent, self_addr, &trace.depth,
- frame_pointer) == -EBUSY)
+ frame_pointer, NULL) == -EBUSY)
return;
trace.func = self_addr;
#define alloc_thread_stack_node(tsk, node) ((unsigned long *) 0)
#define task_thread_info(tsk) ((struct thread_info *) 0)
#endif
-#define free_thread_stack(ti) /* nothing */
+#define free_thread_stack(tsk) /* nothing */
#define task_stack_page(tsk) ((void *)(tsk))
#define __HAVE_THREAD_FUNCTIONS
return;
}
- err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0);
+ err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0, NULL);
if (err == -EBUSY) {
*parent = old;
return;
if (unlikely(faulted))
goto out;
- if (ftrace_push_return_trace(old_parent_ra, self_ra, &trace.depth, fp)
- == -EBUSY) {
+ if (ftrace_push_return_trace(old_parent_ra, self_ra, &trace.depth, fp,
+ NULL) == -EBUSY) {
*parent_ra_addr = old_parent_ra;
return;
}
return;
if (ftrace_push_return_trace(old, self_addr, &trace.depth,
- 0 ) == -EBUSY)
+ 0, NULL) == -EBUSY)
return;
/* activate parisc_return_to_handler() as return point */
if (!ftrace_graph_entry(&trace))
goto out;
- if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY)
+ if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
+ NULL) == -EBUSY)
goto out;
parent = return_hooker;
/* Only trace if the calling function expects to. */
if (!ftrace_graph_entry(&trace))
goto out;
- if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY)
+ if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
+ NULL) == -EBUSY)
goto out;
parent = (unsigned long) return_to_handler;
out:
return;
}
- err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0);
+ err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0, NULL);
if (err == -EBUSY) {
__raw_writel(old, parent);
return;
def_bool 64BIT
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
- select HAVE_FUNCTION_GRAPH_FP_TEST
select HAVE_KRETPROBES
select HAVE_KPROBES
select HAVE_RCU_TABLE_FREE if SMP
void _mcount(void);
#endif
+#endif /* CONFIG_MCOUNT */
+
+#if defined(CONFIG_SPARC64) && !defined(CC_USE_FENTRY)
+#define HAVE_FUNCTION_GRAPH_FP_TEST
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
return parent + 8UL;
if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
- frame_pointer) == -EBUSY)
+ frame_pointer, NULL) == -EBUSY)
return parent + 8UL;
trace.func = self_addr;
*parent = return_hooker;
err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer);
+ frame_pointer, NULL);
if (err == -EBUSY) {
*parent = old;
return;
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
select HAVE_ARCH_WITHIN_STACK_FRAMES
select HAVE_EBPF_JIT if X86_64
+ select HAVE_ARCH_VMAP_STACK if X86_64
select HAVE_CC_STACKPROTECTOR
select HAVE_CMPXCHG_DOUBLE
select HAVE_CMPXCHG_LOCAL
select HAVE_EXIT_THREAD
select HAVE_FENTRY if X86_64
select HAVE_FTRACE_MCOUNT_RECORD
- select HAVE_FUNCTION_GRAPH_FP_TEST
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS
select SPARSE_IRQ
select SRCU
select SYSCTL_EXCEPTION_TRACE
+ select THREAD_INFO_IN_TASK
select USER_STACKTRACE_SUPPORT
select VIRT_TO_BUS
select X86_DEV_DMA_OPS if X86_64
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
-static struct thread_info *pt_regs_to_thread_info(struct pt_regs *regs)
-{
- unsigned long top_of_stack =
- (unsigned long)(regs + 1) + TOP_OF_KERNEL_STACK_PADDING;
- return (struct thread_info *)(top_of_stack - THREAD_SIZE);
-}
-
#ifdef CONFIG_CONTEXT_TRACKING
/* Called on entry from user mode with IRQs off. */
__visible inline void enter_from_user_mode(void)
{
u32 arch = in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
unsigned long ret = 0;
bool emulated = false;
u32 work;
/* Disable IRQs and retry */
local_irq_disable();
- cached_flags = READ_ONCE(pt_regs_to_thread_info(regs)->flags);
+ cached_flags = READ_ONCE(current_thread_info()->flags);
if (!(cached_flags & EXIT_TO_USERMODE_LOOP_FLAGS))
break;
-
}
}
/* Called with IRQs disabled. */
__visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
u32 cached_flags;
if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled()))
* special case only applies after poking regs and before the
* very next return to user mode.
*/
- ti->status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
+ current->thread.status &= ~(TS_COMPAT|TS_I386_REGS_POKED);
#endif
user_enter_irqoff();
*/
__visible inline void syscall_return_slowpath(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
u32 cached_flags = READ_ONCE(ti->flags);
CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
#ifdef CONFIG_X86_64
__visible void do_syscall_64(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
unsigned long nr = regs->orig_ax;
enter_from_user_mode();
*/
static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
{
- struct thread_info *ti = pt_regs_to_thread_info(regs);
+ struct thread_info *ti = current_thread_info();
unsigned int nr = (unsigned int)regs->orig_ax;
#ifdef CONFIG_IA32_EMULATION
- ti->status |= TS_COMPAT;
+ current->thread.status |= TS_COMPAT;
#endif
if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY) {
POP_GS_EX
.endm
+/*
+ * %eax: prev task
+ * %edx: next task
+ */
+ENTRY(__switch_to_asm)
+ /*
+ * Save callee-saved registers
+ * This must match the order in struct inactive_task_frame
+ */
+ pushl %ebp
+ pushl %ebx
+ pushl %edi
+ pushl %esi
+
+ /* switch stack */
+ movl %esp, TASK_threadsp(%eax)
+ movl TASK_threadsp(%edx), %esp
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+ movl TASK_stack_canary(%edx), %ebx
+ movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset
+#endif
+
+ /* restore callee-saved registers */
+ popl %esi
+ popl %edi
+ popl %ebx
+ popl %ebp
+
+ jmp __switch_to
+END(__switch_to_asm)
+
+/*
+ * A newly forked process directly context switches into this address.
+ *
+ * eax: prev task we switched from
+ * ebx: kernel thread func (NULL for user thread)
+ * edi: kernel thread arg
+ */
ENTRY(ret_from_fork)
pushl %eax
call schedule_tail
popl %eax
+ testl %ebx, %ebx
+ jnz 1f /* kernel threads are uncommon */
+
+2:
/* When we fork, we trace the syscall return in the child, too. */
movl %esp, %eax
call syscall_return_slowpath
jmp restore_all
-END(ret_from_fork)
-
-ENTRY(ret_from_kernel_thread)
- pushl %eax
- call schedule_tail
- popl %eax
- movl PT_EBP(%esp), %eax
- call *PT_EBX(%esp)
- movl $0, PT_EAX(%esp)
+ /* kernel thread */
+1: movl %edi, %eax
+ call *%ebx
/*
- * Kernel threads return to userspace as if returning from a syscall.
- * We should check whether anything actually uses this path and, if so,
- * consider switching it over to ret_from_fork.
+ * A kernel thread is allowed to return here after successfully
+ * calling do_execve(). Exit to userspace to complete the execve()
+ * syscall.
*/
- movl %esp, %eax
- call syscall_return_slowpath
- jmp restore_all
-ENDPROC(ret_from_kernel_thread)
+ movl $0, PT_EAX(%esp)
+ jmp 2b
+END(ret_from_fork)
/*
* Return to user mode is not as complex as all this looks,
* If we need to do entry work or if we guess we'll need to do
* exit work, go straight to the slow path.
*/
- testl $_TIF_WORK_SYSCALL_ENTRY|_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
+ movq PER_CPU_VAR(current_task), %r11
+ testl $_TIF_WORK_SYSCALL_ENTRY|_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
jnz entry_SYSCALL64_slow_path
entry_SYSCALL_64_fastpath:
*/
DISABLE_INTERRUPTS(CLBR_NONE)
TRACE_IRQS_OFF
- testl $_TIF_ALLWORK_MASK, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
+ movq PER_CPU_VAR(current_task), %r11
+ testl $_TIF_ALLWORK_MASK, TASK_TI_flags(%r11)
jnz 1f
LOCKDEP_SYS_EXIT
jmp entry_SYSCALL64_slow_path
1:
- /* Called from C */
- jmp *%rax /* called from C */
+ jmp *%rax /* Called from C */
END(stub_ptregs_64)
.macro ptregs_stub func
#define __SYSCALL_64(nr, sym, qual) __SYSCALL_64_QUAL_##qual(sym)
#include <asm/syscalls_64.h>
+/*
+ * %rdi: prev task
+ * %rsi: next task
+ */
+ENTRY(__switch_to_asm)
+ /*
+ * Save callee-saved registers
+ * This must match the order in inactive_task_frame
+ */
+ pushq %rbp
+ pushq %rbx
+ pushq %r12
+ pushq %r13
+ pushq %r14
+ pushq %r15
+
+ /* switch stack */
+ movq %rsp, TASK_threadsp(%rdi)
+ movq TASK_threadsp(%rsi), %rsp
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+ movq TASK_stack_canary(%rsi), %rbx
+ movq %rbx, PER_CPU_VAR(irq_stack_union)+stack_canary_offset
+#endif
+
+ /* restore callee-saved registers */
+ popq %r15
+ popq %r14
+ popq %r13
+ popq %r12
+ popq %rbx
+ popq %rbp
+
+ jmp __switch_to
+END(__switch_to_asm)
+
/*
* A newly forked process directly context switches into this address.
*
- * rdi: prev task we switched from
+ * rax: prev task we switched from
+ * rbx: kernel thread func (NULL for user thread)
+ * r12: kernel thread arg
*/
ENTRY(ret_from_fork)
- LOCK ; btr $TIF_FORK, TI_flags(%r8)
-
+ movq %rax, %rdi
call schedule_tail /* rdi: 'prev' task parameter */
- testb $3, CS(%rsp) /* from kernel_thread? */
- jnz 1f
+ testq %rbx, %rbx /* from kernel_thread? */
+ jnz 1f /* kernel threads are uncommon */
- /*
- * We came from kernel_thread. This code path is quite twisted, and
- * someone should clean it up.
- *
- * copy_thread_tls stashes the function pointer in RBX and the
- * parameter to be passed in RBP. The called function is permitted
- * to call do_execve and thereby jump to user mode.
- */
- movq RBP(%rsp), %rdi
- call *RBX(%rsp)
- movl $0, RAX(%rsp)
-
- /*
- * Fall through as though we're exiting a syscall. This makes a
- * twisted sort of sense if we just called do_execve.
- */
-
-1:
+2:
movq %rsp, %rdi
call syscall_return_slowpath /* returns with IRQs disabled */
TRACE_IRQS_ON /* user mode is traced as IRQS on */
SWAPGS
jmp restore_regs_and_iret
+
+1:
+ /* kernel thread */
+ movq %r12, %rdi
+ call *%rbx
+ /*
+ * A kernel thread is allowed to return here after successfully
+ * calling do_execve(). Exit to userspace to complete the execve()
+ * syscall.
+ */
+ movq $0, RAX(%rsp)
+ jmp 2b
END(ret_from_fork)
/*
#ifdef CONFIG_X86_ESPFIX64
native_irq_return_ldt:
- pushq %rax
- pushq %rdi
+ /*
+ * We are running with user GSBASE. All GPRs contain their user
+ * values. We have a percpu ESPFIX stack that is eight slots
+ * long (see ESPFIX_STACK_SIZE). espfix_waddr points to the bottom
+ * of the ESPFIX stack.
+ *
+ * We clobber RAX and RDI in this code. We stash RDI on the
+ * normal stack and RAX on the ESPFIX stack.
+ *
+ * The ESPFIX stack layout we set up looks like this:
+ *
+ * --- top of ESPFIX stack ---
+ * SS
+ * RSP
+ * RFLAGS
+ * CS
+ * RIP <-- RSP points here when we're done
+ * RAX <-- espfix_waddr points here
+ * --- bottom of ESPFIX stack ---
+ */
+
+ pushq %rdi /* Stash user RDI */
SWAPGS
movq PER_CPU_VAR(espfix_waddr), %rdi
- movq %rax, (0*8)(%rdi) /* RAX */
- movq (2*8)(%rsp), %rax /* RIP */
+ movq %rax, (0*8)(%rdi) /* user RAX */
+ movq (1*8)(%rsp), %rax /* user RIP */
movq %rax, (1*8)(%rdi)
- movq (3*8)(%rsp), %rax /* CS */
+ movq (2*8)(%rsp), %rax /* user CS */
movq %rax, (2*8)(%rdi)
- movq (4*8)(%rsp), %rax /* RFLAGS */
+ movq (3*8)(%rsp), %rax /* user RFLAGS */
movq %rax, (3*8)(%rdi)
- movq (6*8)(%rsp), %rax /* SS */
+ movq (5*8)(%rsp), %rax /* user SS */
movq %rax, (5*8)(%rdi)
- movq (5*8)(%rsp), %rax /* RSP */
+ movq (4*8)(%rsp), %rax /* user RSP */
movq %rax, (4*8)(%rdi)
- andl $0xffff0000, %eax
- popq %rdi
+ /* Now RAX == RSP. */
+
+ andl $0xffff0000, %eax /* RAX = (RSP & 0xffff0000) */
+ popq %rdi /* Restore user RDI */
+
+ /*
+ * espfix_stack[31:16] == 0. The page tables are set up such that
+ * (espfix_stack | (X & 0xffff0000)) points to a read-only alias of
+ * espfix_waddr for any X. That is, there are 65536 RO aliases of
+ * the same page. Set up RSP so that RSP[31:16] contains the
+ * respective 16 bits of the /userspace/ RSP and RSP nonetheless
+ * still points to an RO alias of the ESPFIX stack.
+ */
orq PER_CPU_VAR(espfix_stack), %rax
SWAPGS
movq %rax, %rsp
- popq %rax
+
+ /*
+ * At this point, we cannot write to the stack any more, but we can
+ * still read.
+ */
+ popq %rax /* Restore user RAX */
+
+ /*
+ * RSP now points to an ordinary IRET frame, except that the page
+ * is read-only and RSP[31:16] are preloaded with the userspace
+ * values. We can now IRET back to userspace.
+ */
jmp native_irq_return_iret
#endif
END(common_interrupt)
#include <asm/timer.h>
#include <asm/desc.h>
#include <asm/ldt.h>
+#include <asm/unwind.h>
#include "perf_event.h"
cyc2ns_read_end(data);
}
-/*
- * callchain support
- */
-
-static int backtrace_stack(void *data, char *name)
-{
- return 0;
-}
-
-static int backtrace_address(void *data, unsigned long addr, int reliable)
-{
- struct perf_callchain_entry_ctx *entry = data;
-
- return perf_callchain_store(entry, addr);
-}
-
-static const struct stacktrace_ops backtrace_ops = {
- .stack = backtrace_stack,
- .address = backtrace_address,
- .walk_stack = print_context_stack_bp,
-};
-
void
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
{
+ struct unwind_state state;
+ unsigned long addr;
+
if (perf_guest_cbs && perf_guest_cbs->is_in_guest()) {
/* TODO: We don't support guest os callchain now */
return;
}
- perf_callchain_store(entry, regs->ip);
+ if (perf_callchain_store(entry, regs->ip))
+ return;
- dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry);
+ for (unwind_start(&state, current, regs, NULL); !unwind_done(&state);
+ unwind_next_frame(&state)) {
+ addr = unwind_get_return_address(&state);
+ if (!addr || perf_callchain_store(entry, addr))
+ return;
+ }
}
static inline int
*/
#define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2, \
output, input...) \
+{ \
+ register void *__sp asm(_ASM_SP); \
asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
"call %P[new2]", feature2) \
- : output : [old] "i" (oldfunc), [new1] "i" (newfunc1), \
- [new2] "i" (newfunc2), ## input)
+ : output, "+r" (__sp) \
+ : [old] "i" (oldfunc), [new1] "i" (newfunc1), \
+ [new2] "i" (newfunc2), ## input); \
+}
/*
* use this macro(s) if you need more than one output parameter
extern struct desc_ptr idt_descr;
extern gate_desc idt_table[];
-extern struct desc_ptr debug_idt_descr;
+extern const struct desc_ptr debug_idt_descr;
extern gate_desc debug_idt_table[];
struct gdt_page {
extern u64 xfeatures_mask;
extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
-extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask);
+extern void __init update_regset_xstate_info(unsigned int size,
+ u64 xstate_mask);
void fpu__xstate_clear_all_cpu_caps(void);
void *get_xsave_addr(struct xregs_state *xsave, int xstate);
# define MCOUNT_ADDR ((unsigned long)(__fentry__))
#else
# define MCOUNT_ADDR ((unsigned long)(mcount))
+# define HAVE_FUNCTION_GRAPH_FP_TEST
#endif
#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
#define ARCH_SUPPORTS_FTRACE_OPS 1
#endif
+#define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+
#ifndef __ASSEMBLY__
extern void mcount(void);
extern atomic_t modifying_ftrace_code;
#ifdef CONFIG_RANDOMIZE_MEMORY
extern unsigned long page_offset_base;
extern unsigned long vmalloc_base;
+extern unsigned long vmemmap_base;
void kernel_randomize_memory(void);
#else
extern void printk_address(unsigned long address);
extern void die(const char *, struct pt_regs *,long);
extern int __must_check __die(const char *, struct pt_regs *, long);
-extern void show_trace(struct task_struct *t, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp);
extern void show_stack_regs(struct pt_regs *regs);
extern void __show_regs(struct pt_regs *regs, int all);
extern unsigned long oops_begin(void);
#define MAXMEM _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL)
#define VMALLOC_SIZE_TB _AC(32, UL)
#define __VMALLOC_BASE _AC(0xffffc90000000000, UL)
-#define VMEMMAP_START _AC(0xffffea0000000000, UL)
+#define __VMEMMAP_BASE _AC(0xffffea0000000000, UL)
#ifdef CONFIG_RANDOMIZE_MEMORY
#define VMALLOC_START vmalloc_base
+#define VMEMMAP_START vmemmap_base
#else
#define VMALLOC_START __VMALLOC_BASE
+#define VMEMMAP_START __VMEMMAP_BASE
#endif /* CONFIG_RANDOMIZE_MEMORY */
#define VMALLOC_END (VMALLOC_START + _AC((VMALLOC_SIZE_TB << 40) - 1, UL))
#define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
unsigned short fsindex;
unsigned short gsindex;
#endif
-#ifdef CONFIG_X86_32
- unsigned long ip;
-#endif
+
+ u32 status; /* thread synchronous flags */
+
#ifdef CONFIG_X86_64
unsigned long fsbase;
unsigned long gsbase;
*/
};
+/*
+ * Thread-synchronous status.
+ *
+ * This is different from the flags in that nobody else
+ * ever touches our thread-synchronous status, so we don't
+ * have to worry about atomic accesses.
+ */
+#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
+
/*
* Set IOPL bits in EFLAGS from given mask
*/
.addr_limit = KERNEL_DS, \
}
-extern unsigned long thread_saved_pc(struct task_struct *tsk);
-
/*
* TOP_OF_KERNEL_STACK_PADDING reserves 8 bytes on top of the ring0 stack.
* This is necessary to guarantee that the entire "struct pt_regs"
.addr_limit = KERNEL_DS, \
}
-/*
- * Return saved PC of a blocked thread.
- * What is this good for? it will be always the scheduler or ret_from_fork.
- */
-#define thread_saved_pc(t) READ_ONCE_NOCHECK(*(unsigned long *)((t)->thread.sp - 8))
-
#define task_pt_regs(tsk) ((struct pt_regs *)(tsk)->thread.sp0 - 1)
extern unsigned long KSTK_ESP(struct task_struct *task);
#endif /* CONFIG_X86_64 */
+extern unsigned long thread_saved_pc(struct task_struct *tsk);
+
extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
unsigned long new_sp);
extern struct real_mode_header *real_mode_header;
extern unsigned char real_mode_blob_end[];
-extern unsigned long init_rsp;
extern unsigned long initial_code;
extern unsigned long initial_gs;
+extern unsigned long initial_stack;
extern unsigned char real_mode_blob[];
extern unsigned char real_mode_relocs[];
DECLARE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid);
#endif
-/* Static state in head.S used to set up a CPU */
-extern unsigned long stack_start; /* Initial stack pointer address */
-
struct task_struct;
struct smp_ops {
#include <linux/uaccess.h>
#include <linux/ptrace.h>
+#include <asm/switch_to.h>
+
+enum stack_type {
+ STACK_TYPE_UNKNOWN,
+ STACK_TYPE_TASK,
+ STACK_TYPE_IRQ,
+ STACK_TYPE_SOFTIRQ,
+ STACK_TYPE_EXCEPTION,
+ STACK_TYPE_EXCEPTION_LAST = STACK_TYPE_EXCEPTION + N_EXCEPTION_STACKS-1,
+};
-extern int kstack_depth_to_print;
-
-struct thread_info;
-struct stacktrace_ops;
-
-typedef unsigned long (*walk_stack_t)(struct task_struct *task,
- unsigned long *stack,
- unsigned long bp,
- const struct stacktrace_ops *ops,
- void *data,
- unsigned long *end,
- int *graph);
-
-extern unsigned long
-print_context_stack(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- unsigned long *end, int *graph);
-
-extern unsigned long
-print_context_stack_bp(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- unsigned long *end, int *graph);
-
-/* Generic stack tracer with callbacks */
-
-struct stacktrace_ops {
- int (*address)(void *data, unsigned long address, int reliable);
- /* On negative return stop dumping */
- int (*stack)(void *data, char *name);
- walk_stack_t walk_stack;
+struct stack_info {
+ enum stack_type type;
+ unsigned long *begin, *end, *next_sp;
};
-void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data);
+bool in_task_stack(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info);
+
+int get_stack_info(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask);
+
+void stack_type_str(enum stack_type type, const char **begin,
+ const char **end);
+
+static inline bool on_stack(struct stack_info *info, void *addr, size_t len)
+{
+ void *begin = info->begin;
+ void *end = info->end;
+
+ return (info->type != STACK_TYPE_UNKNOWN &&
+ addr >= begin && addr < end &&
+ addr + len > begin && addr + len <= end);
+}
+
+extern int kstack_depth_to_print;
#ifdef CONFIG_X86_32
#define STACKSLOTS_PER_LINE 8
-#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)
#else
#define STACKSLOTS_PER_LINE 4
-#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :)
#endif
#ifdef CONFIG_FRAME_POINTER
-static inline unsigned long
-stack_frame(struct task_struct *task, struct pt_regs *regs)
+static inline unsigned long *
+get_frame_pointer(struct task_struct *task, struct pt_regs *regs)
{
- unsigned long bp;
-
if (regs)
- return regs->bp;
+ return (unsigned long *)regs->bp;
- if (task == current) {
- /* Grab bp right from our regs */
- get_bp(bp);
- return bp;
- }
+ if (task == current)
+ return __builtin_frame_address(0);
- /* bp is the last reg pushed by switch_to */
- return *(unsigned long *)task->thread.sp;
+ return (unsigned long *)((struct inactive_task_frame *)task->thread.sp)->bp;
}
#else
-static inline unsigned long
-stack_frame(struct task_struct *task, struct pt_regs *regs)
+static inline unsigned long *
+get_frame_pointer(struct task_struct *task, struct pt_regs *regs)
{
- return 0;
+ return NULL;
+}
+#endif /* CONFIG_FRAME_POINTER */
+
+static inline unsigned long *
+get_stack_pointer(struct task_struct *task, struct pt_regs *regs)
+{
+ if (regs)
+ return (unsigned long *)kernel_stack_pointer(regs);
+
+ if (task == current)
+ return __builtin_frame_address(0);
+
+ return (unsigned long *)task->thread.sp;
}
-#endif
-extern void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp, char *log_lvl);
+void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *stack, char *log_lvl);
-extern void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl);
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl);
extern unsigned int code_bytes;
{
struct stack_frame *frame;
- get_bp(frame);
+ frame = __builtin_frame_address(0);
#ifdef CONFIG_FRAME_POINTER
frame = frame->next_frame;
#define _ASM_X86_SWITCH_TO_H
struct task_struct; /* one of the stranger aspects of C forward declarations */
+
+struct task_struct *__switch_to_asm(struct task_struct *prev,
+ struct task_struct *next);
+
__visible struct task_struct *__switch_to(struct task_struct *prev,
- struct task_struct *next);
+ struct task_struct *next);
struct tss_struct;
void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
struct tss_struct *tss);
-#ifdef CONFIG_X86_32
+/* This runs runs on the previous thread's stack. */
+static inline void prepare_switch_to(struct task_struct *prev,
+ struct task_struct *next)
+{
+#ifdef CONFIG_VMAP_STACK
+ /*
+ * If we switch to a stack that has a top-level paging entry
+ * that is not present in the current mm, the resulting #PF will
+ * will be promoted to a double-fault and we'll panic. Probe
+ * the new stack now so that vmalloc_fault can fix up the page
+ * tables if needed. This can only happen if we use a stack
+ * in vmap space.
+ *
+ * We assume that the stack is aligned so that it never spans
+ * more than one top-level paging entry.
+ *
+ * To minimize cache pollution, just follow the stack pointer.
+ */
+ READ_ONCE(*(unsigned char *)next->thread.sp);
+#endif
+}
+
+asmlinkage void ret_from_fork(void);
+
+/* data that is pointed to by thread.sp */
+struct inactive_task_frame {
+#ifdef CONFIG_X86_64
+ unsigned long r15;
+ unsigned long r14;
+ unsigned long r13;
+ unsigned long r12;
+#else
+ unsigned long si;
+ unsigned long di;
+#endif
+ unsigned long bx;
+ unsigned long bp;
+ unsigned long ret_addr;
+};
-#ifdef CONFIG_CC_STACKPROTECTOR
-#define __switch_canary \
- "movl %P[task_canary](%[next]), %%ebx\n\t" \
- "movl %%ebx, "__percpu_arg([stack_canary])"\n\t"
-#define __switch_canary_oparam \
- , [stack_canary] "=m" (stack_canary.canary)
-#define __switch_canary_iparam \
- , [task_canary] "i" (offsetof(struct task_struct, stack_canary))
-#else /* CC_STACKPROTECTOR */
-#define __switch_canary
-#define __switch_canary_oparam
-#define __switch_canary_iparam
-#endif /* CC_STACKPROTECTOR */
+struct fork_frame {
+ struct inactive_task_frame frame;
+ struct pt_regs regs;
+};
-/*
- * Saving eflags is important. It switches not only IOPL between tasks,
- * it also protects other tasks from NT leaking through sysenter etc.
- */
#define switch_to(prev, next, last) \
do { \
- /* \
- * Context-switching clobbers all registers, so we clobber \
- * them explicitly, via unused output variables. \
- * (EAX and EBP is not listed because EBP is saved/restored \
- * explicitly for wchan access and EAX is the return value of \
- * __switch_to()) \
- */ \
- unsigned long ebx, ecx, edx, esi, edi; \
- \
- asm volatile("pushl %%ebp\n\t" /* save EBP */ \
- "movl %%esp,%[prev_sp]\n\t" /* save ESP */ \
- "movl %[next_sp],%%esp\n\t" /* restore ESP */ \
- "movl $1f,%[prev_ip]\n\t" /* save EIP */ \
- "pushl %[next_ip]\n\t" /* restore EIP */ \
- __switch_canary \
- "jmp __switch_to\n" /* regparm call */ \
- "1:\t" \
- "popl %%ebp\n\t" /* restore EBP */ \
- \
- /* output parameters */ \
- : [prev_sp] "=m" (prev->thread.sp), \
- [prev_ip] "=m" (prev->thread.ip), \
- "=a" (last), \
- \
- /* clobbered output registers: */ \
- "=b" (ebx), "=c" (ecx), "=d" (edx), \
- "=S" (esi), "=D" (edi) \
- \
- __switch_canary_oparam \
- \
- /* input parameters: */ \
- : [next_sp] "m" (next->thread.sp), \
- [next_ip] "m" (next->thread.ip), \
- \
- /* regparm parameters for __switch_to(): */ \
- [prev] "a" (prev), \
- [next] "d" (next) \
+ prepare_switch_to(prev, next); \
\
- __switch_canary_iparam \
- \
- : /* reloaded segment registers */ \
- "memory"); \
+ ((last) = __switch_to_asm((prev), (next))); \
} while (0)
-#else /* CONFIG_X86_32 */
-
-/* frame pointer must be last for get_wchan */
-#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
-#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\t"
-
-#define __EXTRA_CLOBBER \
- , "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
- "r12", "r13", "r14", "r15", "flags"
-
-#ifdef CONFIG_CC_STACKPROTECTOR
-#define __switch_canary \
- "movq %P[task_canary](%%rsi),%%r8\n\t" \
- "movq %%r8,"__percpu_arg([gs_canary])"\n\t"
-#define __switch_canary_oparam \
- , [gs_canary] "=m" (irq_stack_union.stack_canary)
-#define __switch_canary_iparam \
- , [task_canary] "i" (offsetof(struct task_struct, stack_canary))
-#else /* CC_STACKPROTECTOR */
-#define __switch_canary
-#define __switch_canary_oparam
-#define __switch_canary_iparam
-#endif /* CC_STACKPROTECTOR */
-
-/*
- * There is no need to save or restore flags, because flags are always
- * clean in kernel mode, with the possible exception of IOPL. Kernel IOPL
- * has no effect.
- */
-#define switch_to(prev, next, last) \
- asm volatile(SAVE_CONTEXT \
- "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
- "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
- "call __switch_to\n\t" \
- "movq "__percpu_arg([current_task])",%%rsi\n\t" \
- __switch_canary \
- "movq %P[thread_info](%%rsi),%%r8\n\t" \
- "movq %%rax,%%rdi\n\t" \
- "testl %[_tif_fork],%P[ti_flags](%%r8)\n\t" \
- "jnz ret_from_fork\n\t" \
- RESTORE_CONTEXT \
- : "=a" (last) \
- __switch_canary_oparam \
- : [next] "S" (next), [prev] "D" (prev), \
- [threadrsp] "i" (offsetof(struct task_struct, thread.sp)), \
- [ti_flags] "i" (offsetof(struct thread_info, flags)), \
- [_tif_fork] "i" (_TIF_FORK), \
- [thread_info] "i" (offsetof(struct task_struct, stack)), \
- [current_task] "m" (current_task) \
- __switch_canary_iparam \
- : "memory", "cc" __EXTRA_CLOBBER)
-
-#endif /* CONFIG_X86_32 */
-
#endif /* _ASM_X86_SWITCH_TO_H */
* TS_COMPAT is set for 32-bit syscall entries and then
* remains set until we return to user mode.
*/
- if (task_thread_info(task)->status & (TS_COMPAT|TS_I386_REGS_POKED))
+ if (task->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
/*
* Sign-extend the value so (int)-EFOO becomes (long)-EFOO
* and will match correctly in comparisons.
unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
- if (task_thread_info(task)->status & TS_COMPAT)
+ if (task->thread.status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
const unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
- if (task_thread_info(task)->status & TS_COMPAT)
+ if (task->thread.status & TS_COMPAT)
switch (i) {
case 0:
if (!n--) break;
static inline int syscall_get_arch(void)
{
-#ifdef CONFIG_IA32_EMULATION
- /*
- * TS_COMPAT is set for 32-bit syscall entry and then
- * remains set until we return to user mode.
- *
- * x32 tasks should be considered AUDIT_ARCH_X86_64.
- */
- if (task_thread_info(current)->status & TS_COMPAT)
- return AUDIT_ARCH_I386;
-#endif
- /* Both x32 and x86_64 are considered "64-bit". */
- return AUDIT_ARCH_X86_64;
+ /* x32 tasks should be considered AUDIT_ARCH_X86_64. */
+ return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
}
#endif /* CONFIG_X86_32 */
#include <asm/cpufeature.h>
#include <linux/atomic.h>
-struct thread_info {
- struct task_struct *task; /* main task structure */
- __u32 flags; /* low level flags */
- __u32 status; /* thread synchronous flags */
- __u32 cpu; /* current CPU */
-};
-
-#define INIT_THREAD_INFO(tsk) \
-{ \
- .task = &tsk, \
- .flags = 0, \
- .cpu = 0, \
-}
-
-#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
#else /* !__ASSEMBLY__ */
#define TIF_UPROBE 12 /* breakpointed or singlestepping */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* IA32 compatibility process */
-#define TIF_FORK 18 /* ret_from_fork */
#define TIF_NOHZ 19 /* in adaptive nohz mode */
#define TIF_MEMDIE 20 /* is terminating due to OOM killer */
#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */
#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
-#define _TIF_FORK (1 << TIF_FORK)
#define _TIF_NOHZ (1 << TIF_NOHZ)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
*/
#ifndef __ASSEMBLY__
-static inline struct thread_info *current_thread_info(void)
-{
- return (struct thread_info *)(current_top_of_stack() - THREAD_SIZE);
-}
-
static inline unsigned long current_stack_pointer(void)
{
unsigned long sp;
# define cpu_current_top_of_stack (cpu_tss + TSS_sp0)
#endif
-/*
- * ASM operand which evaluates to a 'thread_info' address of
- * the current task, if it is known that "reg" is exactly "off"
- * bytes below the top of the stack currently.
- *
- * ( The kernel stack's size is known at build time, it is usually
- * 2 or 4 pages, and the bottom of the kernel stack contains
- * the thread_info structure. So to access the thread_info very
- * quickly from assembly code we can calculate down from the
- * top of the kernel stack to the bottom, using constant,
- * build-time calculations only. )
- *
- * For example, to fetch the current thread_info->flags value into %eax
- * on x86-64 defconfig kernels, in syscall entry code where RSP is
- * currently at exactly SIZEOF_PTREGS bytes away from the top of the
- * stack:
- *
- * mov ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS), %eax
- *
- * will translate to:
- *
- * 8b 84 24 b8 c0 ff ff mov -0x3f48(%rsp), %eax
- *
- * which is below the current RSP by almost 16K.
- */
-#define ASM_THREAD_INFO(field, reg, off) ((field)+(off)-THREAD_SIZE)(reg)
-
#endif
-/*
- * Thread-synchronous status.
- *
- * This is different from the flags in that nobody else
- * ever touches our thread-synchronous status, so we don't
- * have to worry about atomic accesses.
- */
-#define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/
#ifdef CONFIG_COMPAT
#define TS_I386_REGS_POKED 0x0004 /* regs poked by 32-bit ptracer */
#endif
-
#ifndef __ASSEMBLY__
-static inline bool in_ia32_syscall(void)
-{
#ifdef CONFIG_X86_32
- return true;
-#endif
-#ifdef CONFIG_IA32_EMULATION
- if (current_thread_info()->status & TS_COMPAT)
- return true;
+#define in_ia32_syscall() true
+#else
+#define in_ia32_syscall() (IS_ENABLED(CONFIG_IA32_EMULATION) && \
+ current->thread.status & TS_COMPAT)
#endif
- return false;
-}
/*
* Force syscall return via IRET by making it look as if there was
extern void ist_begin_non_atomic(struct pt_regs *regs);
extern void ist_end_non_atomic(void);
+#ifdef CONFIG_VMAP_STACK
+void __noreturn handle_stack_overflow(const char *message,
+ struct pt_regs *regs,
+ unsigned long fault_address);
+#endif
+
/* Interrupts/Exceptions */
enum {
X86_TRAP_DE = 0, /* 0, Divide-by-zero */
--- /dev/null
+#ifndef _ASM_X86_UNWIND_H
+#define _ASM_X86_UNWIND_H
+
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/stacktrace.h>
+
+struct unwind_state {
+ struct stack_info stack_info;
+ unsigned long stack_mask;
+ struct task_struct *task;
+ int graph_idx;
+#ifdef CONFIG_FRAME_POINTER
+ unsigned long *bp;
+#else
+ unsigned long *sp;
+#endif
+};
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame);
+
+bool unwind_next_frame(struct unwind_state *state);
+
+static inline bool unwind_done(struct unwind_state *state)
+{
+ return state->stack_info.type == STACK_TYPE_UNKNOWN;
+}
+
+static inline
+void unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame)
+{
+ first_frame = first_frame ? : get_stack_pointer(task, regs);
+
+ __unwind_start(state, task, regs, first_frame);
+}
+
+#ifdef CONFIG_FRAME_POINTER
+
+static inline
+unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
+{
+ if (unwind_done(state))
+ return NULL;
+
+ return state->bp + 1;
+}
+
+unsigned long unwind_get_return_address(struct unwind_state *state);
+
+#else /* !CONFIG_FRAME_POINTER */
+
+static inline
+unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
+{
+ return NULL;
+}
+
+static inline
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ if (unwind_done(state))
+ return 0;
+
+ return ftrace_graph_ret_addr(state->task, &state->graph_idx,
+ *state->sp, state->sp);
+}
+
+#endif /* CONFIG_FRAME_POINTER */
+
+#endif /* _ASM_X86_UNWIND_H */
obj-$(CONFIG_PERF_EVENTS) += perf_regs.o
obj-$(CONFIG_TRACING) += tracepoint.o
+ifdef CONFIG_FRAME_POINTER
+obj-y += unwind_frame.o
+else
+obj-y += unwind_guess.o
+endif
+
###
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
saved_magic = 0x12345678;
#else /* CONFIG_64BIT */
#ifdef CONFIG_SMP
- stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
+ initial_stack = (unsigned long)temp_stack + sizeof(temp_stack);
early_gdt_descr.address =
(unsigned long)get_cpu_gdt_table(smp_processor_id());
initial_gs = per_cpu_offset(smp_processor_id());
static struct apic apic_physflat;
static struct apic apic_flat;
-struct apic __read_mostly *apic = &apic_flat;
+struct apic *apic __ro_after_init = &apic_flat;
EXPORT_SYMBOL_GPL(apic);
static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
return 1;
}
-static struct apic apic_flat = {
+static struct apic apic_flat __ro_after_init = {
.name = "flat",
.probe = flat_probe,
.acpi_madt_oem_check = flat_acpi_madt_oem_check,
return 0;
}
-static struct apic apic_physflat = {
+static struct apic apic_physflat __ro_after_init = {
.name = "physical flat",
.probe = physflat_probe,
WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_APIC) && !disable_apic);
}
-struct apic apic_noop = {
+struct apic apic_noop __ro_after_init = {
.name = "noop",
.probe = noop_probe,
.acpi_madt_oem_check = NULL,
return dmi_bigsmp;
}
-static struct apic apic_bigsmp = {
+static struct apic apic_bigsmp __ro_after_init = {
.name = "bigsmp",
.probe = probe_bigsmp,
hpet_msi_write(irq_data_get_irq_handler_data(data), msg);
}
-static struct irq_chip hpet_msi_controller = {
+static struct irq_chip hpet_msi_controller __ro_after_init = {
.name = "HPET-MSI",
.irq_unmask = hpet_msi_unmask,
.irq_mask = hpet_msi_mask,
return 1;
}
-static struct apic apic_default = {
+static struct apic apic_default __ro_after_init = {
.name = "default",
.probe = probe_default,
apic_driver(apic_default);
-struct apic *apic = &apic_default;
+struct apic *apic __ro_after_init = &apic_default;
EXPORT_SYMBOL_GPL(apic);
static int cmdline_apic __initdata;
cpumask_and(retmask, mask, per_cpu(cpus_in_cluster, cpu));
}
-static struct apic apic_x2apic_cluster = {
+static struct apic apic_x2apic_cluster __ro_after_init = {
.name = "cluster x2apic",
.probe = x2apic_cluster_probe,
return apic == &apic_x2apic_phys;
}
-static struct apic apic_x2apic_phys = {
+static struct apic apic_x2apic_phys __ro_after_init = {
.name = "physical x2apic",
.probe = x2apic_phys_probe,
return apic == &apic_x2apic_uv_x;
}
-static struct apic __refdata apic_x2apic_uv_x = {
+static struct apic apic_x2apic_uv_x __ro_after_init = {
.name = "UV large system",
.probe = uv_probe,
void common(void) {
BLANK();
- OFFSET(TI_flags, thread_info, flags);
- OFFSET(TI_status, thread_info, status);
+ OFFSET(TASK_threadsp, task_struct, thread.sp);
+#ifdef CONFIG_CC_STACKPROTECTOR
+ OFFSET(TASK_stack_canary, task_struct, stack_canary);
+#endif
BLANK();
+ OFFSET(TASK_TI_flags, task_struct, thread_info.flags);
OFFSET(TASK_addr_limit, task_struct, thread.addr_limit);
BLANK();
/* Size of SYSENTER_stack */
DEFINE(SIZEOF_SYSENTER_stack, sizeof(((struct tss_struct *)0)->SYSENTER_stack));
+#ifdef CONFIG_CC_STACKPROTECTOR
+ BLANK();
+ OFFSET(stack_canary_offset, stack_canary, canary);
+#endif
+
#if defined(CONFIG_LGUEST) || defined(CONFIG_LGUEST_GUEST) || defined(CONFIG_LGUEST_MODULE)
BLANK();
OFFSET(LGUEST_DATA_irq_enabled, lguest_data, irq_enabled);
OFFSET(TSS_sp0, tss_struct, x86_tss.sp0);
BLANK();
+#ifdef CONFIG_CC_STACKPROTECTOR
+ DEFINE(stack_canary_offset, offsetof(union irq_stack_union, stack_canary));
+ BLANK();
+#endif
+
DEFINE(__NR_syscall_max, sizeof(syscalls_64) - 1);
DEFINE(NR_syscalls, sizeof(syscalls_64));
__setup("clearcpuid=", setup_disablecpuid);
#ifdef CONFIG_X86_64
-struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
-struct desc_ptr debug_idt_descr = { NR_VECTORS * 16 - 1,
- (unsigned long) debug_idt_table };
+struct desc_ptr idt_descr __ro_after_init = {
+ .size = NR_VECTORS * 16 - 1,
+ .address = (unsigned long) idt_table,
+};
+const struct desc_ptr debug_idt_descr = {
+ .size = NR_VECTORS * 16 - 1,
+ .address = (unsigned long) debug_idt_table,
+};
DEFINE_PER_CPU_FIRST(union irq_stack_union,
irq_stack_union) __aligned(PAGE_SIZE) __visible;
EXPORT_PER_CPU_SYMBOL(current_task);
DEFINE_PER_CPU(char *, irq_stack_ptr) =
- init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
+ init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE;
DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
/* May not be marked __init: used by software suspend */
void syscall_init(void)
{
- /*
- * LSTAR and STAR live in a bit strange symbiosis.
- * They both write to the same internal register. STAR allows to
- * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
- */
wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS);
wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
u64 size_or_mask, size_and_mask;
static bool mtrr_aps_delayed_init;
-static const struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM];
+static const struct mtrr_ops *mtrr_ops[X86_VENDOR_NUM] __ro_after_init;
const struct mtrr_ops *mtrr_if;
static void set_mtrr(unsigned int reg, unsigned long base,
unsigned long size, mtrr_type type);
-void set_mtrr_ops(const struct mtrr_ops *ops)
+void __init set_mtrr_ops(const struct mtrr_ops *ops)
{
if (ops->vendor && ops->vendor < X86_VENDOR_NUM)
mtrr_ops[ops->vendor] = ops;
bool get_mtrr_state(void);
void mtrr_bp_pat_init(void);
-extern void set_mtrr_ops(const struct mtrr_ops *ops);
+extern void __init set_mtrr_ops(const struct mtrr_ops *ops);
extern u64 size_or_mask, size_and_mask;
extern const struct mtrr_ops *mtrr_if;
#include <linux/sysfs.h>
#include <asm/stacktrace.h>
-
+#include <asm/unwind.h>
int panic_on_unrecovered_nmi;
int panic_on_io_nmi;
int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
static int die_counter;
+bool in_task_stack(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info)
+{
+ unsigned long *begin = task_stack_page(task);
+ unsigned long *end = task_stack_page(task) + THREAD_SIZE;
+
+ if (stack < begin || stack >= end)
+ return false;
+
+ info->type = STACK_TYPE_TASK;
+ info->begin = begin;
+ info->end = end;
+ info->next_sp = NULL;
+
+ return true;
+}
+
static void printk_stack_address(unsigned long address, int reliable,
- void *data)
+ char *log_lvl)
{
+ touch_nmi_watchdog();
printk("%s [<%p>] %s%pB\n",
- (char *)data, (void *)address, reliable ? "" : "? ",
+ log_lvl, (void *)address, reliable ? "" : "? ",
(void *)address);
}
pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
}
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-static void
-print_ftrace_graph_addr(unsigned long addr, void *data,
- const struct stacktrace_ops *ops,
- struct task_struct *task, int *graph)
+void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *stack, char *log_lvl)
{
- unsigned long ret_addr;
- int index;
-
- if (addr != (unsigned long)return_to_handler)
- return;
-
- index = task->curr_ret_stack;
-
- if (!task->ret_stack || index < *graph)
- return;
-
- index -= *graph;
- ret_addr = task->ret_stack[index].ret;
-
- ops->address(data, ret_addr, 1);
+ struct unwind_state state;
+ struct stack_info stack_info = {0};
+ unsigned long visit_mask = 0;
+ int graph_idx = 0;
- (*graph)++;
-}
-#else
-static inline void
-print_ftrace_graph_addr(unsigned long addr, void *data,
- const struct stacktrace_ops *ops,
- struct task_struct *task, int *graph)
-{ }
-#endif
-
-/*
- * x86-64 can have up to three kernel stacks:
- * process stack
- * interrupt stack
- * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
- */
-
-static inline int valid_stack_ptr(struct task_struct *task,
- void *p, unsigned int size, void *end)
-{
- void *t = task_stack_page(task);
- if (end) {
- if (p < end && p >= (end-THREAD_SIZE))
- return 1;
- else
- return 0;
- }
- return p >= t && p < t + THREAD_SIZE - size;
-}
+ printk("%sCall Trace:\n", log_lvl);
-unsigned long
-print_context_stack(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- unsigned long *end, int *graph)
-{
- struct stack_frame *frame = (struct stack_frame *)bp;
+ unwind_start(&state, task, regs, stack);
/*
- * If we overflowed the stack into a guard page, jump back to the
- * bottom of the usable stack.
+ * Iterate through the stacks, starting with the current stack pointer.
+ * Each stack has a pointer to the next one.
+ *
+ * x86-64 can have several stacks:
+ * - task stack
+ * - interrupt stack
+ * - HW exception stacks (double fault, nmi, debug, mce)
+ *
+ * x86-32 can have up to three stacks:
+ * - task stack
+ * - softirq stack
+ * - hardirq stack
*/
- if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
- PAGE_SIZE)
- stack = (unsigned long *)task_stack_page(task);
-
- while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
- unsigned long addr;
-
- addr = *stack;
- if (__kernel_text_address(addr)) {
- if ((unsigned long) stack == bp + sizeof(long)) {
- ops->address(data, addr, 1);
- frame = frame->next_frame;
- bp = (unsigned long) frame;
- } else {
- ops->address(data, addr, 0);
- }
- print_ftrace_graph_addr(addr, data, ops, task, graph);
- }
- stack++;
- }
- return bp;
-}
-EXPORT_SYMBOL_GPL(print_context_stack);
-
-unsigned long
-print_context_stack_bp(struct task_struct *task,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data,
- unsigned long *end, int *graph)
-{
- struct stack_frame *frame = (struct stack_frame *)bp;
- unsigned long *ret_addr = &frame->return_address;
+ for (; stack; stack = stack_info.next_sp) {
+ const char *str_begin, *str_end;
- while (valid_stack_ptr(task, ret_addr, sizeof(*ret_addr), end)) {
- unsigned long addr = *ret_addr;
+ /*
+ * If we overflowed the task stack into a guard page, jump back
+ * to the bottom of the usable stack.
+ */
+ if (task_stack_page(task) - (void *)stack < PAGE_SIZE)
+ stack = task_stack_page(task);
- if (!__kernel_text_address(addr))
+ if (get_stack_info(stack, task, &stack_info, &visit_mask))
break;
- if (ops->address(data, addr, 1))
- break;
- frame = frame->next_frame;
- ret_addr = &frame->return_address;
- print_ftrace_graph_addr(addr, data, ops, task, graph);
- }
-
- return (unsigned long)frame;
-}
-EXPORT_SYMBOL_GPL(print_context_stack_bp);
-
-static int print_trace_stack(void *data, char *name)
-{
- printk("%s <%s> ", (char *)data, name);
- return 0;
-}
-
-/*
- * Print one address/symbol entries per line.
- */
-static int print_trace_address(void *data, unsigned long addr, int reliable)
-{
- touch_nmi_watchdog();
- printk_stack_address(addr, reliable, data);
- return 0;
-}
-
-static const struct stacktrace_ops print_trace_ops = {
- .stack = print_trace_stack,
- .address = print_trace_address,
- .walk_stack = print_context_stack,
-};
-
-void
-show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp, char *log_lvl)
-{
- printk("%sCall Trace:\n", log_lvl);
- dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
-}
+ stack_type_str(stack_info.type, &str_begin, &str_end);
+ if (str_begin)
+ printk("%s <%s> ", log_lvl, str_begin);
+
+ /*
+ * Scan the stack, printing any text addresses we find. At the
+ * same time, follow proper stack frames with the unwinder.
+ *
+ * Addresses found during the scan which are not reported by
+ * the unwinder are considered to be additional clues which are
+ * sometimes useful for debugging and are prefixed with '?'.
+ * This also serves as a failsafe option in case the unwinder
+ * goes off in the weeds.
+ */
+ for (; stack < stack_info.end; stack++) {
+ unsigned long real_addr;
+ int reliable = 0;
+ unsigned long addr = *stack;
+ unsigned long *ret_addr_p =
+ unwind_get_return_address_ptr(&state);
+
+ if (!__kernel_text_address(addr))
+ continue;
+
+ if (stack == ret_addr_p)
+ reliable = 1;
+
+ /*
+ * When function graph tracing is enabled for a
+ * function, its return address on the stack is
+ * replaced with the address of an ftrace handler
+ * (return_to_handler). In that case, before printing
+ * the "real" address, we want to print the handler
+ * address as an "unreliable" hint that function graph
+ * tracing was involved.
+ */
+ real_addr = ftrace_graph_ret_addr(task, &graph_idx,
+ addr, stack);
+ if (real_addr != addr)
+ printk_stack_address(addr, 0, log_lvl);
+ printk_stack_address(real_addr, reliable, log_lvl);
+
+ if (!reliable)
+ continue;
+
+ /*
+ * Get the next frame from the unwinder. No need to
+ * check for an error: if anything goes wrong, the rest
+ * of the addresses will just be printed as unreliable.
+ */
+ unwind_next_frame(&state);
+ }
-void show_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp)
-{
- show_trace_log_lvl(task, regs, stack, bp, "");
+ if (str_end)
+ printk("%s <%s> ", log_lvl, str_end);
+ }
}
void show_stack(struct task_struct *task, unsigned long *sp)
{
- unsigned long bp = 0;
- unsigned long stack;
+ task = task ? : current;
/*
* Stack frames below this one aren't interesting. Don't show them
* if we're printing for %current.
*/
- if (!sp && (!task || task == current)) {
- sp = &stack;
- bp = stack_frame(current, NULL);
- }
+ if (!sp && task == current)
+ sp = get_stack_pointer(current, NULL);
- show_stack_log_lvl(task, NULL, sp, bp, "");
+ show_stack_log_lvl(task, NULL, sp, "");
}
void show_stack_regs(struct pt_regs *regs)
{
- show_stack_log_lvl(current, regs, (unsigned long *)regs->sp, regs->bp, "");
+ show_stack_log_lvl(current, regs, NULL, "");
}
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
#include <asm/stacktrace.h>
-static void *is_irq_stack(void *p, void *irq)
+void stack_type_str(enum stack_type type, const char **begin, const char **end)
{
- if (p < irq || p >= (irq + THREAD_SIZE))
- return NULL;
- return irq + THREAD_SIZE;
+ switch (type) {
+ case STACK_TYPE_IRQ:
+ case STACK_TYPE_SOFTIRQ:
+ *begin = "IRQ";
+ *end = "EOI";
+ break;
+ default:
+ *begin = NULL;
+ *end = NULL;
+ }
}
-
-static void *is_hardirq_stack(unsigned long *stack, int cpu)
+static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
{
- void *irq = per_cpu(hardirq_stack, cpu);
+ unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack);
+ unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
- return is_irq_stack(stack, irq);
-}
+ /*
+ * This is a software stack, so 'end' can be a valid stack pointer.
+ * It just means the stack is empty.
+ */
+ if (stack < begin || stack > end)
+ return false;
-static void *is_softirq_stack(unsigned long *stack, int cpu)
-{
- void *irq = per_cpu(softirq_stack, cpu);
+ info->type = STACK_TYPE_IRQ;
+ info->begin = begin;
+ info->end = end;
- return is_irq_stack(stack, irq);
+ /*
+ * See irq_32.c -- the next stack pointer is stored at the beginning of
+ * the stack.
+ */
+ info->next_sp = (unsigned long *)*begin;
+
+ return true;
}
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data)
+static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
{
- const unsigned cpu = get_cpu();
- int graph = 0;
- u32 *prev_esp;
+ unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack);
+ unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
- if (!task)
- task = current;
+ /*
+ * This is a software stack, so 'end' can be a valid stack pointer.
+ * It just means the stack is empty.
+ */
+ if (stack < begin || stack > end)
+ return false;
- if (!stack) {
- unsigned long dummy;
+ info->type = STACK_TYPE_SOFTIRQ;
+ info->begin = begin;
+ info->end = end;
- stack = &dummy;
- if (task != current)
- stack = (unsigned long *)task->thread.sp;
- }
+ /*
+ * The next stack pointer is stored at the beginning of the stack.
+ * See irq_32.c.
+ */
+ info->next_sp = (unsigned long *)*begin;
- if (!bp)
- bp = stack_frame(task, regs);
+ return true;
+}
- for (;;) {
- void *end_stack;
+int get_stack_info(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask)
+{
+ if (!stack)
+ goto unknown;
- end_stack = is_hardirq_stack(stack, cpu);
- if (!end_stack)
- end_stack = is_softirq_stack(stack, cpu);
+ task = task ? : current;
- bp = ops->walk_stack(task, stack, bp, ops, data,
- end_stack, &graph);
+ if (in_task_stack(stack, task, info))
+ goto recursion_check;
- /* Stop if not on irq stack */
- if (!end_stack)
- break;
+ if (task != current)
+ goto unknown;
- /* The previous esp is saved on the bottom of the stack */
- prev_esp = (u32 *)(end_stack - THREAD_SIZE);
- stack = (unsigned long *)*prev_esp;
- if (!stack)
- break;
+ if (in_hardirq_stack(stack, info))
+ goto recursion_check;
- if (ops->stack(data, "IRQ") < 0)
- break;
- touch_nmi_watchdog();
+ if (in_softirq_stack(stack, info))
+ goto recursion_check;
+
+ goto unknown;
+
+recursion_check:
+ /*
+ * Make sure we don't iterate through any given stack more than once.
+ * If it comes up a second time then there's something wrong going on:
+ * just break out and report an unknown stack type.
+ */
+ if (visit_mask) {
+ if (*visit_mask & (1UL << info->type))
+ goto unknown;
+ *visit_mask |= 1UL << info->type;
}
- put_cpu();
+
+ return 0;
+
+unknown:
+ info->type = STACK_TYPE_UNKNOWN;
+ return -EINVAL;
}
-EXPORT_SYMBOL(dump_trace);
-void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl)
{
unsigned long *stack;
int i;
- if (sp == NULL) {
- if (regs)
- sp = (unsigned long *)regs->sp;
- else if (task)
- sp = (unsigned long *)task->thread.sp;
- else
- sp = (unsigned long *)&sp;
- }
+ if (!try_get_task_stack(task))
+ return;
+
+ sp = sp ? : get_stack_pointer(task, regs);
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
touch_nmi_watchdog();
}
pr_cont("\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
+
+ put_task_stack(task);
}
u8 *ip;
pr_emerg("Stack:\n");
- show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG);
+ show_stack_log_lvl(current, regs, NULL, KERN_EMERG);
pr_emerg("Code:");
#include <asm/stacktrace.h>
+static char *exception_stack_names[N_EXCEPTION_STACKS] = {
+ [ DOUBLEFAULT_STACK-1 ] = "#DF",
+ [ NMI_STACK-1 ] = "NMI",
+ [ DEBUG_STACK-1 ] = "#DB",
+ [ MCE_STACK-1 ] = "#MC",
+};
-#define N_EXCEPTION_STACKS_END \
- (N_EXCEPTION_STACKS + DEBUG_STKSZ/EXCEPTION_STKSZ - 2)
-
-static char x86_stack_ids[][8] = {
- [ DEBUG_STACK-1 ] = "#DB",
- [ NMI_STACK-1 ] = "NMI",
- [ DOUBLEFAULT_STACK-1 ] = "#DF",
- [ MCE_STACK-1 ] = "#MC",
-#if DEBUG_STKSZ > EXCEPTION_STKSZ
- [ N_EXCEPTION_STACKS ...
- N_EXCEPTION_STACKS_END ] = "#DB[?]"
-#endif
+static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
+ [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
+ [DEBUG_STACK - 1] = DEBUG_STKSZ
};
-static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
- unsigned *usedp, char **idp)
+void stack_type_str(enum stack_type type, const char **begin, const char **end)
{
- unsigned k;
-
- /*
- * Iterate over all exception stacks, and figure out whether
- * 'stack' is in one of them:
- */
- for (k = 0; k < N_EXCEPTION_STACKS; k++) {
- unsigned long end = per_cpu(orig_ist, cpu).ist[k];
- /*
- * Is 'stack' above this exception frame's end?
- * If yes then skip to the next frame.
- */
- if (stack >= end)
- continue;
- /*
- * Is 'stack' above this exception frame's start address?
- * If yes then we found the right frame.
- */
- if (stack >= end - EXCEPTION_STKSZ) {
- /*
- * Make sure we only iterate through an exception
- * stack once. If it comes up for the second time
- * then there's something wrong going on - just
- * break out and return NULL:
- */
- if (*usedp & (1U << k))
- break;
- *usedp |= 1U << k;
- *idp = x86_stack_ids[k];
- return (unsigned long *)end;
- }
- /*
- * If this is a debug stack, and if it has a larger size than
- * the usual exception stacks, then 'stack' might still
- * be within the lower portion of the debug stack:
- */
-#if DEBUG_STKSZ > EXCEPTION_STKSZ
- if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
- unsigned j = N_EXCEPTION_STACKS - 1;
-
- /*
- * Black magic. A large debug stack is composed of
- * multiple exception stack entries, which we
- * iterate through now. Dont look:
- */
- do {
- ++j;
- end -= EXCEPTION_STKSZ;
- x86_stack_ids[j][4] = '1' +
- (j - N_EXCEPTION_STACKS);
- } while (stack < end - EXCEPTION_STKSZ);
- if (*usedp & (1U << j))
- break;
- *usedp |= 1U << j;
- *idp = x86_stack_ids[j];
- return (unsigned long *)end;
- }
-#endif
+ BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+
+ switch (type) {
+ case STACK_TYPE_IRQ:
+ *begin = "IRQ";
+ *end = "EOI";
+ break;
+ case STACK_TYPE_EXCEPTION ... STACK_TYPE_EXCEPTION_LAST:
+ *begin = exception_stack_names[type - STACK_TYPE_EXCEPTION];
+ *end = "EOE";
+ break;
+ default:
+ *begin = NULL;
+ *end = NULL;
}
- return NULL;
}
-static inline int
-in_irq_stack(unsigned long *stack, unsigned long *irq_stack,
- unsigned long *irq_stack_end)
+static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
{
- return (stack >= irq_stack && stack < irq_stack_end);
-}
-
-static const unsigned long irq_stack_size =
- (IRQ_STACK_SIZE - 64) / sizeof(unsigned long);
-
-enum stack_type {
- STACK_IS_UNKNOWN,
- STACK_IS_NORMAL,
- STACK_IS_EXCEPTION,
- STACK_IS_IRQ,
-};
-
-static enum stack_type
-analyze_stack(int cpu, struct task_struct *task, unsigned long *stack,
- unsigned long **stack_end, unsigned long *irq_stack,
- unsigned *used, char **id)
-{
- unsigned long addr;
+ unsigned long *begin, *end;
+ struct pt_regs *regs;
+ unsigned k;
- addr = ((unsigned long)stack & (~(THREAD_SIZE - 1)));
- if ((unsigned long)task_stack_page(task) == addr)
- return STACK_IS_NORMAL;
+ BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
- *stack_end = in_exception_stack(cpu, (unsigned long)stack,
- used, id);
- if (*stack_end)
- return STACK_IS_EXCEPTION;
+ for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+ end = (unsigned long *)raw_cpu_ptr(&orig_ist)->ist[k];
+ begin = end - (exception_stack_sizes[k] / sizeof(long));
+ regs = (struct pt_regs *)end - 1;
- if (!irq_stack)
- return STACK_IS_NORMAL;
+ if (stack < begin || stack >= end)
+ continue;
- *stack_end = irq_stack;
- irq_stack = irq_stack - irq_stack_size;
+ info->type = STACK_TYPE_EXCEPTION + k;
+ info->begin = begin;
+ info->end = end;
+ info->next_sp = (unsigned long *)regs->sp;
- if (in_irq_stack(stack, irq_stack, *stack_end))
- return STACK_IS_IRQ;
+ return true;
+ }
- return STACK_IS_UNKNOWN;
+ return false;
}
-/*
- * x86-64 can have up to three kernel stacks:
- * process stack
- * interrupt stack
- * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
- */
-
-void dump_trace(struct task_struct *task, struct pt_regs *regs,
- unsigned long *stack, unsigned long bp,
- const struct stacktrace_ops *ops, void *data)
+static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
{
- const unsigned cpu = get_cpu();
- unsigned long *irq_stack = (unsigned long *)per_cpu(irq_stack_ptr, cpu);
- unsigned long dummy;
- unsigned used = 0;
- int graph = 0;
- int done = 0;
-
- if (!task)
- task = current;
-
- if (!stack) {
- if (regs)
- stack = (unsigned long *)regs->sp;
- else if (task != current)
- stack = (unsigned long *)task->thread.sp;
- else
- stack = &dummy;
- }
+ unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr);
+ unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long));
- if (!bp)
- bp = stack_frame(task, regs);
/*
- * Print function call entries in all stacks, starting at the
- * current stack address. If the stacks consist of nested
- * exceptions
+ * This is a software stack, so 'end' can be a valid stack pointer.
+ * It just means the stack is empty.
*/
- while (!done) {
- unsigned long *stack_end;
- enum stack_type stype;
- char *id;
+ if (stack < begin || stack > end)
+ return false;
- stype = analyze_stack(cpu, task, stack, &stack_end,
- irq_stack, &used, &id);
+ info->type = STACK_TYPE_IRQ;
+ info->begin = begin;
+ info->end = end;
- /* Default finish unless specified to continue */
- done = 1;
+ /*
+ * The next stack pointer is the first thing pushed by the entry code
+ * after switching to the irq stack.
+ */
+ info->next_sp = (unsigned long *)*(end - 1);
- switch (stype) {
+ return true;
+}
- /* Break out early if we are on the thread stack */
- case STACK_IS_NORMAL:
- break;
+int get_stack_info(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask)
+{
+ if (!stack)
+ goto unknown;
- case STACK_IS_EXCEPTION:
+ task = task ? : current;
- if (ops->stack(data, id) < 0)
- break;
+ if (in_task_stack(stack, task, info))
+ goto recursion_check;
- bp = ops->walk_stack(task, stack, bp, ops,
- data, stack_end, &graph);
- ops->stack(data, "<EOE>");
- /*
- * We link to the next stack via the
- * second-to-last pointer (index -2 to end) in the
- * exception stack:
- */
- stack = (unsigned long *) stack_end[-2];
- done = 0;
- break;
+ if (task != current)
+ goto unknown;
- case STACK_IS_IRQ:
+ if (in_exception_stack(stack, info))
+ goto recursion_check;
- if (ops->stack(data, "IRQ") < 0)
- break;
- bp = ops->walk_stack(task, stack, bp,
- ops, data, stack_end, &graph);
- /*
- * We link to the next stack (which would be
- * the process stack normally) the last
- * pointer (index -1 to end) in the IRQ stack:
- */
- stack = (unsigned long *) (stack_end[-1]);
- irq_stack = NULL;
- ops->stack(data, "EOI");
- done = 0;
- break;
+ if (in_irq_stack(stack, info))
+ goto recursion_check;
- case STACK_IS_UNKNOWN:
- ops->stack(data, "UNK");
- break;
- }
- }
+ goto unknown;
+recursion_check:
/*
- * This handles the process stack:
+ * Make sure we don't iterate through any given stack more than once.
+ * If it comes up a second time then there's something wrong going on:
+ * just break out and report an unknown stack type.
*/
- bp = ops->walk_stack(task, stack, bp, ops, data, NULL, &graph);
- put_cpu();
+ if (visit_mask) {
+ if (*visit_mask & (1UL << info->type))
+ goto unknown;
+ *visit_mask |= 1UL << info->type;
+ }
+
+ return 0;
+
+unknown:
+ info->type = STACK_TYPE_UNKNOWN;
+ return -EINVAL;
}
-EXPORT_SYMBOL(dump_trace);
-void
-show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
- unsigned long *sp, unsigned long bp, char *log_lvl)
+void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+ unsigned long *sp, char *log_lvl)
{
unsigned long *irq_stack_end;
unsigned long *irq_stack;
unsigned long *stack;
- int cpu;
int i;
- preempt_disable();
- cpu = smp_processor_id();
+ if (!try_get_task_stack(task))
+ return;
- irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu));
- irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE);
+ irq_stack_end = (unsigned long *)this_cpu_read(irq_stack_ptr);
+ irq_stack = irq_stack_end - (IRQ_STACK_SIZE / sizeof(long));
- /*
- * Debugging aid: "show_stack(NULL, NULL);" prints the
- * back trace for this cpu:
- */
- if (sp == NULL) {
- if (regs)
- sp = (unsigned long *)regs->sp;
- else if (task)
- sp = (unsigned long *)task->thread.sp;
- else
- sp = (unsigned long *)&sp;
- }
+ sp = sp ? : get_stack_pointer(task, regs);
stack = sp;
for (i = 0; i < kstack_depth_to_print; i++) {
stack++;
touch_nmi_watchdog();
}
- preempt_enable();
pr_cont("\n");
- show_trace_log_lvl(task, regs, sp, bp, log_lvl);
+ show_trace_log_lvl(task, regs, sp, log_lvl);
+
+ put_task_stack(task);
}
void show_regs(struct pt_regs *regs)
{
int i;
- unsigned long sp;
- sp = regs->sp;
show_regs_print_info(KERN_DEFAULT);
__show_regs(regs, 1);
u8 *ip;
printk(KERN_DEFAULT "Stack:\n");
- show_stack_log_lvl(NULL, regs, (unsigned long *)sp,
- 0, KERN_DEFAULT);
+ show_stack_log_lvl(current, regs, NULL, KERN_DEFAULT);
printk(KERN_DEFAULT "Code: ");
on_boot_cpu = 0;
WARN_ON_FPU(current->thread.fpu.fpstate_active);
- current_thread_info()->status = 0;
if (boot_cpu_has(X86_FEATURE_XSAVEOPT) && eagerfpu != DISABLE)
eagerfpu = ENABLE;
}
if (ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer) == -EBUSY) {
+ frame_pointer, parent) == -EBUSY) {
*parent = old;
return;
}
*/
__HEAD
ENTRY(startup_32)
- movl pa(stack_start),%ecx
+ movl pa(initial_stack),%ecx
/* test KEEP_SEGMENTS flag to see if the bootloader is asking
us to not reload segments */
* start_secondary().
*/
ENTRY(start_cpu0)
- movl stack_start, %ecx
+ movl initial_stack, %ecx
movl %ecx, %esp
jmp *(initial_code)
ENDPROC(start_cpu0)
movl %eax,%es
movl %eax,%fs
movl %eax,%gs
- movl pa(stack_start),%ecx
+ movl pa(initial_stack),%ecx
movl %eax,%ss
leal -__PAGE_OFFSET(%ecx),%esp
.data
.balign 4
-ENTRY(stack_start)
+ENTRY(initial_stack)
.long init_thread_union+THREAD_SIZE
__INITRODATA
*/
/*
- * Setup stack for verify_cpu(). "-8" because stack_start is defined
+ * Setup stack for verify_cpu(). "-8" because initial_stack is defined
* this way, see below. Our best guess is a NULL ptr for stack
* termination heuristics and we don't want to break anything which
* might depend on it (kgdb, ...).
movq %rax, %cr0
/* Setup a boot time stack */
- movq stack_start(%rip), %rsp
+ movq initial_stack(%rip), %rsp
/* zero EFLAGS after setting rsp */
pushq $0
* start_secondary().
*/
ENTRY(start_cpu0)
- movq stack_start(%rip),%rsp
+ movq initial_stack(%rip),%rsp
movq initial_code(%rip),%rax
pushq $0 # fake return address to stop unwinder
pushq $__KERNEL_CS # set correct cs
ENDPROC(start_cpu0)
#endif
- /* SMP bootup changes these two */
+ /* Both SMP bootup and ACPI suspend change these variables */
__REFDATA
.balign 8
GLOBAL(initial_code)
.quad x86_64_start_kernel
GLOBAL(initial_gs)
.quad INIT_PER_CPU_VAR(irq_stack_union)
-
- GLOBAL(stack_start)
+ GLOBAL(initial_stack)
.quad init_thread_union+THREAD_SIZE-8
- .word 0
__FINITDATA
bad_address:
if (user_mode(regs))
return;
- if (regs->sp >= curbase + sizeof(struct thread_info) +
- sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
+ if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
regs->sp <= curbase + THREAD_SIZE)
return;
#include <asm/apicdef.h>
#include <asm/apic.h>
#include <asm/nmi.h>
+#include <asm/switch_to.h>
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
{
gdb_regs[GDB_DX] = 0;
gdb_regs[GDB_SI] = 0;
gdb_regs[GDB_DI] = 0;
- gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp;
+ gdb_regs[GDB_BP] = ((struct inactive_task_frame *)p->thread.sp)->bp;
#ifdef CONFIG_X86_32
gdb_regs[GDB_DS] = __KERNEL_DS;
gdb_regs[GDB_ES] = __KERNEL_DS;
gdb_regs[GDB_PS] = 0;
gdb_regs[GDB_CS] = __KERNEL_CS;
- gdb_regs[GDB_PC] = p->thread.ip;
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
#else
- gdb_regs32[GDB_PS] = *(unsigned long *)(p->thread.sp + 8);
+ gdb_regs32[GDB_PS] = 0;
gdb_regs32[GDB_CS] = __KERNEL_CS;
gdb_regs32[GDB_SS] = __KERNEL_DS;
- gdb_regs[GDB_PC] = 0;
gdb_regs[GDB_R8] = 0;
gdb_regs[GDB_R9] = 0;
gdb_regs[GDB_R10] = 0;
gdb_regs[GDB_R14] = 0;
gdb_regs[GDB_R15] = 0;
#endif
+ gdb_regs[GDB_PC] = 0;
gdb_regs[GDB_SP] = p->thread.sp;
}
static struct kobj_attribute type_attr = __ATTR_RO(type);
-static struct bin_attribute data_attr = {
+static struct bin_attribute data_attr __ro_after_init = {
.attr = {
.name = "data",
.mode = S_IRUGO,
#include <asm/x86_init.h>
#include <asm/reboot.h>
-static int kvmclock = 1;
+static int kvmclock __ro_after_init = 1;
static int msr_kvm_system_time = MSR_KVM_SYSTEM_TIME;
static int msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK;
static cycle_t kvm_sched_clock_offset;
#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
#endif
-struct pv_mmu_ops pv_mmu_ops = {
+struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
.read_cr2 = native_read_cr2,
.write_cr2 = native_write_cr2,
#include <asm/tlbflush.h>
#include <asm/mce.h>
#include <asm/vm86.h>
+#include <asm/switch_to.h>
/*
* per-CPU TSS segments. Threads are completely 'soft' on Linux,
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}
+/*
+ * Return saved PC of a blocked thread.
+ * What is this good for? it will be always the scheduler or ret_from_fork.
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+ struct inactive_task_frame *frame =
+ (struct inactive_task_frame *) READ_ONCE(tsk->thread.sp);
+ return READ_ONCE_NOCHECK(frame->ret_addr);
+}
+
/*
* Called from fs/proc with a reference on @p to find the function
* which called into schedule(). This needs to be done carefully
*/
unsigned long get_wchan(struct task_struct *p)
{
- unsigned long start, bottom, top, sp, fp, ip;
+ unsigned long start, bottom, top, sp, fp, ip, ret = 0;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
+ if (!try_get_task_stack(p))
+ return 0;
+
start = (unsigned long)task_stack_page(p);
if (!start)
- return 0;
+ goto out;
/*
* Layout of the stack page:
* PADDING
* ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING
* stack
- * ----------- bottom = start + sizeof(thread_info)
- * thread_info
- * ----------- start
+ * ----------- bottom = start
*
* The tasks stack pointer points at the location where the
* framepointer is stored. The data on the stack is:
*/
top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING;
top -= 2 * sizeof(unsigned long);
- bottom = start + sizeof(struct thread_info);
+ bottom = start;
sp = READ_ONCE(p->thread.sp);
if (sp < bottom || sp > top)
- return 0;
+ goto out;
- fp = READ_ONCE_NOCHECK(*(unsigned long *)sp);
+ fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp);
do {
if (fp < bottom || fp > top)
- return 0;
+ goto out;
ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long)));
- if (!in_sched_functions(ip))
- return ip;
+ if (!in_sched_functions(ip)) {
+ ret = ip;
+ goto out;
+ }
fp = READ_ONCE_NOCHECK(*(unsigned long *)fp);
} while (count++ < 16 && p->state != TASK_RUNNING);
- return 0;
+
+out:
+ put_task_stack(p);
+ return ret;
}
#include <asm/switch_to.h>
#include <asm/vm86.h>
-asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
-asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
-
-/*
- * Return saved PC of a blocked thread.
- */
-unsigned long thread_saved_pc(struct task_struct *tsk)
-{
- return ((unsigned long *)tsk->thread.sp)[3];
-}
-
void __show_regs(struct pt_regs *regs, int all)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
unsigned long arg, struct task_struct *p, unsigned long tls)
{
struct pt_regs *childregs = task_pt_regs(p);
+ struct fork_frame *fork_frame = container_of(childregs, struct fork_frame, regs);
+ struct inactive_task_frame *frame = &fork_frame->frame;
struct task_struct *tsk;
int err;
- p->thread.sp = (unsigned long) childregs;
+ frame->bp = 0;
+ frame->ret_addr = (unsigned long) ret_from_fork;
+ p->thread.sp = (unsigned long) fork_frame;
p->thread.sp0 = (unsigned long) (childregs+1);
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childregs, 0, sizeof(struct pt_regs));
- p->thread.ip = (unsigned long) ret_from_kernel_thread;
- task_user_gs(p) = __KERNEL_STACK_CANARY;
- childregs->ds = __USER_DS;
- childregs->es = __USER_DS;
- childregs->fs = __KERNEL_PERCPU;
- childregs->bx = sp; /* function */
- childregs->bp = arg;
- childregs->orig_ax = -1;
- childregs->cs = __KERNEL_CS | get_kernel_rpl();
- childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED;
+ frame->bx = sp; /* function */
+ frame->di = arg;
p->thread.io_bitmap_ptr = NULL;
return 0;
}
+ frame->bx = 0;
*childregs = *current_pt_regs();
childregs->ax = 0;
if (sp)
childregs->sp = sp;
- p->thread.ip = (unsigned long) ret_from_fork;
task_user_gs(p) = get_user_gs(current_pt_regs());
p->thread.io_bitmap_ptr = NULL;
#include <asm/switch_to.h>
#include <asm/xen/hypervisor.h>
-asmlinkage extern void ret_from_fork(void);
-
__visible DEFINE_PER_CPU(unsigned long, rsp_scratch);
/* Prints also some state that isn't saved in the pt_regs */
{
int err;
struct pt_regs *childregs;
+ struct fork_frame *fork_frame;
+ struct inactive_task_frame *frame;
struct task_struct *me = current;
p->thread.sp0 = (unsigned long)task_stack_page(p) + THREAD_SIZE;
childregs = task_pt_regs(p);
- p->thread.sp = (unsigned long) childregs;
- set_tsk_thread_flag(p, TIF_FORK);
+ fork_frame = container_of(childregs, struct fork_frame, regs);
+ frame = &fork_frame->frame;
+ frame->bp = 0;
+ frame->ret_addr = (unsigned long) ret_from_fork;
+ p->thread.sp = (unsigned long) fork_frame;
p->thread.io_bitmap_ptr = NULL;
savesegment(gs, p->thread.gsindex);
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childregs, 0, sizeof(struct pt_regs));
- childregs->sp = (unsigned long)childregs;
- childregs->ss = __KERNEL_DS;
- childregs->bx = sp; /* function */
- childregs->bp = arg;
- childregs->orig_ax = -1;
- childregs->cs = __KERNEL_CS | get_kernel_rpl();
- childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED;
+ frame->bx = sp; /* function */
+ frame->r12 = arg;
return 0;
}
+ frame->bx = 0;
*childregs = *current_pt_regs();
childregs->ax = 0;
current->personality &= ~READ_IMPLIES_EXEC;
/* in_compat_syscall() uses the presence of the x32
syscall bit flag to determine compat status */
- current_thread_info()->status &= ~TS_COMPAT;
+ current->thread.status &= ~TS_COMPAT;
} else {
set_thread_flag(TIF_IA32);
clear_thread_flag(TIF_X32);
current->mm->context.ia32_compat = TIF_IA32;
current->personality |= force_personality32;
/* Prepare the first "return" to user space */
- current_thread_info()->status |= TS_COMPAT;
+ current->thread.status |= TS_COMPAT;
}
}
EXPORT_SYMBOL_GPL(set_personality_ia32);
return sp;
prev_esp = (u32 *)(context);
- if (prev_esp)
- return (unsigned long)prev_esp;
+ if (*prev_esp)
+ return (unsigned long)*prev_esp;
return (unsigned long)regs;
}
*/
regs->orig_ax = value;
if (syscall_get_nr(child, regs) >= 0)
- task_thread_info(child)->status |= TS_I386_REGS_POKED;
+ child->thread.status |= TS_I386_REGS_POKED;
break;
case offsetof(struct user32, regs.eflags):
#ifdef CONFIG_X86_64
-static struct user_regset x86_64_regsets[] __read_mostly = {
+static struct user_regset x86_64_regsets[] __ro_after_init = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_regs_struct) / sizeof(long),
#endif /* CONFIG_X86_64 */
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
-static struct user_regset x86_32_regsets[] __read_mostly = {
+static struct user_regset x86_32_regsets[] __ro_after_init = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(struct user_regs_struct32) / sizeof(u32),
*/
u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
-void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
+void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
{
#ifdef CONFIG_X86_64
x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
tboot_shutdown(TB_SHUTDOWN_HALT);
}
-struct machine_ops machine_ops = {
+struct machine_ops machine_ops __ro_after_init = {
.power_off = native_machine_power_off,
.shutdown = native_machine_shutdown,
.emergency_restart = native_machine_emergency_restart,
#if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
-__visible unsigned long mmu_cr4_features;
+__visible unsigned long mmu_cr4_features __ro_after_init;
#else
-__visible unsigned long mmu_cr4_features = X86_CR4_PAE;
+__visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
#endif
/* Boot loader ID and version as integers, for the benefit of proc_dointvec */
DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
EXPORT_PER_CPU_SYMBOL(this_cpu_off);
-unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
+unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = {
[0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
};
EXPORT_SYMBOL(__per_cpu_offset);
#ifdef CONFIG_X86_64
per_cpu(irq_stack_ptr, cpu) =
per_cpu(irq_stack_union.irq_stack, cpu) +
- IRQ_STACK_SIZE - 64;
+ IRQ_STACK_SIZE;
#endif
#ifdef CONFIG_NUMA
per_cpu(x86_cpu_to_node_map, cpu) =
* than the tracee.
*/
#ifdef CONFIG_IA32_EMULATION
- if (current_thread_info()->status & (TS_COMPAT|TS_I386_REGS_POKED))
+ if (current->thread.status & (TS_COMPAT|TS_I386_REGS_POKED))
return __NR_ia32_restart_syscall;
#endif
#ifdef CONFIG_X86_X32_ABI
per_cpu(cpu_current_top_of_stack, cpu) =
(unsigned long)task_stack_page(idle) + THREAD_SIZE;
#else
- clear_tsk_thread_flag(idle, TIF_FORK);
initial_gs = per_cpu_offset(cpu);
#endif
}
early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
initial_code = (unsigned long)start_secondary;
- stack_start = idle->thread.sp;
+ initial_stack = idle->thread.sp;
/*
* Enable the espfix hack for this CPU
#include <linux/export.h>
#include <linux/uaccess.h>
#include <asm/stacktrace.h>
+#include <asm/unwind.h>
-static int save_stack_stack(void *data, char *name)
+static int save_stack_address(struct stack_trace *trace, unsigned long addr,
+ bool nosched)
{
- return 0;
-}
-
-static int
-__save_stack_address(void *data, unsigned long addr, bool reliable, bool nosched)
-{
- struct stack_trace *trace = data;
-#ifdef CONFIG_FRAME_POINTER
- if (!reliable)
- return 0;
-#endif
if (nosched && in_sched_functions(addr))
return 0;
+
if (trace->skip > 0) {
trace->skip--;
return 0;
}
- if (trace->nr_entries < trace->max_entries) {
- trace->entries[trace->nr_entries++] = addr;
- return 0;
- } else {
- return -1; /* no more room, stop walking the stack */
- }
-}
-static int save_stack_address(void *data, unsigned long addr, int reliable)
-{
- return __save_stack_address(data, addr, reliable, false);
+ if (trace->nr_entries >= trace->max_entries)
+ return -1;
+
+ trace->entries[trace->nr_entries++] = addr;
+ return 0;
}
-static int
-save_stack_address_nosched(void *data, unsigned long addr, int reliable)
+static void __save_stack_trace(struct stack_trace *trace,
+ struct task_struct *task, struct pt_regs *regs,
+ bool nosched)
{
- return __save_stack_address(data, addr, reliable, true);
-}
+ struct unwind_state state;
+ unsigned long addr;
-static const struct stacktrace_ops save_stack_ops = {
- .stack = save_stack_stack,
- .address = save_stack_address,
- .walk_stack = print_context_stack,
-};
+ if (regs)
+ save_stack_address(trace, regs->ip, nosched);
-static const struct stacktrace_ops save_stack_ops_nosched = {
- .stack = save_stack_stack,
- .address = save_stack_address_nosched,
- .walk_stack = print_context_stack,
-};
+ for (unwind_start(&state, task, regs, NULL); !unwind_done(&state);
+ unwind_next_frame(&state)) {
+ addr = unwind_get_return_address(&state);
+ if (!addr || save_stack_address(trace, addr, nosched))
+ break;
+ }
+
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
void save_stack_trace(struct stack_trace *trace)
{
- dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
- if (trace->nr_entries < trace->max_entries)
- trace->entries[trace->nr_entries++] = ULONG_MAX;
+ __save_stack_trace(trace, current, NULL, false);
}
EXPORT_SYMBOL_GPL(save_stack_trace);
void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
{
- dump_trace(current, regs, NULL, 0, &save_stack_ops, trace);
- if (trace->nr_entries < trace->max_entries)
- trace->entries[trace->nr_entries++] = ULONG_MAX;
+ __save_stack_trace(trace, current, regs, false);
}
void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
- dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
- if (trace->nr_entries < trace->max_entries)
- trace->entries[trace->nr_entries++] = ULONG_MAX;
+ if (!try_get_task_stack(tsk))
+ return;
+
+ __save_stack_trace(trace, tsk, NULL, true);
+
+ put_task_stack(tsk);
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment)
DO_ERROR(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check)
+#ifdef CONFIG_VMAP_STACK
+__visible void __noreturn handle_stack_overflow(const char *message,
+ struct pt_regs *regs,
+ unsigned long fault_address)
+{
+ printk(KERN_EMERG "BUG: stack guard page was hit at %p (stack is %p..%p)\n",
+ (void *)fault_address, current->stack,
+ (char *)current->stack + THREAD_SIZE - 1);
+ die(message, regs, 0);
+
+ /* Be absolutely certain we don't return. */
+ panic(message);
+}
+#endif
+
#ifdef CONFIG_X86_64
/* Runs on IST stack */
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
{
static const char str[] = "double fault";
struct task_struct *tsk = current;
+#ifdef CONFIG_VMAP_STACK
+ unsigned long cr2;
+#endif
#ifdef CONFIG_X86_ESPFIX64
extern unsigned char native_irq_return_iret[];
tsk->thread.error_code = error_code;
tsk->thread.trap_nr = X86_TRAP_DF;
+#ifdef CONFIG_VMAP_STACK
+ /*
+ * If we overflow the stack into a guard page, the CPU will fail
+ * to deliver #PF and will send #DF instead. Similarly, if we
+ * take any non-IST exception while too close to the bottom of
+ * the stack, the processor will get a page fault while
+ * delivering the exception and will generate a double fault.
+ *
+ * According to the SDM (footnote in 6.15 under "Interrupt 14 -
+ * Page-Fault Exception (#PF):
+ *
+ * Processors update CR2 whenever a page fault is detected. If a
+ * second page fault occurs while an earlier page fault is being
+ * deliv- ered, the faulting linear address of the second fault will
+ * overwrite the contents of CR2 (replacing the previous
+ * address). These updates to CR2 occur even if the page fault
+ * results in a double fault or occurs during the delivery of a
+ * double fault.
+ *
+ * The logic below has a small possibility of incorrectly diagnosing
+ * some errors as stack overflows. For example, if the IDT or GDT
+ * gets corrupted such that #GP delivery fails due to a bad descriptor
+ * causing #GP and we hit this condition while CR2 coincidentally
+ * points to the stack guard page, we'll think we overflowed the
+ * stack. Given that we're going to panic one way or another
+ * if this happens, this isn't necessarily worth fixing.
+ *
+ * If necessary, we could improve the test by only diagnosing
+ * a stack overflow if the saved RSP points within 47 bytes of
+ * the bottom of the stack: if RSP == tsk_stack + 48 and we
+ * take an exception, the stack is already aligned and there
+ * will be enough room SS, RSP, RFLAGS, CS, RIP, and a
+ * possible error code, so a stack overflow would *not* double
+ * fault. With any less space left, exception delivery could
+ * fail, and, as a practical matter, we've overflowed the
+ * stack even if the actual trigger for the double fault was
+ * something else.
+ */
+ cr2 = read_cr2();
+ if ((unsigned long)task_stack_page(tsk) - 1 - cr2 < PAGE_SIZE)
+ handle_stack_overflow("kernel stack overflow (double-fault)", regs, cr2);
+#endif
+
#ifdef CONFIG_DOUBLEFAULT
df_debug(regs, error_code);
#endif
--- /dev/null
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+#include <asm/bitops.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+#define FRAME_HEADER_SIZE (sizeof(long) * 2)
+
+unsigned long unwind_get_return_address(struct unwind_state *state)
+{
+ unsigned long addr;
+ unsigned long *addr_p = unwind_get_return_address_ptr(state);
+
+ if (unwind_done(state))
+ return 0;
+
+ addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, *addr_p,
+ addr_p);
+
+ return __kernel_text_address(addr) ? addr : 0;
+}
+EXPORT_SYMBOL_GPL(unwind_get_return_address);
+
+static bool update_stack_state(struct unwind_state *state, void *addr,
+ size_t len)
+{
+ struct stack_info *info = &state->stack_info;
+
+ /*
+ * If addr isn't on the current stack, switch to the next one.
+ *
+ * We may have to traverse multiple stacks to deal with the possibility
+ * that 'info->next_sp' could point to an empty stack and 'addr' could
+ * be on a subsequent stack.
+ */
+ while (!on_stack(info, addr, len))
+ if (get_stack_info(info->next_sp, state->task, info,
+ &state->stack_mask))
+ return false;
+
+ return true;
+}
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ unsigned long *next_bp;
+
+ if (unwind_done(state))
+ return false;
+
+ next_bp = (unsigned long *)*state->bp;
+
+ /* make sure the next frame's data is accessible */
+ if (!update_stack_state(state, next_bp, FRAME_HEADER_SIZE))
+ return false;
+
+ /* move to the next frame */
+ state->bp = next_bp;
+ return true;
+}
+EXPORT_SYMBOL_GPL(unwind_next_frame);
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame)
+{
+ memset(state, 0, sizeof(*state));
+ state->task = task;
+
+ /* don't even attempt to start from user mode regs */
+ if (regs && user_mode(regs)) {
+ state->stack_info.type = STACK_TYPE_UNKNOWN;
+ return;
+ }
+
+ /* set up the starting stack frame */
+ state->bp = get_frame_pointer(task, regs);
+
+ /* initialize stack info and make sure the frame data is accessible */
+ get_stack_info(state->bp, state->task, &state->stack_info,
+ &state->stack_mask);
+ update_stack_state(state, state->bp, FRAME_HEADER_SIZE);
+
+ /*
+ * The caller can provide the address of the first frame directly
+ * (first_frame) or indirectly (regs->sp) to indicate which stack frame
+ * to start unwinding at. Skip ahead until we reach it.
+ */
+ while (!unwind_done(state) &&
+ (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
+ state->bp < first_frame))
+ unwind_next_frame(state);
+}
+EXPORT_SYMBOL_GPL(__unwind_start);
--- /dev/null
+#include <linux/sched.h>
+#include <linux/ftrace.h>
+#include <asm/ptrace.h>
+#include <asm/bitops.h>
+#include <asm/stacktrace.h>
+#include <asm/unwind.h>
+
+bool unwind_next_frame(struct unwind_state *state)
+{
+ struct stack_info *info = &state->stack_info;
+
+ if (unwind_done(state))
+ return false;
+
+ do {
+ for (state->sp++; state->sp < info->end; state->sp++)
+ if (__kernel_text_address(*state->sp))
+ return true;
+
+ state->sp = info->next_sp;
+
+ } while (!get_stack_info(state->sp, state->task, info,
+ &state->stack_mask));
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(unwind_next_frame);
+
+void __unwind_start(struct unwind_state *state, struct task_struct *task,
+ struct pt_regs *regs, unsigned long *first_frame)
+{
+ memset(state, 0, sizeof(*state));
+
+ state->task = task;
+ state->sp = first_frame;
+
+ get_stack_info(first_frame, state->task, &state->stack_info,
+ &state->stack_mask);
+
+ if (!__kernel_text_address(*first_frame))
+ unwind_next_frame(state);
+}
+EXPORT_SYMBOL_GPL(__unwind_start);
static void default_nmi_init(void) { };
static int default_i8042_detect(void) { return 1; };
-struct x86_platform_ops x86_platform = {
+struct x86_platform_ops x86_platform __ro_after_init = {
.calibrate_cpu = native_calibrate_cpu,
.calibrate_tsc = native_calibrate_tsc,
.get_wallclock = mach_get_cmos_time,
EXPORT_SYMBOL_GPL(x86_platform);
#if defined(CONFIG_PCI_MSI)
-struct x86_msi_ops x86_msi = {
+struct x86_msi_ops x86_msi __ro_after_init = {
.setup_msi_irqs = native_setup_msi_irqs,
.teardown_msi_irq = native_teardown_msi_irq,
.teardown_msi_irqs = default_teardown_msi_irqs,
}
#endif
-struct x86_io_apic_ops x86_io_apic_ops = {
+struct x86_io_apic_ops x86_io_apic_ops __ro_after_init = {
.read = native_io_apic_read,
.disable = native_disable_io_apic,
};
avic_handle_ldr_update(vcpu);
}
-static struct kvm_x86_ops svm_x86_ops = {
+static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
.hardware_setup = svm_hardware_setup,
~FEATURE_CONTROL_LMCE;
}
-static struct kvm_x86_ops vmx_x86_ops = {
+static struct kvm_x86_ops vmx_x86_ops __ro_after_init = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
.hardware_setup = hardware_setup,
return;
}
+#ifdef CONFIG_VMAP_STACK
+ /*
+ * Stack overflow? During boot, we can fault near the initial
+ * stack in the direct map, but that's not an overflow -- check
+ * that we're in vmalloc space to avoid this.
+ */
+ if (is_vmalloc_addr((void *)address) &&
+ (((unsigned long)tsk->stack - 1 - address < PAGE_SIZE) ||
+ address - ((unsigned long)tsk->stack + THREAD_SIZE) < PAGE_SIZE)) {
+ register void *__sp asm("rsp");
+ unsigned long stack = this_cpu_read(orig_ist.ist[DOUBLEFAULT_STACK]) - sizeof(void *);
+ /*
+ * We're likely to be running with very little stack space
+ * left. It's plausible that we'd hit this condition but
+ * double-fault even before we get this far, in which case
+ * we're fine: the double-fault handler will deal with it.
+ *
+ * We don't want to make it all the way into the oops code
+ * and then double-fault, though, because we're likely to
+ * break the console driver and lose most of the stack dump.
+ */
+ asm volatile ("movq %[stack], %%rsp\n\t"
+ "call handle_stack_overflow\n\t"
+ "1: jmp 1b"
+ : "+r" (__sp)
+ : "D" ("kernel stack overflow (page fault)"),
+ "S" (regs), "d" (address),
+ [stack] "rm" (stack));
+ unreachable();
+ }
+#endif
+
/*
* 32-bit:
*
* You need to add an if/def entry if you introduce a new memory region
* compatible with KASLR. Your entry must be in logical order with memory
* layout. For example, ESPFIX is before EFI because its virtual address is
- * before. You also need to add a BUILD_BUG_ON in kernel_randomize_memory to
+ * before. You also need to add a BUILD_BUG_ON() in kernel_randomize_memory() to
* ensure that this order is correct and won't be changed.
*/
static const unsigned long vaddr_start = __PAGE_OFFSET_BASE;
-static const unsigned long vaddr_end = VMEMMAP_START;
+
+#if defined(CONFIG_X86_ESPFIX64)
+static const unsigned long vaddr_end = ESPFIX_BASE_ADDR;
+#elif defined(CONFIG_EFI)
+static const unsigned long vaddr_end = EFI_VA_START;
+#else
+static const unsigned long vaddr_end = __START_KERNEL_map;
+#endif
/* Default values */
unsigned long page_offset_base = __PAGE_OFFSET_BASE;
EXPORT_SYMBOL(page_offset_base);
unsigned long vmalloc_base = __VMALLOC_BASE;
EXPORT_SYMBOL(vmalloc_base);
+unsigned long vmemmap_base = __VMEMMAP_BASE;
+EXPORT_SYMBOL(vmemmap_base);
/*
* Memory regions randomized by KASLR (except modules that use a separate logic
} kaslr_regions[] = {
{ &page_offset_base, 64/* Maximum */ },
{ &vmalloc_base, VMALLOC_SIZE_TB },
+ { &vmemmap_base, 1 },
};
/* Get size in bytes used by the memory region */
struct rnd_state rand_state;
unsigned long remain_entropy;
+ /*
+ * All these BUILD_BUG_ON checks ensures the memory layout is
+ * consistent with the vaddr_start/vaddr_end variables.
+ */
+ BUILD_BUG_ON(vaddr_start >= vaddr_end);
+ BUILD_BUG_ON(config_enabled(CONFIG_X86_ESPFIX64) &&
+ vaddr_end >= EFI_VA_START);
+ BUILD_BUG_ON((config_enabled(CONFIG_X86_ESPFIX64) ||
+ config_enabled(CONFIG_EFI)) &&
+ vaddr_end >= __START_KERNEL_map);
+ BUILD_BUG_ON(vaddr_end > __START_KERNEL_map);
+
if (!kaslr_memory_enabled())
return;
unsigned cpu = smp_processor_id();
if (likely(prev != next)) {
+ if (IS_ENABLED(CONFIG_VMAP_STACK)) {
+ /*
+ * If our current stack is in vmalloc space and isn't
+ * mapped in the new pgd, we'll double-fault. Forcibly
+ * map it.
+ */
+ unsigned int stack_pgd_index = pgd_index(current_stack_pointer());
+
+ pgd_t *pgd = next->pgd + stack_pgd_index;
+
+ if (unlikely(pgd_none(*pgd)))
+ set_pgd(pgd, init_mm.pgd[stack_pgd_index]);
+ }
+
#ifdef CONFIG_SMP
this_cpu_write(cpu_tlbstate.state, TLBSTATE_OK);
this_cpu_write(cpu_tlbstate.active_mm, next);
#endif
+
cpumask_set_cpu(cpu, mm_cpumask(next));
/*
#include <asm/ptrace.h>
#include <asm/stacktrace.h>
-
-static int backtrace_stack(void *data, char *name)
-{
- /* Yes, we want all stacks */
- return 0;
-}
-
-static int backtrace_address(void *data, unsigned long addr, int reliable)
-{
- unsigned int *depth = data;
-
- if ((*depth)--)
- oprofile_add_trace(addr);
- return 0;
-}
-
-static struct stacktrace_ops backtrace_ops = {
- .stack = backtrace_stack,
- .address = backtrace_address,
- .walk_stack = print_context_stack,
-};
+#include <asm/unwind.h>
#ifdef CONFIG_COMPAT
static struct stack_frame_ia32 *
struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
if (!user_mode(regs)) {
- unsigned long stack = kernel_stack_pointer(regs);
- if (depth)
- dump_trace(NULL, regs, (unsigned long *)stack, 0,
- &backtrace_ops, &depth);
+ struct unwind_state state;
+ unsigned long addr;
+
+ if (!depth)
+ return;
+
+ oprofile_add_trace(regs->ip);
+
+ if (!--depth)
+ return;
+
+ for (unwind_start(&state, current, regs, NULL);
+ !unwind_done(&state); unwind_next_frame(&state)) {
+ addr = unwind_get_return_address(&state);
+ if (!addr)
+ break;
+
+ oprofile_add_trace(addr);
+
+ if (!--depth)
+ break;
+ }
+
return;
}
static struct {
unsigned long address;
unsigned short segment;
-} pci_indirect = { 0, __KERNEL_CS };
+} pci_indirect __ro_after_init = {
+ .address = 0,
+ .segment = __KERNEL_CS,
+};
-static int pci_bios_present;
+static int pci_bios_present __ro_after_init;
static int __init check_pcibios(void)
{
static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
- int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
+ int err, n, cpu = task_cpu(child);
struct user_i387_struct fpregs;
err = save_i387_registers(userspace_pid[cpu],
static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
{
- int n, cpu = ((struct thread_info *) child->stack)->cpu;
+ int n, cpu = task_cpu(child);
struct user_i387_struct fpregs;
n = copy_from_user(&fpregs, buf, sizeof(fpregs));
static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
{
- int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
+ int err, n, cpu = task_cpu(child);
struct user_fxsr_struct fpregs;
err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
{
- int n, cpu = ((struct thread_info *) child->stack)->cpu;
+ int n, cpu = task_cpu(child);
struct user_fxsr_struct fpregs;
n = copy_from_user(&fpregs, buf, sizeof(fpregs));
* Writes the command to the IOMMUs command buffer and informs the
* hardware about the new command.
*/
-static int iommu_queue_command_sync(struct amd_iommu *iommu,
- struct iommu_cmd *cmd,
- bool sync)
+static int __iommu_queue_command_sync(struct amd_iommu *iommu,
+ struct iommu_cmd *cmd,
+ bool sync)
{
u32 left, tail, head, next_tail;
- unsigned long flags;
again:
- spin_lock_irqsave(&iommu->lock, flags);
head = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET);
tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET);
if (left <= 2) {
struct iommu_cmd sync_cmd;
- volatile u64 sem = 0;
int ret;
- build_completion_wait(&sync_cmd, (u64)&sem);
- copy_cmd_to_buffer(iommu, &sync_cmd, tail);
+ iommu->cmd_sem = 0;
- spin_unlock_irqrestore(&iommu->lock, flags);
+ build_completion_wait(&sync_cmd, (u64)&iommu->cmd_sem);
+ copy_cmd_to_buffer(iommu, &sync_cmd, tail);
- if ((ret = wait_on_sem(&sem)) != 0)
+ if ((ret = wait_on_sem(&iommu->cmd_sem)) != 0)
return ret;
goto again;
/* We need to sync now to make sure all commands are processed */
iommu->need_sync = sync;
+ return 0;
+}
+
+static int iommu_queue_command_sync(struct amd_iommu *iommu,
+ struct iommu_cmd *cmd,
+ bool sync)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&iommu->lock, flags);
+ ret = __iommu_queue_command_sync(iommu, cmd, sync);
spin_unlock_irqrestore(&iommu->lock, flags);
- return 0;
+ return ret;
}
static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd)
static int iommu_completion_wait(struct amd_iommu *iommu)
{
struct iommu_cmd cmd;
- volatile u64 sem = 0;
+ unsigned long flags;
int ret;
if (!iommu->need_sync)
return 0;
- build_completion_wait(&cmd, (u64)&sem);
- ret = iommu_queue_command_sync(iommu, &cmd, false);
+ build_completion_wait(&cmd, (u64)&iommu->cmd_sem);
+
+ spin_lock_irqsave(&iommu->lock, flags);
+
+ iommu->cmd_sem = 0;
+
+ ret = __iommu_queue_command_sync(iommu, &cmd, false);
if (ret)
- return ret;
+ goto out_unlock;
+
+ ret = wait_on_sem(&iommu->cmd_sem);
- return wait_on_sem(&sem);
+out_unlock:
+ spin_unlock_irqrestore(&iommu->lock, flags);
+
+ return ret;
}
static int iommu_flush_dte(struct amd_iommu *iommu, u16 devid)
struct irq_domain *ir_domain;
struct irq_domain *msi_domain;
#endif
+
+ volatile u64 __aligned(8) cmd_sem;
};
#define ACPIHID_UID_LEN 256
save_stack_trace_tsk(task, &trace);
for (i = 0; i < trace.nr_entries; i++) {
- seq_printf(m, "[<%pK>] %pS\n",
+ seq_printf(m, "[<%pK>] %pB\n",
(void *)entries[i], (void *)entries[i]);
}
unlock_trace(task);
unsigned long func;
unsigned long long calltime;
unsigned long long subtime;
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
unsigned long fp;
+#endif
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+ unsigned long *retp;
+#endif
};
/*
extern int
ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
- unsigned long frame_pointer);
+ unsigned long frame_pointer, unsigned long *retp);
+
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+ unsigned long ret, unsigned long *retp);
/*
* Sometimes we don't want to trace a function with the function
return -1;
}
+static inline unsigned long
+ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
+ unsigned long *retp)
+{
+ return ret;
+}
+
static inline void pause_graph_tracing(void) { }
static inline void unpause_graph_tracing(void) { }
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#include <net/net_namespace.h>
#include <linux/sched/rt.h>
+#include <asm/thread_info.h>
+
#ifdef CONFIG_SMP
# define INIT_PUSHABLE_TASKS(tsk) \
.pushable_tasks = PLIST_NODE_INIT(tsk.pushable_tasks, MAX_PRIO),
# define INIT_KASAN(tsk)
#endif
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+# define INIT_TASK_TI(tsk) \
+ .thread_info = INIT_THREAD_INFO(tsk), \
+ .stack_refcount = ATOMIC_INIT(1),
+#else
+# define INIT_TASK_TI(tsk)
+#endif
+
/*
* INIT_TASK is used to set up the first task table, touch at
* your own risk!. Base=0, limit=0x1fffff (=2MB)
*/
#define INIT_TASK(tsk) \
{ \
+ INIT_TASK_TI(tsk) \
.state = 0, \
.stack = init_stack, \
.usage = ATOMIC_INIT(2), \
};
struct task_struct {
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ /*
+ * For reasons of header soup (see current_thread_info()), this
+ * must be the first element of task_struct.
+ */
+ struct thread_info thread_info;
+#endif
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
void *stack;
atomic_t usage;
#ifdef CONFIG_SMP
struct llist_node wake_entry;
int on_cpu;
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ unsigned int cpu; /* current CPU */
+#endif
unsigned int wakee_flips;
unsigned long wakee_flip_decay_ts;
struct task_struct *last_wakee;
#ifdef CONFIG_MMU
struct task_struct *oom_reaper_list;
#endif
+#ifdef CONFIG_VMAP_STACK
+ struct vm_struct *stack_vm_area;
+#endif
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ /* A live task holds one reference. */
+ atomic_t stack_refcount;
+#endif
/* CPU-specific state of this task */
struct thread_struct thread;
/*
# define arch_task_struct_size (sizeof(struct task_struct))
#endif
+#ifdef CONFIG_VMAP_STACK
+static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
+{
+ return t->stack_vm_area;
+}
+#else
+static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t)
+{
+ return NULL;
+}
+#endif
+
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
void yield(void);
union thread_union {
+#ifndef CONFIG_THREAD_INFO_IN_TASK
struct thread_info thread_info;
+#endif
unsigned long stack[THREAD_SIZE/sizeof(long)];
};
cgroup_threadgroup_change_end(tsk);
}
-#ifndef __HAVE_THREAD_FUNCTIONS
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+
+static inline struct thread_info *task_thread_info(struct task_struct *task)
+{
+ return &task->thread_info;
+}
+
+/*
+ * When accessing the stack of a non-current task that might exit, use
+ * try_get_task_stack() instead. task_stack_page will return a pointer
+ * that could get freed out from under you.
+ */
+static inline void *task_stack_page(const struct task_struct *task)
+{
+ return task->stack;
+}
+
+#define setup_thread_stack(new,old) do { } while(0)
+
+static inline unsigned long *end_of_stack(const struct task_struct *task)
+{
+ return task->stack;
+}
+
+#elif !defined(__HAVE_THREAD_FUNCTIONS)
#define task_thread_info(task) ((struct thread_info *)(task)->stack)
-#define task_stack_page(task) ((task)->stack)
+#define task_stack_page(task) ((void *)(task)->stack)
static inline void setup_thread_stack(struct task_struct *p, struct task_struct *org)
{
}
#endif
+
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+static inline void *try_get_task_stack(struct task_struct *tsk)
+{
+ return atomic_inc_not_zero(&tsk->stack_refcount) ?
+ task_stack_page(tsk) : NULL;
+}
+
+extern void put_task_stack(struct task_struct *tsk);
+#else
+static inline void *try_get_task_stack(struct task_struct *tsk)
+{
+ return task_stack_page(tsk);
+}
+
+static inline void put_task_stack(struct task_struct *tsk) {}
+#endif
+
#define task_stack_end_corrupted(task) \
(*(end_of_stack(task)) != STACK_END_MAGIC)
static inline unsigned int task_cpu(const struct task_struct *p)
{
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ return p->cpu;
+#else
return task_thread_info(p)->cpu;
+#endif
}
static inline int task_node(const struct task_struct *p)
struct timespec;
struct compat_timespec;
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+struct thread_info {
+ unsigned long flags; /* low level flags */
+};
+
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .flags = 0, \
+}
+#endif
+
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+#define current_thread_info() ((struct thread_info *)current)
+#endif
+
/*
* System call restart block.
*/
config BUILDTIME_EXTABLE_SORT
bool
+config THREAD_INFO_IN_TASK
+ bool
+ help
+ Select this to move thread_info off the stack into task_struct. To
+ make this work, an arch will need to remove all thread_info fields
+ except flags and fix any runtime bugs.
+
+ One subtle change that will be needed is to use try_get_task_stack()
+ and put_task_stack() in save_thread_stack_tsk() and get_wchan().
+
menu "General setup"
config BROKEN
* Initial thread structure. Alignment of this is handled by a special
* linker map entry.
*/
-union thread_union init_thread_union __init_task_data =
- { INIT_THREAD_INFO(init_task) };
+union thread_union init_thread_union __init_task_data = {
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+ INIT_THREAD_INFO(init_task)
+#endif
+};
* Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
* kmemcache based allocator.
*/
-# if THREAD_SIZE >= PAGE_SIZE
-static unsigned long *alloc_thread_stack_node(struct task_struct *tsk,
- int node)
+# if THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK)
+
+#ifdef CONFIG_VMAP_STACK
+/*
+ * vmalloc() is a bit slow, and calling vfree() enough times will force a TLB
+ * flush. Try to minimize the number of calls by caching stacks.
+ */
+#define NR_CACHED_STACKS 2
+static DEFINE_PER_CPU(struct vm_struct *, cached_stacks[NR_CACHED_STACKS]);
+#endif
+
+static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node)
{
+#ifdef CONFIG_VMAP_STACK
+ void *stack;
+ int i;
+
+ local_irq_disable();
+ for (i = 0; i < NR_CACHED_STACKS; i++) {
+ struct vm_struct *s = this_cpu_read(cached_stacks[i]);
+
+ if (!s)
+ continue;
+ this_cpu_write(cached_stacks[i], NULL);
+
+ tsk->stack_vm_area = s;
+ local_irq_enable();
+ return s->addr;
+ }
+ local_irq_enable();
+
+ stack = __vmalloc_node_range(THREAD_SIZE, THREAD_SIZE,
+ VMALLOC_START, VMALLOC_END,
+ THREADINFO_GFP | __GFP_HIGHMEM,
+ PAGE_KERNEL,
+ 0, node, __builtin_return_address(0));
+
+ /*
+ * We can't call find_vm_area() in interrupt context, and
+ * free_thread_stack() can be called in interrupt context,
+ * so cache the vm_struct.
+ */
+ if (stack)
+ tsk->stack_vm_area = find_vm_area(stack);
+ return stack;
+#else
struct page *page = alloc_pages_node(node, THREADINFO_GFP,
THREAD_SIZE_ORDER);
return page ? page_address(page) : NULL;
+#endif
}
-static inline void free_thread_stack(unsigned long *stack)
+static inline void free_thread_stack(struct task_struct *tsk)
{
- __free_pages(virt_to_page(stack), THREAD_SIZE_ORDER);
+#ifdef CONFIG_VMAP_STACK
+ if (task_stack_vm_area(tsk)) {
+ unsigned long flags;
+ int i;
+
+ local_irq_save(flags);
+ for (i = 0; i < NR_CACHED_STACKS; i++) {
+ if (this_cpu_read(cached_stacks[i]))
+ continue;
+
+ this_cpu_write(cached_stacks[i], tsk->stack_vm_area);
+ local_irq_restore(flags);
+ return;
+ }
+ local_irq_restore(flags);
+
+ vfree(tsk->stack);
+ return;
+ }
+#endif
+
+ __free_pages(virt_to_page(tsk->stack), THREAD_SIZE_ORDER);
}
# else
static struct kmem_cache *thread_stack_cache;
return kmem_cache_alloc_node(thread_stack_cache, THREADINFO_GFP, node);
}
-static void free_thread_stack(unsigned long *stack)
+static void free_thread_stack(struct task_struct *tsk)
{
- kmem_cache_free(thread_stack_cache, stack);
+ kmem_cache_free(thread_stack_cache, tsk->stack);
}
void thread_stack_cache_init(void)
/* SLAB cache for mm_struct structures (tsk->mm) */
static struct kmem_cache *mm_cachep;
-static void account_kernel_stack(unsigned long *stack, int account)
+static void account_kernel_stack(struct task_struct *tsk, int account)
{
- /* All stack pages are in the same zone and belong to the same memcg. */
- struct page *first_page = virt_to_page(stack);
+ void *stack = task_stack_page(tsk);
+ struct vm_struct *vm = task_stack_vm_area(tsk);
+
+ BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0);
+
+ if (vm) {
+ int i;
- mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
- THREAD_SIZE / 1024 * account);
+ BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
- memcg_kmem_update_page_stat(
- first_page, MEMCG_KERNEL_STACK_KB,
- account * (THREAD_SIZE / 1024));
+ for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
+ mod_zone_page_state(page_zone(vm->pages[i]),
+ NR_KERNEL_STACK_KB,
+ PAGE_SIZE / 1024 * account);
+ }
+
+ /* All stack pages belong to the same memcg. */
+ memcg_kmem_update_page_stat(vm->pages[0], MEMCG_KERNEL_STACK_KB,
+ account * (THREAD_SIZE / 1024));
+ } else {
+ /*
+ * All stack pages are in the same zone and belong to the
+ * same memcg.
+ */
+ struct page *first_page = virt_to_page(stack);
+
+ mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
+ THREAD_SIZE / 1024 * account);
+
+ memcg_kmem_update_page_stat(first_page, MEMCG_KERNEL_STACK_KB,
+ account * (THREAD_SIZE / 1024));
+ }
}
-void free_task(struct task_struct *tsk)
+static void release_task_stack(struct task_struct *tsk)
{
- account_kernel_stack(tsk->stack, -1);
+ account_kernel_stack(tsk, -1);
arch_release_thread_stack(tsk->stack);
- free_thread_stack(tsk->stack);
+ free_thread_stack(tsk);
+ tsk->stack = NULL;
+#ifdef CONFIG_VMAP_STACK
+ tsk->stack_vm_area = NULL;
+#endif
+}
+
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+void put_task_stack(struct task_struct *tsk)
+{
+ if (atomic_dec_and_test(&tsk->stack_refcount))
+ release_task_stack(tsk);
+}
+#endif
+
+void free_task(struct task_struct *tsk)
+{
+#ifndef CONFIG_THREAD_INFO_IN_TASK
+ /*
+ * The task is finally done with both the stack and thread_info,
+ * so free both.
+ */
+ release_task_stack(tsk);
+#else
+ /*
+ * If the task had a separate stack allocation, it should be gone
+ * by now.
+ */
+ WARN_ON_ONCE(atomic_read(&tsk->stack_refcount) != 0);
+#endif
rt_mutex_debug_task_free(tsk);
ftrace_graph_exit_task(tsk);
put_seccomp_filter(tsk);
{
struct task_struct *tsk;
unsigned long *stack;
+ struct vm_struct *stack_vm_area;
int err;
if (node == NUMA_NO_NODE)
if (!stack)
goto free_tsk;
+ stack_vm_area = task_stack_vm_area(tsk);
+
err = arch_dup_task_struct(tsk, orig);
+
+ /*
+ * arch_dup_task_struct() clobbers the stack-related fields. Make
+ * sure they're properly initialized before using any stack-related
+ * functions again.
+ */
+ tsk->stack = stack;
+#ifdef CONFIG_VMAP_STACK
+ tsk->stack_vm_area = stack_vm_area;
+#endif
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ atomic_set(&tsk->stack_refcount, 1);
+#endif
+
if (err)
goto free_stack;
- tsk->stack = stack;
#ifdef CONFIG_SECCOMP
/*
* We must handle setting up seccomp filters once we're under
tsk->task_frag.page = NULL;
tsk->wake_q.next = NULL;
- account_kernel_stack(stack, 1);
+ account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
return tsk;
free_stack:
- free_thread_stack(stack);
+ free_thread_stack(tsk);
free_tsk:
free_task_struct(tsk);
return NULL;
atomic_dec(&p->cred->user->processes);
exit_creds(p);
bad_fork_free:
+ put_task_stack(p);
free_task(p);
fork_out:
return ERR_PTR(retval);
static struct kthread *to_live_kthread(struct task_struct *k)
{
struct completion *vfork = ACCESS_ONCE(k->vfork_done);
- if (likely(vfork))
+ if (likely(vfork) && try_get_task_stack(k))
return __to_kthread(vfork);
return NULL;
}
{
struct kthread *kthread = to_live_kthread(k);
- if (kthread)
+ if (kthread) {
__kthread_unpark(k, kthread);
+ put_task_stack(k);
+ }
}
EXPORT_SYMBOL_GPL(kthread_unpark);
wait_for_completion(&kthread->parked);
}
}
+ put_task_stack(k);
ret = 0;
}
return ret;
__kthread_unpark(k, kthread);
wake_up_process(k);
wait_for_completion(&kthread->exited);
+ put_task_stack(k);
}
ret = k->exit_code;
put_task_struct(k);
* task and put them back on the free list.
*/
kprobe_flush_task(prev);
+
+ /* Task is done with its stack. */
+ put_task_stack(prev);
+
put_task_struct(prev);
}
balance_callback(rq);
}
-STACK_FRAME_NON_STANDARD(__schedule); /* switch_to() */
static inline void sched_submit_work(struct task_struct *tsk)
{
* per-task data have been completed by this moment.
*/
smp_wmb();
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+ p->cpu = cpu;
+#else
task_thread_info(p)->cpu = cpu;
+#endif
p->wake_cpu = cpu;
#endif
}
help
See Documentation/trace/ftrace-design.txt
-config HAVE_FUNCTION_GRAPH_FP_TEST
- bool
- help
- See Documentation/trace/ftrace-design.txt
-
config HAVE_DYNAMIC_FTRACE
bool
help
/* Add a function return address to the trace stack on thread info.*/
int
ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
- unsigned long frame_pointer)
+ unsigned long frame_pointer, unsigned long *retp)
{
unsigned long long calltime;
int index;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
current->ret_stack[index].subtime = 0;
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
current->ret_stack[index].fp = frame_pointer;
+#endif
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+ current->ret_stack[index].retp = retp;
+#endif
*depth = current->curr_ret_stack;
return 0;
return;
}
-#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
/*
* The arch may choose to record the frame pointer used
* and check it here to make sure that it is what we expect it
return ret;
}
+/**
+ * ftrace_graph_ret_addr - convert a potentially modified stack return address
+ * to its original value
+ *
+ * This function can be called by stack unwinding code to convert a found stack
+ * return address ('ret') to its original value, in case the function graph
+ * tracer has modified it to be 'return_to_handler'. If the address hasn't
+ * been modified, the unchanged value of 'ret' is returned.
+ *
+ * 'idx' is a state variable which should be initialized by the caller to zero
+ * before the first call.
+ *
+ * 'retp' is a pointer to the return address on the stack. It's ignored if
+ * the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
+ */
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+ unsigned long ret, unsigned long *retp)
+{
+ int index = task->curr_ret_stack;
+ int i;
+
+ if (ret != (unsigned long)return_to_handler)
+ return ret;
+
+ if (index < -1)
+ index += FTRACE_NOTRACE_DEPTH;
+
+ if (index < 0)
+ return ret;
+
+ for (i = 0; i <= index; i++)
+ if (task->ret_stack[i].retp == retp)
+ return task->ret_stack[i].ret;
+
+ return ret;
+}
+#else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+ unsigned long ret, unsigned long *retp)
+{
+ int task_idx;
+
+ if (ret != (unsigned long)return_to_handler)
+ return ret;
+
+ task_idx = task->curr_ret_stack;
+
+ if (!task->ret_stack || task_idx < *idx)
+ return ret;
+
+ task_idx -= *idx;
+ (*idx)++;
+
+ return task->ret_stack[task_idx].ret;
+}
+#endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
+
int __trace_graph_entry(struct trace_array *tr,
struct ftrace_graph_ent *trace,
unsigned long flags,
#include <linux/stacktrace.h>
#include <linux/dma-debug.h>
#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/export.h>
put_hash_bucket(bucket, &flags);
}
-static void check_for_stack(struct device *dev, void *addr)
+static void check_for_stack(struct device *dev,
+ struct page *page, size_t offset)
{
- if (object_is_on_stack(addr))
- err_printk(dev, NULL, "DMA-API: device driver maps memory from "
- "stack [addr=%p]\n", addr);
+ void *addr;
+ struct vm_struct *stack_vm_area = task_stack_vm_area(current);
+
+ if (!stack_vm_area) {
+ /* Stack is direct-mapped. */
+ if (PageHighMem(page))
+ return;
+ addr = page_address(page) + offset;
+ if (object_is_on_stack(addr))
+ err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [addr=%p]\n", addr);
+ } else {
+ /* Stack is vmalloced. */
+ int i;
+
+ for (i = 0; i < stack_vm_area->nr_pages; i++) {
+ if (page != stack_vm_area->pages[i])
+ continue;
+
+ addr = (u8 *)current->stack + i * PAGE_SIZE + offset;
+ err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [probable addr=%p]\n", addr);
+ break;
+ }
+ }
}
static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
if (map_single)
entry->type = dma_debug_single;
+ check_for_stack(dev, page, offset);
+
if (!PageHighMem(page)) {
void *addr = page_address(page) + offset;
- check_for_stack(dev, addr);
check_for_illegal_area(dev, addr, size);
}
entry->sg_call_ents = nents;
entry->sg_mapped_ents = mapped_ents;
+ check_for_stack(dev, sg_page(s), s->offset);
+
if (!PageHighMem(sg_page(s))) {
- check_for_stack(dev, sg_virt(s));
check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
}
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc)
{
- struct pt_regs *regs = task_pt_regs(target);
- if (unlikely(!regs))
+ struct pt_regs *regs;
+
+ if (!try_get_task_stack(target)) {
+ /* Task has no stack, so the task isn't in a syscall. */
+ *callno = -1;
+ return 0;
+ }
+
+ regs = task_pt_regs(target);
+ if (unlikely(!regs)) {
+ put_task_stack(target);
return -EAGAIN;
+ }
*sp = user_stack_pointer(regs);
*pc = instruction_pointer(regs);
if (*callno != -1L && maxargs > 0)
syscall_get_arguments(target, regs, 0, maxargs, args);
+ put_task_stack(target);
return 0;
}
if (args.nr != getpid() ||
args.arg0 != 10 || args.arg1 != 11 || args.arg2 != 12 ||
args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) {
- printf("[FAIL]\tgetpid() failed to preseve regs\n");
+ printf("[FAIL]\tgetpid() failed to preserve regs\n");
nerrs++;
} else {
printf("[OK]\tgetpid() preserves regs\n");
if (args.nr != 0 ||
args.arg0 != getpid() || args.arg1 != SIGUSR1 || args.arg2 != 12 ||
args.arg3 != 13 || args.arg4 != 14 || args.arg5 != 15) {
- printf("[FAIL]\tkill(getpid(), SIGUSR1) failed to preseve regs\n");
+ printf("[FAIL]\tkill(getpid(), SIGUSR1) failed to preserve regs\n");
nerrs++;
} else {
printf("[OK]\tkill(getpid(), SIGUSR1) preserves regs\n");
".type int3, @function\n\t"
".align 4096\n\t"
"int3:\n\t"
- "mov %ss,%eax\n\t"
+ "mov %ss,%ecx\n\t"
"int3\n\t"
".size int3, . - int3\n\t"
".align 4096, 0xcc\n\t"
#ifdef __x86_64__
# define REG_IP REG_RIP
# define REG_SP REG_RSP
-# define REG_AX REG_RAX
+# define REG_CX REG_RCX
struct selectors {
unsigned short cs, gs, fs, ss;
#else
# define REG_IP REG_EIP
# define REG_SP REG_ESP
-# define REG_AX REG_EAX
+# define REG_CX REG_ECX
static greg_t *ssptr(ucontext_t *ctx)
{
ctx->uc_mcontext.gregs[REG_IP] =
sig_cs == code16_sel ? 0 : (unsigned long)&int3;
ctx->uc_mcontext.gregs[REG_SP] = (unsigned long)0x8badf00d5aadc0deULL;
- ctx->uc_mcontext.gregs[REG_AX] = 0;
+ ctx->uc_mcontext.gregs[REG_CX] = 0;
memcpy(&requested_regs, &ctx->uc_mcontext.gregs, sizeof(gregset_t));
- requested_regs[REG_AX] = *ssptr(ctx); /* The asm code does this. */
+ requested_regs[REG_CX] = *ssptr(ctx); /* The asm code does this. */
return;
}
unsigned short ss;
asm ("mov %%ss,%0" : "=r" (ss));
- greg_t asm_ss = ctx->uc_mcontext.gregs[REG_AX];
+ greg_t asm_ss = ctx->uc_mcontext.gregs[REG_CX];
if (asm_ss != sig_ss && sig == SIGTRAP) {
/* Sanity check failure. */
printf("[FAIL]\tSIGTRAP: ss = %hx, frame ss = %hx, ax = %llx\n",
#endif
/* Sanity check on the kernel */
- if (i == REG_AX && requested_regs[i] != resulting_regs[i]) {
- printf("[FAIL]\tAX (saved SP) mismatch: requested 0x%llx; got 0x%llx\n",
+ if (i == REG_CX && requested_regs[i] != resulting_regs[i]) {
+ printf("[FAIL]\tCX (saved SP) mismatch: requested 0x%llx; got 0x%llx\n",
(unsigned long long)requested_regs[i],
(unsigned long long)resulting_regs[i]);
nerrs++;
projects / cascardo / linux.git / commitdiff