select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_ARCH_KGDB
+ select HAVE_HW_BREAKPOINT if CPU_SH4A
select ARCH_HIBERNATION_POSSIBLE if MMU
config SUPERH64
include include/asm-generic/Kbuild.asm
-header-y += cachectl.h cpu-features.h
+header-y += cachectl.h
+header-y += cpu-features.h
+header-y += hw_breakpoint.h
unifdef-y += unistd_32.h
unifdef-y += unistd_64.h
--- /dev/null
+#ifndef __ASM_SH_HW_BREAKPOINT_H
+#define __ASM_SH_HW_BREAKPOINT_H
+
+#include <linux/kdebug.h>
+#include <linux/types.h>
+#include <asm/ubc.h>
+
+#ifdef __KERNEL__
+#define __ARCH_HW_BREAKPOINT_H
+
+struct arch_hw_breakpoint {
+ char *name; /* Contains name of the symbol to set bkpt */
+ unsigned long address;
+ unsigned long asid;
+ u16 len;
+ u16 type;
+};
+
+enum {
+ SH_BREAKPOINT_READ = (1 << 1),
+ SH_BREAKPOINT_WRITE = (1 << 2),
+ SH_BREAKPOINT_RW = SH_BREAKPOINT_READ | SH_BREAKPOINT_WRITE,
+
+ SH_BREAKPOINT_LEN_1 = (1 << 12),
+ SH_BREAKPOINT_LEN_2 = (1 << 13),
+ SH_BREAKPOINT_LEN_4 = SH_BREAKPOINT_LEN_1 | SH_BREAKPOINT_LEN_2,
+ SH_BREAKPOINT_LEN_8 = (1 << 14),
+};
+
+/* Total number of available UBC channels */
+#define HBP_NUM 1 /* XXX */
+
+struct perf_event;
+struct task_struct;
+struct pmu;
+
+extern int arch_check_va_in_userspace(unsigned long va, u16 hbp_len);
+extern int arch_validate_hwbkpt_settings(struct perf_event *bp,
+ struct task_struct *tsk);
+extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+ unsigned long val, void *data);
+
+int arch_install_hw_breakpoint(struct perf_event *bp);
+void arch_uninstall_hw_breakpoint(struct perf_event *bp);
+void hw_breakpoint_pmu_read(struct perf_event *bp);
+void hw_breakpoint_pmu_unthrottle(struct perf_event *bp);
+
+extern void arch_fill_perf_breakpoint(struct perf_event *bp);
+
+extern struct pmu perf_ops_bp;
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_SH_HW_BREAKPOINT_H */
DIE_TRAP,
DIE_NMI,
DIE_OOPS,
+ DIE_BREAKPOINT,
+ DIE_SSTEP,
};
#endif /* __ASM_SH_KDEBUG_H */
#include <asm/page.h>
#include <asm/types.h>
#include <asm/ptrace.h>
+#include <asm/ubc.h>
/*
* Default implementation of macro that returns current
unsigned long sp;
unsigned long pc;
- /* Hardware debugging registers */
- unsigned long ubc_pc;
+ /* Save middle states of ptrace breakpoints */
+ struct perf_event *ptrace_bps[NR_UBC_CHANNELS];
/* floating point info */
union sh_fpu_union fpu;
#endif
};
-/* Count of active tasks with UBC settings */
-extern int ubc_usercnt;
-
#define INIT_THREAD { \
.sp = sizeof(init_stack) + (long) &init_stack, \
}
void default_idle(void);
void cpu_idle_wait(void);
-asmlinkage void break_point_trap(void);
-
#ifdef CONFIG_SUPERH32
#define BUILD_TRAP_HANDLER(name) \
asmlinkage void name##_trap_handler(unsigned long r4, unsigned long r5, \
#define TIF_SECCOMP 6 /* secure computing */
#define TIF_NOTIFY_RESUME 7 /* callback before returning to user */
#define TIF_SYSCALL_TRACEPOINT 8 /* for ftrace syscall instrumentation */
+#define TIF_DEBUG 9 /* uses UBC */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 18
#define TIF_FREEZE 19 /* Freezing for suspend */
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
+#define _TIF_DEBUG (1 << TIF_DEBUG)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE (1 << TIF_FREEZE)
*/
#ifndef __ASM_SH_UBC_H
#define __ASM_SH_UBC_H
-#ifdef __KERNEL__
+#ifdef __KERNEL__
#include <cpu/ubc.h>
/* User Break Controller */
#define BRCR_UBDE (1 << 0)
#endif
+/*
+ * All SH parts have 2 UBC channels. I defy any hardware designer to
+ * invalidate this assertion.
+ */
+#define NR_UBC_CHANNELS 2
+
#endif /* __KERNEL__ */
#endif /* __ASM_SH_UBC_H */
obj-$(CONFIG_DWARF_UNWINDER) += dwarf.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_callchain.o
+obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) += localtimer.o
EXTRA_CFLAGS += -Werror
.long exception_error ! reserved_instruction (filled by trap_init) /* 180 */
.long exception_error ! illegal_slot_instruction (filled by trap_init) /*1A0*/
.long nmi_trap_handler /* 1C0 */ ! Allow trap to debugger
- .long break_point_trap /* 1E0 */
+ .long breakpoint_trap_handler /* 1E0 */
/*
* Pad the remainder of the table out, exceptions residing in far
--- /dev/null
+/*
+ * arch/sh/kernel/hw_breakpoint.c
+ *
+ * Unified kernel/user-space hardware breakpoint facility for the on-chip UBC.
+ *
+ * Copyright (C) 2009 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/perf_event.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/percpu.h>
+#include <linux/kallsyms.h>
+#include <linux/notifier.h>
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
+#include <linux/io.h>
+#include <asm/hw_breakpoint.h>
+#include <asm/mmu_context.h>
+
+struct ubc_context {
+ unsigned long pc;
+ unsigned long state;
+};
+
+/* Per cpu ubc channel state */
+static DEFINE_PER_CPU(struct ubc_context, ubc_ctx[HBP_NUM]);
+
+/*
+ * Stores the breakpoints currently in use on each breakpoint address
+ * register for each cpus
+ */
+static DEFINE_PER_CPU(struct perf_event *, bp_per_reg[HBP_NUM]);
+
+static int __init ubc_init(void)
+{
+ __raw_writel(0, UBC_CAMR0);
+ __raw_writel(0, UBC_CBR0);
+ __raw_writel(0, UBC_CBCR);
+
+ __raw_writel(UBC_CRR_BIE | UBC_CRR_PCB, UBC_CRR0);
+
+ /* dummy read for write posting */
+ (void)__raw_readl(UBC_CRR0);
+
+ return 0;
+}
+arch_initcall(ubc_init);
+
+/*
+ * Install a perf counter breakpoint.
+ *
+ * We seek a free UBC channel and use it for this breakpoint.
+ *
+ * Atomic: we hold the counter->ctx->lock and we only handle variables
+ * and registers local to this cpu.
+ */
+int arch_install_hw_breakpoint(struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ struct ubc_context *ubc_ctx;
+ int i;
+
+ for (i = 0; i < HBP_NUM; i++) {
+ struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+
+ if (!*slot) {
+ *slot = bp;
+ break;
+ }
+ }
+
+ if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot"))
+ return -EBUSY;
+
+ ubc_ctx = &__get_cpu_var(ubc_ctx[i]);
+
+ ubc_ctx->pc = info->address;
+ ubc_ctx->state = info->len | info->type;
+
+ __raw_writel(UBC_CBR_CE | ubc_ctx->state, UBC_CBR0);
+ __raw_writel(ubc_ctx->pc, UBC_CAR0);
+
+ return 0;
+}
+
+/*
+ * Uninstall the breakpoint contained in the given counter.
+ *
+ * First we search the debug address register it uses and then we disable
+ * it.
+ *
+ * Atomic: we hold the counter->ctx->lock and we only handle variables
+ * and registers local to this cpu.
+ */
+void arch_uninstall_hw_breakpoint(struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ struct ubc_context *ubc_ctx;
+ int i;
+
+ for (i = 0; i < HBP_NUM; i++) {
+ struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+
+ if (*slot == bp) {
+ *slot = NULL;
+ break;
+ }
+ }
+
+ if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot"))
+ return;
+
+ ubc_ctx = &__get_cpu_var(ubc_ctx[i]);
+ ubc_ctx->pc = 0;
+ ubc_ctx->state &= ~(info->len | info->type);
+
+ __raw_writel(ubc_ctx->pc, UBC_CBR0);
+ __raw_writel(ubc_ctx->state, UBC_CAR0);
+}
+
+static int get_hbp_len(u16 hbp_len)
+{
+ unsigned int len_in_bytes = 0;
+
+ switch (hbp_len) {
+ case SH_BREAKPOINT_LEN_1:
+ len_in_bytes = 1;
+ break;
+ case SH_BREAKPOINT_LEN_2:
+ len_in_bytes = 2;
+ break;
+ case SH_BREAKPOINT_LEN_4:
+ len_in_bytes = 4;
+ break;
+ case SH_BREAKPOINT_LEN_8:
+ len_in_bytes = 8;
+ break;
+ }
+ return len_in_bytes;
+}
+
+/*
+ * Check for virtual address in user space.
+ */
+int arch_check_va_in_userspace(unsigned long va, u16 hbp_len)
+{
+ unsigned int len;
+
+ len = get_hbp_len(hbp_len);
+
+ return (va <= TASK_SIZE - len);
+}
+
+/*
+ * Check for virtual address in kernel space.
+ */
+static int arch_check_va_in_kernelspace(unsigned long va, u8 hbp_len)
+{
+ unsigned int len;
+
+ len = get_hbp_len(hbp_len);
+
+ return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+}
+
+/*
+ * Store a breakpoint's encoded address, length, and type.
+ */
+static int arch_store_info(struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+ /*
+ * User-space requests will always have the address field populated
+ * For kernel-addresses, either the address or symbol name can be
+ * specified.
+ */
+ if (info->name)
+ info->address = (unsigned long)kallsyms_lookup_name(info->name);
+ if (info->address) {
+ info->asid = get_asid();
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+int arch_bp_generic_fields(int sh_len, int sh_type,
+ int *gen_len, int *gen_type)
+{
+ /* Len */
+ switch (sh_len) {
+ case SH_BREAKPOINT_LEN_1:
+ *gen_len = HW_BREAKPOINT_LEN_1;
+ break;
+ case SH_BREAKPOINT_LEN_2:
+ *gen_len = HW_BREAKPOINT_LEN_2;
+ break;
+ case SH_BREAKPOINT_LEN_4:
+ *gen_len = HW_BREAKPOINT_LEN_4;
+ break;
+ case SH_BREAKPOINT_LEN_8:
+ *gen_len = HW_BREAKPOINT_LEN_8;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Type */
+ switch (sh_type) {
+ case SH_BREAKPOINT_READ:
+ *gen_type = HW_BREAKPOINT_R;
+ case SH_BREAKPOINT_WRITE:
+ *gen_type = HW_BREAKPOINT_W;
+ break;
+ case SH_BREAKPOINT_RW:
+ *gen_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int arch_build_bp_info(struct perf_event *bp)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+ info->address = bp->attr.bp_addr;
+
+ /* Len */
+ switch (bp->attr.bp_len) {
+ case HW_BREAKPOINT_LEN_1:
+ info->len = SH_BREAKPOINT_LEN_1;
+ break;
+ case HW_BREAKPOINT_LEN_2:
+ info->len = SH_BREAKPOINT_LEN_2;
+ break;
+ case HW_BREAKPOINT_LEN_4:
+ info->len = SH_BREAKPOINT_LEN_4;
+ break;
+ case HW_BREAKPOINT_LEN_8:
+ info->len = SH_BREAKPOINT_LEN_8;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Type */
+ switch (bp->attr.bp_type) {
+ case HW_BREAKPOINT_R:
+ info->type = SH_BREAKPOINT_READ;
+ break;
+ case HW_BREAKPOINT_W:
+ info->type = SH_BREAKPOINT_WRITE;
+ break;
+ case HW_BREAKPOINT_W | HW_BREAKPOINT_R:
+ info->type = SH_BREAKPOINT_RW;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Validate the arch-specific HW Breakpoint register settings
+ */
+int arch_validate_hwbkpt_settings(struct perf_event *bp,
+ struct task_struct *tsk)
+{
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+ unsigned int align;
+ int ret;
+
+ ret = arch_build_bp_info(bp);
+ if (ret)
+ return ret;
+
+ ret = -EINVAL;
+
+ switch (info->len) {
+ case SH_BREAKPOINT_LEN_1:
+ align = 0;
+ break;
+ case SH_BREAKPOINT_LEN_2:
+ align = 1;
+ break;
+ case SH_BREAKPOINT_LEN_4:
+ align = 3;
+ break;
+ case SH_BREAKPOINT_LEN_8:
+ align = 7;
+ break;
+ default:
+ return ret;
+ }
+
+ if (bp->callback)
+ ret = arch_store_info(bp);
+
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Check that the low-order bits of the address are appropriate
+ * for the alignment implied by len.
+ */
+ if (info->address & align)
+ return -EINVAL;
+
+ /* Check that the virtual address is in the proper range */
+ if (tsk) {
+ if (!arch_check_va_in_userspace(info->address, info->len))
+ return -EFAULT;
+ } else {
+ if (!arch_check_va_in_kernelspace(info->address, info->len))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/*
+ * Release the user breakpoints used by ptrace
+ */
+void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
+{
+ int i;
+ struct thread_struct *t = &tsk->thread;
+
+ for (i = 0; i < HBP_NUM; i++) {
+ unregister_hw_breakpoint(t->ptrace_bps[i]);
+ t->ptrace_bps[i] = NULL;
+ }
+}
+
+static int __kprobes hw_breakpoint_handler(struct die_args *args)
+{
+ int cpu, i, rc = NOTIFY_STOP;
+ struct perf_event *bp;
+ unsigned long val;
+
+ val = __raw_readl(UBC_CBR0);
+ __raw_writel(val & ~UBC_CBR_CE, UBC_CBR0);
+
+ cpu = get_cpu();
+ for (i = 0; i < HBP_NUM; i++) {
+ /*
+ * The counter may be concurrently released but that can only
+ * occur from a call_rcu() path. We can then safely fetch
+ * the breakpoint, use its callback, touch its counter
+ * while we are in an rcu_read_lock() path.
+ */
+ rcu_read_lock();
+
+ bp = per_cpu(bp_per_reg[i], cpu);
+ if (bp) {
+ rc = NOTIFY_DONE;
+ } else {
+ rcu_read_unlock();
+ break;
+ }
+
+ (bp->callback)(bp, args->regs);
+
+ rcu_read_unlock();
+ }
+
+ if (bp) {
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+ __raw_writel(UBC_CBR_CE | info->len | info->type, UBC_CBR0);
+ __raw_writel(info->address, UBC_CAR0);
+ }
+
+ put_cpu();
+
+ return rc;
+}
+
+BUILD_TRAP_HANDLER(breakpoint)
+{
+ unsigned long ex = lookup_exception_vector();
+ TRAP_HANDLER_DECL;
+
+ notify_die(DIE_BREAKPOINT, "breakpoint", regs, 0, ex, SIGTRAP);
+}
+
+/*
+ * Handle debug exception notifications.
+ */
+int __kprobes hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+ unsigned long val, void *data)
+{
+ if (val != DIE_BREAKPOINT)
+ return NOTIFY_DONE;
+
+ return hw_breakpoint_handler(data);
+}
+
+void hw_breakpoint_pmu_read(struct perf_event *bp)
+{
+ /* TODO */
+}
+
+void hw_breakpoint_pmu_unthrottle(struct perf_event *bp)
+{
+ /* TODO */
+}
#include <linux/fs.h>
#include <linux/ftrace.h>
#include <linux/preempt.h>
+#include <linux/hw_breakpoint.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/syscalls.h>
#include <asm/watchdog.h>
-int ubc_usercnt = 0;
-
#ifdef CONFIG_32BIT
static void watchdog_trigger_immediate(void)
{
*/
void exit_thread(void)
{
- if (current->thread.ubc_pc) {
- current->thread.ubc_pc = 0;
- ubc_usercnt -= 1;
- }
}
void flush_thread(void)
{
-#if defined(CONFIG_SH_FPU)
struct task_struct *tsk = current;
+
+ flush_ptrace_hw_breakpoint(tsk);
+
+#if defined(CONFIG_SH_FPU)
/* Forget lazy FPU state */
clear_fpu(tsk, task_pt_regs(tsk));
clear_used_math();
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
+
#if defined(CONFIG_SH_DSP)
struct task_struct *tsk = current;
-#endif
-#if defined(CONFIG_SH_DSP)
if (is_dsp_enabled(tsk)) {
/* We can use the __save_dsp or just copy the struct:
* __save_dsp(p);
p->thread.sp = (unsigned long) childregs;
p->thread.pc = (unsigned long) ret_from_fork;
- p->thread.ubc_pc = 0;
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
return 0;
}
-/* Tracing by user break controller. */
-static void ubc_set_tracing(int asid, unsigned long pc)
-{
-#if defined(CONFIG_CPU_SH4A)
- unsigned long val;
-
- val = (UBC_CBR_ID_INST | UBC_CBR_RW_READ | UBC_CBR_CE);
- val |= (UBC_CBR_AIE | UBC_CBR_AIV_SET(asid));
-
- ctrl_outl(val, UBC_CBR0);
- ctrl_outl(pc, UBC_CAR0);
- ctrl_outl(0x0, UBC_CAMR0);
- ctrl_outl(0x0, UBC_CBCR);
-
- val = (UBC_CRR_RES | UBC_CRR_PCB | UBC_CRR_BIE);
- ctrl_outl(val, UBC_CRR0);
-
- /* Read UBC register that we wrote last, for checking update */
- val = ctrl_inl(UBC_CRR0);
-
-#else /* CONFIG_CPU_SH4A */
- ctrl_outl(pc, UBC_BARA);
-
-#ifdef CONFIG_MMU
- ctrl_outb(asid, UBC_BASRA);
-#endif
-
- ctrl_outl(0, UBC_BAMRA);
-
- if (current_cpu_data.type == CPU_SH7729 ||
- current_cpu_data.type == CPU_SH7710 ||
- current_cpu_data.type == CPU_SH7712 ||
- current_cpu_data.type == CPU_SH7203){
- ctrl_outw(BBR_INST | BBR_READ | BBR_CPU, UBC_BBRA);
- ctrl_outl(BRCR_PCBA | BRCR_PCTE, UBC_BRCR);
- } else {
- ctrl_outw(BBR_INST | BBR_READ, UBC_BBRA);
- ctrl_outw(BRCR_PCBA, UBC_BRCR);
- }
-#endif /* CONFIG_CPU_SH4A */
-}
-
/*
* switch_to(x,y) should switch tasks from x to y.
*
: "r" (task_thread_info(next)));
#endif
- /* If no tasks are using the UBC, we're done */
- if (ubc_usercnt == 0)
- /* If no tasks are using the UBC, we're done */;
- else if (next->thread.ubc_pc && next->mm) {
- int asid = 0;
-#ifdef CONFIG_MMU
- asid |= cpu_asid(smp_processor_id(), next->mm);
-#endif
- ubc_set_tracing(asid, next->thread.ubc_pc);
- } else {
-#if defined(CONFIG_CPU_SH4A)
- ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
- ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
-#else
- ctrl_outw(0, UBC_BBRA);
- ctrl_outw(0, UBC_BBRB);
-#endif
- }
-
/*
* If the task has used fpu the last 5 timeslices, just do a full
* restore of the math state immediately to avoid the trap; the
return pc;
}
-
-asmlinkage void break_point_trap(void)
-{
- /* Clear tracing. */
-#if defined(CONFIG_CPU_SH4A)
- ctrl_outl(UBC_CBR_INIT, UBC_CBR0);
- ctrl_outl(UBC_CRR_INIT, UBC_CRR0);
-#else
- ctrl_outw(0, UBC_BBRA);
- ctrl_outw(0, UBC_BBRB);
- ctrl_outl(0, UBC_BRCR);
-#endif
- current->thread.ubc_pc = 0;
- ubc_usercnt -= 1;
-
- force_sig(SIGTRAP, current);
-}
void user_enable_single_step(struct task_struct *child)
{
- /* Next scheduling will set up UBC */
- if (child->thread.ubc_pc == 0)
- ubc_usercnt += 1;
-
- child->thread.ubc_pc = get_stack_long(child,
- offsetof(struct pt_regs, pc));
-
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-
- /*
- * Ensure the UBC is not programmed at the next context switch.
- *
- * Normally this is not needed but there are sequences such as
- * singlestep, signal delivery, and continue that leave the
- * ubc_pc non-zero leading to spurious SIGTRAPs.
- */
- if (child->thread.ubc_pc != 0) {
- ubc_usercnt -= 1;
- child->thread.ubc_pc = 0;
- }
}
/*
projects / cascardo / linux.git / commitdiff