#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/ptrace.h>
+#include <linux/kprobes.h>
#include <linux/stat.h>
#include <linux/uaccess.h>
{
unsigned long flags;
local_dbg_save(flags);
- asm volatile("msr mdscr_el1, %0" :: "r" (mdscr));
+ write_sysreg(mdscr, mdscr_el1);
local_dbg_restore(flags);
}
+NOKPROBE_SYMBOL(mdscr_write);
static u32 mdscr_read(void)
{
- u32 mdscr;
- asm volatile("mrs %0, mdscr_el1" : "=r" (mdscr));
- return mdscr;
+ return read_sysreg(mdscr_el1);
}
+NOKPROBE_SYMBOL(mdscr_read);
/*
* Allow root to disable self-hosted debug from userspace.
mdscr_write(mdscr);
}
}
+NOKPROBE_SYMBOL(enable_debug_monitors);
void disable_debug_monitors(enum dbg_active_el el)
{
mdscr_write(mdscr);
}
}
+NOKPROBE_SYMBOL(disable_debug_monitors);
/*
* OS lock clearing.
*/
-static void clear_os_lock(void *unused)
+static int clear_os_lock(unsigned int cpu)
{
- asm volatile("msr oslar_el1, %0" : : "r" (0));
-}
-
-static int os_lock_notify(struct notifier_block *self,
- unsigned long action, void *data)
-{
- if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE)
- clear_os_lock(NULL);
- return NOTIFY_OK;
+ write_sysreg(0, oslar_el1);
+ isb();
+ return 0;
}
-static struct notifier_block os_lock_nb = {
- .notifier_call = os_lock_notify,
-};
-
static int debug_monitors_init(void)
{
- cpu_notifier_register_begin();
-
- /* Clear the OS lock. */
- on_each_cpu(clear_os_lock, NULL, 1);
- isb();
- local_dbg_enable();
-
- /* Register hotplug handler. */
- __register_cpu_notifier(&os_lock_nb);
-
- cpu_notifier_register_done();
- return 0;
+ return cpuhp_setup_state(CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
+ "CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING",
+ clear_os_lock, NULL);
}
postcore_initcall(debug_monitors_init);
*/
static void set_regs_spsr_ss(struct pt_regs *regs)
{
- unsigned long spsr;
-
- spsr = regs->pstate;
- spsr &= ~DBG_SPSR_SS;
- spsr |= DBG_SPSR_SS;
- regs->pstate = spsr;
+ regs->pstate |= DBG_SPSR_SS;
}
+NOKPROBE_SYMBOL(set_regs_spsr_ss);
static void clear_regs_spsr_ss(struct pt_regs *regs)
{
- unsigned long spsr;
-
- spsr = regs->pstate;
- spsr &= ~DBG_SPSR_SS;
- regs->pstate = spsr;
+ regs->pstate &= ~DBG_SPSR_SS;
}
+NOKPROBE_SYMBOL(clear_regs_spsr_ss);
/* EL1 Single Step Handler hooks */
static LIST_HEAD(step_hook);
return retval;
}
+NOKPROBE_SYMBOL(call_step_hook);
static void send_user_sigtrap(int si_code)
{
return 0;
if (user_mode(regs)) {
- send_user_sigtrap(TRAP_HWBKPT);
+ send_user_sigtrap(TRAP_TRACE);
/*
* ptrace will disable single step unless explicitly
*/
user_rewind_single_step(current);
} else {
+#ifdef CONFIG_KPROBES
+ if (kprobe_single_step_handler(regs, esr) == DBG_HOOK_HANDLED)
+ return 0;
+#endif
if (call_step_hook(regs, esr) == DBG_HOOK_HANDLED)
return 0;
return 0;
}
+NOKPROBE_SYMBOL(single_step_handler);
/*
* Breakpoint handler is re-entrant as another breakpoint can
return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
}
+NOKPROBE_SYMBOL(call_break_hook);
static int brk_handler(unsigned long addr, unsigned int esr,
struct pt_regs *regs)
{
if (user_mode(regs)) {
send_user_sigtrap(TRAP_BRKPT);
- } else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
- pr_warning("Unexpected kernel BRK exception at EL1\n");
+ }
+#ifdef CONFIG_KPROBES
+ else if ((esr & BRK64_ESR_MASK) == BRK64_ESR_KPROBES) {
+ if (kprobe_breakpoint_handler(regs, esr) != DBG_HOOK_HANDLED)
+ return -EFAULT;
+ }
+#endif
+ else if (call_break_hook(regs, esr) != DBG_HOOK_HANDLED) {
+ pr_warn("Unexpected kernel BRK exception at EL1\n");
return -EFAULT;
}
return 0;
}
+NOKPROBE_SYMBOL(brk_handler);
int aarch32_break_handler(struct pt_regs *regs)
{
send_user_sigtrap(TRAP_BRKPT);
return 0;
}
+NOKPROBE_SYMBOL(aarch32_break_handler);
static int __init debug_traps_init(void)
{
hook_debug_fault_code(DBG_ESR_EVT_HWSS, single_step_handler, SIGTRAP,
- TRAP_HWBKPT, "single-step handler");
+ TRAP_TRACE, "single-step handler");
hook_debug_fault_code(DBG_ESR_EVT_BRK, brk_handler, SIGTRAP,
TRAP_BRKPT, "ptrace BRK handler");
return 0;
if (test_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP))
set_regs_spsr_ss(task_pt_regs(task));
}
+NOKPROBE_SYMBOL(user_rewind_single_step);
void user_fastforward_single_step(struct task_struct *task)
{
mdscr_write(mdscr_read() | DBG_MDSCR_SS);
enable_debug_monitors(DBG_ACTIVE_EL1);
}
+NOKPROBE_SYMBOL(kernel_enable_single_step);
void kernel_disable_single_step(void)
{
mdscr_write(mdscr_read() & ~DBG_MDSCR_SS);
disable_debug_monitors(DBG_ACTIVE_EL1);
}
+NOKPROBE_SYMBOL(kernel_disable_single_step);
int kernel_active_single_step(void)
{
WARN_ON(!irqs_disabled());
return mdscr_read() & DBG_MDSCR_SS;
}
+NOKPROBE_SYMBOL(kernel_active_single_step);
/* ptrace API */
void user_enable_single_step(struct task_struct *task)
{
- set_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
- set_regs_spsr_ss(task_pt_regs(task));
+ struct thread_info *ti = task_thread_info(task);
+
+ if (!test_and_set_ti_thread_flag(ti, TIF_SINGLESTEP))
+ set_regs_spsr_ss(task_pt_regs(task));
}
+NOKPROBE_SYMBOL(user_enable_single_step);
void user_disable_single_step(struct task_struct *task)
{
clear_ti_thread_flag(task_thread_info(task), TIF_SINGLESTEP);
}
+NOKPROBE_SYMBOL(user_disable_single_step);
projects / cascardo / linux.git / blobdiff