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Diffstat (limited to 'arch/arm64/kernel/hw_breakpoint.c')
-rw-r--r--arch/arm64/kernel/hw_breakpoint.c60
1 files changed, 24 insertions, 36 deletions
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index 722ac45f9f7b..ab76b36dce82 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -22,6 +22,7 @@
#include <asm/current.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
+#include <asm/exception.h>
#include <asm/hw_breakpoint.h>
#include <asm/traps.h>
#include <asm/cputype.h>
@@ -618,8 +619,7 @@ NOKPROBE_SYMBOL(toggle_bp_registers);
/*
* Debug exception handlers.
*/
-static int breakpoint_handler(unsigned long unused, unsigned long esr,
- struct pt_regs *regs)
+void do_breakpoint(unsigned long esr, struct pt_regs *regs)
{
int i, step = 0, *kernel_step;
u32 ctrl_reg;
@@ -662,7 +662,7 @@ unlock:
}
if (!step)
- return 0;
+ return;
if (user_mode(regs)) {
debug_info->bps_disabled = 1;
@@ -670,7 +670,7 @@ unlock:
/* If we're already stepping a watchpoint, just return. */
if (debug_info->wps_disabled)
- return 0;
+ return;
if (test_thread_flag(TIF_SINGLESTEP))
debug_info->suspended_step = 1;
@@ -681,7 +681,7 @@ unlock:
kernel_step = this_cpu_ptr(&stepping_kernel_bp);
if (*kernel_step != ARM_KERNEL_STEP_NONE)
- return 0;
+ return;
if (kernel_active_single_step()) {
*kernel_step = ARM_KERNEL_STEP_SUSPEND;
@@ -690,10 +690,8 @@ unlock:
kernel_enable_single_step(regs);
}
}
-
- return 0;
}
-NOKPROBE_SYMBOL(breakpoint_handler);
+NOKPROBE_SYMBOL(do_breakpoint);
/*
* Arm64 hardware does not always report a watchpoint hit address that matches
@@ -752,8 +750,7 @@ static int watchpoint_report(struct perf_event *wp, unsigned long addr,
return step;
}
-static int watchpoint_handler(unsigned long addr, unsigned long esr,
- struct pt_regs *regs)
+void do_watchpoint(unsigned long addr, unsigned long esr, struct pt_regs *regs)
{
int i, step = 0, *kernel_step, access, closest_match = 0;
u64 min_dist = -1, dist;
@@ -808,7 +805,7 @@ static int watchpoint_handler(unsigned long addr, unsigned long esr,
rcu_read_unlock();
if (!step)
- return 0;
+ return;
/*
* We always disable EL0 watchpoints because the kernel can
@@ -821,7 +818,7 @@ static int watchpoint_handler(unsigned long addr, unsigned long esr,
/* If we're already stepping a breakpoint, just return. */
if (debug_info->bps_disabled)
- return 0;
+ return;
if (test_thread_flag(TIF_SINGLESTEP))
debug_info->suspended_step = 1;
@@ -832,7 +829,7 @@ static int watchpoint_handler(unsigned long addr, unsigned long esr,
kernel_step = this_cpu_ptr(&stepping_kernel_bp);
if (*kernel_step != ARM_KERNEL_STEP_NONE)
- return 0;
+ return;
if (kernel_active_single_step()) {
*kernel_step = ARM_KERNEL_STEP_SUSPEND;
@@ -841,44 +838,41 @@ static int watchpoint_handler(unsigned long addr, unsigned long esr,
kernel_enable_single_step(regs);
}
}
-
- return 0;
}
-NOKPROBE_SYMBOL(watchpoint_handler);
+NOKPROBE_SYMBOL(do_watchpoint);
/*
* Handle single-step exception.
*/
-int reinstall_suspended_bps(struct pt_regs *regs)
+bool try_step_suspended_breakpoints(struct pt_regs *regs)
{
struct debug_info *debug_info = &current->thread.debug;
- int handled_exception = 0, *kernel_step;
-
- kernel_step = this_cpu_ptr(&stepping_kernel_bp);
+ int *kernel_step = this_cpu_ptr(&stepping_kernel_bp);
+ bool handled_exception = false;
/*
- * Called from single-step exception handler.
- * Return 0 if execution can resume, 1 if a SIGTRAP should be
- * reported.
+ * Called from single-step exception entry.
+ * Return true if we stepped a breakpoint and can resume execution,
+ * false if we need to handle a single-step.
*/
if (user_mode(regs)) {
if (debug_info->bps_disabled) {
debug_info->bps_disabled = 0;
toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL0, 1);
- handled_exception = 1;
+ handled_exception = true;
}
if (debug_info->wps_disabled) {
debug_info->wps_disabled = 0;
toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL0, 1);
- handled_exception = 1;
+ handled_exception = true;
}
if (handled_exception) {
if (debug_info->suspended_step) {
debug_info->suspended_step = 0;
/* Allow exception handling to fall-through. */
- handled_exception = 0;
+ handled_exception = false;
} else {
user_disable_single_step(current);
}
@@ -892,17 +886,17 @@ int reinstall_suspended_bps(struct pt_regs *regs)
if (*kernel_step != ARM_KERNEL_STEP_SUSPEND) {
kernel_disable_single_step();
- handled_exception = 1;
+ handled_exception = true;
} else {
- handled_exception = 0;
+ handled_exception = false;
}
*kernel_step = ARM_KERNEL_STEP_NONE;
}
- return !handled_exception;
+ return handled_exception;
}
-NOKPROBE_SYMBOL(reinstall_suspended_bps);
+NOKPROBE_SYMBOL(try_step_suspended_breakpoints);
/*
* Context-switcher for restoring suspended breakpoints.
@@ -987,12 +981,6 @@ static int __init arch_hw_breakpoint_init(void)
pr_info("found %d breakpoint and %d watchpoint registers.\n",
core_num_brps, core_num_wrps);
- /* Register debug fault handlers. */
- hook_debug_fault_code(DBG_ESR_EVT_HWBP, breakpoint_handler, SIGTRAP,
- TRAP_HWBKPT, "hw-breakpoint handler");
- hook_debug_fault_code(DBG_ESR_EVT_HWWP, watchpoint_handler, SIGTRAP,
- TRAP_HWBKPT, "hw-watchpoint handler");
-
/*
* Reset the breakpoint resources. We assume that a halting
* debugger will leave the world in a nice state for us.
generated by cgit (git 2.34.1) at 2025-07-31 13:57:05 +0000