diff options
Diffstat (limited to 'arch/arm64/kernel/hw_breakpoint.c')
| -rw-r--r-- | arch/arm64/kernel/hw_breakpoint.c | 71 |
1 files changed, 26 insertions, 45 deletions
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index b29a311bb055..ab76b36dce82 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -21,6 +21,8 @@ #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> @@ -617,8 +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; @@ -661,7 +662,7 @@ unlock: } if (!step) - return 0; + return; if (user_mode(regs)) { debug_info->bps_disabled = 1; @@ -669,7 +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; @@ -680,7 +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; @@ -689,10 +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 @@ -751,8 +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; @@ -779,7 +777,7 @@ static int watchpoint_handler(unsigned long addr, unsigned long esr, * Check that the access type matches. * 0 => load, otherwise => store */ - access = (esr & AARCH64_ESR_ACCESS_MASK) ? HW_BREAKPOINT_W : + access = (esr & ESR_ELx_WNR) ? HW_BREAKPOINT_W : HW_BREAKPOINT_R; if (!(access & hw_breakpoint_type(wp))) continue; @@ -807,7 +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 @@ -820,7 +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; @@ -831,7 +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; @@ -840,44 +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 = ¤t->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); } @@ -891,17 +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. @@ -973,14 +968,6 @@ static int hw_breakpoint_reset(unsigned int cpu) return 0; } -#ifdef CONFIG_CPU_PM -extern void cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int)); -#else -static inline void cpu_suspend_set_dbg_restorer(int (*hw_bp_restore)(unsigned int)) -{ -} -#endif - /* * One-time initialisation. */ @@ -994,12 +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. |