diff options
| -rw-r--r-- | arch/arm64/include/asm/exception.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-common.c | 31 | ||||
| -rw-r--r-- | arch/arm64/kernel/hw_breakpoint.c | 17 |
3 files changed, 40 insertions, 12 deletions
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index c8e7c61b8ac4..0362fecc5f69 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -63,8 +63,12 @@ void do_debug_exception(unsigned long addr_if_watchpoint, unsigned long esr, struct pt_regs *regs); #ifdef CONFIG_HAVE_HW_BREAKPOINT void do_breakpoint(unsigned long esr, struct pt_regs *regs); +void do_watchpoint(unsigned long addr, unsigned long esr, + struct pt_regs *regs); #else static inline void do_breakpoint(unsigned long esr, struct pt_regs *regs) {} +static inline void do_watchpoint(unsigned long addr, unsigned long esr, + struct pt_regs *regs) {} #endif /* CONFIG_HAVE_HW_BREAKPOINT */ void do_el0_softstep(unsigned long esr, struct pt_regs *regs); void do_el1_softstep(unsigned long esr, struct pt_regs *regs); diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 7265bef96672..8a6d951c14cc 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -553,6 +553,18 @@ static void noinstr el1_softstp(struct pt_regs *regs, unsigned long esr) arm64_exit_el1_dbg(regs); } +static void noinstr el1_watchpt(struct pt_regs *regs, unsigned long esr) +{ + /* Watchpoints are the only debug exception to write FAR_EL1 */ + unsigned long far = read_sysreg(far_el1); + + arm64_enter_el1_dbg(regs); + debug_exception_enter(regs); + do_watchpoint(far, esr, regs); + debug_exception_exit(regs); + arm64_exit_el1_dbg(regs); +} + static void noinstr el1_dbg(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); @@ -608,6 +620,8 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) el1_softstp(regs, esr); break; case ESR_ELx_EC_WATCHPT_CUR: + el1_watchpt(regs, esr); + break; case ESR_ELx_EC_BRK64: el1_dbg(regs, esr); break; @@ -832,6 +846,19 @@ static void noinstr el0_softstp(struct pt_regs *regs, unsigned long esr) exit_to_user_mode(regs); } +static void noinstr el0_watchpt(struct pt_regs *regs, unsigned long esr) +{ + /* Watchpoints are the only debug exception to write FAR_EL1 */ + unsigned long far = read_sysreg(far_el1); + + enter_from_user_mode(regs); + debug_exception_enter(regs); + do_watchpoint(far, esr, regs); + debug_exception_exit(regs); + local_daif_restore(DAIF_PROCCTX); + exit_to_user_mode(regs); +} + static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr) { /* Only watchpoints write FAR_EL1, otherwise its UNKNOWN */ @@ -917,6 +944,8 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs) el0_softstp(regs, esr); break; case ESR_ELx_EC_WATCHPT_LOW: + el0_watchpt(regs, esr); + break; case ESR_ELx_EC_BRK64: el0_dbg(regs, esr); break; @@ -1041,6 +1070,8 @@ asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs) el0_softstp(regs, esr); break; case ESR_ELx_EC_WATCHPT_LOW: + el0_watchpt(regs, esr); + break; case ESR_ELx_EC_BKPT32: el0_dbg(regs, esr); break; diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index 8a80e13347c8..ab76b36dce82 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -750,8 +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; @@ -806,7 +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 @@ -819,7 +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; @@ -830,7 +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; @@ -839,10 +838,8 @@ 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. @@ -984,10 +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_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. |