From 2c51572435e8d7bded99ff4c83fc392cdae47772 Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Fri, 20 May 2016 18:06:22 -0700 Subject: [PATCH] arm64: Add stack dump to exception handler Some exceptions (like from calling a NULL function pointer) are easier to narrow down with a dump of the call stack. Let's take a page out of ARM32's book and add that feature to ARM64 as well. Also change the output format to two register columns, to make it easier to fit a whole exception dump on one screen. Applying to both coreboot and libpayload and syncing the output format between both back up. Change-Id: I19768d13d8fa8adb84f0edda2af12f20508eb2db Signed-off-by: Julius Werner Reviewed-on: https://review.coreboot.org/14931 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- payloads/libpayload/arch/arm64/exception.c | 30 ++++++++++++++--- src/arch/arm64/armv8/exception.c | 38 ++++++++++++++++------ 2 files changed, 54 insertions(+), 14 deletions(-) diff --git a/payloads/libpayload/arch/arm64/exception.c b/payloads/libpayload/arch/arm64/exception.c index 2330a98456..078a7000d3 100644 --- a/payloads/libpayload/arch/arm64/exception.c +++ b/payloads/libpayload/arch/arm64/exception.c @@ -60,15 +60,35 @@ static struct exception_handler_info exceptions[EXC_COUNT] = { [EXC_SERROR_ELX_32] = {"_serror_elx_32"}, }; +static void dump_stack(uintptr_t addr, size_t bytes) +{ + int i, j; + const int words_per_line = 8; + uint64_t *ptr = (void *)ALIGN_DOWN(addr, words_per_line * sizeof(*ptr)); + + printf("Dumping stack:\n"); + for (i = bytes / sizeof(*ptr); i >= 0; i -= words_per_line) { + printf("%p: ", ptr + i); + for (j = i; j < i + words_per_line; j++) + printf("%016llx ", *(ptr + j)); + printf("\n"); + } +} + static void print_regs(struct exception_state *state) { int i; - printf("ELR = 0x%016llx\n",state->elr); - printf("ESR = 0x%08llx\n",state->esr); - for (i = 0; i < 31; i++) { - printf("X%02d = 0x%016llx\n", i, state->regs[i]); + printf("ELR = 0x%016llx ESR = 0x%08llx\n", + state->elr, state->esr); + printf("FAR = 0x%016llx SPSR = 0x%08x\n", + raw_read_far_current(), raw_read_spsr_current()); + for (i = 0; i < 30; i += 2) { + printf("X%02d = 0x%016llx X%02d = 0x%016llx\n", + i, state->regs[i], i + 1, state->regs[i + 1]); } + printf("X30 = 0x%016llx SP = 0x%016llx\n", + state->regs[30], raw_read_sp_el0()); } void exception_dispatch(struct exception_state *state, int idx); @@ -89,6 +109,8 @@ void exception_dispatch(struct exception_state *state, int idx) printf("exception _not_used.\n"); } print_regs(state); + /* Few words below SP in case we need state from a returned function. */ + dump_stack(raw_read_sp_el0() - 32, 512); if (test_exc) { state->elr += 4; diff --git a/src/arch/arm64/armv8/exception.c b/src/arch/arm64/armv8/exception.c index b872a55a8a..c5cbbfea3b 100644 --- a/src/arch/arm64/armv8/exception.c +++ b/src/arch/arm64/armv8/exception.c @@ -57,22 +57,38 @@ static const char *exception_names[NUM_EXC_VIDS] = { [EXC_VID_LOW32_SERR] = "_serror_elx_32" }; +static void dump_stack(uintptr_t addr, size_t bytes) +{ + int i, j; + const int words_per_line = 8; + uint64_t *ptr = (void *)ALIGN_DOWN(addr, words_per_line * sizeof(*ptr)); + + printk(BIOS_DEBUG, "Dumping stack:\n"); + for (i = bytes / sizeof(*ptr); i >= 0; i -= words_per_line) { + printk(BIOS_DEBUG, "%p: ", ptr + i); + for (j = i; j < i + words_per_line; j++) + printk(BIOS_DEBUG, "%016llx ", *(ptr + j)); + printk(BIOS_DEBUG, "\n"); + } +} + static void print_regs(struct exc_state *exc_state) { int i; struct elx_state *elx = &exc_state->elx; struct regs *regs = &exc_state->regs; - uint64_t elx_esr = raw_read_esr_current(); - uint64_t elx_far = raw_read_far_current(); - - printk(BIOS_DEBUG, "ELR = 0x%016llx\n", elx->elr); - printk(BIOS_DEBUG, "ESR = 0x%016llx\n", elx_esr); - printk(BIOS_DEBUG, "SPSR = 0x%08llx\n", elx->spsr); - printk(BIOS_DEBUG, "FAR = 0x%016llx\n", elx_far); - printk(BIOS_DEBUG, "SP = 0x%016llx\n", regs->sp); - for (i = X0_INDEX; i < XMAX_INDEX; i++) - printk(BIOS_DEBUG, "X%02d = 0x%016llx\n", i, regs->x[i]); + printk(BIOS_DEBUG, "ELR = 0x%016llx ESR = 0x%08x\n", + elx->elr, raw_read_esr_current()); + printk(BIOS_DEBUG, "FAR = 0x%016llx SPSR = 0x%08x\n", + raw_read_far_current(), raw_read_spsr_current()); + for (i = 0; i < 30; i += 2) { + printk(BIOS_DEBUG, + "X%02d = 0x%016llx X%02d = 0x%016llx\n", + i, regs->x[i], i + 1, regs->x[i + 1]); + } + printk(BIOS_DEBUG, "X30 = 0x%016llx SP = 0x%016llx\n", + regs->x[30], regs->sp); } @@ -119,6 +135,8 @@ static void print_exception_info(struct exc_state *state, uint64_t idx) printk(BIOS_DEBUG, "exception %s\n", exception_names[idx]); print_regs(state); + /* Few words below SP in case we need state from a returned function. */ + dump_stack(state->regs.sp - 32, 512); } static void print_exception_and_die(struct exc_state *state, uint64_t idx)