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 <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/14931
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/payloads/libpayload/arch/arm64/exception.c b/payloads/libpayload/arch/arm64/exception.c
index 2330a98..078a700 100644
--- a/payloads/libpayload/arch/arm64/exception.c
+++ b/payloads/libpayload/arch/arm64/exception.c
@@ -60,15 +60,35 @@
[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 @@
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 b872a55..c5cbbfe 100644
--- a/src/arch/arm64/armv8/exception.c
+++ b/src/arch/arm64/armv8/exception.c
@@ -57,22 +57,38 @@
[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 @@
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)