Changes in v2:
* Basically moved arm64_print_stackframe_entry() after arm64_unwind_frame()
in arm64_back_trace_cmd() to make the output consistent with the format
on x86
Then, we had to calculate the end address of a stack frame, frame_top,
for particular cases.
-Takahiro AKASHI
======8<======
>From d8683645599a238578a0f586af563bc9f847d52c Mon Sep 17 00:00:00 2001
From: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Date: Wed, 8 Jun 2016 11:14:22 +0900
Subject: [PATCH v2] arm64: dump a stack frame based on fp
Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
---
arm64.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++----------------
defs.h | 5 +++
2 files changed, 110 insertions(+), 35 deletions(-)
diff --git a/arm64.c b/arm64.c
index bdea79c..7b5b394 100644
--- a/arm64.c
+++ b/arm64.c
@@ -43,9 +43,10 @@ static void arm64_stackframe_init(void);
static int arm64_eframe_search(struct bt_info *);
static int arm64_is_kernel_exception_frame(struct bt_info *, ulong);
static int arm64_in_exception_text(ulong);
+static int arm64_in_exp_entry(ulong);
static void arm64_back_trace_cmd(struct bt_info *);
static void arm64_print_text_symbols(struct bt_info *, struct arm64_stackframe *, FILE *);
-static int arm64_print_stackframe_entry(struct bt_info *, int, struct arm64_stackframe *, FILE *);
+static int arm64_print_stackframe_entry(struct bt_info *, int, struct arm64_stackframe *, struct arm64_stackframe *, FILE *);
static void arm64_display_full_frame(struct bt_info *, ulong);
static int arm64_unwind_frame(struct bt_info *, struct arm64_stackframe *);
static int arm64_get_dumpfile_stackframe(struct bt_info *, struct arm64_stackframe *);
@@ -597,6 +598,10 @@ arm64_dump_machdep_table(ulong arg)
fprintf(fp, " __exception_text_end: %lx\n", ms->__exception_text_end);
fprintf(fp, " __irqentry_text_start: %lx\n", ms->__irqentry_text_start);
fprintf(fp, " __irqentry_text_end: %lx\n", ms->__irqentry_text_end);
+ fprintf(fp, " exp_entry1_start: %lx\n", ms->exp_entry1_start);
+ fprintf(fp, " exp_entry1_end: %lx\n", ms->exp_entry1_end);
+ fprintf(fp, " exp_entry2_start: %lx\n", ms->exp_entry2_start);
+ fprintf(fp, " exp_entry2_end: %lx\n", ms->exp_entry2_end);
fprintf(fp, " panic_task_regs: %lx\n", (ulong)ms->panic_task_regs);
fprintf(fp, " PTE_PROT_NONE: %lx\n", ms->PTE_PROT_NONE);
fprintf(fp, " PTE_FILE: ");
@@ -1283,6 +1288,16 @@ arm64_stackframe_init(void)
machdep->machspec->__irqentry_text_end = sp2->value;
}
+ if ((sp1 = kernel_symbol_search("vectors")) &&
+ (sp1n = kernel_symbol_search("cpu_switch_to")) &&
+ (sp2 = kernel_symbol_search("ret_fast_syscall")) &&
+ (sp2n = kernel_symbol_search("sys_rt_sigreturn_wrapper"))) {
+ machdep->machspec->exp_entry1_start = sp1->value;
+ machdep->machspec->exp_entry1_end = sp1n->value;
+ machdep->machspec->exp_entry2_start = sp2->value;
+ machdep->machspec->exp_entry2_end = sp2n->value;
+ }
+
if ((sp1 = kernel_symbol_search("crash_kexec")) &&
(sp1n = next_symbol(NULL, sp1)) &&
(sp2 = kernel_symbol_search("crash_save_cpu")) &&
@@ -1484,18 +1499,54 @@ arm64_in_exception_text(ulong ptr)
return FALSE;
}
+static int
+arm64_in_exp_entry(ulong addr)
+{
+ struct machine_specific *ms;
+
+ ms = machdep->machspec;
+ if ((ms->exp_entry1_start <= addr) && (addr < ms->exp_entry1_end))
+ return TRUE;
+ if ((ms->exp_entry2_start <= addr) && (addr < ms->exp_entry2_end))
+ return TRUE;
+ return FALSE;
+}
+
#define BACKTRACE_CONTINUE (1)
#define BACKTRACE_COMPLETE_KERNEL (2)
-#define BACKTRACE_COMPLETE_USER (3)
static int
-arm64_print_stackframe_entry(struct bt_info *bt, int level, struct arm64_stackframe *frame, FILE *ofp)
+arm64_print_stackframe_entry(struct bt_info *bt, int level, struct arm64_stackframe *frame, struct arm64_stackframe *caller_frame, FILE *ofp)
{
char *name, *name_plus_offset;
ulong symbol_offset;
struct syment *sp;
struct load_module *lm;
char buf[BUFSIZE];
+ unsigned long frame_top;
+
+ if (caller_frame->fp) {
+#if 0 /* FIXME: Need to debug here */
+ if (arm64_in_exp_entry(caller_frame->pc))
+ frame_top = caller_frame->fp - sizeof(struct arm64_pt_regs);
+ else
+#endif
+ frame_top = caller_frame->fp;
+ } else if (frame->fp && !arm64_in_exp_entry(frame->pc))
+ frame_top = bt->stacktop - USER_EFRAME_OFFSET;
+ else
+ frame_top = bt->stacktop - 0x10;
+
+ if (CRASHDEBUG(1)) {
+ fprintf(ofp, " cur sp:%016lx fp:%016lx pc:%016lx\n",
+ frame->sp, frame->fp, frame->pc);
+ fprintf(ofp, " nxt sp:%016lx fp:%016lx pc:%016lx\n",
+ caller_frame->sp, caller_frame->fp, caller_frame->pc);
+
+ fprintf(ofp, " frame: <%lx-%lx> check(%d, %d)\n",
+ bt->frameptr, frame_top,
+ INSTACK(frame_top, bt), INSTACK(bt->frameptr, bt));
+ }
name = closest_symbol(frame->pc);
name_plus_offset = NULL;
@@ -1507,13 +1558,16 @@ arm64_print_stackframe_entry(struct bt_info *bt, int level, struct arm64_stackfr
value_to_symstr(frame->pc, buf, bt->radix);
}
- if (bt->flags & BT_FULL) {
- arm64_display_full_frame(bt, frame->sp);
- bt->frameptr = frame->sp;
- }
+ if (bt->flags & BT_FULL)
+ arm64_display_full_frame(bt, frame_top);
+ bt->frameptr = frame_top;
fprintf(ofp, "%s#%d [%8lx] %s at %lx", level < 10 ? " " : "", level,
- frame->sp, name_plus_offset ? name_plus_offset : name, frame->pc);
+#if 1 /* FIXME */
+ (frame->fp ? : frame->sp), name_plus_offset ? name_plus_offset : name, frame->pc);
+#else
+ frame->fp, name_plus_offset ? name_plus_offset : name, frame->pc);
+#endif
if (BT_REFERENCE_CHECK(bt))
arm64_do_bt_reference_check(bt, frame->pc, name);
@@ -1571,12 +1625,10 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame)
{
unsigned long high, low, fp;
unsigned long stack_mask;
- unsigned long irq_stack_ptr, orig_sp, sp_in;
+ unsigned long irq_stack_ptr, orig_sp;
struct arm64_pt_regs *ptregs;
struct machine_specific *ms;
- sp_in = frame->sp;
-
stack_mask = (unsigned long)(ARM64_STACK_SIZE) - 1;
fp = frame->fp;
@@ -1612,8 +1664,17 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame)
if (INSTACK(orig_sp, bt) && (INSTACK(frame->fp, bt) || (frame->fp == 0))) {
ptregs = (struct arm64_pt_regs *)&bt->stackbuf[(ulong)(STACK_OFFSET_TYPE(orig_sp))];
frame->sp = orig_sp;
- frame->pc = ptregs->pc;
- bt->bptr = sp_in;
+
+ /*
+ * if frame->fp == 0, ptregs->pc is a pc
+ * where an exception in user mode was taken.
+ * So don't update frame->pc since we have
+ * a pseudo stack frame for exception entry.
+ */
+ if (frame->fp)
+ frame->pc = ptregs->pc;
+
+ bt->bptr = fp;
if (CRASHDEBUG(1))
error(INFO,
"arm64_unwind_frame: switch stacks: fp: %lx sp: %lx pc: %lx\n",
@@ -1634,10 +1695,11 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame)
static void
arm64_back_trace_cmd(struct bt_info *bt)
{
- struct arm64_stackframe stackframe;
+ struct arm64_stackframe stackframe, cur_frame;
int level;
ulong exception_frame;
FILE *ofp;
+ int end_stack = 0;
ofp = BT_REFERENCE_CHECK(bt) ? pc->nullfp : fp;
@@ -1657,7 +1719,7 @@ arm64_back_trace_cmd(struct bt_info *bt)
stackframe.fp = GET_STACK_ULONG(bt->bptr - 8);
stackframe.pc = GET_STACK_ULONG(bt->bptr);
stackframe.sp = bt->bptr + 8;
- bt->frameptr = stackframe.sp;
+ bt->frameptr = stackframe.fp;
} else if (bt->hp && bt->hp->esp) {
if (arm64_on_irq_stack(bt->tc->processor, bt->hp->esp)) {
arm64_set_irq_stack(bt);
@@ -1703,23 +1765,9 @@ arm64_back_trace_cmd(struct bt_info *bt)
while (1) {
bt->instptr = stackframe.pc;
- switch (arm64_print_stackframe_entry(bt, level, &stackframe, ofp))
- {
- case BACKTRACE_COMPLETE_KERNEL:
- return;
- case BACKTRACE_COMPLETE_USER:
- goto complete_user;
- case BACKTRACE_CONTINUE:
- break;
- }
-
- if (exception_frame) {
- arm64_print_exception_frame(bt, exception_frame, KERNEL_MODE, ofp);
- exception_frame = 0;
- }
-
+ cur_frame = stackframe;
if (!arm64_unwind_frame(bt, &stackframe))
- break;
+ end_stack = 1;
if (arm64_in_exception_text(bt->instptr) && INSTACK(stackframe.fp, bt)) {
if (!(bt->flags & BT_IRQSTACK) ||
@@ -1731,9 +1779,30 @@ arm64_back_trace_cmd(struct bt_info *bt)
!arm64_on_irq_stack(bt->tc->processor, stackframe.sp)) {
bt->flags &= ~BT_IRQSTACK;
if (arm64_switch_stack(bt, &stackframe, ofp) == USER_MODE)
- break;
+ end_stack = 1;
+ else
+ arm64_print_exception_frame(bt, stackframe.sp,
+ KERNEL_MODE, ofp);
+
+ /* Next, we will display a process stack. */
+ bt->frameptr = stackframe.sp;
}
+ switch (arm64_print_stackframe_entry(bt, level, &cur_frame, &stackframe, ofp))
+ {
+ case BACKTRACE_COMPLETE_KERNEL:
+ return;
+ case BACKTRACE_CONTINUE:
+ break;
+ }
+
+ if (end_stack)
+ break;
+
+ if (arm64_in_exp_entry(cur_frame.pc) && exception_frame) {
+ arm64_print_exception_frame(bt, exception_frame, KERNEL_MODE, ofp);
+ exception_frame = 0;
+ }
level++;
}
@@ -1912,7 +1981,6 @@ arm64_switch_stack(struct bt_info *bt, struct arm64_stackframe *frame, FILE *ofp
if (frame->fp == 0)
return USER_MODE;
- arm64_print_exception_frame(bt, frame->sp, KERNEL_MODE, ofp);
return KERNEL_MODE;
}
@@ -2004,8 +2072,10 @@ arm64_print_exception_frame(struct bt_info *bt, ulong pt_regs, int mode, FILE *o
ulong LR, SP, offset;
char buf[BUFSIZE];
- if (bt->flags & BT_FULL)
- arm64_display_full_frame(bt, pt_regs);
+ if (mode == KERNEL_MODE)
+ fprintf(ofp, "--- <Exception in kernel> ---\n");
+ else
+ fprintf(ofp, "--- <Exception in user> ---\n");
if (CRASHDEBUG(1))
fprintf(ofp, "pt_regs: %lx\n", pt_regs);
diff --git a/defs.h b/defs.h
index d6f719c..90d8406 100644
--- a/defs.h
+++ b/defs.h
@@ -3060,6 +3060,11 @@ struct machine_specific {
ulong *irq_stacks;
ulong __irqentry_text_start;
ulong __irqentry_text_end;
+ /* for exception vector code */
+ ulong exp_entry1_start;
+ ulong exp_entry1_end;
+ ulong exp_entry2_start;
+ ulong exp_entry2_end;
/* only needed for v4.6 or later kernel */
ulong kimage_voffset;
ulong kimage_text;
--
2.8.1
--
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