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-rw-r--r--arch/arm64/kernel/entry.S10
-rw-r--r--arch/arm64/kernel/stacktrace.c13
2 files changed, 9 insertions, 14 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index c6aee646eb6b..a31a0a713c85 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -261,16 +261,16 @@ alternative_else_nop_endif
stp lr, x21, [sp, #S_LR]
/*
- * In order to be able to dump the contents of struct pt_regs at the
- * time the exception was taken (in case we attempt to walk the call
- * stack later), chain it together with the stack frames.
+ * For exceptions from EL0, terminate the callchain here.
+ * For exceptions from EL1, create a synthetic frame record so the
+ * interrupted code shows up in the backtrace.
*/
.if \el == 0
- stp xzr, xzr, [sp, #S_STACKFRAME]
+ mov x29, xzr
.else
stp x29, x22, [sp, #S_STACKFRAME]
- .endif
add x29, sp, #S_STACKFRAME
+ .endif
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
alternative_if_not ARM64_HAS_PAN
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index fa56af1a59c3..0fb42129b469 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -44,6 +44,10 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
unsigned long fp = frame->fp;
struct stack_info info;
+ /* Terminal record; nothing to unwind */
+ if (!fp)
+ return -EINVAL;
+
if (fp & 0xf)
return -EINVAL;
@@ -104,15 +108,6 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
frame->pc = ptrauth_strip_insn_pac(frame->pc);
- /*
- * Frames created upon entry from EL0 have NULL FP and PC values, so
- * don't bother reporting these. Frames created by __noreturn functions
- * might have a valid FP even if PC is bogus, so only terminate where
- * both are NULL.
- */
- if (!frame->fp && !frame->pc)
- return -EINVAL;
-
return 0;
}
NOKPROBE_SYMBOL(unwind_frame);