diff options
| author | Will Deacon <will@kernel.org> | 2021-02-12 15:14:22 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-02-12 15:14:22 +0000 |
| commit | d23fa87cde1dcdcc892d385a7bb5eb6f0420b917 (patch) | |
| tree | b84cf7bcc44406c86b8e9c1f30937344f8f5c383 /arch/arm64 | |
| parent | 82a1c2b94ac088674caa246dfe0c09f4e6fe05d0 (diff) | |
| parent | 6106e1112cc69a367f495da2e66f13e2bca369fb (diff) | |
| download | linux-d23fa87cde1dcdcc892d385a7bb5eb6f0420b917.tar.bz2 | |
Merge branch 'for-next/stacktrace' into for-next/core
Remove synthetic frame record from exception stack when entering from
userspace.
* for-next/stacktrace:
arm64: remove EL0 exception frame record
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/stacktrace.c | 13 |
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); |