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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-02-27 11:45:30 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 08:19:02 +0100 |
| commit | e89f1814df0a1a6feee354df06f6c0bf4d148432 (patch) | |
| tree | 832891752c76b28576d66524801b389e852bdbf3 | |
| parent | b30e5af1adf9be61f7e0feb42c6a6d3e94a4ef04 (diff) | |
| download | linux-e89f1814df0a1a6feee354df06f6c0bf4d148432.tar.gz linux-e89f1814df0a1a6feee354df06f6c0bf4d148432.tar.bz2 linux-e89f1814df0a1a6feee354df06f6c0bf4d148432.zip | |
powerpc/32: Clear on-stack exception marker upon exception return
commit 9580b71b5a7863c24a9bd18bcd2ad759b86b1eff upstream.
Clear the on-stack STACK_FRAME_REGS_MARKER on exception exit in order
to avoid confusing stacktrace like the one below.
Call Trace:
[c0e9dca0] [c01c42a0] print_address_description+0x64/0x2bc (unreliable)
[c0e9dcd0] [c01c4684] kasan_report+0xfc/0x180
[c0e9dd10] [c0895130] memchr+0x24/0x74
[c0e9dd30] [c00a9e38] msg_print_text+0x124/0x574
[c0e9dde0] [c00ab710] console_unlock+0x114/0x4f8
[c0e9de40] [c00adc60] vprintk_emit+0x188/0x1c4
--- interrupt: c0e9df00 at 0x400f330
LR = init_stack+0x1f00/0x2000
[c0e9de80] [c00ae3c4] printk+0xa8/0xcc (unreliable)
[c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
[c0e9df50] [c0c15434] start_kernel+0x310/0x488
[c0e9dff0] [00003484] 0x3484
With this patch the trace becomes:
Call Trace:
[c0e9dca0] [c01c42c0] print_address_description+0x64/0x2bc (unreliable)
[c0e9dcd0] [c01c46a4] kasan_report+0xfc/0x180
[c0e9dd10] [c0895150] memchr+0x24/0x74
[c0e9dd30] [c00a9e58] msg_print_text+0x124/0x574
[c0e9dde0] [c00ab730] console_unlock+0x114/0x4f8
[c0e9de40] [c00adc80] vprintk_emit+0x188/0x1c4
[c0e9de80] [c00ae3e4] printk+0xa8/0xcc
[c0e9df20] [c0c27e44] early_irq_init+0x38/0x108
[c0e9df50] [c0c15434] start_kernel+0x310/0x488
[c0e9dff0] [00003484] 0x3484
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 22b45a4955cd..db5575c69792 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -757,6 +757,9 @@ fast_exception_return: mtcr r10 lwz r10,_LINK(r11) mtlr r10 + /* Clear the exception_marker on the stack to avoid confusing stacktrace */ + li r10, 0 + stw r10, 8(r11) REST_GPR(10, r11) mtspr SPRN_SRR1,r9 mtspr SPRN_SRR0,r12 @@ -987,6 +990,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) mtcrf 0xFF,r10 mtlr r11 + /* Clear the exception_marker on the stack to avoid confusing stacktrace */ + li r10, 0 + stw r10, 8(r1) /* * Once we put values in SRR0 and SRR1, we are in a state * where exceptions are not recoverable, since taking an @@ -1024,6 +1030,9 @@ exc_exit_restart_end: mtlr r11 lwz r10,_CCR(r1) mtcrf 0xff,r10 + /* Clear the exception_marker on the stack to avoid confusing stacktrace */ + li r10, 0 + stw r10, 8(r1) REST_2GPRS(9, r1) .globl exc_exit_restart exc_exit_restart: |