| Message ID | d273fd9f1cc7ee36e1ee4da20631d507c39efe6d.1551267823.git.christophe.leroy@c-s.fr (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 9580b71b5a7863c24a9bd18bcd2ad759b86b1eff |
| Headers | show |
| Series | powerpc/32: Clear on-stack exception marker upon exception return | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | next/apply_patch Successfully applied |
| snowpatch_ozlabs/build-ppc64le | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-ppc64be | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-ppc64e | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-pmac32 | warning | build succeeded but added 17 new sparse warning(s) |
| snowpatch_ozlabs/checkpatch | fail | total: 1 errors, 0 warnings, 0 checks, 27 lines checked |
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 96dce6a4b61e..b61cfd29c76f 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -730,6 +730,9 @@ 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) #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS) mtspr SPRN_NRI, r0 @@ -961,6 +964,9 @@ 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 @@ -997,6 +1003,9 @@ 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:
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 Cc: Nicolai Stange <nstange@suse.de> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/kernel/entry_32.S | 9 +++++++++ 1 file changed, 9 insertions(+)