diff mbox series

[11/12] powerpc/entry32: Blacklist syscall exit points for kprobe.

Message ID 51d2b8f8edf167a3084a08091a42c57f93ea4d8c.1585474724.git.christophe.leroy@c-s.fr (mailing list archive)
State Superseded
Headers show
Series [01/12] powerpc/52xx: Blacklist functions running with MMU disabled for kprobe | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (c6624071c338732402e8c726df6a4074473eaa0e)
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 21 lines checked
snowpatch_ozlabs/needsstable success Patch has no Fixes tags

Commit Message

Christophe Leroy March 29, 2020, 9:41 a.m. UTC
kprobe does not handle events happening in real mode.

The very last part of syscall cannot support a trap.
Add a symbol syscall_exit_finish to identify that part and
blacklist it from kprobe.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/entry_32.S | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9a1a45d6038a..7035e838d422 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -463,6 +463,7 @@  END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
 	lwz	r7,_NIP(r1)
 	lwz	r2,GPR2(r1)
 	lwz	r1,GPR1(r1)
+syscall_exit_finish:
 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
 	mtspr	SPRN_NRI, r0
 #endif
@@ -470,6 +471,7 @@  END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
 	mtspr	SPRN_SRR1,r8
 	SYNC
 	RFI
+_ASM_NOKPROBE_SYMBOL(syscall_exit_finish)
 #ifdef CONFIG_44x
 2:	li	r7,0
 	iccci	r0,r0
@@ -604,6 +606,7 @@  ret_from_kernel_syscall:
 	mtspr	SPRN_SRR1, r10
 	SYNC
 	RFI
+_ASM_NOKPROBE_SYMBOL(ret_from_kernel_syscall)
 
 /*
  * The fork/clone functions need to copy the full register set into