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Subject[PATCH v2 11/12] powerpc/entry32: Blacklist syscall exit points for kprobe.
Date
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>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
arch/powerpc/kernel/entry_32.S | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 215aa3a6d4f7..577d17fe0d94 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
--
2.25.0
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