From 7cdf4401388572f720403a7038a178a4b30ac14c Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 31 Mar 2020 16:03:46 +0000 Subject: [PATCH] powerpc/entry32: Blacklist syscall exit points for kprobe. 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 Acked-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/23eddf49abb03d1359fa0be4206998eb3800f42c.1585670437.git.christophe.leroy@c-s.fr --- 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 c9fc6ea36bc6..5fa192b33509 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -462,6 +462,7 @@ 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 @@ -469,6 +470,7 @@ 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 @@ -600,6 +602,7 @@ 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