Commit 7cdf4401 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

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: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Acked-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/23eddf49abb03d1359fa0be4206998eb3800f42c.1585670437.git.christophe.leroy@c-s.fr
parent a616c442

arch/powerpc/kernel/entry_32.S

+3 −0
Original line number Diff line number Diff line
@@ -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