diff mbox series

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

Message ID b9a05b240cd24df2ae206ccfe1fa43b4894d53d8.1585474724.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State Superseded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

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Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (c6624071c338732402e8c726df6a4074473eaa0e)
snowpatch_ozlabs/build-ppc64le success Build succeeded
snowpatch_ozlabs/build-ppc64be success Build succeeded
snowpatch_ozlabs/build-ppc64e success Build succeeded
snowpatch_ozlabs/build-pmac32 success Build succeeded
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 57 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 exception exits cannot support a trap.
Blacklist them from kprobe.

While we are at it, remove exc_exit_start symbol which is not
used to avoid having to blacklist it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/entry_32.S | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 7035e838d422..e161fb7a0568 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -810,6 +810,7 @@  fast_exception_return:
 	lwz	r11,GPR11(r11)
 	SYNC
 	RFI
+_ASM_NOKPROBE_SYMBOL(fast_exception_return)
 
 #if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
 /* check if the exception happened in a restartable section */
@@ -1049,6 +1050,8 @@  exc_exit_restart:
 exc_exit_restart_end:
 	SYNC
 	RFI
+_ASM_NOKPROBE_SYMBOL(exc_exit_restart)
+_ASM_NOKPROBE_SYMBOL(exc_exit_restart_end)
 
 #else /* !(CONFIG_4xx || CONFIG_BOOKE) */
 	/*
@@ -1070,7 +1073,6 @@  exc_exit_restart_end:
 exc_exit_restart:
 	lwz	r11,_NIP(r1)
 	lwz	r12,_MSR(r1)
-exc_exit_start:
 	mtspr	SPRN_SRR0,r11
 	mtspr	SPRN_SRR1,r12
 	REST_2GPRS(11, r1)
@@ -1080,6 +1082,7 @@  exc_exit_restart_end:
 	PPC405_ERR77_SYNC
 	rfi
 	b	.			/* prevent prefetch past rfi */
+_ASM_NOKPROBE_SYMBOL(exc_exit_restart)
 
 /*
  * Returning from a critical interrupt in user mode doesn't need
@@ -1193,6 +1196,7 @@  ret_from_crit_exc:
 	mtspr	SPRN_SRR0,r9;
 	mtspr	SPRN_SRR1,r10;
 	RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
+_ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
 #endif /* CONFIG_40x */
 
 #ifdef CONFIG_BOOKE
@@ -1204,6 +1208,7 @@  ret_from_crit_exc:
 	RESTORE_xSRR(SRR0,SRR1);
 	RESTORE_MMU_REGS;
 	RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
+_ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
 
 	.globl	ret_from_debug_exc
 ret_from_debug_exc:
@@ -1214,6 +1219,7 @@  ret_from_debug_exc:
 	RESTORE_xSRR(CSRR0,CSRR1);
 	RESTORE_MMU_REGS;
 	RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, PPC_RFDI)
+_ASM_NOKPROBE_SYMBOL(ret_from_debug_exc)
 
 	.globl	ret_from_mcheck_exc
 ret_from_mcheck_exc:
@@ -1225,6 +1231,7 @@  ret_from_mcheck_exc:
 	RESTORE_xSRR(DSRR0,DSRR1);
 	RESTORE_MMU_REGS;
 	RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, PPC_RFMCI)
+_ASM_NOKPROBE_SYMBOL(ret_from_mcheck_exc)
 #endif /* CONFIG_BOOKE */
 
 /*