Blacklist all functions involved when we return from a trap. We:
- convert some of the labels into private labels,
- remove the duplicate 'restore' label, and
- blacklist most functions involved during returning from a trap.
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
arch/powerpc/kernel/entry_64.S | 46 ++++++++++++++++++++++++------------------
arch/powerpc/kernel/traps.c | 1 +
2 files changed, 27 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 22aaa377149f..e7e05eb590a5 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -184,7 +184,7 @@ __system_call:
#ifdef CONFIG_PPC_BOOK3S
/* No MSR:RI on BookE */
andi. r10,r8,MSR_RI
- beq- unrecov_restore
+ beq- .Lunrecov_restore
#endif
/*
* Disable interrupts so current_thread_info()->flags can't change,
@@ -643,18 +643,18 @@ _GLOBAL(ret_from_except_lite)
* Use the internal debug mode bit to do this.
*/
andis. r0,r3,DBCR0_IDM@h
- beq restore
+ beq fast_exc_return_irq
mfmsr r0
rlwinm r0,r0,0,~MSR_DE /* Clear MSR.DE */
mtmsr r0
mtspr SPRN_DBCR0,r3
li r10, -1
mtspr SPRN_DBSR,r10
- b restore
+ b fast_exc_return_irq
#else
addi r3,r1,STACK_FRAME_OVERHEAD
bl restore_math
- b restore
+ b fast_exc_return_irq
#endif
1: andi. r0,r4,_TIF_NEED_RESCHED
beq 2f
@@ -667,7 +667,7 @@ _GLOBAL(ret_from_except_lite)
bne 3f /* only restore TM if nothing else to do */
addi r3,r1,STACK_FRAME_OVERHEAD
bl restore_tm_state
- b restore
+ b fast_exc_return_irq
3:
#endif
bl save_nvgprs
@@ -719,14 +719,14 @@ resume_kernel:
#ifdef CONFIG_PREEMPT
/* Check if we need to preempt */
andi. r0,r4,_TIF_NEED_RESCHED
- beq+ restore
+ beq+ fast_exc_return_irq
/* Check that preempt_count() == 0 and interrupts are enabled */
lwz r8,TI_PREEMPT(r9)
cmpwi cr1,r8,0
ld r0,SOFTE(r1)
cmpdi r0,0
crandc eq,cr1*4+eq,eq
- bne restore
+ bne fast_exc_return_irq
/*
* Here we are preempting the current task. We want to make
@@ -757,7 +757,6 @@ resume_kernel:
.globl fast_exc_return_irq
fast_exc_return_irq:
-restore:
/*
* This is the main kernel exit path. First we check if we
* are about to re-enable interrupts
@@ -765,11 +764,11 @@ restore:
ld r5,SOFTE(r1)
lbz r6,PACASOFTIRQEN(r13)
cmpwi cr0,r5,0
- beq restore_irq_off
+ beq .Lrestore_irq_off
/* We are enabling, were we already enabled ? Yes, just return */
cmpwi cr0,r6,1
- beq cr0,do_restore
+ beq cr0,.Ldo_restore
/*
* We are about to soft-enable interrupts (we are hard disabled
@@ -778,14 +777,14 @@ restore:
*/
lbz r0,PACAIRQHAPPENED(r13)
cmpwi cr0,r0,0
- bne- restore_check_irq_replay
+ bne- .Lrestore_check_irq_replay
/*
* Get here when nothing happened while soft-disabled, just
* soft-enable and move-on. We will hard-enable as a side
* effect of rfi
*/
-restore_no_replay:
+.Lrestore_no_replay:
TRACE_ENABLE_INTS
li r0,1
stb r0,PACASOFTIRQEN(r13);
@@ -793,7 +792,7 @@ restore_no_replay:
/*
* Final return path. BookE is handled in a different file
*/
-do_restore:
+.Ldo_restore:
#ifdef CONFIG_PPC_BOOK3E
b exception_return_book3e
#else
@@ -827,7 +826,7 @@ fast_exception_return:
REST_8GPRS(5, r1)
andi. r0,r3,MSR_RI
- beq- unrecov_restore
+ beq- .Lunrecov_restore
/* Load PPR from thread struct before we clear MSR:RI */
BEGIN_FTR_SECTION
@@ -885,7 +884,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
* make sure that in this case, we also clear PACA_IRQ_HARD_DIS
* or that bit can get out of sync and bad things will happen
*/
-restore_irq_off:
+.Lrestore_irq_off:
ld r3,_MSR(r1)
lbz r7,PACAIRQHAPPENED(r13)
andi. r0,r3,MSR_EE
@@ -895,13 +894,13 @@ restore_irq_off:
1: li r0,0
stb r0,PACASOFTIRQEN(r13);
TRACE_DISABLE_INTS
- b do_restore
+ b .Ldo_restore
/*
* Something did happen, check if a re-emit is needed
* (this also clears paca->irq_happened)
*/
-restore_check_irq_replay:
+.Lrestore_check_irq_replay:
/* XXX: We could implement a fast path here where we check
* for irq_happened being just 0x01, in which case we can
* clear it and return. That means that we would potentially
@@ -911,7 +910,7 @@ restore_check_irq_replay:
*/
bl __check_irq_replay
cmpwi cr0,r3,0
- beq restore_no_replay
+ beq .Lrestore_no_replay
/*
* We need to re-emit an interrupt. We do so by re-using our
@@ -960,10 +959,17 @@ restore_check_irq_replay:
#endif /* CONFIG_PPC_DOORBELL */
1: b ret_from_except /* What else to do here ? */
-unrecov_restore:
+.Lunrecov_restore:
addi r3,r1,STACK_FRAME_OVERHEAD
bl unrecoverable_exception
- b unrecov_restore
+ b .Lunrecov_restore
+
+_ASM_NOKPROBE_SYMBOL(ret_from_except);
+_ASM_NOKPROBE_SYMBOL(ret_from_except_lite);
+_ASM_NOKPROBE_SYMBOL(resume_kernel);
+_ASM_NOKPROBE_SYMBOL(fast_exc_return_irq);
+_ASM_NOKPROBE_SYMBOL(fast_exception_return);
+
#ifdef CONFIG_PPC_RTAS
/*
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index ece130515cd0..8ce51787b2ba 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1952,6 +1952,7 @@ void unrecoverable_exception(struct pt_regs *regs)
regs->trap, regs->nip);
die("Unrecoverable exception", regs, SIGABRT);
}
+NOKPROBE_SYMBOL(unrecoverable_exception);
#if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x)
/*
--
2.12.1
