[PATCH v2 09/12] powerpc/32: Blacklist functions running with MMU disabled for kprobe

From: Christophe Leroy
Date: Tue Mar 31 2020 - 12:04:17 EST


kprobe does not handle events happening in real mode, all
functions running with MMU disabled have to be blacklisted.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Acked-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/cpu_setup_6xx.S | 2 ++
arch/powerpc/kernel/entry_32.S | 3 +++
arch/powerpc/kernel/fpu.S | 1 +
arch/powerpc/kernel/idle_6xx.S | 1 +
arch/powerpc/kernel/idle_e500.S | 1 +
arch/powerpc/kernel/l2cr_6xx.S | 1 +
arch/powerpc/kernel/misc.S | 2 ++
arch/powerpc/kernel/misc_32.S | 2 ++
arch/powerpc/kernel/swsusp_32.S | 2 ++
arch/powerpc/kernel/vector.S | 1 +
10 files changed, 16 insertions(+)

diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S
index f6517f67265a..f8b5ff64b604 100644
--- a/arch/powerpc/kernel/cpu_setup_6xx.S
+++ b/arch/powerpc/kernel/cpu_setup_6xx.S
@@ -288,6 +288,7 @@ _GLOBAL(__init_fpu_registers)
mtmsr r10
isync
blr
+_ASM_NOKPROBE_SYMBOL(__init_fpu_registers)


/* Definitions for the table use to save CPU states */
@@ -483,4 +484,5 @@ _GLOBAL(__restore_cpu_setup)
1:
mtcr r7
blr
+_ASM_NOKPROBE_SYMBOL(__restore_cpu_setup)

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index e652f6506888..94f78c03cb79 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -313,6 +313,7 @@ stack_ovf:
mtspr SPRN_SRR1,r10
SYNC
RFI
+_ASM_NOKPROBE_SYMBOL(stack_ovf)
#endif

#ifdef CONFIG_TRACE_IRQFLAGS
@@ -1337,6 +1338,7 @@ nonrecoverable:
bl unrecoverable_exception
/* shouldn't return */
b 4b
+_ASM_NOKPROBE_SYMBOL(nonrecoverable)

.section .bss
.align 2
@@ -1391,4 +1393,5 @@ _GLOBAL(enter_rtas)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
RFI /* return to caller */
+_ASM_NOKPROBE_SYMBOL(enter_rtas)
#endif /* CONFIG_PPC_RTAS */
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 3235a8da6af7..1dfccf58fbb1 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -119,6 +119,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
/* restore registers and return */
/* we haven't used ctr or xer or lr */
blr
+_ASM_NOKPROBE_SYMBOL(load_up_fpu)

/*
* save_fpu(tsk)
diff --git a/arch/powerpc/kernel/idle_6xx.S b/arch/powerpc/kernel/idle_6xx.S
index 433d97bea1f3..69df840f7253 100644
--- a/arch/powerpc/kernel/idle_6xx.S
+++ b/arch/powerpc/kernel/idle_6xx.S
@@ -187,6 +187,7 @@ BEGIN_FTR_SECTION
mtspr SPRN_HID1, r9
END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
b transfer_to_handler_cont
+_ASM_NOKPROBE_SYMBOL(power_save_ppc32_restore)

.data

diff --git a/arch/powerpc/kernel/idle_e500.S b/arch/powerpc/kernel/idle_e500.S
index 308f499e146c..72c85b6f3898 100644
--- a/arch/powerpc/kernel/idle_e500.S
+++ b/arch/powerpc/kernel/idle_e500.S
@@ -90,3 +90,4 @@ _GLOBAL(power_save_ppc32_restore)
#endif

b transfer_to_handler_cont
+_ASM_NOKPROBE_SYMBOL(power_save_ppc32_restore)
diff --git a/arch/powerpc/kernel/l2cr_6xx.S b/arch/powerpc/kernel/l2cr_6xx.S
index 2020d255585f..5f07aa5e9851 100644
--- a/arch/powerpc/kernel/l2cr_6xx.S
+++ b/arch/powerpc/kernel/l2cr_6xx.S
@@ -455,5 +455,6 @@ _GLOBAL(__inval_enable_L1)
sync

blr
+_ASM_NOKPROBE_SYMBOL(__inval_enable_L1)


diff --git a/arch/powerpc/kernel/misc.S b/arch/powerpc/kernel/misc.S
index 65f9f731c229..5be96feccb55 100644
--- a/arch/powerpc/kernel/misc.S
+++ b/arch/powerpc/kernel/misc.S
@@ -36,6 +36,8 @@ _GLOBAL(add_reloc_offset)
add r3,r3,r5
mtlr r0
blr
+_ASM_NOKPROBE_SYMBOL(reloc_offset)
+_ASM_NOKPROBE_SYMBOL(add_reloc_offset)

.align 3
2: PPC_LONG 1b
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index d80212be8698..1edcc41e15fc 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -246,6 +246,7 @@ _GLOBAL(real_readb)
sync
isync
blr
+_ASM_NOKPROBE_SYMBOL(real_readb)

/*
* Do an IO access in real mode
@@ -263,6 +264,7 @@ _GLOBAL(real_writeb)
sync
isync
blr
+_ASM_NOKPROBE_SYMBOL(real_writeb)

#endif /* CONFIG_40x */

diff --git a/arch/powerpc/kernel/swsusp_32.S b/arch/powerpc/kernel/swsusp_32.S
index cbdf86228eaa..f73f4d72fea4 100644
--- a/arch/powerpc/kernel/swsusp_32.S
+++ b/arch/powerpc/kernel/swsusp_32.S
@@ -395,6 +395,7 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)

li r3,0
blr
+_ASM_NOKPROBE_SYMBOL(swsusp_arch_resume)

/* FIXME:This construct is actually not useful since we don't shut
* down the instruction MMU, we could just flip back MSR-DR on.
@@ -406,4 +407,5 @@ turn_on_mmu:
sync
isync
rfi
+_ASM_NOKPROBE_SYMBOL(turn_on_mmu)

diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index d20c5e79e03c..efc5b52f95d2 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -89,6 +89,7 @@ _GLOBAL(load_up_altivec)
REST_32VRS(0,r4,r6)
/* restore registers and return */
blr
+_ASM_NOKPROBE_SYMBOL(load_up_altivec)

/*
* save_altivec(tsk)
--
2.25.0