Re: [PATCH v2] powerpc/kprobes: Blacklist functions running with MMU disabled on PPC32
Le 27/03/2020 à 10:07, Naveen N. Rao a écrit : Christophe Leroy wrote: kprobe does not handle events happening in real mode, all functions running with MMU disabled have to be blacklisted. As already done for PPC64, do it for PPC32. Signed-off-by: Christophe Leroy --- v2: - Don't rename nonrecoverable as local, mark it noprobe instead. - Add missing linux/kprobes.h include in pq2.c --- arch/powerpc/include/asm/ppc_asm.h | 10 +++ arch/powerpc/kernel/cpu_setup_6xx.S | 4 +- arch/powerpc/kernel/entry_32.S | 65 arch/powerpc/kernel/fpu.S | 1 + arch/powerpc/kernel/idle_6xx.S | 2 +- arch/powerpc/kernel/idle_e500.S | 2 +- arch/powerpc/kernel/l2cr_6xx.S | 2 +- arch/powerpc/kernel/misc.S | 2 + arch/powerpc/kernel/misc_32.S | 4 +- arch/powerpc/kernel/swsusp_32.S | 6 +- arch/powerpc/kernel/vector.S | 1 + arch/powerpc/mm/book3s32/hash_low.S | 38 ++-- arch/powerpc/mm/mem.c | 2 + arch/powerpc/platforms/52xx/lite5200_sleep.S | 2 + arch/powerpc/platforms/82xx/pq2.c | 3 + arch/powerpc/platforms/83xx/suspend-asm.S | 1 + arch/powerpc/platforms/powermac/cache.S | 2 + arch/powerpc/platforms/powermac/sleep.S | 13 ++-- 18 files changed, 86 insertions(+), 74 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 6b03dff61a05..e8f34ba89497 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -267,8 +267,18 @@ GLUE(.,name): .pushsection "_kprobe_blacklist","aw"; \ PPC_LONG (entry) ; \ .popsection +#define _NOKPROBE_ENTRY(entry) \ + _ASM_NOKPROBE_SYMBOL(entry) \ + _ENTRY(entry) +#define _NOKPROBE_GLOBAL(entry) \ + _ASM_NOKPROBE_SYMBOL(entry) \ + _GLOBAL(entry) #else #define _ASM_NOKPROBE_SYMBOL(entry) +#define _NOKPROBE_ENTRY(entry) \ + _ENTRY(entry) +#define _NOKPROBE_GLOBAL(entry) \ + _GLOBAL(entry) #endif Michael hasn't preferred including NOKPROBE variants of those macros previously, since he would like to see some cleanups there: https://patchwork.ozlabs.org/patch/696138/ Ok [...] @@ -194,8 +188,7 @@ transfer_to_handler: bt- 31-TLF_NAPPING,4f bt- 31-TLF_SLEEPING,7f #endif /* CONFIG_PPC_BOOK3S_32 || CONFIG_E500 */ - .globl transfer_to_handler_cont -transfer_to_handler_cont: +_NOKPROBE_ENTRY(transfer_to_handler_cont) 3: mflr r9 tovirt_novmstack r2, r2 /* set r2 to current */ @@ -297,6 +290,7 @@ reenable_mmu: * On kernel stack overflow, load up an initial stack pointer * and call StackOverflow(regs), which should not return. */ +_ASM_NOKPROBE_SYMBOL(stack_ovf) stack_ovf: The current convention is to add the NOKPROBE annotation at the _end_ of the associated function/symbol... Ok. For big functions that looks unpractical, but I'll do that. [...] @@ -1033,17 +1026,15 @@ exc_exit_restart_end: li r10, 0 stw r10, 8(r1) REST_2GPRS(9, r1) - .globl exc_exit_restart +_NOKPROBE_ENTRY(exc_exit_restart) 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) lwz r1,GPR1(r1) - .globl exc_exit_restart_end -exc_exit_restart_end: +.Lexc_exit_restart_end: I think it would be good to break this into smaller patches to handle specific code paths, if possible. At the very least, it would be good to move changes to symbol visibility to a separate patch since this also changes the names printed in a backtrace. Ok. I removed most symbol visibility changes. I only kept the ones in book3s32/hash_low.S and did a separate patch for it. I split into patches per platform, then one bigger for everything in arch/powerpc/kernel/ except entries, then I did one for exception entry, one for syscall exit and one for exception exit. Christophe
Re: [PATCH v2] powerpc/kprobes: Blacklist functions running with MMU disabled on PPC32
Christophe Leroy wrote: kprobe does not handle events happening in real mode, all functions running with MMU disabled have to be blacklisted. As already done for PPC64, do it for PPC32. Signed-off-by: Christophe Leroy --- v2: - Don't rename nonrecoverable as local, mark it noprobe instead. - Add missing linux/kprobes.h include in pq2.c --- arch/powerpc/include/asm/ppc_asm.h | 10 +++ arch/powerpc/kernel/cpu_setup_6xx.S | 4 +- arch/powerpc/kernel/entry_32.S | 65 arch/powerpc/kernel/fpu.S| 1 + arch/powerpc/kernel/idle_6xx.S | 2 +- arch/powerpc/kernel/idle_e500.S | 2 +- arch/powerpc/kernel/l2cr_6xx.S | 2 +- arch/powerpc/kernel/misc.S | 2 + arch/powerpc/kernel/misc_32.S| 4 +- arch/powerpc/kernel/swsusp_32.S | 6 +- arch/powerpc/kernel/vector.S | 1 + arch/powerpc/mm/book3s32/hash_low.S | 38 ++-- arch/powerpc/mm/mem.c| 2 + arch/powerpc/platforms/52xx/lite5200_sleep.S | 2 + arch/powerpc/platforms/82xx/pq2.c| 3 + arch/powerpc/platforms/83xx/suspend-asm.S| 1 + arch/powerpc/platforms/powermac/cache.S | 2 + arch/powerpc/platforms/powermac/sleep.S | 13 ++-- 18 files changed, 86 insertions(+), 74 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 6b03dff61a05..e8f34ba89497 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -267,8 +267,18 @@ GLUE(.,name): .pushsection "_kprobe_blacklist","aw"; \ PPC_LONG (entry) ; \ .popsection +#define _NOKPROBE_ENTRY(entry) \ + _ASM_NOKPROBE_SYMBOL(entry) \ + _ENTRY(entry) +#define _NOKPROBE_GLOBAL(entry)\ + _ASM_NOKPROBE_SYMBOL(entry) \ + _GLOBAL(entry) #else #define _ASM_NOKPROBE_SYMBOL(entry) +#define _NOKPROBE_ENTRY(entry) \ + _ENTRY(entry) +#define _NOKPROBE_GLOBAL(entry)\ + _GLOBAL(entry) #endif Michael hasn't preferred including NOKPROBE variants of those macros previously, since he would like to see some cleanups there: https://patchwork.ozlabs.org/patch/696138/ #define FUNC_START(name) _GLOBAL(name) diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S index f6517f67265a..1cb947268546 100644 --- a/arch/powerpc/kernel/cpu_setup_6xx.S +++ b/arch/powerpc/kernel/cpu_setup_6xx.S @@ -276,7 +276,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_NO_DPM) * in some 750 cpus where using a not yet initialized FPU register after * power on reset may hang the CPU */ -_GLOBAL(__init_fpu_registers) +_NOKPROBE_GLOBAL(__init_fpu_registers) mfmsr r10 ori r11,r10,MSR_FP mtmsr r11 @@ -381,7 +381,7 @@ _GLOBAL(__save_cpu_setup) * restore CPU state as backed up by the previous * function. This does not include cache setting */ -_GLOBAL(__restore_cpu_setup) +_NOKPROBE_GLOBAL(__restore_cpu_setup) /* Some CR fields are volatile, we back it up all */ mfcrr7 diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 16af0d8d90a8..f788d586254d 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -44,24 +44,21 @@ .align 12 #ifdef CONFIG_BOOKE - .globl mcheck_transfer_to_handler -mcheck_transfer_to_handler: +_NOKPROBE_ENTRY(mcheck_transfer_to_handler) mfspr r0,SPRN_DSRR0 stw r0,_DSRR0(r11) mfspr r0,SPRN_DSRR1 stw r0,_DSRR1(r11) /* fall through */ - .globl debug_transfer_to_handler -debug_transfer_to_handler: +_NOKPROBE_ENTRY(debug_transfer_to_handler) mfspr r0,SPRN_CSRR0 stw r0,_CSRR0(r11) mfspr r0,SPRN_CSRR1 stw r0,_CSRR1(r11) /* fall through */ - .globl crit_transfer_to_handler -crit_transfer_to_handler: +_NOKPROBE_ENTRY(crit_transfer_to_handler) #ifdef CONFIG_PPC_BOOK3E_MMU mfspr r0,SPRN_MAS0 stw r0,MAS0(r11) @@ -97,8 +94,7 @@ crit_transfer_to_handler: #endif #ifdef CONFIG_40x - .globl crit_transfer_to_handler -crit_transfer_to_handler: +_NOKPROBE_ENTRY(crit_transfer_to_handler) lwz r0,crit_r10@l(0) stw r0,GPR10(r11) lwz r0,crit_r11@l(0) @@ -124,13 +120,11 @@ crit_transfer_to_handler: * Note that we rely on the caller having set cr0.eq iff the exception * occurred in kernel mode (i.e. MSR:PR = 0). */ - .globl transfer_to_handler_full -transfer_to_handler_full: +_NOKPROBE_ENTRY(transfer_to_handler_full) SAVE_NVGPRS(r11) /* fall through */ - .globl transfer_to_handler
[PATCH v2] powerpc/kprobes: Blacklist functions running with MMU disabled on PPC32
kprobe does not handle events happening in real mode, all functions running with MMU disabled have to be blacklisted. As already done for PPC64, do it for PPC32. Signed-off-by: Christophe Leroy --- v2: - Don't rename nonrecoverable as local, mark it noprobe instead. - Add missing linux/kprobes.h include in pq2.c --- arch/powerpc/include/asm/ppc_asm.h | 10 +++ arch/powerpc/kernel/cpu_setup_6xx.S | 4 +- arch/powerpc/kernel/entry_32.S | 65 arch/powerpc/kernel/fpu.S| 1 + arch/powerpc/kernel/idle_6xx.S | 2 +- arch/powerpc/kernel/idle_e500.S | 2 +- arch/powerpc/kernel/l2cr_6xx.S | 2 +- arch/powerpc/kernel/misc.S | 2 + arch/powerpc/kernel/misc_32.S| 4 +- arch/powerpc/kernel/swsusp_32.S | 6 +- arch/powerpc/kernel/vector.S | 1 + arch/powerpc/mm/book3s32/hash_low.S | 38 ++-- arch/powerpc/mm/mem.c| 2 + arch/powerpc/platforms/52xx/lite5200_sleep.S | 2 + arch/powerpc/platforms/82xx/pq2.c| 3 + arch/powerpc/platforms/83xx/suspend-asm.S| 1 + arch/powerpc/platforms/powermac/cache.S | 2 + arch/powerpc/platforms/powermac/sleep.S | 13 ++-- 18 files changed, 86 insertions(+), 74 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 6b03dff61a05..e8f34ba89497 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -267,8 +267,18 @@ GLUE(.,name): .pushsection "_kprobe_blacklist","aw"; \ PPC_LONG (entry) ; \ .popsection +#define _NOKPROBE_ENTRY(entry) \ + _ASM_NOKPROBE_SYMBOL(entry) \ + _ENTRY(entry) +#define _NOKPROBE_GLOBAL(entry)\ + _ASM_NOKPROBE_SYMBOL(entry) \ + _GLOBAL(entry) #else #define _ASM_NOKPROBE_SYMBOL(entry) +#define _NOKPROBE_ENTRY(entry) \ + _ENTRY(entry) +#define _NOKPROBE_GLOBAL(entry)\ + _GLOBAL(entry) #endif #define FUNC_START(name) _GLOBAL(name) diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S index f6517f67265a..1cb947268546 100644 --- a/arch/powerpc/kernel/cpu_setup_6xx.S +++ b/arch/powerpc/kernel/cpu_setup_6xx.S @@ -276,7 +276,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_NO_DPM) * in some 750 cpus where using a not yet initialized FPU register after * power on reset may hang the CPU */ -_GLOBAL(__init_fpu_registers) +_NOKPROBE_GLOBAL(__init_fpu_registers) mfmsr r10 ori r11,r10,MSR_FP mtmsr r11 @@ -381,7 +381,7 @@ _GLOBAL(__save_cpu_setup) * restore CPU state as backed up by the previous * function. This does not include cache setting */ -_GLOBAL(__restore_cpu_setup) +_NOKPROBE_GLOBAL(__restore_cpu_setup) /* Some CR fields are volatile, we back it up all */ mfcrr7 diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 16af0d8d90a8..f788d586254d 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -44,24 +44,21 @@ .align 12 #ifdef CONFIG_BOOKE - .globl mcheck_transfer_to_handler -mcheck_transfer_to_handler: +_NOKPROBE_ENTRY(mcheck_transfer_to_handler) mfspr r0,SPRN_DSRR0 stw r0,_DSRR0(r11) mfspr r0,SPRN_DSRR1 stw r0,_DSRR1(r11) /* fall through */ - .globl debug_transfer_to_handler -debug_transfer_to_handler: +_NOKPROBE_ENTRY(debug_transfer_to_handler) mfspr r0,SPRN_CSRR0 stw r0,_CSRR0(r11) mfspr r0,SPRN_CSRR1 stw r0,_CSRR1(r11) /* fall through */ - .globl crit_transfer_to_handler -crit_transfer_to_handler: +_NOKPROBE_ENTRY(crit_transfer_to_handler) #ifdef CONFIG_PPC_BOOK3E_MMU mfspr r0,SPRN_MAS0 stw r0,MAS0(r11) @@ -97,8 +94,7 @@ crit_transfer_to_handler: #endif #ifdef CONFIG_40x - .globl crit_transfer_to_handler -crit_transfer_to_handler: +_NOKPROBE_ENTRY(crit_transfer_to_handler) lwz r0,crit_r10@l(0) stw r0,GPR10(r11) lwz r0,crit_r11@l(0) @@ -124,13 +120,11 @@ crit_transfer_to_handler: * Note that we rely on the caller having set cr0.eq iff the exception * occurred in kernel mode (i.e. MSR:PR = 0). */ - .globl transfer_to_handler_full -transfer_to_handler_full: +_NOKPROBE_ENTRY(transfer_to_handler_full) SAVE_NVGPRS(r11) /* fall through */ - .globl transfer_to_handler -transfer_to_handler: +_NOKPROBE_ENTRY(transfer_to_handler) stw r2,GPR2(r11) stw r12,_NIP(r11) stw r9,_MSR(r11) @@ -194,8 +188,7 @@ transfer_to_handler: bt-
