diff options
| author |   Christophe Leroy <christophe.leroy@c-s.fr> | 2020-03-31 16:03:45 +0000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-06-02 20:59:12 +1000 |
| commit | a616c442119f2ea5641e6abc215d7255b73b982b (patch) | |
| tree | 6718c1944dac37ef60ba252dcbb72014c2d14fae /arch/powerpc/kernel/entry_32.S | |
| parent | powerpc/32: Blacklist functions running with MMU disabled for kprobe (diff) | |
| download | linux-dev-a616c442119f2ea5641e6abc215d7255b73b982b.tar.xz linux-dev-a616c442119f2ea5641e6abc215d7255b73b982b.zip | |
powerpc/entry32: Blacklist exception entry points for kprobe.
kprobe does not handle events happening in real mode.
As exception entry points are running with MMU disabled,
blacklist them.
The handling of TLF_NAPPING and TLF_SLEEPING is moved before the
CONFIG_TRACE_IRQFLAGS which contains 'reenable_mmu' because from there
kprobe will be possible as the kernel will run with MMU enabled.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f61ac599855e674ebb592464d0ea32a3ba9c6644.1585670437.git.christophe.leroy@c-s.fr
Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 37 |
1 files changed, 22 insertions, 15 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index d54f40650ff8..c9fc6ea36bc6 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -50,6 +50,7 @@ mcheck_transfer_to_handler: mfspr r0,SPRN_DSRR1 stw r0,_DSRR1(r11) /* fall through */ +_ASM_NOKPROBE_SYMBOL(mcheck_transfer_to_handler) .globl debug_transfer_to_handler debug_transfer_to_handler: @@ -58,6 +59,7 @@ debug_transfer_to_handler: mfspr r0,SPRN_CSRR1 stw r0,_CSRR1(r11) /* fall through */ +_ASM_NOKPROBE_SYMBOL(debug_transfer_to_handler) .globl crit_transfer_to_handler crit_transfer_to_handler: @@ -93,6 +95,7 @@ crit_transfer_to_handler: rlwinm r0,r1,0,0,(31 - THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ +_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler) #endif #ifdef CONFIG_40x @@ -114,6 +117,7 @@ crit_transfer_to_handler: rlwinm r0,r1,0,0,(31 - THREAD_SHIFT) stw r0,KSP_LIMIT(r8) /* fall through */ +_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler) #endif /* @@ -126,6 +130,7 @@ crit_transfer_to_handler: .globl transfer_to_handler_full transfer_to_handler_full: SAVE_NVGPRS(r11) +_ASM_NOKPROBE_SYMBOL(transfer_to_handler_full) /* fall through */ .globl transfer_to_handler @@ -226,6 +231,23 @@ transfer_to_handler_cont: SYNC RFI /* jump to handler, enable MMU */ +#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500) +4: rlwinm r12,r12,0,~_TLF_NAPPING + stw r12,TI_LOCAL_FLAGS(r2) + b power_save_ppc32_restore + +7: rlwinm r12,r12,0,~_TLF_SLEEPING + stw r12,TI_LOCAL_FLAGS(r2) + lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */ + rlwinm r9,r9,0,~MSR_EE + lwz r12,_LINK(r11) /* and return to address in LR */ + kuap_restore r11, r2, r3, r4, r5 + lwz r2, GPR2(r11) + b fast_exception_return +#endif +_ASM_NOKPROBE_SYMBOL(transfer_to_handler) +_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont) + #ifdef CONFIG_TRACE_IRQFLAGS 1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to * keep interrupts disabled at this point otherwise we might risk @@ -271,21 +293,6 @@ reenable_mmu: bctr /* jump to handler */ #endif /* CONFIG_TRACE_IRQFLAGS */ -#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500) -4: rlwinm r12,r12,0,~_TLF_NAPPING - stw r12,TI_LOCAL_FLAGS(r2) - b power_save_ppc32_restore - -7: rlwinm r12,r12,0,~_TLF_SLEEPING - stw r12,TI_LOCAL_FLAGS(r2) - lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */ - rlwinm r9,r9,0,~MSR_EE - lwz r12,_LINK(r11) /* and return to address in LR */ - kuap_restore r11, r2, r3, r4, r5 - lwz r2, GPR2(r11) - b fast_exception_return -#endif - #ifndef CONFIG_VMAP_STACK /* * On kernel stack overflow, load up an initial stack pointer |