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| author |   Michael Ellerman <mpe@ellerman.id.au> | 2021-12-22 00:50:59 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-12-25 10:55:55 +1100 |
| commit | 314f6c23dd8d417281eb9e8a516dd98036f2e7b3 (patch) | |
| tree | 8c033c69bddd0b97095fd2db5392052b6412f35f /arch/powerpc | |
| parent | powerpc/perf: Fix spelling of "its" (diff) | |
| download | linux-dev-314f6c23dd8d417281eb9e8a516dd98036f2e7b3.tar.xz linux-dev-314f6c23dd8d417281eb9e8a516dd98036f2e7b3.zip | |
powerpc/64s: Mask NIP before checking against SRR0
When CONFIG_PPC_RFI_SRR_DEBUG=y we check that NIP and SRR0 match when
returning from interrupts. This can trigger falsely if NIP has either of
its two low bits set via sigreturn or ptrace, while SRR0 has its low two
bits masked in hardware.
As a quick fix make sure to mask the low bits before doing the check.
Fixes: 59dc5bfca0cb ("powerpc/64s: avoid reloading (H)SRR registers if they are still valid")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20211221135101.2085547-1-mpe@ellerman.id.au
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/interrupt_64.S | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S index d3180139e35a..d729c2e7dae0 100644 --- a/arch/powerpc/kernel/interrupt_64.S +++ b/arch/powerpc/kernel/interrupt_64.S @@ -30,6 +30,7 @@ COMPAT_SYS_CALL_TABLE: .ifc \srr,srr mfspr r11,SPRN_SRR0 ld r12,_NIP(r1) + clrrdi r12,r12,2 100: tdne r11,r12 EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) mfspr r11,SPRN_SRR1 @@ -39,6 +40,7 @@ COMPAT_SYS_CALL_TABLE: .else mfspr r11,SPRN_HSRR0 ld r12,_NIP(r1) + clrrdi r12,r12,2 100: tdne r11,r12 EMIT_BUG_ENTRY 100b,__FILE__,__LINE__,(BUGFLAG_WARNING | BUGFLAG_ONCE) mfspr r11,SPRN_HSRR1 |