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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2018-04-04 16:11:16 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-04-04 21:54:02 +1000 |
| commit | 5d6a03ebc88f82b0b0adcec24eabb9eb2fcd97db (patch) | |
| tree | 44a0155a1e81605c8d8fd357e28ad8ddb98cc9d4 | |
| parent | 7a22d6321c3da61a3778f84caa5b3a398ed019d1 (diff) | |
| download | op-kernel-dev-5d6a03ebc88f82b0b0adcec24eabb9eb2fcd97db.zip op-kernel-dev-5d6a03ebc88f82b0b0adcec24eabb9eb2fcd97db.tar.gz | |
powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it
We get the below warning if we try to use kexec on P9:
kexec_core: Starting new kernel
WARNING: CPU: 0 PID: 1223 at arch/powerpc/kernel/process.c:826 __set_breakpoint+0xb4/0x140
[snip]
NIP __set_breakpoint+0xb4/0x140
LR kexec_prepare_cpus_wait+0x58/0x150
Call Trace:
0xc0000000ee70fb20 (unreliable)
0xc0000000ee70fb20
default_machine_kexec+0x234/0x2c0
machine_kexec+0x84/0x90
kernel_kexec+0xd8/0xe0
SyS_reboot+0x214/0x2c0
system_call+0x58/0x6c
This happens since we are trying to clear hw breakpoint on POWER9,
though we don't have CPU_FTR_DAWR enabled. Guard __set_breakpoint()
within hw_breakpoint_disable() with ppc_breakpoint_available() to
address this.
Fixes: 9654153158d3 ("powerpc: Disable DAWR in the base POWER9 CPU features")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/include/asm/hw_breakpoint.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h index 90c708e..8e7b097 100644 --- a/arch/powerpc/include/asm/hw_breakpoint.h +++ b/arch/powerpc/include/asm/hw_breakpoint.h @@ -80,7 +80,8 @@ static inline void hw_breakpoint_disable(void) brk.address = 0; brk.type = 0; brk.len = 0; - __set_breakpoint(&brk); + if (ppc_breakpoint_available()) + __set_breakpoint(&brk); } extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs); int hw_breakpoint_handler(struct die_args *args); |
