| Message ID | 20180404104116.27819-1-naveen.n.rao@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5d6a03ebc88f82b0b0adcec24eabb9eb2fcd97db |
| Headers | show |
| Series | powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it | expand |
On Wed, 2018-04-04 at 10:41:16 UTC, "Naveen N. Rao" wrote: > 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 [c00000000001bf44] __set_breakpoint+0xb4/0x140 > LR [c000000000061268] kexec_prepare_cpus_wait+0x58/0x150 > Call Trace: > [c0000000ee70fad0] [c0000000ee70fb20] 0xc0000000ee70fb20 (unreliable) > [c0000000ee70faf0] [c0000000ee70fb20] 0xc0000000ee70fb20 > [c0000000ee70fbb0] [c000000000061884] default_machine_kexec+0x234/0x2c0 > [c0000000ee70fc40] [c0000000000605c4] machine_kexec+0x84/0x90 > [c0000000ee70fc70] [c000000000206548] kernel_kexec+0xd8/0xe0 > [c0000000ee70fce0] [c000000000169e74] SyS_reboot+0x214/0x2c0 > [c0000000ee70fe30] [c00000000000bd60] 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. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/5d6a03ebc88f82b0b0adcec24eabb9 cheers
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h index 90c708e5e7c4..8e7b09703ca4 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);
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 [c00000000001bf44] __set_breakpoint+0xb4/0x140 LR [c000000000061268] kexec_prepare_cpus_wait+0x58/0x150 Call Trace: [c0000000ee70fad0] [c0000000ee70fb20] 0xc0000000ee70fb20 (unreliable) [c0000000ee70faf0] [c0000000ee70fb20] 0xc0000000ee70fb20 [c0000000ee70fbb0] [c000000000061884] default_machine_kexec+0x234/0x2c0 [c0000000ee70fc40] [c0000000000605c4] machine_kexec+0x84/0x90 [c0000000ee70fc70] [c000000000206548] kernel_kexec+0xd8/0xe0 [c0000000ee70fce0] [c000000000169e74] SyS_reboot+0x214/0x2c0 [c0000000ee70fe30] [c00000000000bd60] 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. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/include/asm/hw_breakpoint.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)