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From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it
Date: Thu,  5 Apr 2018 00:39:55 +1000 (AEST)	[thread overview]
Message-ID: <40GTBg2P0sz9s31@ozlabs.org> (raw)
In-Reply-To: <20180404104116.27819-1-naveen.n.rao@linux.vnet.ibm.com>

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

      reply	other threads:[~2018-04-04 14:39 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-04 10:41 [PATCH] powerpc/hw_breakpoint: Only disable hw breakpoint if cpu supports it Naveen N. Rao
2018-04-04 14:39 ` Michael Ellerman [this message]

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