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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, mikey@neuling.org
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v5 10/13] powerpc/ptrace: split out ADV_DEBUG_REGS related functions.
In-Reply-To: <25a7f050-f241-6035-e778-16b1ca9928f3@c-s.fr>
References: <cover.1582848567.git.christophe.leroy@c-s.fr> <e2bd7d275bd5933d848aad4fee3ca652a14d039b.1582848567.git.christophe.leroy@c-s.fr> <87imizdbaz.fsf@mpe.ellerman.id.au> <25a7f050-f241-6035-e778-16b1ca9928f3@c-s.fr>
Date:   Tue, 24 Mar 2020 17:23:29 +1100
Message-ID: <87k13axoda.fsf@mpe.ellerman.id.au>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
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Christophe Leroy <christophe.leroy@c-s.fr> writes:
> On 03/20/2020 02:12 AM, Michael Ellerman wrote:
>> Christophe Leroy <christophe.leroy@c-s.fr> writes:
>>> Move ADV_DEBUG_REGS functions out of ptrace.c, into
>>> ptrace-adv.c and ptrace-noadv.c
>>>
>>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>>> ---
>>> v4: Leave hw_breakpoint.h for ptrace.c
>>> ---
>>>   arch/powerpc/kernel/ptrace/Makefile       |   4 +
>>>   arch/powerpc/kernel/ptrace/ptrace-adv.c   | 468 ++++++++++++++++
>>>   arch/powerpc/kernel/ptrace/ptrace-decl.h  |   5 +
>>>   arch/powerpc/kernel/ptrace/ptrace-noadv.c | 236 ++++++++
>>>   arch/powerpc/kernel/ptrace/ptrace.c       | 650 ----------------------
>>>   5 files changed, 713 insertions(+), 650 deletions(-)
>>>   create mode 100644 arch/powerpc/kernel/ptrace/ptrace-adv.c
>>>   create mode 100644 arch/powerpc/kernel/ptrace/ptrace-noadv.c
>> 
>> This is somehow breaking the ptrace-hwbreak selftest on Power8:
>> 
>>    test: ptrace-hwbreak
>>    tags: git_version:v5.6-rc6-892-g7a285a6067d6
>>    PTRACE_SET_DEBUGREG, WO, len: 1: Ok
>>    PTRACE_SET_DEBUGREG, WO, len: 2: Ok
>>    PTRACE_SET_DEBUGREG, WO, len: 4: Ok
>>    PTRACE_SET_DEBUGREG, WO, len: 8: Ok
>>    PTRACE_SET_DEBUGREG, RO, len: 1: Ok
>>    PTRACE_SET_DEBUGREG, RO, len: 2: Ok
>>    PTRACE_SET_DEBUGREG, RO, len: 4: Ok
>>    PTRACE_SET_DEBUGREG, RO, len: 8: Ok
>>    PTRACE_SET_DEBUGREG, RW, len: 1: Ok
>>    PTRACE_SET_DEBUGREG, RW, len: 2: Ok
>>    PTRACE_SET_DEBUGREG, RW, len: 4: Ok
>>    PTRACE_SET_DEBUGREG, RW, len: 8: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, WO, len: 6: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RO, len: 6: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RW, len: 6: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, WO, len: 6: Ok
>>    PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW UNALIGNED, RO, len: 6: Fail
>>    failure: ptrace-hwbreak
>> 
>> I haven't had time to work out why yet.
>> 
>
> A (big) part of commit c3f68b0478e7 ("powerpc/watchpoint: Fix ptrace 
> code that muck around with address/len") was lost during rebase.
>
> I'll send a fix, up to you to squash it in or commit it as is.

Thanks.

cheers