From: Peter Maydell <peter.maydell@linaro.org>
To: Laurent Vivier <laurent@vivier.eu>
Cc: QEMU Developers <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] [PULL 12/13] page_unprotect(): handle calls to pages that are PAGE_WRITE
Date: Thu, 22 Mar 2018 11:07:40 +0000 [thread overview]
Message-ID: <CAFEAcA9ZAxkvc-Rn=oP5Bgksk6zo8PYNkhP8SC1+aaWN_vQduw@mail.gmail.com> (raw)
In-Reply-To: <CAFEAcA9==FswwaKG_eWncv7Eo-zF+OTOKmSC7N-mpTrSEzUJmg@mail.gmail.com>
On 22 March 2018 at 11:05, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 22 March 2018 at 10:36, Laurent Vivier <laurent@vivier.eu> wrote:
>> It goes wrong in this part:
>>
>> + */
>> + if (is_write && info->si_signo == SIGSEGV && info->si_code ==
>> SEGV_ACCERR &&
>> + h2g_valid(address)) {
>>
>> Because, on ppc, si_code is SEGV_MAPERR and not SEGV_ACCERR
>> (on x86_64, si_code is SEGV_ACCERR as expected)
>
> So on PPC if you have a page mapped, and you access it with
> the wrong permissions, you get SEGV_MAPERR? This seems like
> a host kernel bug to me.
...in particular, kernel commit ecb101aed86156e (dated Dec 2017)
fixes a regression introduced in commit c3350602e876 that broke
the ppc kernels so they started returning SEGV_MAPERR here
instead of SEGV_ACCERR. Presumably your host kernel is missing
this fix.
thanks
-- PMM
next prev parent reply other threads:[~2018-03-22 11:08 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-23 14:47 [Qemu-devel] [PULL 00/13] Linux user for 2.12 patches Laurent Vivier
2018-01-23 14:47 ` [Qemu-devel] [PULL 01/13] linux-user: Fix locking order in fork_start() Laurent Vivier
2018-01-23 14:47 ` [Qemu-devel] [PULL 02/13] linux-user: wrap fork() in a start/end exclusive section Laurent Vivier
2018-01-23 14:47 ` [Qemu-devel] [PULL 03/13] linux-user: Fix length calculations in host_to_target_cmsg() Laurent Vivier
2018-01-23 14:47 ` [Qemu-devel] [PULL 04/13] linux-user: Don't use CMSG_ALIGN(sizeof struct cmsghdr) Laurent Vivier
2018-01-23 14:47 ` [Qemu-devel] [PULL 05/13] linux-user: Translate flags argument to dup3 syscall Laurent Vivier
2018-01-23 14:48 ` [Qemu-devel] [PULL 06/13] linux-user/mmap.c: Avoid choosing NULL as start address Laurent Vivier
2018-01-23 14:48 ` [Qemu-devel] [PULL 07/13] linux-user: Fix sched_get/setaffinity conversion Laurent Vivier
2018-01-26 18:23 ` Peter Maydell
2018-01-26 18:33 ` Samuel Thibault
2018-01-23 14:48 ` [Qemu-devel] [PULL 08/13] linux-user: Add AT_SECURE auxval Laurent Vivier
2018-01-23 14:48 ` [Qemu-devel] [PULL 09/13] linux-user: Add getcpu() support Laurent Vivier
2018-01-23 14:48 ` [Qemu-devel] [PULL 10/13] linux-user: remove nmi.c and fw-path-provider.c Laurent Vivier
2018-01-23 14:48 ` [Qemu-devel] [PULL 11/13] linux-user: Propagate siginfo_t through to handle_cpu_signal() Laurent Vivier
2018-01-23 14:48 ` [Qemu-devel] [PULL 12/13] page_unprotect(): handle calls to pages that are PAGE_WRITE Laurent Vivier
2018-03-22 1:52 ` Laurent Vivier
2018-03-22 10:36 ` Laurent Vivier
2018-03-22 11:05 ` Peter Maydell
2018-03-22 11:07 ` Peter Maydell [this message]
2018-03-22 11:13 ` Laurent Vivier
2018-03-22 16:47 ` Laurent Vivier
2018-03-22 11:07 ` Laurent Vivier
2018-03-22 11:10 ` Peter Maydell
2018-01-23 14:48 ` [Qemu-devel] [PULL 13/13] linux-user: implement renameat2 Laurent Vivier
2018-01-23 19:13 ` Palmer Dabbelt
2018-01-23 20:13 ` Laurent Vivier
2018-01-23 20:55 ` Palmer Dabbelt
2018-01-25 11:37 ` [Qemu-devel] [PULL 00/13] Linux user for 2.12 patches Peter Maydell
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