From: Kito Cheng <kito.cheng@sifive.com>
To: Fangrui Song <maskray@google.com>
Cc: Kito Cheng <kito.cheng@gmail.com>,
Jeff Law <jeffreyalaw@gmail.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] RISC-V: Emit .note.GNU-stack for non-linux target as well
Date: Wed, 6 Sep 2023 10:57:50 +0800 [thread overview]
Message-ID: <CALLt3TgBU58cNL7-tc3s_vxBVS7i5vQv+VGicxRg4+bqYcYqNQ@mail.gmail.com> (raw)
In-Reply-To: <CAFP8O3+5MFGzeabnFz8_Ww04ovXx0QJBpN20+nqvfdtHwfr-gQ@mail.gmail.com>
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RISC-V qemu default that to false, which mean stack can't execute anything
by default, that's match RISC-V linux kernel behaviour, but the problem is
risc-v bare metal toolchain may execute code on stack *without* that tag,
that does not cause problems before for running tests on qemu user mode,
but...it causes problems once using newer qemu (with that patch).
Fangrui Song <maskray@google.com> 於 2023年9月6日 週三 04:53 寫道：
> On Tue, Sep 5, 2023 at 5:14 AM Kito Cheng via Gcc-patches <
> gcc-patches@gcc.gnu.org> wrote:
>
>> committed, thanks :)
>>
>> On Tue, Sep 5, 2023 at 3:18 PM Jeff Law via Gcc-patches
>> <gcc-patches@gcc.gnu.org> wrote:
>> >
>> >
>> >
>> > On 8/31/23 03:05, Kito Cheng wrote:
>> > > We only emit that on linux target before, that not problem before,
>> > > however Qemu has fix a bug to make qemu user mode honor
>> PT_GNU_STACK[1],
>> > > that will cause problem when we test baremetal with qemu.
>> > >
>> > > So the straightforward is enable that as well for non-linux toolchian,
>> > > the price is that will increase few bytes for each binary.
>> > >
>> > > [1]
>> https://github.com/qemu/qemu/commit/872f3d046f2381e3f416519e82df96bd60818311
>> > >
>> > > gcc/ChangeLog:
>> > >
>> > > * config/riscv/linux.h (TARGET_ASM_FILE_END): Move ...
>> > > * config/riscv/riscv.cc (TARGET_ASM_FILE_END): to here.
>> > OK.
>> > jeff
>>
>
> Does
> https://github.com/qemu/qemu/commit/872f3d046f2381e3f416519e82df96bd60818311
> use #define EXSTACK_DEFAULT true
> for riscv?
>
>
>
>
> --
> 宋方睿
>
prev parent reply other threads:[~2023-09-06 2:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-31 9:05 Kito Cheng
2023-09-05 7:17 ` Jeff Law
2023-09-05 12:14 ` Kito Cheng
2023-09-05 20:53 ` Fangrui Song
2023-09-06 2:57 ` Kito Cheng [this message]
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