From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Hengqi Chen <hengqi.chen@gmail.com>,
Huacai Chen <chenhuacai@loongson.cn>,
Sasha Levin <sashal@kernel.org>,
chenhuacai@kernel.org, yangtiezhu@loongson.cn,
loongarch@lists.linux.dev, linux-mm@kvack.org
Subject: [PATCH AUTOSEL 6.1 29/29] LoongArch: Preserve syscall nr across execve()
Date: Mon, 11 Dec 2023 08:54:13 -0500 [thread overview]
Message-ID: <20231211135457.381397-29-sashal@kernel.org> (raw)
In-Reply-To: <20231211135457.381397-1-sashal@kernel.org>
From: Hengqi Chen <hengqi.chen@gmail.com>
[ Upstream commit d6c5f06e46a836e6a70c7cfd95bb38a67d9252ec ]
Currently, we store syscall nr in pt_regs::regs[11] and syscall execve()
accidentally overrides it during its execution:
sys_execve()
-> do_execve()
-> do_execveat_common()
-> bprm_execve()
-> exec_binprm()
-> search_binary_handler()
-> load_elf_binary()
-> ELF_PLAT_INIT()
ELF_PLAT_INIT() reset regs[11] to 0, so in syscall_exit_to_user_mode()
we later get a wrong syscall nr. This breaks tools like execsnoop since
it relies on execve() tracepoints.
Skip pt_regs::regs[11] reset in ELF_PLAT_INIT() to fix the issue.
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/loongarch/include/asm/elf.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/loongarch/include/asm/elf.h b/arch/loongarch/include/asm/elf.h
index b9a4ab54285c1..9b16a3b8e7060 100644
--- a/arch/loongarch/include/asm/elf.h
+++ b/arch/loongarch/include/asm/elf.h
@@ -293,7 +293,7 @@ extern const char *__elf_platform;
#define ELF_PLAT_INIT(_r, load_addr) do { \
_r->regs[1] = _r->regs[2] = _r->regs[3] = _r->regs[4] = 0; \
_r->regs[5] = _r->regs[6] = _r->regs[7] = _r->regs[8] = 0; \
- _r->regs[9] = _r->regs[10] = _r->regs[11] = _r->regs[12] = 0; \
+ _r->regs[9] = _r->regs[10] /* syscall n */ = _r->regs[12] = 0; \
_r->regs[13] = _r->regs[14] = _r->regs[15] = _r->regs[16] = 0; \
_r->regs[17] = _r->regs[18] = _r->regs[19] = _r->regs[20] = 0; \
_r->regs[21] = _r->regs[22] = _r->regs[23] = _r->regs[24] = 0; \
--
2.42.0
parent reply other threads:[~2023-12-11 13:57 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20231211135457.381397-1-sashal@kernel.org>]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231211135457.381397-29-sashal@kernel.org \
--to=sashal@kernel.org \
--cc=chenhuacai@kernel.org \
--cc=chenhuacai@loongson.cn \
--cc=hengqi.chen@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=loongarch@lists.linux.dev \
--cc=stable@vger.kernel.org \
--cc=yangtiezhu@loongson.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox