summaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorHengqi Chen <hengqi.chen@gmail.com>2023-12-09 08:49:15 +0100
committerHuacai Chen <chenhuacai@loongson.cn>2023-12-09 08:49:15 +0100
commitd6c5f06e46a836e6a70c7cfd95bb38a67d9252ec (patch)
tree4c0f0e9285c938ebb4ed74d3366e62be36107996 /arch
parentLoongArch: Set unwind stack type to unknown rather than set error flag (diff)
downloadlinux-d6c5f06e46a836e6a70c7cfd95bb38a67d9252ec.tar.xz
linux-d6c5f06e46a836e6a70c7cfd95bb38a67d9252ec.zip
LoongArch: Preserve syscall nr across execve()
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/loongarch/include/asm/elf.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/loongarch/include/asm/elf.h b/arch/loongarch/include/asm/elf.h
index b9a4ab54285c..9b16a3b8e706 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; \