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; \