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>