Re: [PATCH 1/5] linux-user: handle /proc/self/exe for execve

[Alex Bennée]

YAMAMOTO Takashi <yamamoto@midokura.com> writes:

> It seems somehow common to execve /proc/self/exe in docker
> or golang community these days.
> At least, moby "reexec" and runc "libcontainer" do that.
>
> Signed-off-by: YAMAMOTO Takashi <yamamoto@midokura.com>
> ---
>  linux-user/syscall.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index c9f812091c..a2b03ecb8b 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -8470,6 +8470,7 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>  #endif
>      case TARGET_NR_execve:
>          {
> +            const char *path;
>              char **argp, **envp;
>              int argc, envc;
>              abi_ulong gp;
> @@ -8537,7 +8538,11 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>               * before the execve completes and makes it the other
>               * program's problem.
>               */
> -            ret = get_errno(safe_execve(p, argp, envp));
> +            path = p;
> +            if (is_proc_myself(path, "exe")) {
> +                path = exec_path;
> +            }

This still relies on binfmt_misc kicking in to ensure the binary is
re-executed with qemu right?

> +            ret = get_errno(safe_execve(path, argp, envp));
>              unlock_user(p, arg1, 0);
>  
>              goto execve_end;


-- 
Alex Bennée