Re: [PATCH] linux-user: Fix setreuid and setregid to use direct syscalls

[Richard Henderson <richard.henderson@linaro.org>]

On 11/5/24 15:15, Helge Deller wrote:
> The commit fd6f7798ac30 ("linux-user: Use direct syscalls for setuid(),
> etc") added direct syscall wrappers for setuid(), setgid(), etc since the
> system calls have different semantics than the libc functions.
> 
> Add and use the corresponding wrappers for setreuid and setregid which
> were missed in that commit.
> 
> This fixes the build of the debian package of the uid_wrapper library
> (https://cwrap.org/uid_wrapper.html) when running linux-user.
> 
> Signed-off-by: Helge Deller <deller@gmx.de>
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 59b2080b98..0279f23576 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -7233,12 +7233,24 @@ static inline int tswapid(int id)
>   #else
>   #define __NR_sys_setgroups __NR_setgroups
>   #endif
> +#ifdef __NR_sys_setreuid32
> +#define __NR_sys_setreuid __NR_setreuid32
> +#else
> +#define __NR_sys_setreuid __NR_setreuid
> +#endif
> +#ifdef __NR_sys_setregid32
> +#define __NR_sys_setregid __NR_setregid32
> +#else
> +#define __NR_sys_setregid __NR_setregid
> +#endif
>   
>   _syscall1(int, sys_setuid, uid_t, uid)
>   _syscall1(int, sys_setgid, gid_t, gid)
>   _syscall3(int, sys_setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
>   _syscall3(int, sys_setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
>   _syscall2(int, sys_setgroups, int, size, gid_t *, grouplist)
> +_syscall2(int, sys_setreuid, uid_t, ruid, uid_t, euid);
> +_syscall2(int, sys_setregid, gid_t, rgid, gid_t, egid);
>   
>   void syscall_init(void)
>   {
> @@ -11932,9 +11944,9 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
>           return get_errno(high2lowgid(getegid()));
>   #endif
>       case TARGET_NR_setreuid:
> -        return get_errno(setreuid(low2highuid(arg1), low2highuid(arg2)));
> +        return get_errno(sys_setreuid(low2highuid(arg1), low2highuid(arg2)));
>       case TARGET_NR_setregid:
> -        return get_errno(setregid(low2highgid(arg1), low2highgid(arg2)));
> +        return get_errno(sys_setregid(low2highgid(arg1), low2highgid(arg2)));
>       case TARGET_NR_getgroups:
>           { /* the same code as for TARGET_NR_getgroups32 */
>               int gidsetsize = arg1;
> @@ -12264,11 +12276,11 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
>   #endif
>   #ifdef TARGET_NR_setreuid32
>       case TARGET_NR_setreuid32:
> -        return get_errno(setreuid(arg1, arg2));
> +        return get_errno(sys_setreuid(arg1, arg2));
>   #endif
>   #ifdef TARGET_NR_setregid32
>       case TARGET_NR_setregid32:
> -        return get_errno(setregid(arg1, arg2));
> +        return get_errno(sys_setregid(arg1, arg2));
>   #endif
>   #ifdef TARGET_NR_getgroups32
>       case TARGET_NR_getgroups32:
> 

Queued, thanks.


r~