implement fexecve in terms of execveat when it exists

This lets fexecve work even when /proc isn't mounted.

diff --git a/src/process/fexecve.c b/src/process/fexecve.c
index 6507b42949c915e757bfa71935388a0ea4e0a15d..8be3f760ff7ad8ef5df760fc40a46ec3d722be3a 100644 (file)
--- a/src/process/fexecve.c
+++ b/src/process/fexecve.c
@@ -1,10 +1,15 @@
+#define _GNU_SOURCE
 #include <unistd.h>
 #include <errno.h>
+#include <fcntl.h>
+#include "syscall.h"
 
 void __procfdname(char *, unsigned);
 
 int fexecve(int fd, char *const argv[], char *const envp[])
 {
+       int r = __syscall(SYS_execveat, fd, "", argv, envp, AT_EMPTY_PATH);
+       if (r != -ENOSYS) return __syscall_ret(r);
        char buf[15 + 3*sizeof(int)];
        __procfdname(buf, fd);
        execve(buf, argv, envp);