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authorWaldemar Brodkorb <wbx@openadk.org>2019-11-05 17:28:08 +0100
committerWaldemar Brodkorb <wbx@openadk.org>2019-11-05 17:29:01 +0100
commit858ffad217076227089cc17eb832db0bd1497792 (patch)
tree1e5db7c9e7fbf271865ec5acaf09f232a4ca08f3
parent60eae0def70b8a2e768c6a5bec352da9d648b26c (diff)
implement fexecve from glibc
-rw-r--r--include/unistd.h4
-rw-r--r--libc/sysdeps/linux/common/fexecve.c52
2 files changed, 53 insertions, 3 deletions
diff --git a/include/unistd.h b/include/unistd.h
index fdde8f02f..36cd5fcb5 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -585,13 +585,11 @@ extern int execve (const char *__path, char *const __argv[],
char *const __envp[]) __THROW __nonnull ((1, 2));
libc_hidden_proto(execve)
-#if 0 /*def __USE_XOPEN2K8*/
/* Execute the file FD refers to, overlaying the running program image.
ARGV and ENVP are passed to the new program, as for `execve'. */
extern int fexecve (int __fd, char *const __argv[], char *const __envp[])
__THROW __nonnull ((2));
-#endif
-
+libc_hidden_proto(fexecve)
/* Execute PATH with arguments ARGV and environment from `environ'. */
extern int execv (const char *__path, char *const __argv[])
diff --git a/libc/sysdeps/linux/common/fexecve.c b/libc/sysdeps/linux/common/fexecve.c
new file mode 100644
index 000000000..99a35c5b8
--- /dev/null
+++ b/libc/sysdeps/linux/common/fexecve.c
@@ -0,0 +1,52 @@
+/* Copyright (C) 1994-2019 Free Software Foundation, Inc.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+int
+fexecve (int fd, char *const argv[], char *const envp[])
+{
+ if (fd < 0 || argv == NULL || envp == NULL)
+ {
+ __set_errno (EINVAL);
+ return -1;
+ }
+ /* We use the /proc filesystem to get the information. If it is not
+ mounted we fail. */
+ char buf[sizeof "/proc/self/fd/" + sizeof (int) * 3];
+ snprintf (buf, sizeof (buf), "/proc/self/fd/%d", fd);
+
+ /* We do not need the return value. */
+ execve (buf, argv, envp);
+
+ int save = errno;
+
+ /* We come here only if the 'execve' call fails. Determine whether
+ /proc is mounted. If not we return ENOSYS. */
+ struct stat st;
+ if (stat ("/proc/self/fd", &st) != 0 && errno == ENOENT)
+ save = ENOSYS;
+
+ __set_errno (save);
+
+ return -1;
+}
+libc_hidden_def(fexecve)