@@ -82,6 +82,8 @@ tests := tstgetopt testfnm runtests runptests \
tst-execv1 tst-execv2 tst-execl1 tst-execl2 \
tst-execve1 tst-execve2 tst-execle1 tst-execle2 \
tst-execvp3 tst-execvp4 tst-rfc3484 tst-rfc3484-2 \
+ tst-execvpe1 tst-execvpe2 tst-execvpe3 tst-execvpe4 \
+ tst-execvpe5 tst-execvpe6 \
tst-rfc3484-3 \
tst-getaddrinfo3 tst-fnmatch2 tst-cpucount tst-cpuset \
bug-getopt1 bug-getopt2 bug-getopt3 bug-getopt4 \
@@ -228,6 +230,7 @@ tstgetopt-ARGS = -a -b -cfoobar --required foobar --optional=bazbug \
tst-exec-ARGS = -- $(host-test-program-cmd)
tst-exec-static-ARGS = $(tst-exec-ARGS)
+tst-execvpe5-ARGS = -- $(host-test-program-cmd)
tst-spawn-ARGS = -- $(host-test-program-cmd)
tst-spawn-static-ARGS = $(tst-spawn-ARGS)
tst-dir-ARGS = `pwd` `cd $(common-objdir)/$(subdir); pwd` `cd $(common-objdir); pwd` $(objpfx)tst-dir
@@ -15,7 +15,6 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <alloca.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdbool.h>
@@ -23,22 +22,37 @@
#include <string.h>
#include <errno.h>
#include <paths.h>
-
+#include <confstr.h>
+#include <sys/param.h>
/* The file is accessible but it is not an executable file. Invoke
the shell to interpret it as a script. */
static void
-internal_function
-scripts_argv (const char *file, char *const argv[], int argc, char **new_argv)
+maybe_script_execute (const char *path, char *const argv[], char *const envp[])
{
+ /* Linux accepts a very large argument number (INT_MAX to fit on a signed
+ 32-bit integer). To limit stack allocation we set it to a lower
+ bound. */
+ int argc = 0;
+ while (argv[argc++])
+ if (argc > NCARGS)
+ {
+ errno = E2BIG;
+ return;
+ }
+
/* Construct an argument list for the shell. */
+ char *new_argv[argc];
new_argv[0] = (char *) _PATH_BSHELL;
- new_argv[1] = (char *) file;
+ new_argv[1] = (char *) path;
while (argc > 1)
{
new_argv[argc] = argv[argc - 1];
--argc;
}
+
+ /* Execute the shell. */
+ __execve (new_argv[0], new_argv, envp);
}
@@ -47,170 +61,107 @@ scripts_argv (const char *file, char *const argv[], int argc, char **new_argv)
int
__execvpe (const char *file, char *const argv[], char *const envp[])
{
+ /* We check the simple case first. */
if (*file == '\0')
{
- /* We check the simple case first. */
__set_errno (ENOENT);
return -1;
}
- if (strchr (file, '/') != NULL)
+ /* Don't search when it contains a slash. */
+ if (strchr (file, '/'))
{
- /* Don't search when it contains a slash. */
__execve (file, argv, envp);
if (errno == ENOEXEC)
- {
- /* Count the arguments. */
- int argc = 0;
- while (argv[argc++])
- ;
- size_t len = (argc + 1) * sizeof (char *);
- char **script_argv;
- void *ptr = NULL;
- if (__libc_use_alloca (len))
- script_argv = alloca (len);
- else
- script_argv = ptr = malloc (len);
-
- if (script_argv != NULL)
- {
- scripts_argv (file, argv, argc, script_argv);
- __execve (script_argv[0], script_argv, envp);
-
- free (ptr);
- }
- }
+ maybe_script_execute (file, argv, envp);
+
+ return -1;
}
- else
+
+ const char *path = getenv ("PATH");
+ if (!path)
+ path = CS_PATH;
+ /* Although GLIBC does not enforce NAME_MAX, we set it as the maximum
+ size to avoid unbounded stack allocation. Same applies for
+ PATH_MAX. */
+ size_t file_len = __strnlen (file, NAME_MAX + 1);
+ if (file_len > NAME_MAX)
{
- size_t pathlen;
- size_t alloclen = 0;
- char *path = getenv ("PATH");
- if (path == NULL)
- {
- pathlen = confstr (_CS_PATH, (char *) NULL, 0);
- alloclen = pathlen + 1;
- }
- else
- pathlen = strlen (path);
+ errno = ENAMETOOLONG;
+ return -1;
+ }
+ size_t path_len = __strnlen (path, PATH_MAX - 1) + 1;
- size_t len = strlen (file) + 1;
- alloclen += pathlen + len + 1;
+ const char *subp;
+ bool got_eacces = false;
+ for (const char *p = path; ; p = subp)
+ {
+ char buffer[path_len + file_len + 1];
- char *name;
- char *path_malloc = NULL;
- if (__libc_use_alloca (alloclen))
- name = alloca (alloclen);
- else
- {
- path_malloc = name = malloc (alloclen);
- if (name == NULL)
- return -1;
- }
+ subp = __strchrnul (p, ':');
- if (path == NULL)
+ /* PATH is larger than PATH_MAX and thus potentially larger than
+ the stack allocation. */
+ if (subp - p >= path_len)
{
- /* There is no `PATH' in the environment.
- The default search path is the current directory
- followed by the path `confstr' returns for `_CS_PATH'. */
- path = name + pathlen + len + 1;
- path[0] = ':';
- (void) confstr (_CS_PATH, path + 1, pathlen);
+ /* If there is only one path, bail out. */
+ if (!*subp)
+ break;
+ /* Otherwise skip to next one. */
+ continue;
}
- /* Copy the file name at the top. */
- name = (char *) memcpy (name + pathlen + 1, file, len);
- /* And add the slash. */
- *--name = '/';
+ /* Set current path considered plus a '/'. */
+ memcpy (buffer, p, subp - p);
+ buffer[subp - p] = '/';
+ /* And the file to execute. */
+ memcpy (buffer + (subp - p) + (subp > p), file, file_len + 1);
+
+ __execve (buffer, argv, envp);
+
+ if (errno == ENOEXEC)
+ maybe_script_execute (buffer, argv, envp);
- char **script_argv = NULL;
- void *script_argv_malloc = NULL;
- bool got_eacces = false;
- char *p = path;
- do
+ switch (errno)
{
- char *startp;
-
- path = p;
- p = __strchrnul (path, ':');
-
- if (p == path)
- /* Two adjacent colons, or a colon at the beginning or the end
- of `PATH' means to search the current directory. */
- startp = name + 1;
- else
- startp = (char *) memcpy (name - (p - path), path, p - path);
-
- /* Try to execute this name. If it works, execve will not return. */
- __execve (startp, argv, envp);
-
- if (errno == ENOEXEC)
- {
- if (script_argv == NULL)
- {
- /* Count the arguments. */
- int argc = 0;
- while (argv[argc++])
- ;
- size_t arglen = (argc + 1) * sizeof (char *);
- if (__libc_use_alloca (alloclen + arglen))
- script_argv = alloca (arglen);
- else
- script_argv = script_argv_malloc = malloc (arglen);
- if (script_argv == NULL)
- {
- /* A possible EACCES error is not as important as
- the ENOMEM. */
- got_eacces = false;
- break;
- }
- scripts_argv (startp, argv, argc, script_argv);
- }
-
- __execve (script_argv[0], script_argv, envp);
- }
-
- switch (errno)
- {
- case EACCES:
- /* Record the we got a `Permission denied' error. If we end
- up finding no executable we can use, we want to diagnose
- that we did find one but were denied access. */
- got_eacces = true;
- case ENOENT:
- case ESTALE:
- case ENOTDIR:
- /* Those errors indicate the file is missing or not executable
- by us, in which case we want to just try the next path
- directory. */
- case ENODEV:
- case ETIMEDOUT:
- /* Some strange filesystems like AFS return even
- stranger error numbers. They cannot reasonably mean
- anything else so ignore those, too. */
- break;
-
- default:
- /* Some other error means we found an executable file, but
- something went wrong executing it; return the error to our
- caller. */
- return -1;
- }
+ case EACCES:
+ /* Record the we got a 'Permission denied' error. If we end
+ up finding no executable we can use, we want to diagnose
+ that we did find one but were denied access. */
+ got_eacces = true;
+ case ENOENT:
+ case ESTALE:
+ case ENOTDIR:
+ /* Those errors indicate the file is missing or not executable
+ by us, in which case we want to just try the next path
+ directory. */
+ case ENODEV:
+ case ETIMEDOUT:
+ /* Some strange filesystems like AFS return even
+ stranger error numbers. They cannot reasonably mean
+ anything else so ignore those, too. */
+ break;
+
+ default:
+ /* Some other error means we found an executable file, but
+ something went wrong executing it; return the error to our
+ caller. */
+ return -1;
}
- while (*p++ != '\0');
-
- /* We tried every element and none of them worked. */
- if (got_eacces)
- /* At least one failure was due to permissions, so report that
- error. */
- __set_errno (EACCES);
- free (script_argv_malloc);
- free (path_malloc);
+ if (*subp++ == '\0')
+ break;
}
- /* Return the error from the last attempt (probably ENOENT). */
+ /* We tried every element and none of them worked. */
+ if (got_eacces)
+ /* At least one failure was due to permissions, so report that
+ error. */
+ __set_errno (EACCES);
+
return -1;
+
}
+
weak_alias (__execvpe, execvpe)
@@ -3,6 +3,10 @@
#include <stdlib.h>
#include <unistd.h>
+#ifndef EXECVP
+# define EXECVP(__file, __argv) execvp (__file, __argv)
+#endif
+
static int
do_test (void)
{
@@ -19,7 +23,7 @@ do_test (void)
char *argv[] = { (char *) "does-not-exist", NULL };
errno = 0;
- execvp (argv[0], argv);
+ EXECVP (argv[0], argv);
if (errno != ENOENT)
{
@@ -14,6 +14,9 @@ static int do_test (void);
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"
+#ifndef EXECVP
+# define EXECVP(__file, __argv) execvp (__file, __argv)
+#endif
static char *copy;
@@ -70,7 +73,7 @@ do_test (void)
char *argv[] = { basename (copy), NULL };
errno = 0;
- execvp (argv[0], argv);
+ EXECVP (argv[0], argv);
if (errno != EACCES)
{
@@ -12,6 +12,9 @@ static int do_test (void);
#include "../test-skeleton.c"
+#ifndef EXECVP
+# define EXECVP(__file, __argv) execvp (__file, __argv)
+#endif
static char *fname;
@@ -35,7 +38,7 @@ do_test (void)
}
char *argv[] = { fname, NULL };
- execvp (basename (fname), argv);
+ EXECVP (basename (fname), argv);
/* If we come here, the execvp call failed. */
return 1;
@@ -5,6 +5,10 @@
#include <unistd.h>
#include <sys/stat.h>
+#ifndef EXECVP
+# define EXECVP(__file, __argv) execvp (__file, __argv)
+#endif
+
static int
do_test (void)
{
@@ -27,7 +31,7 @@ do_test (void)
unsetenv ("PATH");
char *argv[] = { buf + 9, NULL };
- execvp (argv[0], argv);
+ EXECVP (argv[0], argv);
return 0;
}
new file mode 100644
@@ -0,0 +1,20 @@
+/* Check ENOENT failure for execvpe.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#define EXECVP(__file, __argv) execvpe (__file, __argv, NULL)
+#include <posix/tst-execvp1.c>
new file mode 100644
@@ -0,0 +1,20 @@
+/* Check EACCES for execvpe.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#define EXECVP(__file, __argv) execvpe (__file, __argv, NULL)
+#include <posix/tst-execvp2.c>
new file mode 100644
@@ -0,0 +1,20 @@
+/* Check script execution without shebang for execvpe.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#define EXECVP(__file, __argv) execvpe (__file, __argv, NULL)
+#include <posix/tst-execvp3.c>
new file mode 100644
@@ -0,0 +1,20 @@
+/* Check unexistent binary for execvpe.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#define EXECVP(__file, __argv) execvpe (__file, __argv, NULL)
+#include <posix/tst-execvp4.c>
new file mode 100644
@@ -0,0 +1,130 @@
+/* General tests for execpve.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <wait.h>
+
+
+/* Nonzero if the program gets called via `exec'. */
+static int restart;
+
+
+#define CMDLINE_OPTIONS \
+ { "restart", no_argument, &restart, 1 },
+
+/* Prototype for our test function. */
+extern void do_prepare (int argc, char *argv[]);
+extern int do_test (int argc, char *argv[]);
+
+#include "../test-skeleton.c"
+
+#define EXECVPE_KEY "EXECVPE_ENV"
+#define EXECVPE_VALUE "execvpe_test"
+
+
+static int
+handle_restart (void)
+{
+ /* First check if only one variable is passed on execvpe. */
+ int env_count = 0;
+ for (char **e = environ; *e != NULL; ++e)
+ if (++env_count == INT_MAX)
+ error (EXIT_FAILURE, 0, "environment variable number overflow");
+ if (env_count != 1)
+ error (EXIT_FAILURE, 0, "wrong number of environment variables");
+
+ /* Check if the combinarion os "EXECVPE_ENV=execvpe_test" */
+ const char *env = getenv (EXECVPE_KEY);
+ if (env == NULL)
+ error (EXIT_FAILURE, 0, "test environment variable not found");
+
+ if (strncmp (env, EXECVPE_VALUE, sizeof (EXECVPE_VALUE)))
+ error (EXIT_FAILURE, 0, "test environment variable with wrong value");
+
+ return 0;
+}
+
+
+int
+do_test (int argc, char *argv[])
+{
+ pid_t pid;
+ int status;
+
+ /* We must have
+ - one or four parameters left if called initially
+ + path for ld.so optional
+ + "--library-path" optional
+ + the library path optional
+ + the application name
+ */
+
+ if (restart)
+ {
+ if (argc != 1)
+ error (EXIT_FAILURE, 0, "wrong number of arguments (%d)", argc);
+
+ return handle_restart ();
+ }
+
+ if (argc != 2 && argc != 5)
+ error (EXIT_FAILURE, 0, "wrong number of arguments (%d)", argc);
+
+ /* We want to test the `execvpe' function. To do this we restart the
+ program with an additional parameter. */
+ pid = fork ();
+ if (pid == 0)
+ {
+ /* This is the child. Construct the command line. */
+
+ /* We cast here to char* because the test itself does not modify neither
+ the argument nor the environment list. */
+ char *envs[] = { (char*)(EXECVPE_KEY "=" EXECVPE_VALUE), NULL };
+ if (argc == 5)
+ {
+ char *args[] = { argv[1], argv[2], argv[3], argv[4],
+ (char*)"--direct", (char*)"--restart", NULL };
+ execvpe (args[0], args, envs);
+ }
+ else
+ {
+ char *args[] = { argv[1], argv[1],
+ (char*)"--direct", (char*)"--restart", NULL };
+ execvpe (args[0], args, envs);
+ }
+
+ error (EXIT_FAILURE, errno, "cannot exec");
+ }
+ else if (pid == (pid_t) -1)
+ error (EXIT_FAILURE, errno, "cannot fork");
+
+ /* Wait for the child. */
+ if (waitpid (pid, &status, 0) != pid)
+ error (EXIT_FAILURE, errno, "wrong child");
+
+ if (WTERMSIG (status) != 0)
+ error (EXIT_FAILURE, 0, "Child terminated incorrectly");
+ status = WEXITSTATUS (status);
+
+ return status;
+}
new file mode 100644
@@ -0,0 +1,82 @@
+/* Check execvpe script argument handling.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+
+static char *fname;
+
+static void do_prepare (void);
+#define PREPARE(argc, argv) do_prepare ()
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+
+#include "../test-skeleton.c"
+
+static void
+do_prepare (void)
+{
+ int fd = create_temp_file ("testscript", &fname);
+ dprintf (fd, "echo foo\n");
+ fchmod (fd, 0700);
+ close (fd);
+}
+
+static int
+do_test (void)
+{
+ if (setenv ("PATH", test_dir, 1) != 0)
+ {
+ puts ("setenv failed");
+ return 1;
+ }
+
+ /* To limit stack allocation for argument construction in case of
+ script without shebang execvpe limits total number of argument
+ to NCARGS. */
+ const size_t max_args = NCARGS + 1;
+ char **args = malloc ((NCARGS + 1) * sizeof (char*));
+ if (args == NULL)
+ {
+ puts ("malloc failed");
+ return 1;
+ }
+
+ args[0] = fname;
+ for (int i=1; i < max_args; ++i)
+ args[i] = strdup ("a");
+ args[max_args] = NULL;
+
+ execvpe (basename (fname), args, NULL);
+
+ for (int i=1; i < max_args; ++i)
+ free (args[i]);
+ free (args);
+
+ if (errno != E2BIG)
+ {
+ printf ("errno = %d (%m), expected E2BIG\n", errno);
+ return 1;
+ }
+
+ return 0;
+}
This patch removes all the dynamic allocation on execvpe code and instead use direct stack allocation. This is QoI approach to make it possible use in scenarios where memory is shared with parent (vfork or clone with CLONE_VM). For default process spawn (script file without a shebang), stack allocation is bounded by NAME_MAX plus PATH_MAX plus 1. Large file arguments returns an error (ENAMETOOLONG). This differs than current GLIBC pratice in general, but it used to limit stack allocation for large inputs. Also, path in PATH environment variable larger than PATH_MAX are ignored. The shell direct execution exeception, where execve returns ENOEXEC, might requires a large stack allocation due large input argument list. Tested on i686, x86_64, powerpc64le, and aarch64. Changes from previous version: - Limit argument count in maybe_script_execute to avoid unbound stack allocation. Current limit is NCARGS (131072 for Linux). - Added testcases for execvpe based both on existing execvp and two new to test general e failed execution. * posix/execvpe.c (__execvpe): Remove dynamic allocation. * posix/Makefile (tests): Add tst-execvpe{1,2,3,4,5,6}. * posix/tst-execvp1.c (do_test): Use a macro to call execvp. * posix/tst-execvp2.c (do_test): Likewise. * posix/tst-execvp3.c (do_test): Likewise. * posix/tst-execvp4.c (do_test): Likewise. * posix/tst-execvpe1.c: New file. * posix/tst-execvpe2.c: Likewise. * posix/tst-execvpe3.c: Likewise. * posix/tst-execvpe4.c: Likewise. * posix/tst-execvpe5.c: Likewise. * posix/tst-execvpe6.c: Likewise. --- posix/Makefile | 3 + posix/execvpe.c | 241 ++++++++++++++++++++------------------------------- posix/tst-execvp1.c | 6 +- posix/tst-execvp2.c | 5 +- posix/tst-execvp3.c | 5 +- posix/tst-execvp4.c | 6 +- posix/tst-execvpe1.c | 20 +++++ posix/tst-execvpe2.c | 20 +++++ posix/tst-execvpe3.c | 20 +++++ posix/tst-execvpe4.c | 20 +++++ posix/tst-execvpe5.c | 130 +++++++++++++++++++++++++++ posix/tst-execvpe6.c | 82 ++++++++++++++++++ 13 files changed, 424 insertions(+), 149 deletions(-) create mode 100644 posix/tst-execvpe1.c create mode 100644 posix/tst-execvpe2.c create mode 100644 posix/tst-execvpe3.c create mode 100644 posix/tst-execvpe4.c create mode 100644 posix/tst-execvpe5.c create mode 100644 posix/tst-execvpe6.c -- 1.9.1