glibc/posix/tst-execvp2.c
Adhemerval Zanella 1eb8930608 posix: execvpe cleanup
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.

	* 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.
2016-03-07 00:21:37 -03:00

86 lines
1.5 KiB
C

#include <errno.h>
#include <libgen.h>
#undef basename
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
static void prepare (int argc, char *argv[]);
static int do_test (void);
#define PREPARE(argc, argv) prepare (argc, argv)
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"
#ifndef EXECVP
# define EXECVP(file, argv) execvp (file, argv)
#endif
static char *copy;
static void
prepare (int argc, char *argv[])
{
char *buf;
int off;
asprintf (&buf, "cp %s %n%s-copy", argv[0], &off, argv[0]);
if (buf == NULL)
{
puts ("asprintf failed");
exit (1);
}
if (system (buf) != 0)
{
puts ("system failed");
exit (1);
}
/* Make it not executable. */
copy = buf + off;
if (chmod (copy, 0666) != 0)
{
puts ("chmod failed");
exit (1);
}
add_temp_file (copy);
}
static int
do_test (void)
{
/* Make sure we do not find a binary with the name we are going to
use. */
char *bindir = strdupa (copy);
bindir = canonicalize_file_name (dirname (bindir));
if (bindir == NULL)
{
puts ("canonicalize_file_name failed");
return 1;
}
char *path;
asprintf (&path, "%s:../libio:../elf", bindir);
if (path == NULL)
{
puts ("asprintf failed");
return 1;
}
setenv ("PATH", path, 1);
char *argv[] = { basename (copy), NULL };
errno = 0;
EXECVP (argv[0], argv);
if (errno != EACCES)
{
printf ("errno = %d (%m), expected EACCES\n", errno);
return 1;
}
return 0;
}