diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | posix/execl.c | 68 | ||||
| -rw-r--r-- | posix/execle.c | 70 | ||||
| -rw-r--r-- | posix/execlp.c | 66 |
4 files changed, 86 insertions, 125 deletions
diff --git a/ChangeLog b/ChangeLog index 12b88fdb3a..45fb9cad15 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2016-03-07 Adhemerval Zanella <adhemerval.zanella@linaro.org> + + [BZ #19534] + * posix/execl.c (execl): Remove dynamic memory allocation. + * posix/execle.c (execle): Likewise. + * posix/execlp.c (execlp): Likewise. + 2016-03-06 H.J. Lu <hongjiu.lu@intel.com> * sysdeps/x86_64/multiarch/memcpy-avx512-no-vzeroupper.S: diff --git a/posix/execl.c b/posix/execl.c index 102d19d9af..75aa190b1c 100644 --- a/posix/execl.c +++ b/posix/execl.c @@ -16,58 +16,42 @@ <http://www.gnu.org/licenses/>. */ #include <unistd.h> +#include <errno.h> #include <stdarg.h> -#include <stddef.h> -#include <stdlib.h> -#include <string.h> - -#include <stackinfo.h> - +#include <sys/param.h> /* Execute PATH with all arguments after PATH until a NULL pointer and environment from `environ'. */ int execl (const char *path, const char *arg, ...) { -#define INITIAL_ARGV_MAX 1024 - size_t argv_max = INITIAL_ARGV_MAX; - const char *initial_argv[INITIAL_ARGV_MAX]; - const char **argv = initial_argv; - va_list args; - - argv[0] = arg; - - va_start (args, arg); - unsigned int i = 0; - while (argv[i++] != NULL) + ptrdiff_t argc; + va_list ap; + va_start (ap, arg); + for (argc = 1; va_arg (ap, const char *); argc++) { - if (i == argv_max) + if (argc == INT_MAX) { - argv_max *= 2; - const char **nptr = realloc (argv == initial_argv ? NULL : argv, - argv_max * sizeof (const char *)); - if (nptr == NULL) - { - if (argv != initial_argv) - free (argv); - va_end (args); - return -1; - } - if (argv == initial_argv) - /* We have to copy the already filled-in data ourselves. */ - memcpy (nptr, argv, i * sizeof (const char *)); - - argv = nptr; + va_end (ap); + errno = E2BIG; + return -1; } - - argv[i] = va_arg (args, const char *); } - va_end (args); - - int ret = __execve (path, (char *const *) argv, __environ); - if (argv != initial_argv) - free (argv); - - return ret; + va_end (ap); + + /* Avoid dynamic memory allocation due two main issues: + 1. The function should be async-signal-safe and a running on a signal + handler with a fail outcome might lead to malloc bad state. + 2. It might be used in a vfork/clone(VFORK) scenario where using + malloc also might lead to internal bad state. */ + ptrdiff_t i; + char *argv[argc + 1]; + va_start (ap, arg); + argv[0] = (char *) arg; + for (i = 1; i <= argc; i++) + argv[i] = va_arg (ap, char *); + va_end (ap); + + return __execve (path, argv, __environ); } libc_hidden_def (execl) diff --git a/posix/execle.c b/posix/execle.c index 8edc03a84a..50e843e7d7 100644 --- a/posix/execle.c +++ b/posix/execle.c @@ -17,57 +17,43 @@ #include <unistd.h> #include <stdarg.h> -#include <stddef.h> -#include <stdlib.h> -#include <string.h> - -#include <stackinfo.h> +#include <errno.h> +#include <sys/param.h> /* Execute PATH with all arguments after PATH until a NULL pointer, and the argument after that for environment. */ int execle (const char *path, const char *arg, ...) { -#define INITIAL_ARGV_MAX 1024 - size_t argv_max = INITIAL_ARGV_MAX; - const char *initial_argv[INITIAL_ARGV_MAX]; - const char **argv = initial_argv; - va_list args; - argv[0] = arg; - - va_start (args, arg); - unsigned int i = 0; - while (argv[i++] != NULL) + ptrdiff_t argc; + va_list ap; + va_start (ap, arg); + for (argc = 1; va_arg (ap, const char *); argc++) { - if (i == argv_max) + if (argc == INT_MAX) { - argv_max *= 2; - const char **nptr = realloc (argv == initial_argv ? NULL : argv, - argv_max * sizeof (const char *)); - if (nptr == NULL) - { - if (argv != initial_argv) - free (argv); - va_end (args); - return -1; - } - if (argv == initial_argv) - /* We have to copy the already filled-in data ourselves. */ - memcpy (nptr, argv, i * sizeof (const char *)); - - argv = nptr; + va_end (ap); + errno = E2BIG; + return -1; } - - argv[i] = va_arg (args, const char *); } - - const char *const *envp = va_arg (args, const char *const *); - va_end (args); - - int ret = __execve (path, (char *const *) argv, (char *const *) envp); - if (argv != initial_argv) - free (argv); - - return ret; + va_end (ap); + + /* Avoid dynamic memory allocation due two main issues: + 1. The function should be async-signal-safe and a running on a signal + handler with a fail outcome might lead to malloc bad state. + 2. It might be used in a vfork/clone(VFORK) scenario where using + malloc also might lead to internal bad state. */ + ptrdiff_t i; + char *argv[argc + 1]; + char **envp; + va_start (ap, arg); + argv[0] = (char *) arg; + for (i = 1; i <= argc; i++) + argv[i] = va_arg (ap, char *); + envp = va_arg (ap, char **); + va_end (ap); + + return __execve (path, argv, envp); } libc_hidden_def (execle) diff --git a/posix/execlp.c b/posix/execlp.c index 6700994a5b..d292d97dc3 100644 --- a/posix/execlp.c +++ b/posix/execlp.c @@ -17,11 +17,8 @@ #include <unistd.h> #include <stdarg.h> -#include <stddef.h> -#include <stdlib.h> -#include <string.h> - -#include <stackinfo.h> +#include <errno.h> +#include <sys/param.h> /* Execute FILE, searching in the `PATH' environment variable if it contains no slashes, with all arguments after FILE until a @@ -29,45 +26,32 @@ int execlp (const char *file, const char *arg, ...) { -#define INITIAL_ARGV_MAX 1024 - size_t argv_max = INITIAL_ARGV_MAX; - const char *initial_argv[INITIAL_ARGV_MAX]; - const char **argv = initial_argv; - va_list args; - - argv[0] = arg; - - va_start (args, arg); - unsigned int i = 0; - while (argv[i++] != NULL) + ptrdiff_t argc; + va_list ap; + va_start (ap, arg); + for (argc = 1; va_arg (ap, const char *); argc++) { - if (i == argv_max) + if (argc == INT_MAX) { - argv_max *= 2; - const char **nptr = realloc (argv == initial_argv ? NULL : argv, - argv_max * sizeof (const char *)); - if (nptr == NULL) - { - if (argv != initial_argv) - free (argv); - va_end (args); - return -1; - } - if (argv == initial_argv) - /* We have to copy the already filled-in data ourselves. */ - memcpy (nptr, argv, i * sizeof (const char *)); - - argv = nptr; + va_end (ap); + errno = E2BIG; + return -1; } - - argv[i] = va_arg (args, const char *); } - va_end (args); - - int ret = execvp (file, (char *const *) argv); - if (argv != initial_argv) - free (argv); - - return ret; + va_end (ap); + + /* Although posix does not state execlp as an async-safe function + it can not use malloc to allocate the arguments since it might + be used in a vfork scenario and it may lead to malloc internal + bad state. */ + ptrdiff_t i; + char *argv[argc + 1]; + va_start (ap, arg); + argv[0] = (char *) arg; + for (i = 1; i <= argc; i++) + argv[i] = va_arg (ap, char *); + va_end (ap); + + return __execvpe (file, argv, __environ); } libc_hidden_def (execlp) |