Page Menu
Home
FreeBSD
Search
Configure Global Search
Log In
Files
F144560232
D25038.id72387.diff
No One
Temporary
Actions
View File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Flag For Later
Award Token
Size
3 KB
Referenced Files
None
Subscribers
None
D25038.id72387.diff
View Options
Index: lib/libc/gen/exec.c
===================================================================
--- lib/libc/gen/exec.c
+++ lib/libc/gen/exec.c
@@ -49,6 +49,9 @@
extern char **environ;
+static const char execvPe_err_preamble[] = "execvP: ";
+static const char execvPe_err_trailer[] = ": path too long\n";
+
int
execl(const char *name, const char *arg, ...)
{
@@ -149,8 +152,8 @@
const char **memp;
size_t cnt, lp, ln;
int eacces, save_errno;
- char *cur, buf[MAXPATHLEN];
- const char *p, *bp;
+ char buf[MAXPATHLEN];
+ const char *bp, *np, *op, *p;
struct stat sb;
eacces = 0;
@@ -158,7 +161,7 @@
/* If it's an absolute or relative path name, it's easy. */
if (strchr(name, '/')) {
bp = name;
- cur = NULL;
+ op = NULL;
goto retry;
}
bp = buf;
@@ -169,23 +172,24 @@
return (-1);
}
- cur = alloca(strlen(path) + 1);
- if (cur == NULL) {
- errno = ENOMEM;
- return (-1);
- }
- strcpy(cur, path);
- while ((p = strsep(&cur, ":")) != NULL) {
+ op = path;
+ ln = strlen(name);
+ while (op != NULL) {
+ np = strchrnul(op, ':');
+
/*
* It's a SHELL path -- double, leading and trailing colons
* mean the current directory.
*/
- if (*p == '\0') {
+ if (np == op) {
+ /* Empty component. */
p = ".";
lp = 1;
- } else
- lp = strlen(p);
- ln = strlen(name);
+ } else {
+ /* Non-empty component. */
+ p = op;
+ lp = np - op;
+ }
/*
* If the path is too long complain. This is a possible
@@ -193,10 +197,11 @@
* the user may execute the wrong program.
*/
if (lp + ln + 2 > sizeof(buf)) {
- (void)_write(STDERR_FILENO, "execvP: ", 8);
+ (void)_write(STDERR_FILENO, execvPe_err_preamble,
+ sizeof(execvPe_err_preamble) - 1);
(void)_write(STDERR_FILENO, p, lp);
- (void)_write(STDERR_FILENO, ": path too long\n",
- 16);
+ (void)_write(STDERR_FILENO, execvPe_err_trailer,
+ sizeof(execvPe_err_trailer) - 1);
continue;
}
bcopy(p, buf, lp);
@@ -204,6 +209,12 @@
bcopy(name, buf + lp + 1, ln);
buf[lp + ln + 1] = '\0';
+ /* Advance to the next component or terminate after this. */
+ if (*np == '\0')
+ op = NULL;
+ else
+ op = np + 1;
+
retry: (void)_execve(bp, argv, envp);
switch (errno) {
case E2BIG:
Index: lib/libc/gen/posix_spawn.c
===================================================================
--- lib/libc/gen/posix_spawn.c
+++ lib/libc/gen/posix_spawn.c
@@ -246,8 +246,23 @@
pid_t p;
#ifdef _RFORK_THREAD_STACK_SIZE
char *stack;
-
- stack = malloc(_RFORK_THREAD_STACK_SIZE);
+ size_t cnt, stacksz;
+
+ stacksz = _RFORK_THREAD_STACK_SIZE;
+ if (use_env_path) {
+ /*
+ * We need to make sure we have enough room on the stack for the
+ * potential alloca() in execvPe if it gets kicked back an
+ * ENOEXEC from execve(2), plus the original buffer we gave
+ * ourselves; this protects us in the event that the caller
+ * intentionally or inadvertently supplies enough arguments to
+ * make us blow past the stack we've allocated from it.
+ */
+ stacksz += (2 * sizeof(char *));
+ for (cnt = 0; argv[cnt] != NULL; ++cnt)
+ stacksz += sizeof(char *);
+ }
+ stack = malloc(stacksz);
if (stack == NULL)
return (ENOMEM);
#endif
@@ -273,8 +288,7 @@
* parent. Because of this, we must use rfork_thread instead while
* almost every other arch stores the return address in a register.
*/
- p = rfork_thread(RFSPAWN, stack + _RFORK_THREAD_STACK_SIZE,
- _posix_spawn_thr, &psa);
+ p = rfork_thread(RFSPAWN, stack + stacksz, _posix_spawn_thr, &psa);
free(stack);
#else
p = rfork(RFSPAWN);
File Metadata
Details
Attached
Mime Type
text/plain
Expires
Tue, Feb 10, 2:20 PM (3 h, 58 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
28626043
Default Alt Text
D25038.id72387.diff (3 KB)
Attached To
Mode
D25038: execvPe: obviate the need for potentially large stack allocations
Attached
Detach File
Event Timeline
Log In to Comment