GNU GLOB_BRACE internal implementation constructs a new expression and
calls glob recursively. It then requires a possible large temporary
buffer place the new pattern.
This patch removes the alloca/malloc usage and replaces it with
char_array.
Checked on x86_64-linux-gnu.
---
posix/glob.c | 53 ++++++++++++++++++++++++++++------------------------
1 file changed, 29 insertions(+), 24 deletions(-)
diff --git a/posix/glob.c b/posix/glob.c
index 8c6e1914c5..41e1aeacad 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -382,25 +382,23 @@ __glob (const char *pattern, int flags, int (*errfunc)
(const char *, int),
/* Allocate working buffer large enough for our work. Note that
we have at least an opening and closing brace. */
size_t firstc;
- char *alt_start;
const char *p;
const char *next;
const char *rest;
size_t rest_len;
- char *onealt;
- size_t pattern_len = strlen (pattern) - 1;
- int alloca_onealt = glob_use_alloca (alloca_used, pattern_len);
- if (alloca_onealt)
- onealt = alloca_account (pattern_len, alloca_used);
- else
- {
- onealt = malloc (pattern_len);
- if (onealt == NULL)
- goto err_nospace;
- }
+ struct char_array onealt;
/* We know the prefix for all sub-patterns. */
- alt_start = mempcpy (onealt, pattern, begin - pattern);
+ ptrdiff_t onealtlen = begin - pattern;
+ if (!char_array_init_str_size (&onealt, pattern, onealtlen))
+ {
+ if (!(flags & GLOB_APPEND))
+ {
+ pglob->gl_pathc = 0;
+ pglob->gl_pathv = NULL;
+ }
+ goto err_nospace;
+ }
/* Find the first sub-pattern and at the same time find the
rest after the closing brace. */
@@ -408,9 +406,7 @@ __glob (const char *pattern, int flags, int (*errfunc)
(const char *, int),
if (next == NULL)
{
/* It is an invalid expression. */
- illegal_brace:
- if (__glibc_unlikely (!alloca_onealt))
- free (onealt);
+ char_array_free (&onealt);
flags &= ~GLOB_BRACE;
goto no_brace;
}
@@ -421,8 +417,12 @@ __glob (const char *pattern, int flags, int (*errfunc)
(const char *, int),
{
rest = next_brace_sub (rest + 1, flags);
if (rest == NULL)
- /* It is an illegal expression. */
- goto illegal_brace;
+ {
+ /* It is an illegal expression. */
+ char_array_free (&onealt);
+ flags &= ~GLOB_BRACE;
+ goto no_brace;
+ }
}
/* Please note that we now can be sure the brace expression
is well-formed. */
@@ -441,9 +441,16 @@ __glob (const char *pattern, int flags, int (*errfunc)
(const char *, int),
int result;
/* Construct the new glob expression. */
- mempcpy (mempcpy (alt_start, p, next - p), rest, rest_len);
+ ptrdiff_t nextlen = next - p;
+ if (!char_array_replace_str_pos (&onealt, onealtlen, p, nextlen)
+ || !char_array_replace_str_pos (&onealt, onealtlen + nextlen,
+ rest, rest_len))
+ {
+ char_array_free (&onealt);
+ goto err_nospace;
+ }
- result = __glob (onealt,
+ result = __glob (char_array_str (&onealt),
((flags & ~(GLOB_NOCHECK | GLOB_NOMAGIC))
| GLOB_APPEND),
errfunc, pglob);
@@ -451,8 +458,7 @@ __glob (const char *pattern, int flags, int (*errfunc)
(const char *, int),
/* If we got an error, return it. */
if (result && result != GLOB_NOMATCH)
{
- if (__glibc_unlikely (!alloca_onealt))
- free (onealt);
+ char_array_free (&onealt);
if (!(flags & GLOB_APPEND))
{
globfree (pglob);
@@ -471,8 +477,7 @@ __glob (const char *pattern, int flags, int (*errfunc)
(const char *, int),
assert (next != NULL);
}
- if (__glibc_unlikely (!alloca_onealt))
- free (onealt);
+ char_array_free (&onealt);
if (pglob->gl_pathc != firstc)
/* We found some entries. */
--
2.25.1
