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Avoid too much stack use in fnmatch.

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This commit is contained in:
Ulrich Drepper
2010-08-09 21:09:37 -07:00
parent d22e4cc939
commit f15ce4d8dc
4 changed files with 136 additions and 63 deletions
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132
posix/fnmatch_loop.c
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@@ -1,4 +1,4 @@
/* Copyright (C) 1991-1993,1996-2001,2003-2005,2007
/* Copyright (C) 1991-1993,1996-2001,2003-2005,2007,2010
Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -28,22 +28,24 @@ struct STRUCT
it matches, nonzero if not. */
static int FCT (const CHAR *pattern, const CHAR *string,
const CHAR *string_end, int no_leading_period, int flags,
struct STRUCT *ends)
struct STRUCT *ends, size_t alloca_used)
internal_function;
static int EXT (INT opt, const CHAR *pattern, const CHAR *string,
const CHAR *string_end, int no_leading_period, int flags)
const CHAR *string_end, int no_leading_period, int flags,
size_t alloca_used)
internal_function;
static const CHAR *END (const CHAR *patternp) internal_function;
static int
internal_function
FCT (pattern, string, string_end, no_leading_period, flags, ends)
FCT (pattern, string, string_end, no_leading_period, flags, ends, alloca_used)
const CHAR *pattern;
const CHAR *string;
const CHAR *string_end;
int no_leading_period;
int flags;
struct STRUCT *ends;
size_t alloca_used;
{
register const CHAR *p = pattern, *n = string;
register UCHAR c;
@@ -67,10 +69,8 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
case L('?'):
if (__builtin_expect (flags & FNM_EXTMATCH, 0) && *p == '(')
{
int res;
res = EXT (c, p, n, string_end, no_leading_period,
flags);
int res = EXT (c, p, n, string_end, no_leading_period,
flags, alloca_used);
if (res != -1)
return res;
}
@@ -99,10 +99,8 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
case L('*'):
if (__builtin_expect (flags & FNM_EXTMATCH, 0) && *p == '(')
{
int res;
res = EXT (c, p, n, string_end, no_leading_period,
flags);
int res = EXT (c, p, n, string_end, no_leading_period,
flags, alloca_used);
if (res != -1)
return res;
}
@@ -191,7 +189,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
for (--p; n < endp; ++n, no_leading_period = 0)
if (FCT (p, n, string_end, no_leading_period, flags2,
&end) == 0)
&end, alloca_used) == 0)
goto found;
}
else if (c == L('/') && (flags & FNM_FILE_NAME))
@@ -200,7 +198,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
++n;
if (n < string_end && *n == L('/')
&& (FCT (p, n + 1, string_end, flags & FNM_PERIOD, flags,
NULL) == 0))
NULL, alloca_used) == 0))
return 0;
}
else
@@ -214,7 +212,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
for (--p; n < endp; ++n, no_leading_period = 0)
if (FOLD ((UCHAR) *n) == c
&& (FCT (p, n, string_end, no_leading_period, flags2,
&end) == 0))
&end, alloca_used) == 0))
{
found:
if (end.pattern == NULL)
@@ -749,7 +747,7 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
_NL_COLLATE_SYMB_EXTRAMB);
/* Locate the character in the hashing
table. */
table. */
hash = elem_hash (str, c1);
idx = 0;
@@ -971,9 +969,8 @@ FCT (pattern, string, string_end, no_leading_period, flags, ends)
case L('!'):
if (__builtin_expect (flags & FNM_EXTMATCH, 0) && *p == '(')
{
int res;
res = EXT (c, p, n, string_end, no_leading_period, flags);
int res = EXT (c, p, n, string_end, no_leading_period, flags,
alloca_used);
if (res != -1)
return res;
}
@@ -1052,26 +1049,32 @@ END (const CHAR *pattern)
static int
internal_function
EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
int no_leading_period, int flags)
int no_leading_period, int flags, size_t alloca_used)
{
const CHAR *startp;
int level;
struct patternlist
{
struct patternlist *next;
CHAR malloced;
CHAR str[0];
} *list = NULL;
struct patternlist **lastp = &list;
size_t pattern_len = STRLEN (pattern);
int any_malloced = 0;
const CHAR *p;
const CHAR *rs;
int retval = 0;
/* Parse the pattern. Store the individual parts in the list. */
level = 0;
for (startp = p = pattern + 1; level >= 0; ++p)
if (*p == L('\0'))
/* This is an invalid pattern. */
return -1;
{
/* This is an invalid pattern. */
retval = -1;
goto out;
}
else if (*p == L('['))
{
/* Handle brackets special. */
@@ -1088,8 +1091,11 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
/* Skip over all characters of the list. */
while (*p != L(']'))
if (*p++ == L('\0'))
/* This is no valid pattern. */
return -1;
{
/* This is no valid pattern. */
retval = -1;
goto out;
}
}
else if ((*p == L('?') || *p == L('*') || *p == L('+') || *p == L('@')
|| *p == L('!')) && p[1] == L('('))
@@ -1102,15 +1108,27 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
/* This means we found the end of the pattern. */
#define NEW_PATTERN \
struct patternlist *newp; \
\
if (opt == L('?') || opt == L('@')) \
newp = alloca (sizeof (struct patternlist) \
+ (pattern_len * sizeof (CHAR))); \
size_t slen = (opt == L('?') || opt == L('@') \
? pattern_len : (p - startp + 1)); \
slen = sizeof (struct patternlist) + (slen * sizeof (CHAR)); \
int malloced = ! __libc_use_alloca (alloca_used + slen); \
if (__builtin_expect (malloced, 0)) \
{ \
newp = alloca_account (slen, alloca_used); \
any_malloced = 1; \
} \
else \
newp = alloca (sizeof (struct patternlist) \
+ ((p - startp + 1) * sizeof (CHAR))); \
*((CHAR *) MEMPCPY (newp->str, startp, p - startp)) = L('\0'); \
{ \
newp = malloc (slen); \
if (newp == NULL) \
{ \
retval = -2; \
goto out; \
} \
} \
newp->next = NULL; \
newp->malloced = malloced; \
*((CHAR *) MEMPCPY (newp->str, startp, p - startp)) = L('\0'); \
*lastp = newp; \
lastp = &newp->next
NEW_PATTERN;
@@ -1131,8 +1149,9 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
switch (opt)
{
case L('*'):
if (FCT (p, string, string_end, no_leading_period, flags, NULL) == 0)
return 0;
if (FCT (p, string, string_end, no_leading_period, flags, NULL,
alloca_used) == 0)
goto success;
/* FALLTHROUGH */
case L('+'):
@@ -1143,7 +1162,7 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
current pattern. */
if (FCT (list->str, string, rs, no_leading_period,
flags & FNM_FILE_NAME ? flags : flags & ~FNM_PERIOD,
NULL) == 0
NULL, alloca_used) == 0
/* This was successful. Now match the rest with the rest
of the pattern. */
&& (FCT (p, rs, string_end,
@@ -1151,7 +1170,7 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
? no_leading_period
: rs[-1] == '/' && NO_LEADING_PERIOD (flags) ? 1 : 0,
flags & FNM_FILE_NAME
? flags : flags & ~FNM_PERIOD, NULL) == 0
? flags : flags & ~FNM_PERIOD, NULL, alloca_used) == 0
/* This didn't work. Try the whole pattern. */
|| (rs != string
&& FCT (pattern - 1, rs, string_end,
@@ -1160,18 +1179,21 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
: (rs[-1] == '/' && NO_LEADING_PERIOD (flags)
? 1 : 0),
flags & FNM_FILE_NAME
? flags : flags & ~FNM_PERIOD, NULL) == 0)))
? flags : flags & ~FNM_PERIOD, NULL,
alloca_used) == 0)))
/* It worked. Signal success. */
return 0;
goto success;
}
while ((list = list->next) != NULL);
/* None of the patterns lead to a match. */
return FNM_NOMATCH;
retval = FNM_NOMATCH;
break;
case L('?'):
if (FCT (p, string, string_end, no_leading_period, flags, NULL) == 0)
return 0;
if (FCT (p, string, string_end, no_leading_period, flags, NULL,
alloca_used) == 0)
goto success;
/* FALLTHROUGH */
case L('@'):
@@ -1183,13 +1205,14 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
if (FCT (STRCAT (list->str, p), string, string_end,
no_leading_period,
flags & FNM_FILE_NAME ? flags : flags & ~FNM_PERIOD,
NULL) == 0)
NULL, alloca_used) == 0)
/* It worked. Signal success. */
return 0;
goto success;
while ((list = list->next) != NULL);
/* None of the patterns lead to a match. */
return FNM_NOMATCH;
retval = FNM_NOMATCH;
break;
case L('!'):
for (rs = string; rs <= string_end; ++rs)
@@ -1199,7 +1222,7 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
for (runp = list; runp != NULL; runp = runp->next)
if (FCT (runp->str, string, rs, no_leading_period,
flags & FNM_FILE_NAME ? flags : flags & ~FNM_PERIOD,
NULL) == 0)
NULL, alloca_used) == 0)
break;
/* If none of the patterns matched see whether the rest does. */
@@ -1209,21 +1232,34 @@ EXT (INT opt, const CHAR *pattern, const CHAR *string, const CHAR *string_end,
? no_leading_period
: rs[-1] == '/' && NO_LEADING_PERIOD (flags) ? 1 : 0,
flags & FNM_FILE_NAME ? flags : flags & ~FNM_PERIOD,
NULL) == 0))
NULL, alloca_used) == 0))
/* This is successful. */
return 0;
goto success;
}
/* None of the patterns together with the rest of the pattern
lead to a match. */
return FNM_NOMATCH;
retval = FNM_NOMATCH;
break;
default:
assert (! "Invalid extended matching operator");
retval = -1;
break;
}
return -1;
success:
out:
if (any_malloced)
while (list != NULL)
{
struct patternlist *old = list;
list = list->next;
if (old->malloced)
free (old);
}
return retval;
}