From f15ce4d8dc139523fe0c273580b604b2453acba6 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Mon, 9 Aug 2010 21:09:37 -0700 Subject: Avoid too much stack use in fnmatch. --- posix/fnmatch.c | 57 +++++++++++++++++----- posix/fnmatch_loop.c | 132 ++++++++++++++++++++++++++++++++------------------- 2 files changed, 128 insertions(+), 61 deletions(-) (limited to 'posix') diff --git a/posix/fnmatch.c b/posix/fnmatch.c index 4baef9e..0af5ee6 100644 --- a/posix/fnmatch.c +++ b/posix/fnmatch.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1991,1992,1993,1996,1997,1998,1999,2000,2001,2002,2003,2007 +/* Copyright (C) 1991,1992,1993,1996,1997,1998,1999,2000,2001,2002,2003,2007,2010 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -41,6 +41,12 @@ # include #endif +#ifdef _LIBC +# include +#else +# define alloca_account(size., var) alloca (size) +#endif + /* For platform which support the ISO C amendement 1 functionality we support user defined character classes. */ #if defined _LIBC || (defined HAVE_WCTYPE_H && defined HAVE_WCHAR_H) @@ -330,8 +336,11 @@ fnmatch (pattern, string, flags) mbstate_t ps; size_t n; const char *p; + wchar_t *wpattern_malloc = NULL; wchar_t *wpattern; + wchar_t *wstring_malloc = NULL; wchar_t *wstring; + size_t alloca_used = 0; /* Convert the strings into wide characters. */ memset (&ps, '\0', sizeof (ps)); @@ -343,7 +352,8 @@ fnmatch (pattern, string, flags) #endif if (__builtin_expect (n < 1024, 1)) { - wpattern = (wchar_t *) alloca ((n + 1) * sizeof (wchar_t)); + wpattern = (wchar_t *) alloca_account ((n + 1) * sizeof (wchar_t), + alloca_used); n = mbsrtowcs (wpattern, &p, n + 1, &ps); if (__builtin_expect (n == (size_t) -1, 0)) /* Something wrong. @@ -365,8 +375,11 @@ fnmatch (pattern, string, flags) XXX Do we have to set `errno' to something which mbsrtows hasn't already done? */ return -1; - wpattern = (wchar_t *) alloca ((n + 1) * sizeof (wchar_t)); + wpattern_malloc = wpattern + = (wchar_t *) malloc ((n + 1) * sizeof (wchar_t)); assert (mbsinit (&ps)); + if (wpattern == NULL) + return -2; (void) mbsrtowcs (wpattern, &pattern, n + 1, &ps); } @@ -379,13 +392,18 @@ fnmatch (pattern, string, flags) p = string; if (__builtin_expect (n < 1024, 1)) { - wstring = (wchar_t *) alloca ((n + 1) * sizeof (wchar_t)); + wstring = (wchar_t *) alloca_account ((n + 1) * sizeof (wchar_t), + alloca_used); n = mbsrtowcs (wstring, &p, n + 1, &ps); if (__builtin_expect (n == (size_t) -1, 0)) - /* Something wrong. - XXX Do we have to set `errno' to something which mbsrtows hasn't - already done? */ - return -1; + { + /* Something wrong. + XXX Do we have to set `errno' to something which + mbsrtows hasn't already done? */ + free_return: + free (wpattern_malloc); + return -1; + } if (p) { memset (&ps, '\0', sizeof (ps)); @@ -400,19 +418,32 @@ fnmatch (pattern, string, flags) /* Something wrong. XXX Do we have to set `errno' to something which mbsrtows hasn't already done? */ - return -1; - wstring = (wchar_t *) alloca ((n + 1) * sizeof (wchar_t)); + goto free_return; + + wstring_malloc = wstring + = (wchar_t *) malloc ((n + 1) * sizeof (wchar_t)); + if (wstring == NULL) + { + free (wpattern_malloc); + return -2; + } assert (mbsinit (&ps)); (void) mbsrtowcs (wstring, &string, n + 1, &ps); } - return internal_fnwmatch (wpattern, wstring, wstring + n, - flags & FNM_PERIOD, flags, NULL); + int res = internal_fnwmatch (wpattern, wstring, wstring + n, + flags & FNM_PERIOD, flags, NULL, + alloca_used); + + free (wstring_malloc); + free (wpattern_malloc); + + return res; } # endif /* mbstate_t and mbsrtowcs or _LIBC. */ return internal_fnmatch (pattern, string, string + strlen (string), - flags & FNM_PERIOD, flags, NULL); + flags & FNM_PERIOD, flags, NULL, 0); } # ifdef _LIBC diff --git a/posix/fnmatch_loop.c b/posix/fnmatch_loop.c index 67c0ee4..c8e52a6 100644 --- a/posix/fnmatch_loop.c +++ b/posix/fnmatch_loop.c @@ -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; } -- cgit v1.1