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authorJörg Frings-Fürst <debian@jff.email>2022-02-07 06:57:44 +0100
committerJörg Frings-Fürst <debian@jff.email>2022-02-07 06:57:44 +0100
commit6ffaa52cf732a84c0f8259dbc9b8183960ec5c33 (patch)
treed3136c22e3e805cfc0efe78412cce905a17e0c8d /lib/malloca.c
parent591cbf5878b7d4105b275585b9db1324c9dfce56 (diff)
parentaf151c593704a40e10efb28d1e3dd59a23a661f3 (diff)
Merge branch 'release/debian/1.0-1'debian/1.0-1
Diffstat (limited to 'lib/malloca.c')
-rw-r--r--lib/malloca.c51
1 files changed, 25 insertions, 26 deletions
diff --git a/lib/malloca.c b/lib/malloca.c
index 2ec944c..e7beaaf 100644
--- a/lib/malloca.c
+++ b/lib/malloca.c
@@ -1,28 +1,19 @@
/* Safe automatic memory allocation.
- Copyright (C) 2003, 2006-2007, 2009-2018 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2006-2007, 2009-2022 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003, 2018.
- This program is free software: you can redistribute it and/or
- modify it under the terms of either:
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
- * the GNU Lesser General Public License as published by the Free
- Software Foundation; either version 3 of the License, or (at your
- option) any later version.
-
- or
-
- * the GNU General Public License as published by the Free
- Software Foundation; either version 2 of the License, or (at your
- option) any later version.
-
- or both in parallel, as here.
- This program is distributed in the hope that it will be useful,
+ This file is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
+ GNU Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, see <https://www.gnu.org/licenses/>. */
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
#define _GL_USE_STDLIB_ALLOC 1
#include <config.h>
@@ -30,6 +21,8 @@
/* Specification. */
#include "malloca.h"
+#include "idx.h"
+#include "intprops.h"
#include "verify.h"
/* The speed critical point in this file is freea() applied to an alloca()
@@ -54,24 +47,30 @@ mmalloca (size_t n)
#if HAVE_ALLOCA
/* Allocate one more word, used to determine the address to pass to freea(),
and room for the alignment ≡ sa_alignment_max mod 2*sa_alignment_max. */
- size_t nplus = n + sizeof (small_t) + 2 * sa_alignment_max - 1;
-
- if (nplus >= n)
+ uintptr_t alignment2_mask = 2 * sa_alignment_max - 1;
+ int plus = sizeof (small_t) + alignment2_mask;
+ idx_t nplus;
+ if (!INT_ADD_WRAPV (n, plus, &nplus) && !xalloc_oversized (nplus, 1))
{
char *mem = (char *) malloc (nplus);
if (mem != NULL)
{
- char *p =
- (char *)((((uintptr_t)mem + sizeof (small_t) + sa_alignment_max - 1)
- & ~(uintptr_t)(2 * sa_alignment_max - 1))
- + sa_alignment_max);
+ uintptr_t umem = (uintptr_t)mem, umemplus;
+ /* The INT_ADD_WRAPV avoids signed integer overflow on
+ theoretical platforms where UINTPTR_MAX <= INT_MAX. */
+ INT_ADD_WRAPV (umem, sizeof (small_t) + sa_alignment_max - 1,
+ &umemplus);
+ idx_t offset = ((umemplus & ~alignment2_mask)
+ + sa_alignment_max - umem);
+ void *vp = mem + offset;
+ small_t *p = vp;
/* Here p >= mem + sizeof (small_t),
and p <= mem + sizeof (small_t) + 2 * sa_alignment_max - 1
hence p + n <= mem + nplus.
So, the memory range [p, p+n) lies in the allocated memory range
[mem, mem + nplus). */
- ((small_t *) p)[-1] = p - mem;
+ p[-1] = offset;
/* p ≡ sa_alignment_max mod 2*sa_alignment_max. */
return p;
}