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9bf8e29ca1
As discussed previously on libc-alpha [1], this patch follows up the idea and add both the __attribute_alloc_size__ on malloc functions (malloc, calloc, realloc, reallocarray, valloc, pvalloc, and memalign) and limit maximum requested allocation size to up PTRDIFF_MAX (taking into consideration internal padding and alignment). This aligns glibc with gcc expected size defined by default warning -Walloc-size-larger-than value which warns for allocation larger than PTRDIFF_MAX. It also aligns with gcc expectation regarding libc and expected size, such as described in PR#67999 [2] and previously discussed ISO C11 issues [3] on libc-alpha. From the RFC thread [4] and previous discussion, it seems that consensus is only to limit such requested size for malloc functions, not the system allocation one (mmap, sbrk, etc.). The implementation changes checked_request2size to check for both overflow and maximum object size up to PTRDIFF_MAX. No additional checks are done on sysmalloc, so it can still issue mmap with values larger than PTRDIFF_T depending on the requested size. The __attribute_alloc_size__ is for functions that return a pointer only, which means it cannot be applied to posix_memalign (see remarks in GCC PR#87683 [5]). The runtimes checks to limit maximum requested allocation size does applies to posix_memalign. Checked on x86_64-linux-gnu and i686-linux-gnu. [1] https://sourceware.org/ml/libc-alpha/2018-11/msg00223.html [2] https://gcc.gnu.org/bugzilla//show_bug.cgi?id=67999 [3] https://sourceware.org/ml/libc-alpha/2011-12/msg00066.html [4] https://sourceware.org/ml/libc-alpha/2018-11/msg00224.html [5] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87683 [BZ #23741] * malloc/hooks.c (malloc_check, realloc_check): Use __builtin_add_overflow on overflow check and adapt to checked_request2size change. * malloc/malloc.c (__libc_malloc, __libc_realloc, _mid_memalign, __libc_pvalloc, __libc_calloc, _int_memalign): Limit maximum allocation size to PTRDIFF_MAX. (REQUEST_OUT_OF_RANGE): Remove macro. (checked_request2size): Change to inline function and limit maximum requested size to PTRDIFF_MAX. (__libc_malloc, __libc_realloc, _int_malloc, _int_memalign): Limit maximum allocation size to PTRDIFF_MAX. (_mid_memalign): Use _int_memalign call for overflow check. (__libc_pvalloc): Use __builtin_add_overflow on overflow check. (__libc_calloc): Use __builtin_mul_overflow for overflow check and limit maximum requested size to PTRDIFF_MAX. * malloc/malloc.h (malloc, calloc, realloc, reallocarray, memalign, valloc, pvalloc): Add __attribute_alloc_size__. * stdlib/stdlib.h (malloc, realloc, reallocarray, valloc): Likewise. * malloc/tst-malloc-too-large.c (do_test): Add check for allocation larger than PTRDIFF_MAX. * malloc/tst-memalign.c (do_test): Disable -Walloc-size-larger-than= around tests of malloc with negative sizes. * malloc/tst-posix_memalign.c (do_test): Likewise. * malloc/tst-pvalloc.c (do_test): Likewise. * malloc/tst-valloc.c (do_test): Likewise. * malloc/tst-reallocarray.c (do_test): Replace call to reallocarray with resulting size allocation larger than PTRDIFF_MAX with reallocarray_nowarn. (reallocarray_nowarn): New function. * NEWS: Mention the malloc function semantic change.
125 lines
3.0 KiB
C
125 lines
3.0 KiB
C
/* Test for memalign.
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Copyright (C) 2013-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <malloc.h>
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#include <stdio.h>
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#include <string.h>
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#include <unistd.h>
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#include <libc-diag.h>
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static int errors = 0;
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static void
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merror (const char *msg)
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{
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++errors;
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printf ("Error: %s\n", msg);
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}
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static int
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do_test (void)
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{
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void *p;
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unsigned long pagesize = getpagesize ();
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unsigned long ptrval;
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int save;
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errno = 0;
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DIAG_PUSH_NEEDS_COMMENT;
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#if __GNUC_PREREQ (7, 0)
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/* GCC 7 warns about too-large allocations; here we want to test
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that they fail. */
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DIAG_IGNORE_NEEDS_COMMENT (7, "-Walloc-size-larger-than=");
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#endif
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/* An attempt to allocate a huge value should return NULL and set
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errno to ENOMEM. */
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p = memalign (sizeof (void *), -1);
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#if __GNUC_PREREQ (7, 0)
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DIAG_POP_NEEDS_COMMENT;
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#endif
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save = errno;
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if (p != NULL)
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merror ("memalign (sizeof (void *), -1) succeeded.");
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if (p == NULL && save != ENOMEM)
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merror ("memalign (sizeof (void *), -1) errno is not set correctly");
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free (p);
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errno = 0;
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/* Test to expose integer overflow in malloc internals from BZ #15857. */
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p = memalign (pagesize, -pagesize);
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save = errno;
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if (p != NULL)
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merror ("memalign (pagesize, -pagesize) succeeded.");
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if (p == NULL && save != ENOMEM)
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merror ("memalign (pagesize, -pagesize) errno is not set correctly");
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free (p);
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errno = 0;
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/* Test to expose integer overflow in malloc internals from BZ #16038. */
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p = memalign (-1, pagesize);
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save = errno;
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if (p != NULL)
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merror ("memalign (-1, pagesize) succeeded.");
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if (p == NULL && save != EINVAL)
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merror ("memalign (-1, pagesize) errno is not set correctly");
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free (p);
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/* A zero-sized allocation should succeed with glibc, returning a
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non-NULL value. */
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p = memalign (sizeof (void *), 0);
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if (p == NULL)
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merror ("memalign (sizeof (void *), 0) failed.");
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free (p);
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/* Check the alignment of the returned pointer is correct. */
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p = memalign (0x100, 10);
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if (p == NULL)
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merror ("memalign (0x100, 10) failed.");
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ptrval = (unsigned long) p;
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if ((ptrval & 0xff) != 0)
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merror ("pointer is not aligned to 0x100");
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free (p);
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return errors != 0;
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}
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#define TEST_FUNCTION do_test ()
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#include "../test-skeleton.c"
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