delta/glibc.git/malloc/malloc.h, branch fw/tst-mallocfork2

malloc: make malloc fail with requests larger than PTRDIFF_MAX (BZ#23741)

2019-04-18T20:30:06+00:00

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.

Update copyright dates with scripts/update-copyrights.

2019-01-01T00:11:28+00:00

	* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.

Update copyright dates with scripts/update-copyrights.

2018-01-01T00:32:25+00:00

	* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.

Add reallocarray function

2017-05-30T21:27:57+00:00

The reallocarray function is an extension from OpenBSD.  It is an
integer-overflow-safe replacement for realloc(p, X*Y) and
malloc(X*Y) (realloc(NULL, X*Y)).  It can therefore help in preventing
certain security issues in code.

This is an updated version of a patch originally submitted by Rüdiger
Sonderfeld in May 2014 [1].

Checked on i686-linux-gnu and x86_64-linux-gnu.

[1] .

2017-05-30  Dennis Wölfing  
            Rüdiger Sonderfeld  

	* include/stdlib.h (__libc_reallocarray): New declaration.
	* malloc/Makefile (routines): Add reallocarray.
	(tests): Add tst-reallocarray.c.
	* malloc/Versions: Add reallocarray and __libc_reallocarray.
	* malloc/malloc-internal.h (check_mul_overflow_size_t): New inline
	function.
	* malloc/malloc.h (reallocarray): New declaration.
	* stdlib/stdlib.h (reallocarray): Likewise.
	* malloc/reallocarray.c: New file.
	* malloc/tst-reallocarray.c: New test file.
	* manual/memory.texi: Document reallocarray.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Add reallocarray.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/tilepro/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.

malloc: Turn cfree into a compatibility symbol

2017-04-18T09:50:58+00:00

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2017-01-01T00:14:16+00:00

malloc: Remove malloc_get_state, malloc_set_state [BZ #19473]

2016-10-26T11:28:28+00:00

After the removal of __malloc_initialize_hook, newly compiled
Emacs binaries are no longer able to use these interfaces.
malloc_get_state is only used during the Emacs build process,
so we provide a stub implementation only.  Existing Emacs binaries
will not call this stub function, but still reference the symbol.

The rewritten tst-mallocstate test constructs a dumped heap
which should approximates what existing Emacs binaries pass
to glibc malloc.

malloc: Remove __malloc_initialize_hook from the API [BZ #19564]

2016-06-10T08:46:05+00:00

__malloc_initialize_hook is interposed by application code, so
the usual approach to define a compatibility symbol does not work.
This commit adds a new mechanism based on #pragma GCC poison in
.

malloc: Remove max_total_mem member form struct malloc_par

2016-02-19T16:07:04+00:00

Also note that sumblks in struct mallinfo is always 0.
No functional change.

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2016-01-04T16:05:18+00:00