Commit Graph

944 Commits

Author SHA1 Message Date
Florian Weimer
7519dee356 malloc: Simplify checked_request2size interface
In-band signaling avoids an uninitialized variable warning when
building with -Og and GCC 12.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-07-05 11:04:45 +02:00
Adhemerval Zanella
a4ea49f85e malloc: Fix duplicate inline for do_set_mxfast 2022-03-23 12:28:44 -03:00
Florian Weimer
d653fd2d9e malloc: Exit early on test failure in tst-realloc
This addresses more (correct) use-after-free warnings reported by
GCC 12 on some targets.

Fixes commit c094c232eb ("Avoid
-Wuse-after-free in tests [BZ #26779].").

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-03-10 08:50:51 +01:00
H.J. Lu
1fe00d3eb6 build: Properly generate .d dependency files [BZ #28922]
1. Also generate .d dependency files for $(tests-container) and
$(tests-printers).
2. elf: Add tst-auditmod17.os to extra-test-objs.
3. iconv: Add tst-gconv-init-failure-mod.os to extra-test-objs.
4. malloc: Rename extra-tests-objs to extra-test-objs.
5. linux: Add tst-sysconf-iov_max-uapi.o to extra-test-objs.
6. x86_64: Add tst-x86_64mod-1.o, tst-platformmod-2.o, test-libmvec.o,
test-libmvec-avx.o, test-libmvec-avx2.o and test-libmvec-avx512f.o to
extra-test-objs.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-02-25 10:35:45 -08:00
Adhemerval Zanella
d7703d3176 malloc: Remove LD_TRACE_PRELINKING usage from mtrace
The fix for BZ#22716 replacde LD_TRACE_LOADED_OBJECTS with
LD_TRACE_PRELINKING so mtrace could record executable address
position.

To provide the same information, LD_TRACE_LOADED_OBJECTS is
extended where a value or '2' also prints the executable address
as well.  It avoid adding another loader environment variable
to be used solely for mtrace.  The vDSO will be printed as
a default library (with '=>' pointing the same name), which is
ok since both mtrace and ldd already handles it.

The mtrace script is changed to also parse the new format.  To
correctly support PIE and non-PIE executables, both the default
mtrace address and the one calculated as used (it fixes mtrace
for non-PIE exectuable as for BZ#22716 for PIE).

Checked on x86_64-linux-gnu.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-02-10 09:16:13 -03:00
Carlos O'Donell
f77bcb70b8 malloc: Fix tst-mallocalign1 macro spacing.
Reported by Andreas Schwab <schwab@linux-m68k.org>
2022-02-01 11:05:26 -05:00
Carlos O'Donell
3a7bed5f5a malloc: Fix -Wuse-after-free warning in tst-mallocalign1 [BZ #26779]
The test leaks bits from the freed pointer via the return value
in ret, and the compiler correctly identifies this issue.
We switch the test to use TEST_VERIFY and terminate the test
if any of the pointers return an unexpected alignment.

This fixes another -Wuse-after-free error when compiling glibc
with gcc 12.

Tested on x86_64 and i686 without regression.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-01-31 00:39:28 -05:00
Martin Sebor
c094c232eb Avoid -Wuse-after-free in tests [BZ #26779].
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-01-26 10:38:23 -07:00
Paul Eggert
634b5ebac6 Update copyright dates not handled by scripts/update-copyrights.
I've updated copyright dates in glibc for 2022.  This is the patch for
the changes not generated by scripts/update-copyrights and subsequent
build / regeneration of generated files.  As well as the usual annual
updates, mainly dates in --version output (minus csu/version.c which
previously had to be handled manually but is now successfully updated
by update-copyrights), there is a small change to the copyright notice
in NEWS which should let NEWS get updated automatically next year.

Please remember to include 2022 in the dates for any new files added
in future (which means updating any existing uncommitted patches you
have that add new files to use the new copyright dates in them).
2022-01-01 11:42:26 -08:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Adhemerval Zanella
83b8d5027d malloc: Remove memusage.h
And use machine-sp.h instead.  The Linux implementation is based on
already provided CURRENT_STACK_FRAME (used on nptl code) and
STACK_GROWS_UPWARD is replaced with _STACK_GROWS_UP.
2021-12-28 14:57:57 -03:00
Adhemerval Zanella
a75b1e35c5 malloc: Use hp-timing on libmemusage
Instead of reimplemeting on GETTIME macro.
2021-12-28 14:57:57 -03:00
Adhemerval Zanella
5a5f7a160d malloc: Remove atomic_* usage
These typedef are used solely on memusage and can be replaced with
generic types.
2021-12-28 14:57:57 -03:00
Samuel Thibault
53c38911b8 malloc: Add missing shared thread library flags 2021-12-27 22:10:15 +01:00
Patrick McGehearty
0a4df6f534 Remove upper limit on tunable MALLOC_MMAP_THRESHOLD
The current limit on MALLOC_MMAP_THRESHOLD is either 1 Mbyte (for
32-bit apps) or 32 Mbytes (for 64-bit apps).  This value was set by a
patch dated 2006 (15 years ago).  Attempts to set the threshold higher
are currently ignored.

The default behavior is appropriate for many highly parallel
applications where many processes or threads are sharing RAM. In other
situations where the number of active processes or threads closely
matches the number of cores, a much higher limit may be desired by the
application designer. By today's standards on personal computers and
small servers, 2 Gbytes of RAM per core is commonly available. On
larger systems 4 Gbytes or more of RAM is sometimes available.
Instead of raising the limit to match current needs, this patch
proposes to remove the limit of the tunable, leaving the decision up
to the user of a tunable to judge the best value for their needs.

This patch does not change any of the defaults for malloc tunables,
retaining the current behavior of the dynamic malloc mmap threshold.

bugzilla 27801 - Remove upper limit on tunable MALLOC_MMAP_THRESHOLD
Reviewed-by: DJ Delorie <dj@redhat.com>

malloc/
        malloc.c changed do_set_mmap_threshold to remove test
        for HEAP_MAX_SIZE.
2021-12-16 17:24:37 +00:00
Adhemerval Zanella
0f982c1827 malloc: Enable huge page support on main arena
This patch adds support huge page support on main arena allocation,
enable with tunable glibc.malloc.hugetlb=2.  The patch essentially
disable the __glibc_morecore() sbrk() call (similar when memory
tag does when sbrk() call does not support it) and fallback to
default page size if the memory allocation fails.

Checked on x86_64-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:39 -03:00
Adhemerval Zanella
0849eed45d malloc: Move MORECORE fallback mmap to sysmalloc_mmap_fallback
So it can be used on hugepage code as well.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:39 -03:00
Adhemerval Zanella
c1beb51d08 malloc: Add Huge Page support to arenas
It is enabled as default for glibc.malloc.hugetlb set to 2 or higher.
It also uses a non configurable minimum value and maximum value,
currently set respectively to 1 and 4 selected huge page size.

The arena allocation with huge pages does not use MAP_NORESERVE.  As
indicate by kernel internal documentation [1], the flag might trigger
a SIGBUS on soft page faults if at memory access there is no left
pages in the pool.

On systems without a reserved huge pages pool, is just stress the
mmap(MAP_HUGETLB) allocation failure.  To improve test coverage it is
required to create a pool with some allocated pages.

Checked on x86_64-linux-gnu with no reserved pages, 10 reserved pages
(which trigger mmap(MAP_HUGETBL) failures) and with 256 reserved pages
(which does not trigger mmap(MAP_HUGETLB) failures).

[1] https://www.kernel.org/doc/html/v4.18/vm/hugetlbfs_reserv.html#resv-map-modifications

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:39 -03:00
Adhemerval Zanella
98d5fcb8d0 malloc: Add Huge Page support for mmap
With the morecore hook removed, there is not easy way to provide huge
pages support on with glibc allocator without resorting to transparent
huge pages.  And some users and programs do prefer to use the huge pages
directly instead of THP for multiple reasons: no splitting, re-merging
by the VM, no TLB shootdowns for running processes, fast allocation
from the reserve pool, no competition with the rest of the processes
unlike THP, no swapping all, etc.

This patch extends the 'glibc.malloc.hugetlb' tunable: the value
'2' means to use huge pages directly with the system default size,
while a positive value means and specific page size that is matched
against the supported ones by the system.

Currently only memory allocated on sysmalloc() is handled, the arenas
still uses the default system page size.

To test is a new rule is added tests-malloc-hugetlb2, which run the
addes tests with the required GLIBC_TUNABLE setting.  On systems without
a reserved huge pages pool, is just stress the mmap(MAP_HUGETLB)
allocation failure.  To improve test coverage it is required to create
a pool with some allocated pages.

Checked on x86_64-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:38 -03:00
Adhemerval Zanella
6cc3ccc67e malloc: Move mmap logic to its own function
So it can be used with different pagesize and flags.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:15 -03:00
Adhemerval Zanella
7478c9959a malloc: Add THP/madvise support for sbrk
To increase effectiveness with Transparent Huge Page with madvise, the
large page size is use instead page size for sbrk increment for the
main arena.

Checked on x86_64-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:15 -03:00
Adhemerval Zanella
5f6d8d97c6 malloc: Add madvise support for Transparent Huge Pages
Linux Transparent Huge Pages (THP) current supports three different
states: 'never', 'madvise', and 'always'.  The 'never' is
self-explanatory and 'always' will enable THP for all anonymous
pages.  However, 'madvise' is still the default for some system and
for such case THP will be only used if the memory range is explicity
advertise by the program through a madvise(MADV_HUGEPAGE) call.

To enable it a new tunable is provided, 'glibc.malloc.hugetlb',
where setting to a value diffent than 0 enables the madvise call.

This patch issues the madvise(MADV_HUGEPAGE) call after a successful
mmap() call at sysmalloc() with sizes larger than the default huge
page size.  The madvise() call is disable is system does not support
THP or if it has the mode set to "never" and on Linux only support
one page size for THP, even if the architecture supports multiple
sizes.

To test is a new rule is added tests-malloc-hugetlb1, which run the
addes tests with the required GLIBC_TUNABLE setting.

Checked on x86_64-linux-gnu.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-12-15 17:35:14 -03:00
Stafford Horne
f1bcfde3a7 malloc: Fix malloc debug for 2.35 onwards
The change 1e5a5866cb ("Remove malloc hooks [BZ #23328]") has broken
ports that are using GLIBC_2_35, like the new OpenRISC port I am working
on.

The libc_malloc_debug.so library used to bring in the debug
infrastructure is currently essentially empty for GLIBC_2_35 ports like
mine causing mtrace tests to fail:

    cat sysdeps/unix/sysv/linux/or1k/shlib-versions
    DEFAULT                 GLIBC_2.35
    ld=ld-linux-or1k.so.1

    FAIL: posix/bug-glob2-mem
    FAIL: posix/bug-regex14-mem
    FAIL: posix/bug-regex2-mem
    FAIL: posix/bug-regex21-mem
    FAIL: posix/bug-regex31-mem
    FAIL: posix/bug-regex36-mem
    FAIL: malloc/tst-mtrace.

The issue seems to be with the ifdefs in malloc/malloc-debug.c. The
ifdefs are currently essentially exluding all symbols for ports > 2.35.

Removing the top level SHLIB_COMPAT ifdef allows things to just work.

Fixes: 1e5a5866cb ("Remove malloc hooks [BZ #23328]")
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-11-17 21:33:39 +09:00
Florian Weimer
f1d333b5bf elf: Introduce GLRO (dl_libc_freeres), called from __libc_freeres
This will be used to deallocate memory allocated using the non-minimal
malloc.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-11-17 12:20:29 +01:00
Joseph Myers
7ca9377bab Disable -Waggressive-loop-optimizations warnings in tst-dynarray.c
My build-many-glibcs.py bot shows -Waggressive-loop-optimizations
errors building the glibc testsuite for 32-bit architectures with GCC
mainline, which seem to have appeared between GCC commits
4abc0c196b10251dc80d0743ba9e8ab3e56c61ed and
d8edfadfc7a9795b65177a50ce44fd348858e844:

In function 'dynarray_long_noscratch_resize',
    inlined from 'test_long_overflow' at tst-dynarray.c:489:5,
    inlined from 'do_test' at tst-dynarray.c:571:3:
../malloc/dynarray-skeleton.c:391:36: error: iteration 1073741823 invokes undefined behavior [-Werror=aggressive-loop-optimizations]
  391 |             DYNARRAY_ELEMENT_INIT (&list->u.dynarray_header.array[i]);
tst-dynarray.c:39:37: note: in definition of macro 'DYNARRAY_ELEMENT_INIT'
   39 | #define DYNARRAY_ELEMENT_INIT(e) (*(e) = 23)
      |                                     ^
In file included from tst-dynarray.c:42:
../malloc/dynarray-skeleton.c:389:37: note: within this loop
  389 |         for (size_t i = old_size; i < size; ++i)
      |                                   ~~^~~~~~
In function 'dynarray_long_resize',
    inlined from 'test_long_overflow' at tst-dynarray.c:479:5,
    inlined from 'do_test' at tst-dynarray.c:571:3:
../malloc/dynarray-skeleton.c:391:36: error: iteration 1073741823 invokes undefined behavior [-Werror=aggressive-loop-optimizations]
  391 |             DYNARRAY_ELEMENT_INIT (&list->u.dynarray_header.array[i]);
tst-dynarray.c:27:37: note: in definition of macro 'DYNARRAY_ELEMENT_INIT'
   27 | #define DYNARRAY_ELEMENT_INIT(e) (*(e) = 17)
      |                                     ^
In file included from tst-dynarray.c:28:
../malloc/dynarray-skeleton.c:389:37: note: within this loop
  389 |         for (size_t i = old_size; i < size; ++i)
      |                                   ~~^~~~~~

I don't know what GCC change made these errors appear, or why they
only appear for 32-bit architectures.  However, the warnings appear to
be both true (that iteration would indeed involve undefined behavior
if executed) and useless in this particular case (that iteration is
never executed, because the allocation size overflows and so the
allocation fails - but the check for allocation size overflow is in a
separate source file and so can't be seen by the compiler when
compiling this test).  So use the DIAG_* macros to disable
-Waggressive-loop-optimizations around the calls in question to
dynarray_long_resize and dynarray_long_noscratch_resize in this test.

Tested with build-many-glibcs.py (GCC mainline) for arm-linux-gnueabi,
where it restores a clean testsuite build.
2021-10-29 14:40:45 +00:00
Siddhesh Poyarekar
88e316b064 Handle NULL input to malloc_usable_size [BZ #28506]
Hoist the NULL check for malloc_usable_size into its entry points in
malloc-debug and malloc and assume non-NULL in all callees.  This fixes
BZ #28506

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
2021-10-29 14:53:55 +05:30
Jonathan Wakely
8a9a593115 Add alloc_align attribute to memalign et al
GCC 4.9.0 added the alloc_align attribute to say that a function
argument specifies the alignment of the returned pointer. Clang supports
the attribute too. Using the attribute can allow a compiler to generate
better code if it knows the returned pointer has a minimum alignment.
See https://gcc.gnu.org/PR60092 for more details.

GCC implicitly knows the semantics of aligned_alloc and posix_memalign,
but not the obsolete memalign. As a result, GCC generates worse code
when memalign is used, compared to aligned_alloc.  Clang knows about
aligned_alloc and memalign, but not posix_memalign.

This change adds a new __attribute_alloc_align__ macro to <sys/cdefs.h>
and then uses it on memalign (where it helps GCC) and aligned_alloc
(where GCC and Clang already know the semantics, but it doesn't hurt)
and xposix_memalign. It can't be used on posix_memalign because that
doesn't return a pointer (the allocated pointer is returned via a void**
parameter instead).

Unlike the alloc_size attribute, alloc_align only allows a single
argument. That means the new __attribute_alloc_align__ macro doesn't
really need to be used with double parentheses to protect a comma
between its arguments. For consistency with __attribute_alloc_size__
this patch defines it the same way, so that double parentheses are
required.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-10-21 00:19:20 +01:00
Adhemerval Zanella
11a02b035b misc: Add __get_nprocs_sched
This is an internal function meant to return the number of avaliable
processor where the process can scheduled, different than the
__get_nprocs which returns a the system available online CPU.

The Linux implementation currently only calls __get_nprocs(), which
in tuns calls sched_getaffinity.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-09-27 09:13:06 -03:00
Siddhesh Poyarekar
30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30
Siddhesh Poyarekar
f2e33c3268 mtrace: Fix output with PIE and ASLR [BZ #22716]
Record only the relative address of the caller in mtrace file.  Use
LD_TRACE_PRELINKING to get the executable as well as binary vs
executable load offsets so that we may compute a base to add to the
relative address in the mtrace file.  This allows us to get a valid
address to pass to addr2line in all cases.

Fixes BZ #22716.

Co-authored-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Andreas Schwab <schwab@linux-m68k.org>
Reviewed-by: DJ Delorie <dj@redhat.com>
2021-08-23 08:14:22 +05:30
Siddhesh Poyarekar
dc906e94f7 mtrace: Use a static buffer for printing [BZ #25947]
Use a static buffer for mtrace printing now that it no longer adds to
default libc footprint.

Reviewed-by: DJ Delorie <dj@redhat.com>
2021-08-12 06:38:15 +05:30
Siddhesh Poyarekar
505a964ae0 tst-mxfast: Don't run with mcheck
The test may not show predictable behaviour with -lmcheck since the
padding won't always guarantee fastbin usage.
2021-08-05 07:36:55 +05:30
Siddhesh Poyarekar
ddcc612ce9 Exclude static tests for mcheck and malloc-check
mcheck and malloc-check no longer work with static binaries, so drop
those tests.

Reported-by: Samuel Thibault <samuel.thibault@gnu.org>
Tested-by: Samuel Thibault <samuel.thibault@gnu.org>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2021-07-26 10:47:46 +05:30
Siddhesh Poyarekar
5b8d271571 Fix build and tests with --disable-tunables
Remove unused code and declare __libc_mallopt when !IS_IN (libc) to
allow the debug hook to build with --disable-tunables.

Also, run tst-ifunc-isa-2* tests only when tunables are enabled since
the result depends on it.

Tested on x86_64.

Reported-by: Matheus Castanho <msc@linux.ibm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-23 13:57:56 +05:30
Siddhesh Poyarekar
6856975ed4 mcheck Fix malloc_usable_size [BZ #22057]
Interpose malloc_usable_size to return the correct mcheck value for
malloc_usable_size.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:16 +05:30
Siddhesh Poyarekar
1e5a5866cb Remove malloc hooks [BZ #23328]
Make malloc hooks symbols compat-only so that new applications cannot
link against them and remove the declarations from the API.  Also
remove the unused malloc-hooks.h.

Finally, mark all symbols in libc_malloc_debug.so as compat so that
the library cannot be linked against.

Add a note about the deprecation in NEWS.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:12 +05:30
Siddhesh Poyarekar
0552fd2c7d Move malloc_{g,s}et_state to libc_malloc_debug
These deprecated functions are only safe to call from
__malloc_initialize_hook and as a result, are not useful in the
general case.  Move the implementations to libc_malloc_debug so that
existing binaries that need it will now have to preload the debug DSO
to work correctly.

This also allows simplification of the core malloc implementation by
dropping all the undumping support code that was added to make
malloc_set_state work.

One known breakage is that of ancient emacs binaries that depend on
this.  They will now crash when running with this libc.  With
LD_BIND_NOW=1, it will terminate immediately because of not being able
to find malloc_set_state but with lazy binding it will crash in
unpredictable ways.  It will need a preloaded libc_malloc_debug.so so
that its initialization hook is executed to allow its malloc
implementation to work properly.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:10 +05:30
Siddhesh Poyarekar
b5bd5bfe88 glibc.malloc.check: Wean away from malloc hooks
The malloc-check debugging feature is tightly integrated into glibc
malloc, so thanks to an idea from Florian Weimer, much of the malloc
implementation has been moved into libc_malloc_debug.so to support
malloc-check.  Due to this, glibc malloc and malloc-check can no
longer work together; they use altogether different (but identical)
structures for heap management.  This should not make a difference
though since the malloc check hook is not disabled anywhere.
malloc_set_state does, but it does so early enough that it shouldn't
cause any problems.

The malloc check tunable is now in the debug DSO and has no effect
when the DSO is not preloaded.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:08 +05:30
Siddhesh Poyarekar
9dad716d4d mtrace: Wean away from malloc hooks
Wean mtrace away from the malloc hooks and move them into the debug
DSO.  Split the API away from the implementation so that we can add
the API to libc.so as well as libc_malloc_debug.so, with the libc
implementations being empty.

Update localplt data since memalign no longer has any callers after
this change.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:06 +05:30
Siddhesh Poyarekar
cc35896ea3 Simplify __malloc_initialized
Now that mcheck no longer needs to check __malloc_initialized (and no
other third party hook can since the symbol is not exported), make the
variable boolean and static so that it is used strictly within malloc.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:04 +05:30
Siddhesh Poyarekar
c142eb253f mcheck: Wean away from malloc hooks [BZ #23489]
Split the mcheck implementation into the debugging hooks and API so
that the API can be replicated in libc and libc_malloc_debug.so.  The
libc APIs always result in failure.

The mcheck implementation has also been moved entirely into
libc_malloc_debug.so and with it, all of the hook initialization code
can now be moved into the debug library.  Now the initialization can
be done independently of libc internals.

With this patch, libc_malloc_debug.so can no longer be used with older
libcs, which is not its goal anyway.  tst-vfork3 breaks due to this
since it spawns shell scripts, which in turn execute using the system
glibc.  Move the test to tests-container so that only the built glibc
is used.

This move also fixes bugs in the mcheck version of memalign and
realloc, thus allowing removal of the tests from tests-mcheck
exclusion list.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:02 +05:30
Siddhesh Poyarekar
2d2d9f2b48 Move malloc hooks into a compat DSO
Remove all malloc hook uses from core malloc functions and move it
into a new library libc_malloc_debug.so.  With this, the hooks now no
longer have any effect on the core library.

libc_malloc_debug.so is a malloc interposer that needs to be preloaded
to get hooks functionality back so that the debugging features that
depend on the hooks, i.e. malloc-check, mcheck and mtrace work again.
Without the preloaded DSO these debugging features will be nops.
These features will be ported away from hooks in subsequent patches.

Similarly, legacy applications that need hooks functionality need to
preload libc_malloc_debug.so.

The symbols exported by libc_malloc_debug.so are maintained at exactly
the same version as libc.so.

Finally, static binaries will no longer be able to use malloc
debugging features since they cannot preload the debugging DSO.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:37:59 +05:30
Siddhesh Poyarekar
55a4dd3930 Remove __morecore and __default_morecore
Make the __morecore and __default_morecore symbols compat-only and
remove their declarations from the API.  Also, include morecore.c
directly into malloc.c; this should ideally get merged into malloc in
a future cleanup.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:37:57 +05:30
Siddhesh Poyarekar
57b07bede1 Remove __after_morecore_hook
Remove __after_morecore_hook from the API and finalize the symbol so
that it can no longer be used in new applications.  Old applications
using __after_morecore_hook will find that their hook is no longer
called.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:37:54 +05:30
Siddhesh Poyarekar
0075c4f39d Make mcheck tests conditional on GLIBC_2.23 or earlier
Targets with base versions of 2.24 or later won't have
__malloc_initialize_hook because of which the tests will essentially
be the same as the regular malloc tests.  Avoid running them instead
and save time.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:37:41 +05:30
Samuel Thibault
63c60cff12 malloc: Fix tst-mallocfork3-malloc-check link
It uses pthread.
2021-07-22 00:42:38 +02:00
Siddhesh Poyarekar
191e406826 tst-safe-linking: make false positives even more improbable
There is a 1 in 16 chance of a corruption escaping safe-linking and to
guard against spurious failures, tst-safe-linking runs each subtest 10
times to ensure that the chance is reduced to 1 in 2^40.  However, in
the 1 in 16 chance that a corruption does escape safe linking, it
could well be caught by other sanity checks we do in malloc, which
then results in spurious test failures like below:

test test_fastbin_consolidate failed with a different error
  expected: malloc_consolidate(): unaligned fastbin chunk detected

  actual:   malloc_consolidate(): invalid chunk size

This failure is seen more frequently on i686; I was able to reproduce
it in about 5 min of running it in a loop.

Guard against such failures by recording them and retrying the test.
Also, do not fail the test if we happened to get defeated by the 1 in
2^40 odds if in at least one of the instances it was detected by other
checks.

Finally, bolster the odds to 2^64 by running 16 times instead of 10.
The test still has a chance of failure so it is still flaky in theory.
However in practice if we see a failure here then it's more likely
that there's a bug than it being an issue with the test.  Add more
printfs and also dump them to stdout so that in the event the test
actually fails, we will have some data to try and understand why it
may have failed.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-19 08:29:25 +05:30
H.J. Lu
84ea6ea24b mcheck: Align struct hdr to MALLOC_ALIGNMENT bytes [BZ #28068]
1. Align struct hdr to MALLOC_ALIGNMENT bytes so that malloc hooks in
libmcheck align memory to MALLOC_ALIGNMENT bytes.
2. Remove tst-mallocalign1 from tests-exclude-mcheck for i386 and x32.
3. Add tst-pvalloc-fortify and tst-reallocarray to tests-exclude-mcheck
since they use malloc_usable_size (see BZ #22057).

This fixed BZ #28068.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-07-12 18:13:32 -07:00
Florian Weimer
7c241325d6 Force building with -fno-common
As a result, is not necessary to specify __attribute__ ((nocommon))
on individual definitions.

GCC 10 defaults to -fno-common on all architectures except ARC,
but this change is compatible with older GCC versions and ARC, too.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-09 20:09:14 +02:00
H.J. Lu
dc76a059fd Add a generic malloc test for MALLOC_ALIGNMENT
1. Add sysdeps/generic/malloc-size.h to define size related macros for
malloc.
2. Move x86_64/tst-mallocalign1.c to malloc and replace ALIGN_MASK with
MALLOC_ALIGN_MASK.
3. Add tst-mallocalign1 to tests-exclude-mcheck for i386 and x32 since
mcheck doesn't honor MALLOC_ALIGNMENT.
2021-07-09 06:39:30 -07:00