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* stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)Adhemerval Zanella Netto2022-07-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The implementation is based on scalar Chacha20 with per-thread cache. It uses getrandom or /dev/urandom as fallback to get the initial entropy, and reseeds the internal state on every 16MB of consumed buffer. To improve performance and lower memory consumption the per-thread cache is allocated lazily on first arc4random functions call, and if the memory allocation fails getentropy or /dev/urandom is used as fallback. The cache is also cleared on thread exit iff it was initialized (so if arc4random is not called it is not touched). Although it is lock-free, arc4random is still not async-signal-safe (the per thread state is not updated atomically). The ChaCha20 implementation is based on RFC8439 [1], omitting the final XOR of the keystream with the plaintext because the plaintext is a stream of zeros. This strategy is similar to what OpenBSD arc4random does. The arc4random_uniform is based on previous work by Florian Weimer, where the algorithm is based on Jérémie Lumbroso paper Optimal Discrete Uniform Generation from Coin Flips, and Applications (2013) [2], who credits Donald E. Knuth and Andrew C. Yao, The complexity of nonuniform random number generation (1976), for solving the general case. The main advantage of this method is the that the unit of randomness is not the uniform random variable (uint32_t), but a random bit. It optimizes the internal buffer sampling by initially consuming a 32-bit random variable and then sampling byte per byte. Depending of the upper bound requested, it might lead to better CPU utilization. Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu. Co-authored-by: Florian Weimer <fweimer@redhat.com> Reviewed-by: Yann Droneaud <ydroneaud@opteya.com> [1] https://datatracker.ietf.org/doc/html/rfc8439 [2] https://arxiv.org/pdf/1304.1916.pdf
* malloc: Simplify implementation of __malloc_assertFlorian Weimer2022-07-211-10/+5
| | | | | | | | | | It is prudent not to run too much code after detecting heap corruption, and __fxprintf is really complex. The line number and file name do not carry much information, so it is not included in the error message. (__libc_message only supports %s formatting.) The function name and assertion should provide some context. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* malloc: Simplify checked_request2size interfaceFlorian Weimer2022-07-052-15/+18
| | | | | | | In-band signaling avoids an uninitialized variable warning when building with -Og and GCC 12. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* malloc: Fix duplicate inline for do_set_mxfastAdhemerval Zanella2022-03-231-2/+1
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* malloc: Exit early on test failure in tst-reallocFlorian Weimer2022-03-101-31/+15
| | | | | | | | | | This addresses more (correct) use-after-free warnings reported by GCC 12 on some targets. Fixes commit c094c232eb3246154265bb035182f92fe1b17ab8 ("Avoid -Wuse-after-free in tests [BZ #26779]."). Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* build: Properly generate .d dependency files [BZ #28922]H.J. Lu2022-02-251-1/+1
| | | | | | | | | | | | | 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>
* malloc: Remove LD_TRACE_PRELINKING usage from mtraceAdhemerval Zanella2022-02-101-24/+31
| | | | | | | | | | | | | | | | | | | | | | 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>
* malloc: Fix tst-mallocalign1 macro spacing.Carlos O'Donell2022-02-011-1/+1
| | | | Reported by Andreas Schwab <schwab@linux-m68k.org>
* malloc: Fix -Wuse-after-free warning in tst-mallocalign1 [BZ #26779]Carlos O'Donell2022-01-311-9/+11
| | | | | | | | | | | | | | 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>
* Avoid -Wuse-after-free in tests [BZ #26779].Martin Sebor2022-01-265-1/+58
| | | | Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Update copyright dates not handled by scripts/update-copyrights.Paul Eggert2022-01-013-3/+3
| | | | | | | | | | | | | | 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).
* Update copyright dates with scripts/update-copyrightsPaul Eggert2022-01-0188-88/+88
| | | | | | | | | | | | | | | | | | | | | | | 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
* malloc: Remove memusage.hAdhemerval Zanella2021-12-281-6/+7
| | | | | | 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.
* malloc: Use hp-timing on libmemusageAdhemerval Zanella2021-12-281-3/+21
| | | | Instead of reimplemeting on GETTIME macro.
* malloc: Remove atomic_* usageAdhemerval Zanella2021-12-281-18/+18
| | | | | These typedef are used solely on memusage and can be replaced with generic types.
* malloc: Add missing shared thread library flagsSamuel Thibault2021-12-271-0/+16
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* Remove upper limit on tunable MALLOC_MMAP_THRESHOLDPatrick McGehearty2021-12-161-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* malloc: Enable huge page support on main arenaAdhemerval Zanella2021-12-153-6/+14
| | | | | | | | | | | | 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>
* malloc: Move MORECORE fallback mmap to sysmalloc_mmap_fallbackAdhemerval Zanella2021-12-151-32/+53
| | | | | | So it can be used on hugepage code as well. Reviewed-by: DJ Delorie <dj@redhat.com>
* malloc: Add Huge Page support to arenasAdhemerval Zanella2021-12-153-44/+99
| | | | | | | | | | | | | | | | | | | | | | | 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>
* malloc: Add Huge Page support for mmapAdhemerval Zanella2021-12-153-9/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* malloc: Move mmap logic to its own functionAdhemerval Zanella2021-12-151-76/+88
| | | | | | So it can be used with different pagesize and flags. Reviewed-by: DJ Delorie <dj@redhat.com>
* malloc: Add THP/madvise support for sbrkAdhemerval Zanella2021-12-151-5/+29
| | | | | | | | | | 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>
* malloc: Add madvise support for Transparent Huge PagesAdhemerval Zanella2021-12-154-0/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* malloc: Fix malloc debug for 2.35 onwardsStafford Horne2021-11-171-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* elf: Introduce GLRO (dl_libc_freeres), called from __libc_freeresFlorian Weimer2021-11-171-0/+5
| | | | | | | This will be used to deallocate memory allocated using the non-minimal malloc. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Disable -Waggressive-loop-optimizations warnings in tst-dynarray.cJoseph Myers2021-10-291-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Handle NULL input to malloc_usable_size [BZ #28506]Siddhesh Poyarekar2021-10-293-35/+25
| | | | | | | | | | 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>
* Add alloc_align attribute to memalign et alJonathan Wakely2021-10-211-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* misc: Add __get_nprocs_schedAdhemerval Zanella2021-09-271-1/+1
| | | | | | | | | | | 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>
* Remove "Contributed by" linesSiddhesh Poyarekar2021-09-0317-20/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mtrace: Fix output with PIE and ASLR [BZ #22716]Siddhesh Poyarekar2021-08-232-11/+10
| | | | | | | | | | | | | | 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>
* mtrace: Use a static buffer for printing [BZ #25947]Siddhesh Poyarekar2021-08-121-11/+3
| | | | | | | Use a static buffer for mtrace printing now that it no longer adds to default libc footprint. Reviewed-by: DJ Delorie <dj@redhat.com>
* tst-mxfast: Don't run with mcheckSiddhesh Poyarekar2021-08-051-1/+2
| | | | | The test may not show predictable behaviour with -lmcheck since the padding won't always guarantee fastbin usage.
* Exclude static tests for mcheck and malloc-checkSiddhesh Poyarekar2021-07-261-10/+3
| | | | | | | | | 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>
* Fix build and tests with --disable-tunablesSiddhesh Poyarekar2021-07-233-30/+28
| | | | | | | | | | | | | 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>
* mcheck Fix malloc_usable_size [BZ #22057]Siddhesh Poyarekar2021-07-223-3/+9
| | | | | | | | 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>
* Remove malloc hooks [BZ #23328]Siddhesh Poyarekar2021-07-224-41/+41
| | | | | | | | | | | | | | 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>
* Move malloc_{g,s}et_state to libc_malloc_debugSiddhesh Poyarekar2021-07-225-167/+193
| | | | | | | | | | | | | | | | | | | | | | | 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>
* glibc.malloc.check: Wean away from malloc hooksSiddhesh Poyarekar2021-07-227-80/+213
| | | | | | | | | | | | | | | | | | 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>
* mtrace: Wean away from malloc hooksSiddhesh Poyarekar2021-07-224-302/+253
| | | | | | | | | | | | | 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>
* Simplify __malloc_initializedSiddhesh Poyarekar2021-07-222-18/+18
| | | | | | | | | 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>
* mcheck: Wean away from malloc hooks [BZ #23489]Siddhesh Poyarekar2021-07-226-458/+592
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* Move malloc hooks into a compat DSOSiddhesh Poyarekar2021-07-2213-111/+453
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* Remove __morecore and __default_morecoreSiddhesh Poyarekar2021-07-226-46/+19
| | | | | | | | | | 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>
* Remove __after_morecore_hookSiddhesh Poyarekar2021-07-223-24/+6
| | | | | | | | | | 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>
* Make mcheck tests conditional on GLIBC_2.23 or earlierSiddhesh Poyarekar2021-07-221-0/+3
| | | | | | | | | | 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>
* malloc: Fix tst-mallocfork3-malloc-check linkSamuel Thibault2021-07-221-0/+1
| | | | It uses pthread.
* tst-safe-linking: make false positives even more improbableSiddhesh Poyarekar2021-07-191-6/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mcheck: Align struct hdr to MALLOC_ALIGNMENT bytes [BZ #28068]H.J. Lu2021-07-122-2/+5
| | | | | | | | | | | | 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>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-09 11:23:01 +0000