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2021-03-26Add OTHER_SHLIB_COMPATAdhemerval Zanella
It is similar to SHLIB_COMPAT, but allows to check versions from other libraries. It is used to move compat symbol from other libraries to libc.
2021-03-26misc: Fix tst-select timeout handling (BZ#27648)Adhemerval Zanella
Instead of polling the stderr, create two pipes and fork to check if child timeout as expected similar to tst-pselect.c. Also lower the timeout value. Checked on x86_64-linux-gnu.
2021-03-26malloc: Ensure mtag code path in checked_request2size is coldSzabolcs Nagy
This is a workaround (hack) for a gcc optimization issue (PR 99551). Without this the generated code may evaluate the expression in the cold path which causes performance regression for small allocations in the memory tagging disabled (common) case. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Remove unnecessary tagging around _mid_memalignSzabolcs Nagy
The internal _mid_memalign already returns newly tagged memory. (__libc_memalign and posix_memalign already relied on this, this patch fixes the other call sites.) Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Rename chunk2rawmemSzabolcs Nagy
The previous patch ensured that all chunk to mem computations use chunk2rawmem, so now we can rename it to chunk2mem, and in the few cases where the tag of mem is relevant chunk2mem_tag can be used. Replaced tag_at (chunk2rawmem (x)) with chunk2mem_tag (x). Renamed chunk2rawmem to chunk2mem. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Use chunk2rawmem throughoutSzabolcs Nagy
The difference between chunk2mem and chunk2rawmem is that the latter does not get the memory tag for the returned pointer. It turns out chunk2rawmem almost always works: The input of chunk2mem is a chunk pointer that is untagged so it can access the chunk header. All memory that is not user allocated heap memory is untagged, which in the current implementation means that it has the 0 tag, but this patch does not rely on the tag value. The patch relies on that chunk operations are either done on untagged chunks or without doing memory access to the user owned part. Internal interface contracts: sysmalloc: Returns untagged memory. _int_malloc: Returns untagged memory. _int_free: Takes untagged memory. _int_memalign: Returns untagged memory. _int_realloc: Takes and returns tagged memory. So only _int_realloc and functions outside this list need care. Alignment checks do not need the right tag and tcache works with untagged memory. tag_at was kept in realloc after an mremap, which is not strictly necessary, since the pointer is only used to retag the memory, but this way the tag is guaranteed to be different from the old tag. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Use different tag after mremapSzabolcs Nagy
The comment explained why different tag is used after mremap, but for that correctly tagged pointer should be passed to tag_new_usable. Use chunk2mem to get the tag. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Use memsize instead of CHUNK_AVAILABLE_SIZESzabolcs Nagy
This is a pure refactoring change that does not affect behaviour. The CHUNK_AVAILABLE_SIZE name was unclear, the memsize name tries to follow the existing convention of mem denoting the allocation that is handed out to the user, while chunk is its internally used container. The user owned memory for a given chunk starts at chunk2mem(p) and the size is memsize(p). It is not valid to use on dumped heap chunks. Moved the definition next to other chunk and mem related macros. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26aarch64: Optimize __libc_mtag_tag_zero_regionSzabolcs Nagy
This is a target hook for memory tagging, the original was a naive implementation. Uses the same algorithm as __libc_mtag_tag_region, but with instructions that also zero the memory. This was not benchmarked on real cpu, but expected to be faster than the naive implementation.
2021-03-26aarch64: Optimize __libc_mtag_tag_regionSzabolcs Nagy
This is a target hook for memory tagging, the original was a naive implementation. The optimized version relies on "dc gva" to tag 64 bytes at a time for large allocations and optimizes small cases without adding too many branches. This was not benchmarked on real cpu, but expected to be faster than the naive implementation.
2021-03-26aarch64: inline __libc_mtag_new_tagSzabolcs Nagy
This is a common operation when heap tagging is enabled, so inline the instructions instead of using an extern call.
2021-03-26aarch64: inline __libc_mtag_address_get_tagSzabolcs Nagy
This is a common operation when heap tagging is enabled, so inline the instruction instead of using an extern call. The .inst directive is used instead of the name of the instruction (or acle intrinsics) because malloc.c is not compiled for armv8.5-a+memtag architecture, runtime cpu support detection is used. Prototypes are removed from the comments as they were not always correct.
2021-03-26malloc: Use mtag_enabled instead of USE_MTAGSzabolcs Nagy
Use the runtime check where possible: it should not cause slow down in the !USE_MTAG case since then mtag_enabled is constant false, but it allows compiling the tagging logic so it's less likely to break or diverge when developers only test the !USE_MTAG case. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Use branches instead of mtag_granule_maskSzabolcs Nagy
The branches may be better optimized since mtag_enabled is widely used. Granule size larger than a chunk header is not supported since then we cannot have both the chunk header and user area granule aligned. To fix that for targets with large granule, the chunk layout has to change. So code that attempted to handle the granule mask generally was changed. This simplified CHUNK_AVAILABLE_SIZE and the logic in malloc_usable_size. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Change calloc when tagging is disabledSzabolcs Nagy
When glibc is built with memory tagging support (USE_MTAG) but it is not enabled at runtime (mtag_enabled) then unconditional memset was used even though that can be often avoided. This is for performance when tagging is supported but not enabled. The extra check should have no overhead: tag_new_zero_region already had a runtime check which the compiler can now optimize away. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Only support zeroing and not arbitrary memset with mtagSzabolcs Nagy
The memset api is suboptimal and does not provide much benefit. Memory tagging only needs a zeroing memset (and only for memory that's sized and aligned to multiples of the tag granule), so change the internal api and the target hooks accordingly. This is to simplify the implementation of the target hook. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Use global flag instead of function pointer dispatch for mtagSzabolcs Nagy
A flag check can be faster than function pointers because of how branch prediction and speculation works and it can also remove a layer of indirection when there is a mismatch between the malloc internal tag_* api and __libc_mtag_* target hooks. Memory tagging wrapper functions are moved to malloc.c from arena.c and the logic now checks mmap_enabled. The definition of tag_new_usable is moved after chunk related definitions. This refactoring also allows using mtag_enabled checks instead of USE_MTAG ifdefs when memory tagging support only changes code logic when memory tagging is enabled at runtime. Note: an "if (false)" code block is optimized away even at -O0 by gcc. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Refactor TAG_ macros to avoid indirectionSzabolcs Nagy
This does not change behaviour, just removes one layer of indirection in the internal memory tagging logic. Use tag_ and mtag_ prefixes instead of __tag_ and __mtag_ since these are all symbols with internal linkage, private to malloc.c, so there is no user namespace pollution issue. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Ensure the generic mtag hooks are not usedSzabolcs Nagy
Use inline functions instead of macros, because macros can cause unused variable warnings and type conversion issues. We assume these functions may appear in the code but only in dead code paths (hidden by a runtime check), so it's important that they can compile with correct types, but if they are actually used that should be an error. Currently the hooks are only used when USE_MTAG is true which only happens on aarch64 and then the aarch64 specific code is used not this generic header. However followup refactoring will allow the hooks to be used with !USE_MTAG. Note: the const qualifier in the comment was wrong: changing tags is a write operation. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Avoid taggig mmaped memory on freeSzabolcs Nagy
Either the memory belongs to the dumped area, in which case we don't want to tag (the dumped area has the same tag as malloc internal data so tagging is unnecessary, but chunks there may not have the right alignment for the tag granule), or the memory will be unmapped immediately (and thus tagging is not useful). Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Simplify __mtag_tag_new_usableSzabolcs Nagy
The chunk cannot be a dumped one here. The only non-obvious cases are free and realloc which may be called on a dumped area chunk, but in both cases it can be verified that tagging is already avoided for dumped area chunks. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Move MTAG_MMAP_FLAGS definitionSzabolcs Nagy
This is only used internally in malloc.c, the extern declaration was wrong, __mtag_mmap_flags has internal linkage. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Fix a potential realloc issue with memory taggingSzabolcs Nagy
At an _int_free call site in realloc the wrong size was used for tag clearing: the chunk header of the next chunk was also cleared which in practice may work, but logically wrong. The tag clearing is moved before the memcpy to save a tag computation, this avoids a chunk2mem. Another chunk2mem is removed because newmem does not have to be recomputed. Whitespaces got fixed too. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26malloc: Fix a realloc crash with heap tagging [BZ 27468]Szabolcs Nagy
_int_free must be called with a chunk that has its tag reset. This was missing in a rare case that could crash when heap tagging is enabled: when in a multi-threaded process the current arena runs out of memory during realloc, but another arena still has space to finish the realloc then _int_free was called without clearing the user allocation tags. Fixes bug 27468. Reviewed-by: DJ Delorie <dj@redhat.com>
2021-03-26S390: Also check vector support in memmove ifunc-selector [BZ #27511]Stefan Liebler
The arch13 memmove variant is currently selected by the ifunc selector if the Miscellaneous-Instruction-Extensions Facility 3 facility bit is present, but the function is also using vector instructions. If the vector support is not present, one is receiving an operation exception. Therefore this patch also checks for vector support in the ifunc selector and in ifunc-impl-list.c. Just to be sure, the configure check is now also testing an arch13 vector instruction and an arch13 Miscellaneous-Instruction-Extensions Facility 3 instruction.
2021-03-26S390: Don't test nanoseconds in io/tst-stat.cStefan Liebler
Both new tests io/tst-stat and io/tst-stat-lfs (_FILE_OFFSET_BITS=64) are comparing the nanosecond fields with the statx result. Unfortunately on s390(31bit) those fields are always zero if old KABI with non-LFS support is used. With _FILE_OFFSET_BITS=64 stat is using statx internally. As suggested by Adhemerval this patch disables the nanosecond check for s390(31bit). Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-25Support for multiple versions in versioned_symbol, compat_symbolFlorian Weimer
This essentially folds compat_symbol_unique functionality into compat_symbol. This change eliminates the need for intermediate aliases for defining multiple symbol versions, for both compat_symbol and versioned_symbol. Some binutils versions do not suport multiple versions per symbol on some targets, so aliases are automatically introduced, similar to what compat_symbol_unique did. To reduce symbol table sizes, a configure check is added to avoid these aliases if they are not needed. The new mechanism works with data symbols as well as function symbols, due to the way an assembler-level redirect is used. It is not compatible with weak symbols for old binutils versions, which is why the definition of __malloc_initialize_hook had to be changed. This is not a loss of functionality because weak symbols do not matter to dynamic linking. The placeholder symbol needs repeating in nptl/libpthread-compat.c now that compat_symbol is used, but that seems more obvious than introducing yet another macro. A subtle difference was that compat_symbol_unique made the symbol global automatically. compat_symbol does not do this, so static had to be removed from the definition of __libpthread_version_placeholder. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-25locale: Use compat_symbol_reference in _nl_postload_ctypeFlorian Weimer
These symbol usages are not definitions, so compat_symbol_reference is more appropriate than compat_symbol. compat_symbol_reference is also safe to emit multiple times (in case the inline assembly is duplicated; this is possible because it is nested in a function). compat_symbol does not necessarily have this property because it is intended to provide a symbol definition. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-25Change how the symbol_version_reference macro is definedFlorian Weimer
A subsequent change will require including <config.h> for defining symbol_version_reference. <libc-symbol.h> should not include <config.h> for _ISOMAC, so it cannot define symbol_version_reference anymore, but symbol_version_reference is needed <shlib-compat.h> even for _ISOMAC. Moving the definition of symbol_version_reference to a separate file <libc-symver.h> makes it possible to use a single definition for both cases. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-24stdlib: Fix BZ #26241 testcase on GNU/HurdSamuel Thibault
GNU/Hurd's readlink system call is partly implemented in userspace, which also allocates a buffer on the stack for the result, and thus needs one more path. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-24elf: Fix not compiling ifunc tests that need gcc ifunc supportSamuel Thibault
2021-03-24htl: Add missing fork.hSamuel Thibault
2b47727c68b6 ("posix: Consolidate register-atfork") introduced a fork.h header to declare the atfork unregister hook, but was missing adding it for htl. This fixes tst-atfork2.
2021-03-23hurd: handle EINTR during critical sectionsSamuel Thibault
During critical sections, signal handling is deferred and thus RPCs return EINTR, even if SA_RESTART is set. We thus have to restart the whole critical section in that case. This also adds HURD_CRITICAL_UNLOCK in the cases where one wants to break the section in the middle.
2021-03-23tst: Add test for sigtimedwaitLukasz Majewski
This change adds new test to assess sigtimedwait's timeout related functionality - the sigset_t is configured for SIGUSR1, which will not be triggered, so sigtimedwait just waits for timeout. To be more specific - two use cases are checked: - if sigtimedwait times out immediately when passed struct timespec has zero values of tv_nsec and tv_sec. - if sigtimedwait times out after timeout specified in passed argument Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-23tst: Provide test for selectLukasz Majewski
This change adds new test to assess select()'s timeout related functionality (the rdfs set provides valid fd - stderr - but during normal program operation there is no data to be read, so one just waits for timeout). To be more specific - two use cases are checked: - if select() times out immediately when passed struct timeval has zero values of tv_usec and tv_sec. - if select() times out after timeout specified in passed argument Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-23tst: Add test for ntp_gettimexLukasz Majewski
This test is a wrapper on tst-ntp_gettime test. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-23tst: Add test for ntp_gettimeLukasz Majewski
This code provides test to check if time on target machine is properly read via ntp_gettime syscall. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-03-23fix: Always export ntp_gettimex functionLukasz Majewski
After this patch applied the ntp_gettimex function is always declared in the sys/timex.h header. Currently it is not when __REDIRECT_NTH is defined (i.e. in ARM 32 bit port).
2021-03-19nptl: Remove MULTI_PAGE_ALIASING [BZ #23554]H.J. Lu
MULTI_PAGE_ALIASING was introduced to mitigate an aliasing issue on Pentium 4. It is no longer needed for processors after Pentium 4.
2021-03-19elf: Add EM_INTELGT for Intel Graphics TechnologyH.J. Lu
Add EM_INTELGT (205) for Intel Graphics Technology which has been added to gABI: https://groups.google.com/g/generic-abi/c/ofBevXA48dM
2021-03-18support: Use syscall function instead of INLINE_SYSCALL_CALLAdhemerval Zanella
It fixes the build on ARM in thumb mode that requires an out of the line helper (__libc_do_syscall) to issue the syscall.
2021-03-18signal: Add __libc_sigactionAdhemerval Zanella
The generic implementation basically handle the system agnostic logic (filtering out the invalid signals) while the __libc_sigaction is the function with implements the system and architecture bits. Checked on x86_64-linux-gnu and i686-linux-gnu.
2021-03-18nptl: Move system to libcAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Move fcntl from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Remove sendmsg from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Remove recvmsg from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Remove sigwait from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Remove tcdrain from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Remove pause from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.
2021-03-18nptl: Remove msync from libpthreadAdhemerval Zanella
The libc version is identical and built with same flags. Checked on x86_64-linux-gnu.