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* dlfcn: Move dladdr1 into libcFlorian Weimer2021-06-031-2/+1
| | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* dlfcn: Move dlmopen into libcFlorian Weimer2021-06-031-6/+6
| | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* dlfcn: Move dlsym into libcFlorian Weimer2021-06-031-2/+2
| | | | | | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. In elf/Makefile, remove the $(libdl) dependency from testobj1.so because it the unused libdl DSO now causes elf/tst-unused-deps to fail. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* dlfcn: Move dladdr into libcFlorian Weimer2021-06-031-2/+1
| | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* dlfcn: Move dlclose into libcFlorian Weimer2021-06-031-2/+5
| | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* dlfcn: Move dlerror into libcFlorian Weimer2021-06-021-5/+3
| | | | | | | | | | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. There is a minor functionality enhancement: dlerror now sets errno if it was set as part of the exception. (This is the result of using %m in asprintf, to avoid the strerror PLT call.) The previous errno value upon function return was unpredictable. Documenting this as a feature is premature; we need to make sure that the error codes are meaningful when they are set by the dynamic loader. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Update floating-point feature test macro handling for C2XJoseph Myers2021-06-011-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ISO C2X has made some changes to the handling of feature test macros related to features from the floating-point TSes, and to exactly what such features are present in what headers, that require corresponding changes in glibc. * For the few features that were controlled by __STDC_WANT_IEC_60559_BFP_EXT__ (and the corresponding DFP macro) in C2X, there is now instead a new feature test macro __STDC_WANT_IEC_60559_EXT__ covering both binary and decimal FP. This controls CR_DECIMAL_DIG in <float.h> (provided by GCC; I implemented support for the new feature test macro for GCC 11) and the totalorder and payload functions in <math.h>. C2X no longer says anything about __STDC_WANT_IEC_60559_BFP_EXT__ (so it's appropriate for that macro to continue to enable exactly the features from TS 18661-1). * The SNAN macros for each floating-point type have moved to <float.h> (and been renamed in the process). Thus, the copies in <math.h> should only be defined for __STDC_WANT_IEC_60559_BFP_EXT__, not for C2X. * The fmaxmag and fminmag functions have been removed (replaced by new functions for the new min/max operations in IEEE 754-2019). Thus those should also only be declared for __STDC_WANT_IEC_60559_BFP_EXT__. * The _FloatN / _FloatNx handling for the last two points in glibc is trickier, since __STDC_WANT_IEC_60559_TYPES_EXT__ is still in C2X (the integration of TS 18661-3 as an Annex, that is, which hasn't yet been merged into the C standard git repository but has been accepted by WG14), so C2X with that macro should not declare some things that are declared for older standards with that macro. The approach taken here is to provide the declarations (when __STDC_WANT_IEC_60559_TYPES_EXT__ is enabled) only when (defined __USE_GNU || !__GLIBC_USE (ISOC2X)), so if C2X features are enabled then those declarations (that are only in TS 18661-3 and not in C2X) will only be provided if _GNU_SOURCE is defined as well. Thus _GNU_SOURCE remains a superset of the TS features as well as of C2X. Some other somewhat related changes in C2X are not addressed here. There's an open proposal not to include the fmin and fmax functions for the _FloatN / _FloatNx types, given the new min/max operations, which could be handled like the previous point if adopted. And the fromfp functions have been changed to return a result in floating type rather than intmax_t / uintmax_t; my inclination there is to treat that like that change of totalorder type (new symbol versions etc. for the ABI change; old versions become compat symbols and are no longer supported as an API). Tested for x86_64 and x86.
* Add cast_to_pointer to cast an integer to void * pointerH.J. Lu2021-05-221-0/+3
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* nptl: Move pthread_create, thrd_create into libcFlorian Weimer2021-05-211-1/+5
| | | | | | | | | | | | | | | | | | | The symbols were moved using scripts/move-symbol-to-libc.py. The libpthread placeholder symbols need some changes because some symbol versions have gone away completely. But __errno_location@@GLIBC_2.0 still exists, so the GLIBC_2.0 version is still there. The internal __pthread_create symbol now points to the correct function, so the sysdeps/nptl/thrd_create.c override is no longer necessary. There was an issue how the hidden alias of pthread_getattr_default_np was defined, so this commit cleans up that aspects and removes the GLIBC_PRIVATE export altogether. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* hurd: Add execveatSamuel Thibault2021-05-181-0/+2
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* Add C2X timespec_getresJoseph Myers2021-05-171-0/+6
| | | | | | | | | | | | | | | | | | | ISO C2X adds a timespec_getres function alongside the C11 timespec_get, with functionality similar to that of POSIX clock_getres (including allowing a NULL pointer to be passed to the function). Implement this function for glibc, similarly to the implementation of timespec_get. This includes a basic test like that of timespec_get, but no documentation in the manual, given that TIME_UTC and timespec_get aren't documented in the manual at all. The handling of 64-bit time follows that in timespec_get; people maintaining patch series for 64-bit time will need to update them accordingly (to export __timespec_getres64, redirect calls in time.h and run the test for _TIME_BITS=64). Tested for x86_64 and x86, and (previous version; only testcase differs) with build-many-glibcs.py.
* Enable support for GCC 11 -Wmismatched-dealloc.Martin Sebor2021-05-161-4/+4
| | | | | | | | | | | | | | | | | | | | | | | To help detect common kinds of memory (and other resource) management bugs, GCC 11 adds support for the detection of mismatched calls to allocation and deallocation functions. At each call site to a known deallocation function GCC checks the set of allocation functions the former can be paired with and, if the two don't match, issues a -Wmismatched-dealloc warning (something similar happens in C++ for mismatched calls to new and delete). GCC also uses the same mechanism to detect attempts to deallocate objects not allocated by any allocation function (or pointers past the first byte into allocated objects) by -Wfree-nonheap-object. This support is enabled for built-in functions like malloc and free. To extend it beyond those, GCC extends attribute malloc to designate a deallocation function to which pointers returned from the allocation function may be passed to deallocate the allocated objects. Another, optional argument designates the positional argument to which the pointer must be passed. This change is the first step in enabling this extended support for Glibc.
* linux: implement ttyname as a wrapper around ttyname_r.Érico Nogueira2021-05-071-2/+2
| | | | | | | | | | | | | Big win in binary size and avoids duplicating the logic in multiple places. On x86_64, dropped from 1883206 to 1881790, a 1416 byte decrease. Also changed logic to track if ttyname_buf has been allocated by checking if it's NULL instead of tracking buflen as an additional variable. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* linux: Use sched_getaffinity for __get_nprocs (BZ #27645)Adhemerval Zanella2021-05-071-0/+8
| | | | | | | | Both the sysfs and procfs parsing (through GET_NPROCS_PARSER) are removed in favor the syscall. The initial scratch buffer should fit to most of the common usage (1024 bytes with maps to 8192 CPUs). Checked on x86_64-linux-gnu and aarch64-linux-gnu.
* nptl: Move pthread_barrier_init into libcFlorian Weimer2021-05-061-0/+3
| | | | | | The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* nptl: Move sem_close, sem_open into libcFlorian Weimer2021-05-052-0/+2
| | | | | | | | | | | The symbols were moved using move-symbol-to-libc.py. Both functions are moved at the same time because they depend on internal functions in sysdeps/pthread/sem_routines.c, which are moved in this commit as well. Additional hidden prototypes are required to avoid check-localplt failures. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* dlfcn: dlerror needs to call free from the base namespace [BZ #24773]Florian Weimer2021-04-211-2/+0
| | | | | | | | | | | | Calling free directly may end up freeing a pointer allocated by the dynamic loader using malloc from libc.so in the base namespace using the allocator from libc.so in a secondary namespace, which results in crashes. This commit redirects the free call through GLRO and the dynamic linker, to reach the correct namespace. It also cleans up the dlerror handling along the way, so that pthread_setspecific is no longer needed (which avoids triggering bug 24774).
* nptl: Move __pthread_unwind_next into libcFlorian Weimer2021-04-211-2/+2
| | | | | | | | | | | | | | | | | | | It's necessary to stub out __libc_disable_asynccancel and __libc_enable_asynccancel via rtld-stubbed-symbols because the new direct references to the unwinder result in symbol conflicts when the rtld exception handling from libc is linked in during the construction of librtld.map. unwind-forcedunwind.c is merged into unwind-resume.c. libc now needs the functions that were previously only used in libpthread. The GLIBC_PRIVATE exports of __libc_longjmp and __libc_siglongjmp are no longer needed, so switch them to hidden symbols. The symbol __pthread_unwind_next has been moved using scripts/move-symbol-to-libc.py. Reviewed-by: Adhemerva Zanella <adhemerval.zanella@linaro.org>
* Set the retain attribute on _elf_set_element if CC supports [BZ #27492]Fangrui Song2021-04-161-4/+10
| | | | | | | | | | | | | | | | | | | | | | So that text_set_element/data_set_element/bss_set_element defined variables will be retained by the linker. Note: 'used' and 'retain' are orthogonal: 'used' makes sure the variable will not be optimized out; 'retain' prevents section garbage collection if the linker support SHF_GNU_RETAIN. GNU ld 2.37 and LLD 13 will support -z start-stop-gc which allow C identifier name sections to be GCed even if there are live __start_/__stop_ references. Without the change, there are some static linking problems, e.g. _IO_cleanup (libio/genops.c) may be discarded by ld --gc-sections, so stdout is not flushed on exit. Note: GCC may warning 'retain' attribute ignored while __has_attribute(retain) is 1 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99587). Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* linux: Normalize and return timeout on select (BZ #27651)Adhemerval Zanella2021-04-121-0/+5
| | | | | | | | | | | | | | | | | | | | The commit 2433d39b697, which added time64 support to select, changed the function to use __NR_pselect6 (or __NR_pelect6_time64) on all architectures. However, on architectures where the symbol was implemented with __NR_select the kernel normalizes the passed timeout instead of return EINVAL. For instance, the input timeval { 0, 5000000 } is interpreted as { 5, 0 }. And as indicated by BZ #27651, this semantic seems to be expected and changing it results in some performance issues (most likely the program does not check the return code and keeps issuing select with unormalized tv_usec argument). To avoid a different semantic depending whether which syscall the architecture used to issue, select now always normalize the timeout input. This is a slight change for some ABIs (for instance aarch64). Checked on x86_64-linux-gnu and i686-linux-gnu.
* nptl: Remove pwrite from libpthreadAdhemerval Zanella2021-03-261-1/+1
| | | | | | | The libc version is identical and built with same flags, it is also uses as the default version. Checked on x86_64-linux-gnu.
* nptl: Remove pread from libpthreadAdhemerval Zanella2021-03-261-1/+1
| | | | | | | The libc version is identical and built with same flags, it is also uses as the default version. Checked on x86_64-linux-gnu.
* nptl: Remove lseek from libpthreadAdhemerval Zanella2021-03-261-2/+1
| | | | | | | | | | | The libc version is identical and built with same flags. The libc version is set as the default version. The libpthread compat symbol requires to mask it when building the loader object otherwise ld might complain about a missing versioned symbol (as for alpha). Checked on x86_64-linux-gnu.
* Add OTHER_SHLIB_COMPATAdhemerval Zanella2021-03-261-0/+9
| | | | | | 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.
* malloc: Move MTAG_MMAP_FLAGS definitionSzabolcs Nagy2021-03-261-7/+0
| | | | | | | 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>
* Support for multiple versions in versioned_symbol, compat_symbolFlorian Weimer2021-03-252-45/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Change how the symbol_version_reference macro is definedFlorian Weimer2021-03-252-13/+6
| | | | | | | | | | | | 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>
* posix: Consolidate register-atforkAdhemerval Zanella2021-03-121-0/+63
| | | | | | | | | | | | | Both htl and nptl uses a different data structure to implement atfork handlers. The nptl one was refactored by 27761a1042d to use a dynarray which simplifies the code. This patch moves the nptl one to be the generic implementation and replace Hurd linked one. Different than previous NPTL, Hurd also uses a global lock, so performance should be similar. Checked on x86_64-linux-gnu, i686-linux-gnu, and with a build for i686-gnu.
* <shlib-compat.h>: Support compat_symbol_reference for _ISOMACFlorian Weimer2021-03-091-13/+13
| | | | | | This is helpful for testing compat symbols in cases where _ISOMAC is activated implicitly due to -DMODULE_NAME=testsuite and cannot be disabled easily.
* linux: Consolidate statvfs implementationsAdhemerval Zanella2021-02-111-2/+1
| | | | | | | | | There is no need to handle ENOSYS on fstatfs64 call, required only for alpha (where is already fallbacks to fstatfs). Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* linux: Consolidate fstatfs implementationsAdhemerval Zanella2021-02-111-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | The __NR_fstatfs64 syscall is supported on all architectures but aarch64, mips64, riscv64, and x86_64. And newer ABIs also uses the new fstatfs64 interface (where the struct size is used as first argument). So the default implementation now uses: 1. __NR_fstatfs64 for non-LFS call and handle overflow directly There is no need to handle __NR_fstatfs since all architectures that only support are LFS only. 2. __NR_fstatfs if defined or __NR_fstatfs64 otherwise for LFS call. Alpha is the only outlier, it is a 64-bit architecture which provides non-LFS interface and only provides __NR_fstatfs64 on newer kernels (5.1+). Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* setrlimit/getrlimit: Use __nonnull to avoid null pointerXiaoming Ni2021-02-101-2/+2
| | | | | | | | | | | | | | | | Add __nonnull((2)) to the setrlimit()/getrlimit() function declaration to avoid null pointer access. ----- v2 According to the suggestions of the Adhemerval Zanella and Zack Weinberg: use __nonnull() to check null pointers in the compilation phase. do not add pointer check code to setrlimit()/getrlimit(). The validity of the "resource" parameter is checked in the syscall. v1 https://public-inbox.org/libc-alpha/20201230114131.47589-1-nixiaoming@huawei.com/ ----- Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* linux: Require /dev/shm as the shared memory file systemFlorian Weimer2021-02-081-0/+41
| | | | | | | | | | | | | | | | | | | | | Previously, glibc would pick an arbitrary tmpfs file system from /proc/mounts if /dev/shm was not available. This could lead to an unsuitable file system being picked for the backing storage for shm_open, sem_open, and related functions. This patch introduces a new function, __shm_get_name, which builds the file name under the appropriate (now hard-coded) directory. It is called from the various shm_* and sem_* function. Unlike the SHM_GET_NAME macro it replaces, the callers handle the return values and errno updates. shm-directory.c is moved directly into the posix subdirectory because it can be implemented directly using POSIX functionality. It resides in libc because it is needed by both librt and nptl/htl. In the sem_open implementation, tmpfname is initialized directly from a string constant. This happens to remove one alloca call. Checked on x86_64-linux-gnu.
* sysconf: Add _SC_MINSIGSTKSZ/_SC_SIGSTKSZ [BZ #20305]H.J. Lu2021-02-013-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add _SC_MINSIGSTKSZ for the minimum signal stack size derived from AT_MINSIGSTKSZ, which is the minimum number of bytes of free stack space required in order to gurantee successful, non-nested handling of a single signal whose handler is an empty function, and _SC_SIGSTKSZ which is the suggested minimum number of bytes of stack space required for a signal stack. If AT_MINSIGSTKSZ isn't available, sysconf (_SC_MINSIGSTKSZ) returns MINSIGSTKSZ. On Linux/x86 with XSAVE, the signal frame used by kernel is composed of the following areas and laid out as: ------------------------------ | alignment padding | ------------------------------ | xsave buffer | ------------------------------ | fsave header (32-bit only) | ------------------------------ | siginfo + ucontext | ------------------------------ Compute AT_MINSIGSTKSZ value as size of xsave buffer + size of fsave header (32-bit only) + size of siginfo and ucontext + alignment padding. If _SC_SIGSTKSZ_SOURCE or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ are redefined as /* Default stack size for a signal handler: sysconf (SC_SIGSTKSZ). */ # undef SIGSTKSZ # define SIGSTKSZ sysconf (_SC_SIGSTKSZ) /* Minimum stack size for a signal handler: SIGSTKSZ. */ # undef MINSIGSTKSZ # define MINSIGSTKSZ SIGSTKSZ Compilation will fail if the source assumes constant MINSIGSTKSZ or SIGSTKSZ. The reason for not simply increasing the kernel's MINSIGSTKSZ #define (apart from the fact that it is rarely used, due to glibc's shadowing definitions) was that userspace binaries will have baked in the old value of the constant and may be making assumptions about it. For example, the type (char [MINSIGSTKSZ]) changes if this #define changes. This could be a problem if an newly built library tries to memcpy() or dump such an object defined by and old binary. Bounds-checking and the stack sizes passed to things like sigaltstack() and makecontext() could similarly go wrong.
* Prepare for glibc 2.33 release glibc-2.33Adhemerval Zanella2021-02-011-1/+1
| | | | Update version.h, features.h, and ChangeLog.old/ChangeLog.22.
* Revert "Make libc symbols hidden in static PIE" [BZ #27237]Szabolcs Nagy2021-01-271-7/+2
| | | | | | | | | This reverts commit 2682695e5c7acf1e60dd3b5c3a14d4e82416262c. Fixes bug 27237. That commit turned out to be too intrusive affecting crt files, test system and benchmark files. They should not be affected, but the build system does not set the MODULE_NAME and LIBC_NONSHARED reliably.
* Revert "linux: Move {f}xstat{at} to compat symbols" for static buildAdhemerval Zanella2021-01-211-9/+14
| | | | | | | | | | | | | | This reverts commit 20b39d59467b0c1d858e89ded8b0cebe55e22f60 for static library. This avoids the need to rebuild the world for the case where libstdc++ (and potentially other libraries) are linked to a old glibc. To avoid requering to provide xstat symbols for newer ABIs (such as riscv32) a new LIB_COMPAT macro is added. It is similar to SHLIB_COMPAT but also works for static case (thus evaluating similar to SHLIB_COMPAT for both shared and static case). Checked with a check-abi on all affected ABIs. I also check if the static library does contains the xstat symbols.
* Make libc symbols hidden in static PIESzabolcs Nagy2021-01-211-2/+7
| | | | | | | | | | | | | | | | | | | | | | Hidden visibility can avoid indirections and RELATIVE relocs in static PIE libc. The check should use IS_IN_LIB instead of IS_IN(libc) since all symbols are defined locally in static PIE and the optimization is useful in all libraries not just libc. However the test system links objects from libcrypt.a into dynamic linked test binaries where hidden visibility does not work. I think mixing static and shared libc components in the same binary should not be supported usage, but to be safe only use hidden in libc.a. On some targets (i386) this optimization cannot be applied because hidden visibility PIE ifunc functions don't work, so it is gated by NO_HIDDEN_EXTERN_FUNC_IN_PIE. From -static-pie linked 'int main(){}' this shaves off 71 relative relocs on aarch64 and reduces code size by about 2k. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* malloc: Add scratch_buffer_dupfreeAdhemerval Zanella2021-01-051-0/+16
| | | | | It returns a copy of the buffer up to a defined size. It will be used on realpath sync with gnulib.
* Import filename.h from gnulibAdhemerval Zanella2021-01-051-0/+112
| | | | And use to simplify stdlib/canonicalize.c implementation.
* Import idx.h from gnulibAdhemerval Zanella2021-01-051-0/+114
| | | | And use to simplify stdlib/canonicalize.c implementation.
* Sync intprops.h with gnulibAdhemerval Zanella2021-01-041-12/+58
| | | | | | It sync with gnulib commit 43ee1a6bf. Checked on x86_64-linux-gnu.
* Update copyright dates with scripts/update-copyrightsPaul Eggert2021-01-0237-37/+37
| | | | | | | | | | | | | | | | 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 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
* string: Enable __FORTIFY_LEVEL=3Siddhesh Poyarekar2020-12-311-2/+3
| | | | | | This change enhances fortified string functions to use __builtin_dynamic_object_size under _FORTIFY_SOURCE=3 whenever the compiler supports it.
* Introduce _FORTIFY_SOURCE=3Siddhesh Poyarekar2020-12-311-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new _FORTIFY_SOURCE level of 3 to enable additional fortifications that may have a noticeable performance impact, allowing more fortification coverage at the cost of some performance. With llvm 9.0 or later, this will replace the use of __builtin_object_size with __builtin_dynamic_object_size. __builtin_dynamic_object_size ----------------------------- __builtin_dynamic_object_size is an LLVM builtin that is similar to __builtin_object_size. In addition to what __builtin_object_size does, i.e. replace the builtin call with a constant object size, __builtin_dynamic_object_size will replace the call site with an expression that evaluates to the object size, thus expanding its applicability. In practice, __builtin_dynamic_object_size evaluates these expressions through malloc/calloc calls that it can associate with the object being evaluated. A simple motivating example is below; -D_FORTIFY_SOURCE=2 would miss this and emit memcpy, but -D_FORTIFY_SOURCE=3 with the help of __builtin_dynamic_object_size is able to emit __memcpy_chk with the allocation size expression passed into the function: void *copy_obj (const void *src, size_t alloc, size_t copysize) { void *obj = malloc (alloc); memcpy (obj, src, copysize); return obj; } Limitations ----------- If the object was allocated elsewhere that the compiler cannot see, or if it was allocated in the function with a function that the compiler does not recognize as an allocator then __builtin_dynamic_object_size also returns -1. Further, the expression used to compute object size may be non-trivial and may potentially incur a noticeable performance impact. These fortifications are hence enabled at a new _FORTIFY_SOURCE level to allow developers to make a choice on the tradeoff according to their environment.
* Warn on unsupported fortification levelsSiddhesh Poyarekar2020-12-311-0/+3
| | | | | | | | | Make the _FORTIFY_SOURCE macro soup in features.h warn about unsupported fortification levels. For example, it will warn about _FORTIFY_SOURCE=3 and over with an indication of which level has been selected. Co-authored-by: Paul Eggert <eggert@cs.ucla.edu>
* malloc: Basic support for memory tagging in the malloc() familyRichard Earnshaw2020-12-211-0/+8
| | | | | | | | | | | | | | | | | This patch adds the basic support for memory tagging. Various flavours are supported, particularly being able to turn on tagged memory at run-time: this allows the same code to be used on systems where memory tagging support is not present without neededing a separate build of glibc. Also, depending on whether the kernel supports it, the code will use mmap for the default arena if morecore does not, or cannot support tagged memory (on AArch64 it is not available). All the hooks use function pointers to allow this to work without needing ifuncs. Reviewed-by: DJ Delorie <dj@redhat.com>
* Replace __libc_multiple_libcs with __libc_initial flagFlorian Weimer2020-12-161-1/+6
| | | | | | | | | | | | | | Change sbrk to fail for !__libc_initial (in the generic implementation). As a result, sbrk is (relatively) safe to use for the __libc_initial case (from the main libc). It is therefore no longer necessary to avoid using it in that case (or updating the brk cache), and the __libc_initial flag does not need to be updated as part of dlmopen or static dlopen. As before, direct brk system calls on Linux may lead to memory corruption. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Mark __libc_freeres_fn as used [BZ #27002]H.J. Lu2020-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | GCC 11 with commit 6fbec038f7a7ddf29f074943611b53210d17c40c Author: H.J. Lu <hjl.tools@gmail.com> Date: Mon Feb 3 11:55:43 2020 -0800 Use SHF_GNU_RETAIN to preserve symbol definitions places used symbols in SECTION_RETAIN sections if assembler supports it. Mark __libc_freeres_fn as used to avoid gconv_dl.c: In function 'free_mem': gconv_dl.c:191:1: error: 'do_release_all' without 'used' attribute and 'free_mem' with 'used' attribute are placed in a section with the same name [-Werror=attributes] 191 | do_release_all (void *nodep) | ^~~~~~~~~~~~~~ In file included from <command-line>: gconv_dl.c:202:18: note: 'free_mem' was declared here 202 | libc_freeres_fn (free_mem) | ^~~~~~~~ ./../include/libc-symbols.h:316:15: note: in definition of macro 'libc_freeres_fn' 316 | static void name (void) | ^~~~ cc1: all warnings being treated as errors
* Handle out-of-memory case in svc_tcp.c/svc_unix.c:rendezvous_request.Stefan Liebler2020-12-101-0/+1
| | | | | | | | | | | | | | | | | | | | | If glibc is build with -O3 on at least 390 (-m31) or x86 (-m32), gcc 11 dumps this warning: svc_tcp.c: In function 'rendezvous_request': svc_tcp.c:274:3: error: 'memcpy' offset [0, 15] is out of the bounds [0, 0] [-Werror=array-bounds] 274 | memcpy (&xprt->xp_raddr, &addr, sizeof (addr)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors In out-of-memory case, if one of the mallocs in makefd_xprt function returns NULL, a message is dumped, makefd_xprt returns NULL and the subsequent memcpy would copy to NULL. Instead of a segfaulting, we delay a bit (see also __svc_accept_failed and Bug 14889 (CVE-2011-4609) - svc_run() produces high cpu usage when accept() fails with EMFILE (CVE-2011-4609). The same applies to svc_unix.c. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-07-20 12:58:18 +0000