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* Update syscall lists for Linux 6.8Joseph Myers2024-03-132-0/+10
| | | | | | | | Linux 6.8 adds five new syscalls. Update syscall-names.list and regenerate the arch-syscall.h headers with build-many-glibcs.py update-syscalls. Tested with build-many-glibcs.py.
* x86-64: Update _dl_tlsdesc_dynamic to preserve AMX registersH.J. Lu2024-02-297-0/+184
| | | | | | | | | | | | | | | | _dl_tlsdesc_dynamic should also preserve AMX registers which are caller-saved. Add X86_XSTATE_TILECFG_ID and X86_XSTATE_TILEDATA_ID to x86-64 TLSDESC_CALL_STATE_SAVE_MASK. Compute the AMX state size and save it in xsave_state_full_size which is only used by _dl_tlsdesc_dynamic_xsave and _dl_tlsdesc_dynamic_xsavec. This fixes the AMX part of BZ #31372. Tested on AMX processor. AMX test is enabled only for compilers with the fix for https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114098 GCC 14 and GCC 11/12/13 branches have the bug fix. Reviewed-by: Sunil K Pandey <skpgkp2@gmail.com>
* sysdeps/unix/sysv/linux/x86_64/Makefile: Add the end markerH.J. Lu2024-02-281-3/+6
| | | | Add the end marker to tests, tests-container and modules-names.
* Linux: Switch back to assembly syscall wrapper for prctl (bug 29770)Florian Weimer2024-02-171-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit ff026950e280bc3e9487b41b460fb31bc5b57721 ("Add a C wrapper for prctl [BZ #25896]") replaced the assembler wrapper with a C function. However, on powerpc64le-linux-gnu, the C variadic function implementation requires extra work in the caller to set up the parameter save area. Calling a function that needs a parameter save area without one (because the prototype used indicates the function is not variadic) corrupts the caller's stack. The Linux manual pages project documents prctl as a non-variadic function. This has resulted in various projects over the years using non-variadic prototypes, including the sanitizer libraries in LLVm and GCC (GCC PR 113728). This commit switches back to the assembler implementation on most targets and only keeps the C implementation for x86-64 x32. Also add the __prctl_time64 alias from commit b39ffab860cd743a82c91946619f1b8158b0b65e ("Linux: Add time64 alias for prctl") to sysdeps/unix/sysv/linux/syscalls.list; it was not yet present in commit ff026950e280bc3e9487b41b460fb31bc5b57721. This restores the old ABI on powerpc64le-linux-gnu, thus fixing bug 29770. Reviewed-By: Simon Chopin <simon.chopin@canonical.com>
* Update syscall lists for Linux 6.7Joseph Myers2024-01-172-0/+6
| | | | | | | | | Linux 6.7 adds the futex_requeue, futex_wait and futex_wake syscalls, and enables map_shadow_stack for architectures previously missing it. Update syscall-names.list and regenerate the arch-syscall.h headers with build-many-glibcs.py update-syscalls. Tested with build-many-glibcs.py.
* x86-64: Check if mprotect works before rewriting PLTH.J. Lu2024-01-151-0/+43
| | | | | | | | | | | | | | | | Systemd execution environment configuration may prohibit changing a memory mapping to become executable: MemoryDenyWriteExecute= Takes a boolean argument. If set, attempts to create memory mappings that are writable and executable at the same time, or to change existing memory mappings to become executable, or mapping shared memory segments as executable, are prohibited. When it is set, systemd service stops working if PLT rewrite is enabled. Check if mprotect works before rewriting PLT. This fixes BZ #31230. This also works with SELinux when deny_execmem is on. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* math: remove exp10 wrappersWilco Dijkstra2024-01-122-0/+2
| | | | | | | | Remove the error handling wrapper from exp10. This is very similar to the changes done to exp and exp2, except that we also need to handle pow10 and pow10l. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* x86-64/cet: Make CET feature check specific to Linux/x86H.J. Lu2024-01-112-0/+32
| | | | | | CET feature bits in TCB, which are Linux specific, are used to check if CET features are active. Move CET feature check to Linux/x86 directory. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
* i386: Remove CET support bitsH.J. Lu2024-01-101-1/+1
| | | | | | | | | | | | 1. Remove _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk. 2. Move CET offsets from x86 cpu-features-offsets.sym to x86-64 features-offsets.sym. 3. Rename x86 cet-control.h to x86-64 feature-control.h since it is only for x86-64 and also used for PLT rewrite. 4. Add x86-64 ldsodefs.h to include feature-control.h. 5. Change TUNABLE_CALLBACK (set_plt_rewrite) to x86-64 only. 6. Move x86 dl-procruntime.c to x86-64. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* x86-64/cet: Move dl-cet.[ch] to x86_64 directoriesH.J. Lu2024-01-101-1/+46
| | | | | | Since CET is only enabled for x86-64, move dl-cet.[ch] to x86_64 directories. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* x86: Move CET infrastructure to x86_64Adhemerval Zanella2024-01-097-0/+424
| | | | | | | | The CET is only supported for x86_64 and there is no plan to add kernel support for i386. Move the Makefile rules and files from the generic x86 folder to x86_64 one. Checked on x86_64-linux-gnu and i686-linux-gnu.
* x86: Fixup some nits in longjmp asm implementationNoah Goldstein2024-01-051-1/+1
| | | | Replace a stray `nop` with a `.p2align` directive.
* x86-64/cet: Check the restore token in longjmpH.J. Lu2024-01-041-139/+40
| | | | | | | | | | | | | | | | | | | | | | setcontext and swapcontext put a restore token on the old shadow stack which is used to restore the target shadow stack when switching user contexts. When longjmp from a user context, the target shadow stack can be different from the current shadow stack and INCSSP can't be used to restore the shadow stack pointer to the target shadow stack. Update longjmp to search for a restore token. If found, use the token to restore the shadow stack pointer before using INCSSP to pop the shadow stack. Stop the token search and use INCSSP if the shadow stack entry value is the same as the current shadow stack pointer. It is a user error if there is a shadow stack switch without leaving a restore token on the old shadow stack. The only difference between __longjmp.S and __longjmp_chk.S is that __longjmp_chk.S has a check for invalid longjmp usages. Merge __longjmp.S and __longjmp_chk.S by adding the CHECK_INVALID_LONGJMP macro. Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
* Implement C23 <stdbit.h>Joseph Myers2024-01-032-0/+140
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | C23 adds a header <stdbit.h> with various functions and type-generic macros for bit-manipulation of unsigned integers (plus macro defines related to endianness). Implement this header for glibc. The functions have both inline definitions in the header (referenced by macros defined in the header) and copies with external linkage in the library (which are implemented in terms of those macros to avoid duplication). They are documented in the glibc manual. Tests, as well as verifying results for various inputs (of both the macros and the out-of-line functions), verify the types of those results (which showed up a bug in an earlier version with the type-generic macro stdc_has_single_bit wrongly returning a promoted type), that the macros can be used at top level in a source file (so don't use ({})), that they evaluate their arguments exactly once, and that the macros for the type-specific functions have the expected implicit conversions to the relevant argument type. Jakub previously referred to -Wconversion warnings in type-generic macros, so I've included a test with -Wconversion (but the only warnings I saw and fixed from that test were actually in inline functions in the <stdbit.h> header - not anything coming from use of the type-generic macros themselves). This implementation of the type-generic macros does not handle unsigned __int128, or unsigned _BitInt types with a width other than that of a standard integer type (and C23 doesn't require the header to handle such types either). Support for those types, using the new type-generic built-in functions Jakub's added for GCC 14, can reasonably be added in a followup (along of course with associated tests). This implementation doesn't do anything special to handle C++, or have any tests of functionality in C++ beyond the existing tests that all headers can be compiled in C++ code; it's not clear exactly what form this header should take in C++, but probably not one using macros. DIS ballot comment AT-107 asks for the word "count" to be added to the names of the stdc_leading_zeros, stdc_leading_ones, stdc_trailing_zeros and stdc_trailing_ones functions and macros. I don't think it's likely to be accepted (accepting any technical comments would mean having an FDIS ballot), but if it is accepted at the WG14 meeting (22-26 January in Strasbourg, starting with DIS ballot comment handling) then there would still be time to update glibc for the renaming before the 2.39 release. The new functions and header are placed in the stdlib/ directory in glibc, rather than creating a new toplevel stdbit/ or putting them in string/ alongside ffs. Tested for x86_64 and x86.
* Update copyright dates with scripts/update-copyrightsPaul Eggert2024-01-0128-28/+28
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* x86/cet: Enable shadow stack during startupH.J. Lu2024-01-011-0/+47
| | | | | | | | | | | | | | | | | | | | | | | Previously, CET was enabled by kernel before passing control to user space and the startup code must disable CET if applications or shared libraries aren't CET enabled. Since the current kernel only supports shadow stack and won't enable shadow stack before passing control to user space, we need to enable shadow stack during startup if the application and all shared library are shadow stack enabled. There is no need to disable shadow stack at startup. Shadow stack can only be enabled in a function which will never return. Otherwise, shadow stack will underflow at the function return. 1. GL(dl_x86_feature_1) is set to the CET features which are supported by the processor and are not disabled by the tunable. Only non-zero features in GL(dl_x86_feature_1) should be enabled. After enabling shadow stack with ARCH_SHSTK_ENABLE, ARCH_SHSTK_STATUS is used to check if shadow stack is really enabled. 2. Use ARCH_SHSTK_ENABLE in RTLD_START in dynamic executable. It is safe since RTLD_START never returns. 3. Call arch_prctl (ARCH_SHSTK_ENABLE) from ARCH_SETUP_TLS in static executable. Since the start function using ARCH_SETUP_TLS never returns, it is safe to enable shadow stack in ARCH_SETUP_TLS.
* x86/cet: Sync with Linux kernel 6.6 shadow stack interfaceH.J. Lu2024-01-017-88/+111
| | | | | | | | | | | | | | | | | | | | | | | Sync with Linux kernel 6.6 shadow stack interface. Since only x86-64 is supported, i386 shadow stack codes are unchanged and CET shouldn't be enabled for i386. 1. When the shadow stack base in TCB is unset, the default shadow stack is in use. Use the current shadow stack pointer as the marker for the default shadow stack. It is used to identify if the current shadow stack is the same as the target shadow stack when switching ucontexts. If yes, INCSSP will be used to unwind shadow stack. Otherwise, shadow stack restore token will be used. 2. Allocate shadow stack with the map_shadow_stack syscall. Since there is no function to explicitly release ucontext, there is no place to release shadow stack allocated by map_shadow_stack in ucontext functions. Such shadow stacks will be leaked. 3. Rename arch_prctl CET commands to ARCH_SHSTK_XXX. 4. Rewrite the CET control functions with the current kernel shadow stack interface. Since CET is no longer enabled by kernel, a separate patch will enable shadow stack during startup.
* Update syscall lists for Linux 6.6Adhemerval Zanella2023-11-032-0/+3
| | | | | Linux 6.6 has one new syscall for all architectures, fchmodat2, and the map_shadow_stack on x86_64.
* crypt: Remove libcrypt supportAdhemerval Zanella2023-10-302-14/+0
| | | | | | | | | | | | | | | | | | All the crypt related functions, cryptographic algorithms, and make requirements are removed, with only the exception of md5 implementation which is moved to locale folder since it is required by localedef for integrity protection (libc's locale-reading code does not check these, but localedef does generate them). Besides thec code itself, both internal documentation and the manual is also adjusted. This allows to remove both --enable-crypt and --enable-nss-crypt configure options. Checked with a build for all affected ABIs. Co-authored-by: Zack Weinberg <zack@owlfolio.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Update syscall lists for Linux 6.5Joseph Myers2023-09-122-0/+2
| | | | | | | | Linux 6.5 has one new syscall, cachestat, and also enables the cacheflush syscall for hppa. Update syscall-names.list and regenerate the arch-syscall.h headers with build-many-glibcs.py update-syscalls. Tested with build-many-glibcs.py.
* linux: Add pidfd_getpidAdhemerval Zanella Netto2023-09-052-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | This interface allows to obtain the associated process ID from the process file descriptor. It is done by parsing the procps fdinfo information. Its prototype is: pid_t pidfd_getpid (int fd) It returns the associated pid or -1 in case of an error and sets the errno accordingly. The possible errno values are those from open, read, and close (used on procps parsing), along with: - EBADF if the FD is negative, does not have a PID associated, or if the fdinfo fields contain a value larger than pid_t. - EREMOTE if the PID is in a separate namespace. - ESRCH if the process is already terminated. Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid support), Linux 5.4 (full support), and Linux 6.2. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* posix: Add pidfd_spawn and pidfd_spawnp (BZ 30349)Adhemerval Zanella Netto2023-09-052-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Returning a pidfd allows a process to keep a race-free handle for a child process, otherwise, the caller will need to either use pidfd_open (which still might be subject to TOCTOU) or keep the old racy interface base on pid_t. To correct use pifd_spawn, the kernel must support not only returning the pidfd with clone/clone3 but also waitid (P_PIDFD) (added on Linux 5.4). If kernel does not support the waitid, pidfd return ENOSYS. It avoids the need to racy workarounds, such as reading the procfs fdinfo to get the pid to use along with other wait interfaces. These interfaces are similar to the posix_spawn and posix_spawnp, with the only difference being it returns a process file descriptor (int) instead of a process ID (pid_t). Their prototypes are: int pidfd_spawn (int *restrict pidfd, const char *restrict file, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict], char *const envp[restrict]) int pidfd_spawnp (int *restrict pidfd, const char *restrict path, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict_arr], char *const envp[restrict_arr]); A new symbol is used instead of a posix_spawn extension to avoid possible issues with language bindings that might track the return argument lifetime. Although on Linux pid_t and int are interchangeable, POSIX only states that pid_t should be a signed integer. Both symbols reuse the posix_spawn posix_spawn_file_actions_t and posix_spawnattr_t, to void rehash posix_spawn API or add a new one. It also means that both interfaces support the same attribute and file actions, and a new flag or file action on posix_spawn is also added automatically for pidfd_spawn. Also, using posix_spawn plumbing allows the reusing of most of the current testing with some changes: - waitid is used instead of waitpid since it is a more generic interface. - tst-posix_spawn-setsid.c is adapted to take into consideration that the caller can check for session id directly. The test now spawns itself and writes the session id as a file instead. - tst-spawn3.c need to know where pidfd_spawn is used so it keeps an extra file description unused. Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid support), Linux 5.4 (full support), and Linux 6.2. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* linux: Add posix_spawnattr_{get, set}cgroup_np (BZ 26371)Adhemerval Zanella Netto2023-09-052-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions allow to posix_spawn and posix_spawnp to use CLONE_INTO_CGROUP with clone3, allowing the child process to be created in a different cgroup version 2. These are GNU extensions that are available only for Linux, and also only for the architectures that implement clone3 wrapper (HAVE_CLONE3_WRAPPER). To create a process on a different cgroupv2, one can use the: posix_spawnattr_t attr; posix_spawnattr_init (&attr); posix_spawnattr_setflags (&attr, POSIX_SPAWN_SETCGROUP); posix_spawnattr_setcgroup_np (&attr, cgroup); posix_spawn (...) Similar to other posix_spawn flags, POSIX_SPAWN_SETCGROUP control whether the cgroup file descriptor will be used or not with clone3. There is no fallback if either clone3 does not support the flag or if the architecture does not provide the clone3 wrapper, in this case posix_spawn returns EOPNOTSUPP. Checked on x86_64-linux-gnu. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* configure: Use autoconf 2.71Siddhesh Poyarekar2023-07-173-0/+3
| | | | | | | | | | | | | | Bump autoconf requirement to 2.71 to allow regenerating configure on more recent distributions. autoconf 2.71 has been in Fedora since F36 and is the current version in Debian stable (bookworm). It appears to be current in Gentoo as well. All sysdeps configure and preconfigure scripts have also been regenerated; all changes are trivial transformations that do not affect functionality. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* x86: Adjust Linux x32 dl-cache inclusion pathAdhemerval Zanella2023-06-261-1/+1
| | | | | | It fixes the x32 build failure introduced by 45e2483a6c. Checked on a x86_64-linux-gnu-x32 build.
* x86: Make dl-cache.h and readelflib.c not Linux-specificSergey Bugaev2023-06-261-51/+0
| | | | | | | These files could be useful to any port that wants to use ld.so.cache. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Add the wcslcpy, wcslcat functionsFlorian Weimer2023-06-142-0/+8
| | | | | | | These functions are about to be added to POSIX, under Austin Group issue 986. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Implement strlcpy and strlcat [BZ #178]Florian Weimer2023-06-142-0/+8
| | | | | | | | | | | These functions are about to be added to POSIX, under Austin Group issue 986. The fortified strlcat implementation does not raise SIGABRT if the destination buffer does not contain a null terminator, it just inherits the non-failing regular strlcat behavior. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* Fix misspellings in sysdeps/unix -- BZ 25337Paul Pluzhnikov2023-05-231-1/+1
| | | | | | | Applying this commit results in bit-identical rebuild of libc.so.6 math/libm.so.6 elf/ld-linux-x86-64.so.2 mathvec/libmvec.so.1 Reviewed-by: Florian Weimer <fweimer@redhat.com>
* hurd: Implement prefer_map_32bit_exec tunableSergey Bugaev2023-04-245-120/+0
| | | | | | | This makes the prefer_map_32bit_exec tunable no longer Linux-specific. Signed-off-by: Sergey Bugaev <bugaevc@gmail.com> Message-Id: <20230423215526.346009-4-bugaevc@gmail.com>
* math: Remove the error handling wrapper from fmod and fmodfAdhemerval Zanella Netto2023-04-032-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The error handling is moved to sysdeps/ieee754 version with no SVID support. The compatibility symbol versions still use the wrapper with SVID error handling around the new code. There is no new symbol version nor compatibility code on !LIBM_SVID_COMPAT targets (e.g. riscv). The ia64 is unchanged, since it still uses the arch specific __libm_error_region on its implementation. For both i686 and m68k, which provive arch specific implementation, wrappers are added so no new symbol are added (which would require to change the implementations). It shows an small improvement, the results for fmod: Architecture | Input | master | patch -----------------|-----------------|----------|-------- x86_64 (Ryzen 9) | subnormals | 12.5049 | 9.40992 x86_64 (Ryzen 9) | normal | 296.939 | 296.738 x86_64 (Ryzen 9) | close-exponents | 16.0244 | 13.119 aarch64 (N1) | subnormal | 6.81778 | 4.33313 aarch64 (N1) | normal | 155.620 | 152.915 aarch64 (N1) | close-exponents | 8.21306 | 5.76138 armhf (N1) | subnormal | 15.1083 | 14.5746 armhf (N1) | normal | 244.833 | 241.738 armhf (N1) | close-exponents | 21.8182 | 22.457 Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu. Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
* Remove --enable-tunables configure optionAdhemerval Zanella Netto2023-03-291-2/+0
| | | | | | | | | | | | And make always supported. The configure option was added on glibc 2.25 and some features require it (such as hwcap mask, huge pages support, and lock elisition tuning). It also simplifies the build permutations. Changes from v1: * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs more discussion. * Cleanup more code. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
* C2x scanf binary constant handlingJoseph Myers2023-03-022-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | C2x adds binary integer constants starting with 0b or 0B, and supports those constants for the %i scanf format (in addition to the %b format, which isn't yet implemented for scanf in glibc). Implement that scanf support for glibc. As with the strtol support, this is incompatible with previous C standard versions, in that such an input string starting with 0b or 0B was previously required to be parsed as 0 (with the rest of the input potentially matching subsequent parts of the scanf format string). Thus this patch adds 12 new __isoc23_* functions per long double format (12, 24 or 36 depending on how many long double formats the glibc configuration supports), with appropriate header redirection support (generally very closely following that for the __isoc99_* scanf functions - note that __GLIBC_USE (DEPRECATED_SCANF) takes precedence over __GLIBC_USE (C2X_STRTOL), so the case of GNU extensions to C89 continues to get old-style GNU %a and does not get this new feature). The function names would remain as __isoc23_* even if C2x ends up published in 2024 rather than 2023. When scanf %b support is added, I think it will be appropriate for all versions of scanf to follow C2x rules for inputs to the %b format (given that there are no compatibility concerns for a new format). Tested for x86_64 (full glibc testsuite). The first version was also tested for powerpc (32-bit) and powerpc64le (stdio-common/ and wcsmbs/ tests), and with build-many-glibcs.py.
* x86-64: Add glibc.cpu.prefer_map_32bit_exec [BZ #28656]H.J. Lu2023-02-226-0/+165
| | | | | | | | | | | | | | | | | | | Crossing 2GB boundaries with indirect calls and jumps can use more branch prediction resources on Intel Golden Cove CPU (see the "Misprediction for Branches >2GB" section in Intel 64 and IA-32 Architectures Optimization Reference Manual.) There is visible performance improvement on workloads with many PLT calls when executable and shared libraries are mmapped below 2GB. Add the Prefer_MAP_32BIT_EXEC bit so that mmap will try to map executable or denywrite pages in shared libraries with MAP_32BIT first. NB: Prefer_MAP_32BIT_EXEC reduces bits available for address space layout randomization (ASLR), which is always disabled for SUID programs and can only be enabled by the tunable, glibc.cpu.prefer_map_32bit_exec, or the environment variable, LD_PREFER_MAP_32BIT_EXEC. This works only between shared libraries or between shared libraries and executables with addresses below 2GB. PIEs are usually loaded at a random address above 4GB by the kernel.
* C2x strtol binary constant handlingJoseph Myers2023-02-162-0/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | C2x adds binary integer constants starting with 0b or 0B, and supports those constants in strtol-family functions when the base passed is 0 or 2. Implement that strtol support for glibc. As discussed at <https://sourceware.org/pipermail/libc-alpha/2020-December/120414.html>, this is incompatible with previous C standard versions, in that such an input string starting with 0b or 0B was previously required to be parsed as 0 (with the rest of the string unprocessed). Thus, as proposed there, this patch adds 20 new __isoc23_* functions with appropriate header redirection support. This patch does *not* do anything about scanf %i (which will need 12 new functions per long double variant, so 12, 24 or 36 depending on the glibc configuration), instead leaving that for a future patch. The function names would remain as __isoc23_* even if C2x ends up published in 2024 rather than 2023. Making this change leads to the question of what should happen to internal uses of these functions in glibc and its tests. The header redirection (which applies for _GNU_SOURCE or any other feature test macros enabling C2x features) has the effect of redirecting internal uses but without those uses then ending up at a hidden alias (see the comment in include/stdio.h about interaction with libc_hidden_proto). It seems desirable for the default for internal uses to be the same versions used by normal code using _GNU_SOURCE, so rather than doing anything to disable that redirection, similar macro definitions to those in include/stdio.h are added to the include/ headers for the new functions. Given that the default for uses in glibc is for the redirections to apply, the next question is whether the C2x semantics are correct for all those uses. Uses with the base fixed to 10, 16 or any other value other than 0 or 2 can be ignored. I think this leaves the following internal uses to consider (an important consideration for review of this patch will be both whether this list is complete and whether my conclusions on all entries in it are correct): benchtests/bench-malloc-simple.c benchtests/bench-string.h elf/sotruss-lib.c math/libm-test-support.c nptl/perf.c nscd/nscd_conf.c nss/nss_files/files-parse.c posix/tst-fnmatch.c posix/wordexp.c resolv/inet_addr.c rt/tst-mqueue7.c soft-fp/testit.c stdlib/fmtmsg.c support/support_test_main.c support/test-container.c sysdeps/pthread/tst-mutex10.c I think all of these places are OK with the new semantics, except for resolv/inet_addr.c, where the POSIX semantics of inet_addr do not allow for binary constants; thus, I changed that file (to use __strtoul_internal, whose semantics are unchanged) and added a test for this case. In the case of posix/wordexp.c I think accepting binary constants is OK since POSIX explicitly allows additional forms of shell arithmetic expressions, and in stdlib/fmtmsg.c SEV_LEVEL is not in POSIX so again I think accepting binary constants is OK. Functions such as __strtol_internal, which are only exported for compatibility with old binaries from when those were used in inline functions in headers, have unchanged semantics; the __*_l_internal versions (purely internal to libc and not exported) have a new argument to specify whether to accept binary constants. As well as for the standard functions, the header redirection also applies to the *_l versions (GNU extensions), and to legacy functions such as strtoq, to avoid confusing inconsistency (the *q functions redirect to __isoc23_*ll rather than needing their own __isoc23_* entry points). For the functions that are only declared with _GNU_SOURCE, this means the old versions are no longer available for normal user programs at all. An internal __GLIBC_USE_C2X_STRTOL macro is used to control the redirections in the headers, and cases in glibc that wish to avoid the redirections - the function implementations themselves and the tests of the old versions of the GNU functions - then undefine and redefine that macro to allow the old versions to be accessed. (There would of course be greater complexity should we wish to make any of the old versions into compat symbols / avoid them being defined at all for new glibc ABIs.) strtol_l.c has some similarity to strtol.c in gnulib, but has already diverged some way (and isn't listed at all at https://sourceware.org/glibc/wiki/SharedSourceFiles unlike strtoll.c and strtoul.c); I haven't made any attempts at gnulib compatibility in the changes to that file. I note incidentally that inttypes.h and wchar.h are missing the __nonnull present on declarations of this family of functions in stdlib.h; I didn't make any changes in that regard for the new declarations added.
* Linux: Do not align the stack for __clone3Adhemerval Zanella Netto2023-02-011-3/+0
| | | | | | | | | | All internal callers of __clone3 should provide an already aligned stack. Removing the stack alignment in __clone3 is a net gain: it simplifies the internal function contract (mask/unmask signals) along with the arch-specific code. Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Update copyright dates with scripts/update-copyrightsJoseph Myers2023-01-0625-25/+25
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* Introduce <pointer_guard.h>, extracted from <sysdep.h>Florian Weimer2022-10-183-40/+62
| | | | | | | | | | | | | | This allows us to define a generic no-op version of PTR_MANGLE and PTR_DEMANGLE. In the future, we can use PTR_MANGLE and PTR_DEMANGLE unconditionally in C sources, avoiding an unintended loss of hardening due to missing include files or unlucky header inclusion ordering. In i386 and x86_64, we can avoid a <tls.h> dependency in the C code by using the computed constant from <tcb-offsets.h>. <sysdep.h> no longer includes these definitions, so there is no cyclic dependency anymore when computing the <tcb-offsets.h> constants. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Assume only FLAG_ELF_LIBC6 suportLucas A. M. Magalhaes2022-08-041-26/+0
| | | | | | | | | | | The older libc versions are obsolete for over twenty years now. This patch removes the special flags for libc5 and libc4 and assumes that all libraries cached are libc6 compatible and use FLAG_ELF_LIBC6. Checked with a build for all affected architectures. Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Remove left over LD_LIBRARY_VERSION usagesAdhemerval Zanella2022-08-041-2/+0
| | | | | The environment variable was removed by d2db60d8d830ef68c8d20a77ac3572d610aa40b1.
* stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)Adhemerval Zanella Netto2022-07-222-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* stdlib: Implement mbrtoc8, c8rtomb, and the char8_t typedef.Tom Honermann2022-07-062-0/+4
| | | | | | | | | | | | | | | | | This change provides implementations for the mbrtoc8 and c8rtomb functions adopted for C++20 via WG21 P0482R6 and for C2X via WG14 N2653. It also provides the char8_t typedef from WG14 N2653. The mbrtoc8 and c8rtomb functions are declared in uchar.h in C2X mode or when the _GNU_SOURCE macro or C++20 __cpp_char8_t feature test macro is defined. The char8_t typedef is declared in uchar.h in C2X mode or when the _GNU_SOURCE macro is defined and the C++20 __cpp_char8_t feature test macro is not defined (if __cpp_char8_t is defined, then char8_t is a builtin type). Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Replace __libc_multiple_threads with __libc_single_threadedAdhemerval Zanella2022-07-052-2/+2
| | | | | | | | | | | And also fixes the SINGLE_THREAD_P macro for SINGLE_THREAD_BY_GLOBAL, since header inclusion single-thread.h is in the wrong order, the define needs to come before including sysdeps/unix/sysdep.h. The macro is now moved to a per-arch single-threade.h header. The SINGLE_THREAD_P is used on some more places. Checked on aarch64-linux-gnu and x86_64-linux-gnu.
* linux: Add mount_setattrAdhemerval Zanella2022-07-052-0/+2
| | | | | | | | | | It was added on Linux 5.12 (2a1867219c7b27f928e2545782b86daaf9ad50bd) to allow change the properties of a mount or a mount tree using file descriptors which the new mount api is based on. Checked on x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* linux: Add open_treeAdhemerval Zanella2022-07-052-0/+2
| | | | | | | It was added on Linux 5.2 (a07b20004793d8926f78d63eb5980559f7813404) to return a O_PATH-opened file descriptor to an existing mountpoint. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* linux: Add fspickAdhemerval Zanella2022-07-052-0/+2
| | | | | | | | | It was added on Linux 5.2 (cf3cba4a429be43e5527a3f78859b1bfd9ebc5fb) that can be used to pick an existing mountpoint into an filesystem context which can thereafter be used to reconfigure a superblock with fsconfig syscall. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* linux: Add fsconfigAdhemerval Zanella2022-07-052-0/+2
| | | | | | | | | | | | | It was added on Linux 5.2 (ecdab150fddb42fe6a739335257949220033b782) as a way to a configure filesystem creation context and trigger actions upon it, to be used in conjunction with fsopen, fspick and fsmount. The fsconfig_command commands are currently only defined as an enum, so they can't be checked on tst-mount-consts.py with current test support. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* linux: Add move_mountAdhemerval Zanella2022-06-242-0/+2
| | | | | | | | | It was added on Linux 5.2 (2db154b3ea8e14b04fee23e3fdfd5e9d17fbc6ae) as way t move a mount from one place to another and, in the next commit, allow to attach an unattached mount tree. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* linux: Add fsmountAdhemerval Zanella2022-06-242-0/+2
| | | | | | | | | | It was added on 5.2 (93766fbd2696c2c4453dd8e1070977e9cd4e6b6d) to provide a way by which a filesystem opened with fsopen and configured by a series of fsconfig calls can have a detached mount object created for it. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* linux: Add fsopenAdhemerval Zanella2022-06-242-0/+2
| | | | | | | | | It was added on Linux 5.2 (24dcb3d90a1f67fe08c68a004af37df059d74005) to start the process of preparing to create a superblock that will then be mountable, using an fd as a context handle. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-11-12 10:20:01 +0000