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* sysconf: Add _SC_MINSIGSTKSZ/_SC_SIGSTKSZ [BZ #20305]H.J. Lu2021-02-0123-3/+416
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* hurd TIOCFLUSH: Cope BSD 4.1 semanticSamuel Thibault2021-02-011-0/+4
| | | | | | BSD 4.1 did not have an argument for TIOCFLUSH, BSD 4.2 added it. There are still a lot of applications out there that pass a NULL argument to TIOCFLUSH, so we should rather cope with it.
* tst-mallinfo2.c: Remove useless trailing semicolon for macroYang Xu2021-02-011-1/+1
| | | | | | Macros should not use a trailing semicolon, so remove it. Reviewed-by: DJ Delorie <dj@redhat.com>
* elf: Replace a --defsym trick with an object file to be compatible with LLDFangrui Song2021-02-011-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing code specifies -Wl,--defsym=malloc=0 and other malloc.os definitions before libc_pic.a so that libc_pic.a(malloc.os) is not fetched. This trick is used to avoid multiple definition errors which would happen as a chain result: dl-allobjs.os has an undefined __libc_scratch_buffer_set_array_size __libc_scratch_buffer_set_array_size fetches libc_pic.a(scratch_buffer_set_array_size.os) libc_pic.a(scratch_buffer_set_array_size.os) has an undefined free free fetches libc_pic.a(malloc.os) libc_pic.a(malloc.os) has an undefined __libc_message __libc_message fetches libc_pic.a(libc_fatal.os) libc_fatal.os will cause a multiple definition error (__GI___libc_fatal) >>> defined at dl-fxstatat64.c >>> /tmp/p/glibc/Release/elf/dl-allobjs.os:(__GI___libc_fatal) >>> defined at libc_fatal.c >>> libc_fatal.os:(.text+0x240) in archive /tmp/p/glibc/Release/libc_pic.a LLD processes --defsym after all input files, so this trick does not suppress multiple definition errors with LLD. Split the step into two and use an object file to make the intention more obvious and make LLD work. This is conceptually more appropriate because --defsym defines a SHN_ABS symbol while a normal definition is relative to the image base. See https://sourceware.org/pipermail/libc-alpha/2020-March/111910.html for discussions about the --defsym semantics. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
* Open master branch for glibc 2.34 development glibc-2.33.9000Adhemerval Zanella2021-02-012-2/+26
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* Prepare for glibc 2.33 release glibc-2.33Adhemerval Zanella2021-02-013-3/+12849
| | | | Update version.h, features.h, and ChangeLog.old/ChangeLog.22.
* Update NEWS with bugsAdhemerval Zanella2021-02-011-2/+118
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* Update translationsAdhemerval Zanella2021-02-011-0/+6965
| | | | Add missing Serbian translation.
* NEWS: Fix typo in CVE-2021-3326 entryFlorian Weimer2021-01-291-1/+1
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* elf: Fix tests that rely on ld.so.cache for cross-compilingAdhemerval Zanella2021-01-293-0/+26
| | | | | | | | | | | | | | | | For configurations with cross-compiling equal to 'maybe' or 'no', ldconfig will not run and thus the ld.so.cache will not be created on the container testroot.pristine. This lead to failures on both tst-glibc-hwcaps-prepend-cache and tst-ldconfig-ld_so_conf-update on environments where the same compiler can be used to build different ABIs (powerpc and x86 for instance). This patch addas a new test-container hook, ldconfig.run, that triggers a ldconfig execution prior the test execution. Checked on x86_64-linux-gnu and i686-linux-gnu.
* NEWS: Mention CVE-2021-3326 (iconv assertion with ISO-20220-JP-3)Florian Weimer2021-01-291-0/+6
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* NEWS: Add entry for glibc-hwcaps and deprecate legacy hwcapsFlorian Weimer2021-01-291-0/+21
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* x86: Properly set usable CET feature bits [BZ #26625]H.J. Lu2021-01-2910-13/+120
| | | | | | | | | | | | | | | | | | | | | | | | commit 94cd37ebb293321115a36a422b091fdb72d2fb08 Author: H.J. Lu <hjl.tools@gmail.com> Date: Wed Sep 16 05:27:32 2020 -0700 x86: Use HAS_CPU_FEATURE with IBT and SHSTK [BZ #26625] broke GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK since it can no longer disable IBT nor SHSTK. Handle IBT and SHSTK with: 1. Revert commit 94cd37ebb293321115a36a422b091fdb72d2fb08. 2. Clears the usable CET feature bits if kernel doesn't support CET. 3. Add GLIBC_TUNABLES tests without dlopen. 4. Add tests to verify that CPU_FEATURE_USABLE on IBT and SHSTK matches _get_ssp. 5. Update GLIBC_TUNABLES tests with dlopen to verify that CET is disabled with GLIBC_TUNABLES. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Update translationsAdhemerval Zanella2021-01-2835-10000/+13994
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* Update libc.pot for 2.33 releaseAdhemerval Zanella2021-01-281-341/+403
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* Update ia64 libm-test-ulpsAdhemerval Zanella2021-01-281-2/+2
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* sh: Update libm-tests-ulpsAdhemerval Zanella2021-01-281-19/+23
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* ia64: Fix brk call on statupAdhemerval Zanella2021-01-281-0/+22
| | | | | | | | | brk used by statup before TCB is properly set, so we can't use IA64_USE_NEW_STUB. This patch fixes a regression introduced by 720480934ab910. Checked on ia64-linux-gnu.
* Update sparc libm-test-ulpsAdhemerval Zanella2021-01-281-11/+12
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* Update alpha libm-test-ulpsAdhemerval Zanella2021-01-281-11/+12
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* powerpc64: Workaround sigtramp vdso return callRaoni Fassina Firmino2021-01-281-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A not so recent kernel change[1] changed how the trampoline `__kernel_sigtramp_rt64` is used to call signal handlers. This was exposed on the test misc/tst-sigcontext-get_pc Before kernel 5.9, the kernel set LR to the trampoline address and jumped directly to the signal handler, and at the end the signal handler, as any other function, would `blr` to the address set. In other words, the trampoline was executed just at the end of the signal handler and the only thing it did was call sigreturn. But since kernel 5.9 the kernel set CTRL to the signal handler and calls to the trampoline code, the trampoline then `bctrl` to the address in CTRL, setting the LR to the next instruction in the middle of the trampoline, when the signal handler returns, the rest of the trampoline code executes the same code as before. Here is the full trampoline code as of kernel 5.11.0-rc5 for reference: V_FUNCTION_BEGIN(__kernel_sigtramp_rt64) .Lsigrt_start: bctrl /* call the handler */ addi r1, r1, __SIGNAL_FRAMESIZE li r0,__NR_rt_sigreturn sc .Lsigrt_end: V_FUNCTION_END(__kernel_sigtramp_rt64) This new behavior breaks how `backtrace()` uses to detect the trampoline frame to correctly reconstruct the stack frame when it is called from inside a signal handling. This workaround rely on the fact that the trampoline code is at very least two (maybe 3?) instructions in size (as it is in the 32 bits version, only on `li` and `sc`), so it is safe to check the return address be in the range __kernel_sigtramp_rt64 .. + 4. [1] subject: powerpc/64/signal: Balance return predictor stack in signal trampoline commit: 0138ba5783ae0dcc799ad401a1e8ac8333790df9 url: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0138ba5783ae0dcc799ad401a1e8ac8333790df9 Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Fix nss/tst-reload2 for systems without PATH_MAXDJ Delorie2021-01-271-0/+4
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* nsswitch: do not reload if "/" changesDJ Delorie2021-01-279-1/+178
| | | | | | | | | | | https://sourceware.org/bugzilla/show_bug.cgi?id=27077 Before reloading nsswitch.conf, verify that the root directory hasn't changed - if it has, it's likely that we've entered a container and should not trust the nsswitch inside the container nor load any shared objects therein. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* elf: Limit tst-prelink-cmp target archsMatheus Castanho2021-01-273-8/+51
| | | | | | | | | | | | | | elf/tst-prelink-cmp was initially added for x86 (commit fe534fe898) to validate the fix for Bug 19178, and later applied to all architectures that use GLOB_DAT relocations (commit 89569c8bb6). However, that bug only affected targets that handle GLOB_DAT relocations as ELF_TYPE_CLASS_EXTERN_PROTECTED_DATA, so the test should only apply to targets defining DL_EXTERN_PROTECTED_DATA, which gates the usage of the elf type class above. For all other targets not meeting that criteria, the test now returns with UNSUPPORTED status. Fixes the test on POWER10 processors, which started using R_PPC64_GLOB_DAT. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* gconv: Fix assertion failure in ISO-2022-JP-3 module (bug 27256)Florian Weimer2021-01-273-20/+178
| | | | | | | | | | | | | | | | | | The conversion loop to the internal encoding does not follow the interface contract that __GCONV_FULL_OUTPUT is only returned after the internal wchar_t buffer has been filled completely. This is enforced by the first of the two asserts in iconv/skeleton.c: /* We must run out of output buffer space in this rerun. */ assert (outbuf == outerr); assert (nstatus == __GCONV_FULL_OUTPUT); This commit solves this issue by queuing a second wide character which cannot be written immediately in the state variable, like other converters already do (e.g., BIG5-HKSCS or TSCII). Reported-by: Tavis Ormandy <taviso@gmail.com>
* 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.
* benchtests: Do not build bench-timing-type with MODULE_NAME=libcArjun Shankar2021-01-261-7/+7
| | | | | | | | | Since commit 2682695e5c7a, `make bench-build' with `--enable-static-pie' fails due to bench-timing-type being incorrectly built with MODULE_NAME set to `libc'. This commit sets MODULE_NAME to nonlib, thus fixing the build failure. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* aarch64: Fix the list of tested IFUNC variants [BZ #26818]Szabolcs Nagy2021-01-252-4/+6
| | | | | | | | | | | | | | Some IFUNC variants are not compatible with BTI and MTE so don't set them as usable for testing and benchmarking on a BTI or MTE enabled system. As far as IFUNC selectors are concerned a system is BTI enabled if the cpu supports it and glibc was built with BTI branch protection. Most IFUNC variants are BTI compatible, but thunderx2 memcpy and memmove use a jump table with indirect jump, without a BTI j. Fixes bug 26818.
* Update INSTALL with package versions that are known to workTulio Magno Quites Machado Filho2021-01-252-25/+25
| | | | | | | Most packages have been tested with their latest releases, except for Python, whose latest version is 3.9.1. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* aarch64: Move and update the definition of MTE_ENABLEDSzabolcs Nagy2021-01-252-11/+11
| | | | | | | | | | | | The hwcap value is now in linux 5.10 and in glibc bits/hwcap.h, so use that definition. Move the definition to init-arch.h so all ifunc selectors can use it and expose an "mte" shorthand for mte enabled runtime. For now we allow user code to enable tag checks and use PROT_MTE mappings without libc involvment, this is not guaranteed ABI, but can be useful for testing and debugging with MTE.
* Fix misplaced constAndreas Schwab2021-01-252-2/+2
| | | | | Constify __x86_cacheinfo_p and __x86_cpu_features_p, not their pointer target types.
* Update C-SKY libm-test-ulpsMao Han2021-01-232-54/+61
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* manual: Correct argument order in mount examples [BZ #27207]John McCabe2021-01-221-2/+2
| | | | Reviewed-by: DJ Delorie <dj@redhat.com>
* linux: mips: Fix getdents64 fallback on mips64-n32Adhemerval Zanella2021-01-222-24/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC mainline shows the following error: ../sysdeps/unix/sysv/linux/mips/mips64/getdents64.c: In function '__getdents64': ../sysdeps/unix/sysv/linux/mips/mips64/getdents64.c:121:7: error: 'memcpy' forming offset [4, 7] is out of the bounds [0, 4] [-Werror=array-bounds] 121 | memcpy (((char *) dp + offsetof (struct dirent64, d_ino)), | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 122 | KDP_MEMBER (kdp, d_ino), sizeof ((struct dirent64){0}.d_ino)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ../sysdeps/unix/sysv/linux/mips/mips64/getdents64.c:123:7: error: 'memcpy' forming offset [4, 7] is out of the bounds [0, 4] [-Werror=array-bounds] 123 | memcpy (((char *) dp + offsetof (struct dirent64, d_off)), | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 124 | KDP_MEMBER (kdp, d_off), sizeof ((struct dirent64){0}.d_off)); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The issue is due both d_ino and d_off fields for mips64-n32 kernel_dirent are 32-bits, while this is using memcpy to copy 64 bits from it into the glibc dirent64. The fix is to use a temporary buffer to read the correct type from kernel_dirent. Checked with a build-many-glibcs.py for mips64el-linux-gnu and I also checked the tst-getdents64 on mips64el 4.1.4 kernel with and without fallback enabled (by manually setting the getdents64_supported).
* x86: Properly match CPU features in /proc/cpuinfo [BZ #27222]H.J. Lu2021-01-221-13/+30
| | | | | | | | | | | | | | Search " YYY " and " YYY\n", instead of "YYY", to avoid matching "XXXYYYZZZ" with "YYY". Update /proc/cpuinfo CPU feature names: /proc/cpuinfo glibc ------------------------------------------------ avx512vbmi AVX512_VBMI dts DS pni SSE3 tsc_deadline_timer TSC_DEADLINE
* x86-64: Update tst-glibc-hwcaps-2.c for x86-64 baselineH.J. Lu2021-01-221-1/+1
| | | | | Return EXIT_FAILURE only if the level 2 libx86-64-isa-level.so is used on x86-64 baseline machine.
* powerpc64: Select POWER9 machine for the scv instructionFlorian Weimer2021-01-223-1/+10
| | | | | | | | | It is not available with the baseline ISA. Fixes commit 68ab82f56690ada86ac1e0c46bad06ba189a10ef ("powerpc: Runtime selection between sc and scv for syscalls"). Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* x86: Check ifunc resolver with CPU_FEATURE_USABLE [BZ #27072]H.J. Lu2021-01-216-0/+184
| | | | | | | | Check ifunc resolver with CPU_FEATURE_USABLE and tunables in dynamic and static executables to verify that CPUID features are initialized early in static PIE. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Revert "linux: Move {f}xstat{at} to compat symbols" for static buildAdhemerval Zanella2021-01-2117-37/+40
| | | | | | | | | | | | | | 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.
* aarch64: revert memcpy optimze for kunpeng to avoid performance degradationShuo Wang2021-01-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 863d775c481704baaa41855fc93e5a1ca2dc6bf6, kunpeng920 is added to default memcpy version, however, there is performance degradation when the copy size is some large bytes, eg: 100k. This is the result, tested in glibc-2.28: before backport after backport Performance improvement memcpy_1k 0.005 0.005 0.00% memcpy_10k 0.032 0.029 10.34% memcpy_100k 0.356 0.429 -17.02% memcpy_1m 7.470 11.153 -33.02% This is the demo #include "stdio.h" #include "string.h" #include "stdlib.h" char a[1024*1024] = {12}; char b[1024*1024] = {13}; int main(int argc, char *argv[]) { int i = atoi(argv[1]); int j; int size = atoi(argv[2]); for (j = 0; j < i; j++) memcpy(b, a, size*1024); return 0; } # gcc -g -O0 memcpy.c -o memcpy # time taskset -c 10 ./memcpy 100000 1024 Co-authored-by: liqingqing <liqingqing3@huawei.com>
* 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>
* csu: Move static pie self relocation later [BZ #27072]Szabolcs Nagy2021-01-211-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | IFUNC resolvers may depend on tunables and cpu feature setup so move static pie self relocation after those. It is hard to guarantee that the ealy startup code does not rely on relocations so this is a bit fragile. It would be more robust to handle RELATIVE relocs early and only IRELATIVE relocs later, but the current relocation processing code cannot do that. The early startup code up to relocation processing includes _dl_aux_init (auxvec); __libc_init_secure (); __tunables_init (__environ); ARCH_INIT_CPU_FEATURES (); _dl_relocate_static_pie (); These are simple enough that RELATIVE relocs can be avoided. The following steps include ARCH_SETUP_IREL (); ARCH_SETUP_TLS (); ARCH_APPLY_IREL (); On some targets IRELATIVE processing relies on TLS setup on others TLS setup relies on IRELATIVE relocs, so the right position for _dl_relocate_static_pie is target dependent. For now move self relocation as early as possible on targets that support static PIE. Fixes bug 27072. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* Use hidden visibility for early static PIE codeSzabolcs Nagy2021-01-218-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | | Extern symbol access in position independent code usually involves GOT indirection which needs RELATIVE reloc in a static linked PIE. (On some targets this is avoided e.g. because the linker can relax a GOT access to a pc-relative access, but this is not generally true.) Code that runs before static PIE self relocation must avoid relying on dynamic relocations which can be ensured by using hidden visibility. However we cannot just make all symbols hidden: On i386, all calls to IFUNC functions must go through PLT and calls to hidden functions CANNOT go through PLT in PIE since EBX used in PIE PLT may not be set up for local calls to hidden IFUNC functions. This patch aims to make symbol references hidden in code that is used before and by _dl_relocate_static_pie when building a static PIE libc. Note: for an object that is used in the startup code, its references and definition may not have consistent visibility: it is only forced hidden in the startup code. This is needed for fixing bug 27072. Co-authored-by: H.J. Lu <hjl.tools@gmail.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* csu: Avoid weak ref for __ehdr_start in static PIESzabolcs Nagy2021-01-211-0/+4
| | | | | | | | | | | | | All linkers support __ehdr_start that support static PIE linking, so there is no need to check for its presence via a weak reference. This avoids a RELATIVE relocation in static PIE startup code on some targets. With non-PIE static linking the weak ref check is kept in case the linker does not support __ehdr_start. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* configure: Check for static PIE supportSzabolcs Nagy2021-01-219-0/+39
| | | | | | | | | | | | | | Add SUPPORT_STATIC_PIE that targets can define if they support static PIE. This requires PI_STATIC_AND_HIDDEN support and various linker features as described in commit 9d7a3741c9e59eba87fb3ca6b9f979befce07826 Add --enable-static-pie configure option to build static PIE [BZ #19574] Currently defined on x86_64, i386 and aarch64 where static PIE is known to work. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Avoid RELATIVE relocs in __tunables_initSzabolcs Nagy2021-01-213-4/+14
| | | | | | | | | | | | | | | | | | | | | | | With static pie linking pointers in the tunables list need RELATIVE relocs since the absolute address is not known at link time. We want to avoid relocations so the static pie self relocation can be done after tunables are initialized. This is a simple fix that embeds the tunable strings into the tunable list instead of using pointers. It is possible to have a more compact representation of tunables with some additional complexity in the generator and tunable parser logic. Such optimization will be useful if the list of tunables grows. There is still an issue that tunables_strdup allocates and the failure handling code path is sufficiently complex that it can easily have RELATIVE relocations. It is possible to avoid the early allocation and only change environment variables in a setuid exe after relocations are processed. But that is a bigger change and early failure is fatal anyway so it is not as critical to fix right away. This is bug 27181. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* elf: Make the tunable struct definition internal onlySzabolcs Nagy2021-01-213-38/+43
| | | | | | | | | | | | | | | | | The representation of the tunables including type information and the tunable list structure are only used in the implementation not in the tunables api that is exposed to usage within glibc. This patch moves the representation related definitions into the existing dl-tunable-types.h and uses that only for implementation. The tunable callback and related types are moved to dl-tunables.h because they are part of the tunables api. This reduces the details exposed in the tunables api so the internals are easier to change. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* <sys/platform/x86.h>: Remove the C preprocessor magicH.J. Lu2021-01-2124-847/+1162
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In <sys/platform/x86.h>, define CPU features as enum instead of using the C preprocessor magic to make it easier to wrap this functionality in other languages. Move the C preprocessor magic to internal header for better GCC codegen when more than one features are checked in a single expression as in x86-64 dl-hwcaps-subdirs.c. 1. Rename COMMON_CPUID_INDEX_XXX to CPUID_INDEX_XXX. 2. Move CPUID_INDEX_MAX to sysdeps/x86/include/cpu-features.h. 3. Remove struct cpu_features and __x86_get_cpu_features from <sys/platform/x86.h>. 4. Add __x86_get_cpuid_feature_leaf to <sys/platform/x86.h> and put it in libc. 5. Make __get_cpu_features() private to glibc. 6. Replace __x86_get_cpu_features(N) with __get_cpu_features(). 7. Add _dl_x86_get_cpu_features to GLIBC_PRIVATE. 8. Use a single enum index for each CPU feature detection. 9. Pass the CPUID feature leaf to __x86_get_cpuid_feature_leaf. 10. Return zero struct cpuid_feature for the older glibc binary with a smaller CPUID_INDEX_MAX [BZ #27104]. 11. Inside glibc, use the C preprocessor magic so that cpu_features data can be loaded just once leading to more compact code for glibc. 256 bits are used for each CPUID leaf. Some leaves only contain a few features. We can add exceptions to such leaves. But it will increase code sizes and it is harder to provide backward/forward compatibilities when new features are added to such leaves in the future. When new leaves are added, _rtld_global_ro offsets will change which leads to race condition during in-place updates. We may avoid in-place updates by 1. Rename the old glibc. 2. Install the new glibc. 3. Remove the old glibc. NB: A function, __x86_get_cpuid_feature_leaf , is used to avoid the copy relocation issue with IFUNC resolver as shown in IFUNC resolver tests.
* posix: Fix fnmatch.c on bootstrapAdhemerval Zanella2021-01-201-1/+1
| | | | | | | | | Only define FALLTHROUGH for _LIBC and do not check __clang_major__ value. It partially syncs with gnulib 5c52f00c69f39fe. Checked with build-many-glibcs.py for aarch64-linux-gnu.
* stdlib: Add testcase for BZ #26241Adhemerval Zanella2021-01-202-1/+103
| | | | | | | | | | | | | | | | | | Old implementation of realpath allocates a PATH_MAX using alloca for each symlink in the path, leading to MAXSYMLINKS times PATH_MAX maximum stack usage. The test create a symlink with __eloop_threshold() loops and creates a thread with minimum stack size (obtained through support_small_stack_thread_attribute). The thread issues a stack allocations that fill the thread allocated stack minus some slack plus and the realpath usage (which assumes a bounded stack usage). If realpath uses more than about 2 * PATH_MAX plus some slack it triggers a stackoverflow. Checked on x86_64-linux-gnu and i686-linux-gnu. Reviewed-by: DJ Delorie <dj@redhat.com>
generated by cgit-pink 1.4.1 (git 2.36.1) at 2024-12-13 10:06:28 +0000