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* Argument Syntax: Use "option", @option, and @command.Carlos O'Donell2020-10-301-6/+6
| | | | Suggested-by: David O'Brien <daobrien@redhat.com>
* Reword description of SXID_* tunable propertiesSiddhesh Poyarekar2020-10-221-5/+6
| | | | | | | | | | | | | The SXID_* tunable properties only influence processes that are AT_SECURE, so make that a bit more explicit in the documentation and comment. Revisiting the code after a few years I managed to confuse myself, so I imagine there could be others who may have incorrectly assumed like I did that the SXID_ERASE tunables are not inherited by children of non-AT_SECURE processes. Reviewed-by: Florian Weimer <fweimer@redhat.com>
* Move vtimes to a compatibility symbolAdhemerval Zanella2020-10-191-61/+0
| | | | | | | | | | | | | | I couldn't pinpoint which standard has added it, but no other POSIX system supports it and/or no longer provide it. The 'struct vtimes' also has a lot of drawbacks due its limited internal type size. I couldn't also see find any project that actually uses this symbol, either in some dignostic way (such as sanitizer). So I think it should be safer to just move to compat symbol, instead of deprecated. The idea it to avoid new ports to export such broken interface (riscv32 for instance). Checked on x86_64-linux-gnu and i686-linux-gnu.
* manual: correct the spelling of "MALLOC_PERTURB_" [BZ #23015]Benno Schulenberg2020-10-131-1/+1
| | | | Reported-by: Martin Dorey <martin.dorey@hds.com>
* manual: replace an obsolete collation example with a valid oneBenno Schulenberg2020-10-131-3/+3
| | | | | | | | | | | | | In the Spanish language, the digraph "ll" has not been considered a separate letter since 1994: https://www.rae.es/consultas/exclusion-de-ch-y-ll-del-abecedario Since January 1998 (commit 49891c106244888123557fca7fddda4fa1f96b1d), glibc's locale data no longer specifies "ch" and "ll" as separate collation elements. So, it's better to not use "ll" in an example. Also, the Czech "ch" is a better example as it collates in a more surprising place.
* <sys/platform/x86.h>: Add FSRCS/FSRS/FZLRM supportH.J. Lu2020-10-091-0/+9
| | | | | Add Fast Short REP CMP and SCA (FSRCS), Fast Short REP STO (FSRS) and Fast Zero-Length REP MOV (FZLRM) support to <sys/platform/x86.h>.
* <sys/platform/x86.h>: Add Intel HRESET supportH.J. Lu2020-10-091-0/+3
| | | | Add Intel HRESET support to <sys/platform/x86.h>.
* <sys/platform/x86.h>: Add AVX-VNNI supportH.J. Lu2020-10-091-0/+3
| | | | Add AVX-VNNI support to <sys/platform/x86.h>.
* <sys/platform/x86.h>: Add AVX512_FP16 supportH.J. Lu2020-10-091-0/+3
| | | | Add AVX512_FP16 support to <sys/platform/x86.h>.
* <sys/platform/x86.h>: Add Intel UINTR supportH.J. Lu2020-10-091-0/+3
| | | | Add Intel UINTR support to <sys/platform/x86.h>.
* Linux: Require properly configured /dev/pts for PTYsFlorian Weimer2020-10-071-8/+3
| | | | | | | | | | | | | Current systems do not have BSD terminals, so the fallback code in posix_openpt/getpt does not do anything. Also remove the file system check for /dev/pts. Current systems always have a devpts file system mounted there if /dev/ptmx exists. grantpt is now essentially a no-op. It only verifies that the argument is a ptmx-descriptor. Therefore, this change indirectly addresses bug 24941. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* manual: Fix typoJonathan Wakely2020-10-051-1/+1
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* Set tunable value as well as min/max valuesH.J. Lu2020-09-291-2/+22
| | | | | | | | Some tunable values and their minimum/maximum values must be determinted at run-time. Add TUNABLE_SET_WITH_BOUNDS and TUNABLE_SET_WITH_BOUNDS_FULL to update tunable value together with minimum and maximum values. __tunable_set_val is updated to set tunable value as well as min/max values.
* Reversing calculation of __x86_shared_non_temporal_thresholdPatrick McGehearty2020-09-281-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __x86_shared_non_temporal_threshold determines when memcpy on x86 uses non_temporal stores to avoid pushing other data out of the last level cache. This patch proposes to revert the calculation change made by H.J. Lu's patch of June 2, 2017. H.J. Lu's patch selected a threshold suitable for a single thread getting maximum performance. It was tuned using the single threaded large memcpy micro benchmark on an 8 core processor. The last change changes the threshold from using 3/4 of one thread's share of the cache to using 3/4 of the entire cache of a multi-threaded system before switching to non-temporal stores. Multi-threaded systems with more than a few threads are server-class and typically have many active threads. If one thread consumes 3/4 of the available cache for all threads, it will cause other active threads to have data removed from the cache. Two examples show the range of the effect. John McCalpin's widely parallel Stream benchmark, which runs in parallel and fetches data sequentially, saw a 20% slowdown with this patch on an internal system test of 128 threads. This regression was discovered when comparing OL8 performance to OL7. An example that compares normal stores to non-temporal stores may be found at https://vgatherps.github.io/2018-09-02-nontemporal/. A simple test shows performance loss of 400 to 500% due to a failure to use nontemporal stores. These performance losses are most likely to occur when the system load is heaviest and good performance is critical. The tunable x86_non_temporal_threshold can be used to override the default for the knowledgable user who really wants maximum cache allocation to a single thread in a multi-threaded system. The manual entry for the tunable has been expanded to provide more information about its purpose. modified: sysdeps/x86/cacheinfo.c modified: manual/tunables.texi
* <sys/platform/x86.h>: Add Intel Key Locker supportH.J. Lu2020-09-161-0/+9
| | | | | | | | | | | | | | | | | | | | | | | Add Intel Key Locker: https://software.intel.com/content/www/us/en/develop/download/intel-key-locker-specification.html support to <sys/platform/x86.h>. Intel Key Locker has 1. KL: AES Key Locker instructions. 2. WIDE_KL: AES wide Key Locker instructions. 3. AESKLE: AES Key Locker instructions are enabled by OS. Applications should use if (CPU_FEATURE_USABLE (KL)) and if (CPU_FEATURE_USABLE (WIDE_KL)) to check if AES Key Locker instructions and AES wide Key Locker instructions are usable.
* x86: Install <sys/platform/x86.h> [BZ #26124]H.J. Lu2020-09-111-0/+517
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Install <sys/platform/x86.h> so that programmers can do #if __has_include(<sys/platform/x86.h>) #include <sys/platform/x86.h> #endif ... if (CPU_FEATURE_USABLE (SSE2)) ... if (CPU_FEATURE_USABLE (AVX2)) ... <sys/platform/x86.h> exports only: enum { COMMON_CPUID_INDEX_1 = 0, COMMON_CPUID_INDEX_7, COMMON_CPUID_INDEX_80000001, COMMON_CPUID_INDEX_D_ECX_1, COMMON_CPUID_INDEX_80000007, COMMON_CPUID_INDEX_80000008, COMMON_CPUID_INDEX_7_ECX_1, /* Keep the following line at the end. */ COMMON_CPUID_INDEX_MAX }; struct cpuid_features { struct cpuid_registers cpuid; struct cpuid_registers usable; }; struct cpu_features { struct cpu_features_basic basic; struct cpuid_features features[COMMON_CPUID_INDEX_MAX]; }; /* Get a pointer to the CPU features structure. */ extern const struct cpu_features *__x86_get_cpu_features (unsigned int max) __attribute__ ((const)); Since all feature checks are done through macros, programs compiled with a newer <sys/platform/x86.h> are compatible with the older glibc binaries as long as the layout of struct cpu_features is identical. The features array can be expanded with backward binary compatibility for both .o and .so files. When COMMON_CPUID_INDEX_MAX is increased to support new processor features, __x86_get_cpu_features in the older glibc binaries returns NULL and HAS_CPU_FEATURE/CPU_FEATURE_USABLE return false on the new processor feature. No new symbol version is neeeded. Both CPU_FEATURE_USABLE and HAS_CPU_FEATURE are provided. HAS_CPU_FEATURE can be used to identify processor features. Note: Although GCC has __builtin_cpu_supports, it only supports a subset of <sys/platform/x86.h> and it is equivalent to CPU_FEATURE_USABLE. It doesn't support HAS_CPU_FEATURE.
* Add mallinfo2 function that support sizes >= 4GB.Martin Liska2020-08-311-18/+18
| | | | | The current int type can easily overflow for allocation of more than 4GB.
* manual: Fix sigdescr_np and sigabbrev_np return type (BZ #26343)Adhemerval Zanella2020-08-081-2/+2
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* manual: Put the istrerrorname_np and strerrordesc_np return type in bracesAdhemerval Zanella2020-08-071-2/+2
| | | | Otherwise it is not rendered or indexed correctly.
* manual: Fix strerrorname_np and strerrordesc_np return type (BZ #26343)Adhemerval Zanella2020-08-071-2/+2
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* manual: Fix some @code/@var formatting glitches chapter Date And TimeFlorian Weimer2020-08-051-10/+10
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* manual: New signal and errno string functions are AS-safeFlorian Weimer2020-07-172-4/+4
| | | | | | | | The annotations for sigabbrev_np, sigdescr_np, strerrordesc_np, strerrorname_np are not preliminary. These functions were added precisely because they are AS-safe. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Linux: Remove rseq supportFlorian Weimer2020-07-161-64/+0
| | | | | | | | | | | | | | | | | | The kernel ABI is not finalized, and there are now various proposals to change the size of struct rseq, which would make the glibc ABI dependent on the version of the kernels used for building glibc. This is of course not acceptable. This reverts commit 48699da1c468543ade14777819bd1b4d652709de ("elf: Support at least 32-byte alignment in static dlopen"), commit 8f4632deb3545b2949cec5454afc3cb21a0024ea ("Linux: rseq registration tests"), commit 6e29cb3f61ff5432c78a1c84b0d9b123a350ab36 ("Linux: Use rseq in sched_getcpu if available"), and commit 0c76fc3c2b346dc5401dc055d97d4279632b0fb3 ("Linux: Perform rseq registration at C startup and thread creation"), resolving the conflicts introduced by the ARC port and the TLS static surplus changes. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* manual: Use Unicode instead HTML entities for characters (bug 19737)Florian Weimer2020-07-161-3/+3
| | | | | | | | | | Texinfo no longer treats arguments to @set in @ifhtml blocks as literal HTML, so the & in the entity references was encoded as @amp; in HTML. Using the equivalent Unicode characters avoids this issue. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
* Remove --enable-obsolete-rpc configure flagPetr Vorel2020-07-131-3/+1
| | | | | | | | | | | | | | | | | | | | | | Sun RPC was removed from glibc. This includes rpcgen program, librpcsvc, and Sun RPC headers. Also test for bug #20790 was removed (test for rpcgen). Backward compatibility for old programs is kept only for architectures and ABIs that have been added in or before version 2.28. libtirpc is mature enough, librpcsvc and rpcgen are provided in rpcsvc-proto project. NOTE: libnsl code depends on Sun RPC (installed libnsl headers use installed Sun RPC headers), thus --enable-obsolete-rpc was a dependency for --enable-obsolete-nsl (removed in a previous commit). The arc ABI list file has to be updated because the port was added with the sunrpc symbols Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Documentation for ARC portVineet Gupta2020-07-101-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (a) ABI doc: https://github.com/foss-for-synopsys-dwc-arc-processors/toolchain/wiki/files/ARCv2_ABI.pdf (b) Programmer's Reference Manual (PRM) : needs a download request to be filled https://www.synopsys.com/dw/ipdir.php?ds=arc-hs44-hs46-hs48 https://www.synopsys.com/dw/doc.php/ds/cc/programmers-reference-manual-ARC-HS.pdf As of port merge (and Florian's patch to fix static TLS), glibc testsuite (cross-test setup) has following failures: FAIL: elf/tst-audit14 FAIL: elf/tst-audit15 FAIL: elf/tst-audit16 FAIL: elf/tst-ldconfig-ld_so_conf-update FAIL: elf/tst-libc_dlvsym FAIL: elf/tst-libc_dlvsym-static FAIL: iconv/test-iconvconfig # Needs gconv installed FAIL: io/ftwtest # Requires execution by non-root FAIL: io/tst-lockf FAIL: libio/tst-wfile-sync FAIL: locale/tst-localedef-path-norm FAIL: nptl/test-cond-printers # needs Python3 and target GDB on target FAIL: nptl/test-condattr-printers # ditto FAIL: nptl/test-mutex-printers # ditto FAIL: nptl/test-mutexattr-printers # ditto FAIL: nptl/test-rwlock-printers # ditto FAIL: nptl/test-rwlockattr-printers # ditto FAIL: nptl/tst-umask1 # passes if run natively on target (NFS ACLv3 support needed) FAIL: nss/bug-erange FAIL: nss/tst-nss-files-hosts-getent FAIL: nss/tst-nss-files-hosts-multi FAIL: posix/bug-ga2 FAIL: posix/globtest # require same user on target and host FAIL: posix/tst-getaddrinfo5 FAIL: stdio-common/tst-vfprintf-width-prec FAIL: stdio-common/tst-vfprintf-width-prec-alloc FAIL: stdio-common/tst-vfprintf-width-prec-mem FAIL: string/tst-strerror FAIL: string/tst-strsignal FAIL: sunrpc/bug20790 # missing cpp on target FAIL: timezone/tst-tzset Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* rtld: Avoid using up static TLS surplus for optimizations [BZ #25051]Szabolcs Nagy2020-07-081-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | On some targets static TLS surplus area can be used opportunistically for dynamically loaded modules such that the TLS access then becomes faster (TLSDESC and powerpc TLS optimization). However we don't want all surplus TLS to be used for this optimization because dynamically loaded modules with initial-exec model TLS can only use surplus TLS. The new contract for surplus static TLS use is: - libc.so can have up to 192 bytes of IE TLS, - other system libraries together can have up to 144 bytes of IE TLS. - Some "optional" static TLS is available for opportunistic use. The optional TLS is now tunable: rtld.optional_static_tls, so users can directly affect the allocated static TLS size. (Note that module unloading with dlclose does not reclaim static TLS. After the optional TLS runs out, TLS access is no longer optimized to use static TLS.) The default setting of rtld.optional_static_tls is 512 so the surplus TLS is 3*192 + 4*144 + 512 = 1664 by default, the same as before. Fixes BZ #25051. Tested on aarch64-linux-gnu and x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* rtld: Account static TLS surplus for audit modulesSzabolcs Nagy2020-07-081-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | The new static TLS surplus size computation is surplus_tls = 192 * (nns-1) + 144 * nns + 512 where nns is controlled via the rtld.nns tunable. This commit accounts audit modules too so nns = rtld.nns + audit modules. rtld.nns should only include the namespaces required by the application, namespaces for audit modules are accounted on top of that so audit modules don't use up the static TLS that is reserved for the application. This allows loading many audit modules without tuning rtld.nns or using up static TLS, and it fixes FAIL: elf/tst-auditmany Note that DL_NNS is currently a hard upper limit for nns, and if rtld.nns + audit modules go over the limit that's a fatal error. By default rtld.nns is 4 which allows 12 audit modules. Counting the audit modules is based on existing audit string parsing code, we cannot use GLRO(dl_naudit) before the modules are actually loaded.
* rtld: Add rtld.nns tunable for the number of supported namespacesSzabolcs Nagy2020-07-081-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TLS_STATIC_SURPLUS is 1664 bytes currently which is not enough to support DL_NNS (== 16) number of dynamic link namespaces, if we assume 192 bytes of TLS are reserved for libc use and 144 bytes are reserved for other system libraries that use IE TLS. A new tunable is introduced to control the number of supported namespaces and to adjust the surplus static TLS size as follows: surplus_tls = 192 * (rtld.nns-1) + 144 * rtld.nns + 512 The default is rtld.nns == 4 and then the surplus TLS size is the same as before, so the behaviour is unchanged by default. If an application creates more namespaces than the rtld.nns setting allows, then it is not guaranteed to work, but the limit is not checked. So existing usage will continue to work, but in the future if an application creates more than 4 dynamic link namespaces then the tunable will need to be set. In this patch DL_NNS is a fixed value and provides a maximum to the rtld.nns setting. Static linking used fixed 2048 bytes surplus TLS, this is changed so the same contract is used as for dynamic linking. With static linking DL_NNS == 1 so rtld.nns tunable is forced to 1, so by default the surplus TLS is reduced to 144 + 512 = 656 bytes. This change is not expected to cause problems. Tested on aarch64-linux-gnu and x86_64-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Remove --enable-obsolete-nsl configure flagPetr Vorel2020-07-083-28/+13
| | | | | | | | | | | | | | | | | | | this means that *always* libnsl is only built as shared library for backward compatibility and the NSS modules libnss_nis and libnss_nisplus are not built at all, libnsl's headers aren't installed. This compatibility is kept only for architectures and ABIs that have been added in or before version 2.28. Replacement implementations based on TIRPC, which additionally support IPv6, are available from <https://github.com/thkukuk/>. This change does not affect libnss_compat which does not depended on libnsl since 2.27 and thus can be used without NIS. libnsl code depends on Sun RPC, e.g. on --enable-obsolete-rpc (installed libnsl headers use installed Sun RPC headers), which will be removed in the following commit.
* string: Add strerrorname_np and strerrordesc_npAdhemerval Zanella2020-07-071-0/+23
| | | | | | | | | | | | | | | | | The strerrorname_np returns error number name (e.g. "EINVAL" for EINVAL) while strerrordesc_np returns string describing error number (e.g "Invalid argument" for EINVAL). Different than strerror, strerrordesc_np does not attempt to translate the return description, both functions return NULL for an invalid error number. They should be used instead of sys_errlist and sys_nerr, both are thread and async-signal safe. These functions are GNU extensions. Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, and s390x-linux-gnu. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* string: Add sigabbrev_np and sigdescr_npAdhemerval Zanella2020-07-071-0/+24
| | | | | | | | | | | | | | | | | | The sigabbrev_np returns the abbreviated signal name (e.g. "HUP" for SIGHUP) while sigdescr_np returns the string describing the error number (e.g "Hangup" for SIGHUP). Different than strsignal, sigdescr_np does not attempt to translate the return description and both functions return NULL for an invalid signal number. They should be used instead of sys_siglist or sys_sigabbrev and they are both thread and async-signal safe. They are added as GNU extensions on string.h header (same as strsignal). Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, and s390x-linux-gnu. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* signal: Move sys_siglist to a compat symbolAdhemerval Zanella2020-07-071-5/+0
| | | | | | | | | | | | | | | | | | | The symbol was deprecated by strsignal and its usage imposes issues such as copy relocations. Its internal name is changed to __sys_siglist and __sys_sigabbrev to avoid static linking usage. The compat code is also refactored, since both Linux and Hurd usage the same strategy: export the same array with different object sizes. The libSegfault change avoids calling strsignal on the SIGFAULT signal handler (the current usage is already sketchy, adding a call that potentially issue locale internal function is even sketchier). Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi on all affected platforms. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* x86: Add thresholds for "rep movsb/stosb" to tunablesH.J. Lu2020-07-061-0/+16
| | | | | | | | | | Add x86_rep_movsb_threshold and x86_rep_stosb_threshold to tunables to update thresholds for "rep movsb" and "rep stosb" at run-time. Note that the user specified threshold for "rep movsb" smaller than the minimum threshold will be ignored. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* Use C2x return value from getpayload of non-NaN (bug 26073).Joseph Myers2020-07-061-3/+4
| | | | | | | | | | | | | | | In TS 18661-1, getpayload had an unspecified return value for a non-NaN argument, while C2x requires the return value -1 in that case. This patch implements the return value of -1. I don't think this is worth having a new symbol version that's an alias of the old one, although occasionally we do that in such cases where the new function semantics are a refinement of the old ones (to avoid programs relying on the new semantics running on older glibc versions but not behaving as intended). Tested for x86_64 and x86; also ran math/ tests for aarch64 and powerpc.
* manual: Document __libc_single_threadedFlorian Weimer2020-07-061-0/+113
| | | | | Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com> Reviewed-by: DJ Delorie <dj@redhat.com>
* Linux: Perform rseq registration at C startup and thread creationMathieu Desnoyers2020-07-061-0/+64
| | | | | | | | | | | | | | | | | | | Register rseq TLS for each thread (including main), and unregister for each thread (excluding main). "rseq" stands for Restartable Sequences. See the rseq(2) man page proposed here: https://lkml.org/lkml/2018/9/19/647 Those are based on glibc master branch commit 3ee1e0ec5c. The rseq system call was merged into Linux 4.18. The TLS_STATIC_SURPLUS define is increased to leave additional room for dlopen'd initial-exec TLS, which keeps elf/tst-auditmany working. The increase (76 bytes) is larger than 32 bytes because it has not been increased in quite a while. The cost in terms of additional TLS storage is quite significant, but it will also obscure some initial-exec-related dlopen failures.
* manual: Show copyright information not just in the printed manualFlorian Weimer2020-07-031-9/+11
| | | | | | | | | | | | | | | @insertcopying was not used at all in the Info and HTML versions. As a result, the notices that need to be present according to the GNU Free Documentation License were missing. This commit shows these notices above the table of contents in the HTML version, and as part of the Main Menu node in the Info version. Remove the "This file documents" line because it is redundant with the following line. Tested-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* manual: Add pthread_attr_setsigmask_np, pthread_attr_getsigmask_npFlorian Weimer2020-06-151-0/+72
| | | | And the PTHREAD_ATTR_NO_SIGMASK_NP constant.
* manual/jobs.texi: remove unused var from example codeAurélien Aptel2020-06-031-1/+0
| | | | | | The do_job_notification() function defines a variable without using it. Remove it. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* mbstowcs: Document, test, and fix null pointer dst semantics (Bug 25219)Carlos O'Donell2020-06-011-4/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function mbstowcs, by an XSI extension to POSIX, accepts a null pointer for the destination wchar_t array. This API behaviour allows you to use the function to compute the length of the required wchar_t array i.e. does the conversion without storing it and returns the number of wide characters required. We remove the __write_only__ markup for the first argument because it is not true since the destination may be a null pointer, and so the length argument may not apply. We remove the markup otherwise the new test case cannot be compiled with -Werror=nonnull. We add a new test case for mbstowcs which exercises the destination is a null pointer behaviour which we have now explicitly documented. The mbsrtowcs and mbsnrtowcs behave similarly, and mbsrtowcs is documented as doing this in C11, even if the standard doesn't come out and call out this specific use case. We add one note to each of mbsrtowcs and mbsnrtowcs to call out that they support a null pointer for the destination. The wcsrtombs function behaves similarly but in the other way around and allows you to use a null destination pointer to compute how many bytes you would need to convert the wide character input. We document this particular case also, but leave wcsnrtombs as a references to wcsrtombs, so the reader must still read the details of the semantics for wcsrtombs.
* manual: Fix backtraces code example [BZ #10441]Girish Joshi2020-05-291-6/+7
| | | | | | | | | | | | Validation for pointer returned by backtrace_symbols () added. Type of variables size and i is changed from size_t to int. Variable size is used to collect the result from backtrace () that is an int. i is the loop counter variable so it can be an int. Since, size_t size is changed to int size, in printf %zd is changed to %d. Reviewed-by: DJ Delorie <dj@redhat.com>
* signal: Deprecate additional legacy signal handling functionsFlorian Weimer2020-05-251-0/+6
| | | | | | | | | | This needs a few test adjustments: In some cases, sigignore was used for convenience (replaced with xsignal with SIG_IGN). Tests for the deprecated functions need to disable -Wdeprecated-declarations, and for the sigmask deprecation, -Wno-error. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
* manual: Add missing section and node for clockid_t wait functionsFlorian Weimer2020-05-201-0/+8
| | | | | | | | | | Without this, these functions appear under the node Default Thread Attributes, which is confusing. Eventually, the documentation should be merged with the (yet to be documented) standardized functions. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* x86: Add --enable-cet=permissiveH.J. Lu2020-05-181-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | When CET is enabled, it is an error to dlopen a non CET enabled shared library in CET enabled application. It may be desirable to make CET permissive, that is disable CET when dlopening a non CET enabled shared library. With the new --enable-cet=permissive configure option, CET is disabled when dlopening a non CET enabled shared library. Add DEFAULT_DL_X86_CET_CONTROL to config.h.in: /* The default value of x86 CET control. */ #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property which enables CET features based on ELF property note. --enable-cet=permissive it to /* The default value of x86 CET control. */ #define DEFAULT_DL_X86_CET_CONTROL cet_permissive which enables CET features permissively. Update tst-cet-legacy-5a, tst-cet-legacy-5b, tst-cet-legacy-6a and tst-cet-legacy-6b to check --enable-cet and --enable-cet=permissive.
* manual: Document the O_NOFOLLOW open flagFlorian Weimer2020-05-051-0/+7
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* powerpc64le: blacklist broken GCC compilers (e.g GCC 7.5.0)Paul E. Murphy2020-04-301-2/+8
| | | | | | | | | | | GCC 7.5.0 (PR94200) will refuse to compile if both -mabi=% and -mlong-double-128 are passed on the command line. Surprisingly, it will work happily if the latter is not. For the sake of maintaining status quo, test for and blacklist such compilers. Tested with a GCC 8.3.1 and GCC 7.5.0 compiler for ppc64le. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* powerpc64le: bump binutils version requirement to >= 2.26Paul E. Murphy2020-04-301-0/+4
| | | | | | | This is a small step up from 2.25 which brings in support for rewriting the .gnu.attributes section of libc/libm.so. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* powerpc64le: raise GCC requirement to 7.4 for long double transitionPaul E. Murphy2020-04-301-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add compiler feature tests to ensure we can build ieee128 long double. These test for -mabi=ieeelongdouble, -mno-gnu-attribute, and -Wno-psabi. Likewise, verify some compiler bugs have been addressed. These aren't helpful for building glibc, but may cause test failures when testing the new long double. See notes below from Raji. On powerpc64le, some older compiler versions give error for the function signbit() for 128-bit floating point types. This is fixed by PR83862 in gcc 8.0 and backported to gcc6 and gcc7. This patch adds a test to check compiler version to avoid compiler errors during make check. Likewise, test for -mno-gnu-attribute support which was On powerpc64le, a few files are built on IEEE long double mode (-mabi=ieeelongdouble), whereas most are built on IBM long double mode (-mabi=ibmlongdouble, the default for -mlong-double-128). Since binutils 2.31, linking object files with different long double modes causes errors similar to: ld: libc_pic.a(s_isinfl.os) uses IBM long double, libc_pic.a(ieee128-qefgcvt.os) uses IEEE long double. collect2: error: ld returned 1 exit status make[2]: *** [../Makerules:649: libc_pic.os] Error 1 The warnings are fair and correct, but in order for glibc to have support for both long double modes on powerpc64le, they have to be ignored. This can be accomplished with the use of -mno-gnu-attribute option when building the few files that require IEEE long double mode. However, -mno-gnu-attribute is not available in GCC 6, the minimum version required to build glibc, so this patch adds a test for this feature in powerpc64le builds, and fails early if it's not available. Co-Authored-By: Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com> Co-Authored-By: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com> Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* manual: Fix typos in the fexecve descriptionFlorian Weimer2020-04-291-1/+1
| | | | Reported by Michael Kerrisk.
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