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2017-11-28Properly compute offsets of note descriptor and next note [BZ #22370]H.J. Lu
A note header has 3 4-bytes fields, followed by note name and note descriptor. According to gABI, in a note entry, the note name field, not note name size, is padded for the note descriptor. And the note descriptor field, not note descriptor size, is padded for the next note entry. Notes are aligned to 4 bytes in 32-bit objects and 8 bytes in 64-bit objects. For all GNU notes, the name is "GNU" which is 4 bytes. They have the same format in the first 16 bytes in both 32-bit and 64-bit objects. They differ by note descriptor size and note type. So far, .note.ABI-tag and .note.gnu.build-id notes are always aligned to 4 bytes. The exsting codes compute the note size by aligning the note name size and note descriptor size to 4 bytes. It happens to produce the same value as the actual note size by luck since the name size is 4 and offset of the note descriptor is 16. But it will produce the wrong size when note alignment is 8 bytes in 64-bit objects. This patch defines ELF_NOTE_DESC_OFFSET and ELF_NOTE_NEXT_OFFSET to properly compute offsets of note descriptor and next note. It uses alignment of PT_NOTE segment to support both 4-byte and 8-byte note alignments in 64-bit objects. To handle PT_NOTE segments with incorrect alignment, which may lead to an infinite loop, if segment alignment is less than 4, we treate alignment as 4 bytes since some note segments have 0 or 1 byte alignment. [BZ #22370] * elf/dl-hwcaps.c (ROUND): Removed. (_dl_important_hwcaps): Replace ROUND with ELF_NOTE_DESC_OFFSET and ELF_NOTE_NEXT_OFFSET. * elf/dl-load.c (ROUND): Removed. (open_verify): Replace ROUND with ELF_NOTE_NEXT_OFFSET. * elf/readelflib.c (ROUND): Removed. (process_elf_file): Replace ROUND with ELF_NOTE_NEXT_OFFSET. * include/elf.h [!_ISOMAC]: Include <libc-pointer-arith.h>. [!_ISOMAC] (ELF_NOTE_DESC_OFFSET): New. [!_ISOMAC] (ELF_NOTE_NEXT_OFFSET): Likewise.
2017-11-27Consolidate link map sortingAndreas Schwab
Combine the four places where link maps are sorted into a single function. This also moves the logic to skip the first map (representing the main binary) to the callers.
2017-11-13ld.so: Add architecture specific fieldsH.J. Lu
To support Intel Control-flow Enforcement Technology (CET) run-time control: 1. An architecture specific field in the writable ld.so namespace is needed to indicate if CET features are enabled at run-time. 2. An architecture specific field in struct link_map is needed if CET features are enabled in an ELF module. This patch adds dl-procruntime.c to the writable ld.so namespace and link_map.h to struct link_map. Tested with build-many-glibcs.py. * elf/dl-support.c: Include <dl-procruntime.c>. * include/link.h: Include <link_map.h>. * sysdeps/generic/dl-procruntime.c: New file. * sysdeps/generic/link_map.h: Likewise. * sysdeps/generic/ldsodefs.h: Include <dl-procruntime.c> in the writable ld.so namespace.
2017-11-03Mark lazy tlsdesc helper functions unused to avoid warningsSzabolcs Nagy
These static functions are not needed if a target does not do lazy tlsdesc initialization. * elf/tlsdeschtab.h (_dl_tls_resolve_early_return_p): Mark unused. (_dl_tlsdesc_wake_up_held_fixups): Likewise.
2017-10-30Assume that _DIRENT_HAVE_D_TYPE is always defined.Florian Weimer
References remain in io/fts.c, io/ftw.c, posix/glob.c, sysdeps/posix/getcwd.c. These files are (potentially) externally shared.
2017-10-04Use $(DEFAULT-LDFLAGS-$(@F)) in +link-static-before-libcH.J. Lu
Use $(LDFLAGS-$(@F)) with tst-tls1-static-non-pie may not be sufficient when static PIE is built by default. Use $(DEFAULT-LDFLAGS-$(@F)) in +link-static-before-libc to make sure that tst-tls1-static-non-pie is always built as non-PIE static executable and make sure that crt1.o is used with tst-tls1-static-non-pie. * Makeconfig (+link-static-before-libc): Use $(DEFAULT-LDFLAGS-$(@F)). * elf/Makefile (CRT-tst-tls1-static-non-pie): New. (LDFLAGS-tst-tls1-static-non-pie): Renamed to ... (DEFAULT-LDFLAGS-tst-tls1-static-non-pie): This.
2017-10-04Add a test for main () in a shared objectH.J. Lu
Verify that crt1.o can be used with main () in a shared object. * elf/Makefile (tests): Add tst-main1. (modules-names): Add tst-main1mod. ($(objpfx)tst-main1): New. (CRT-tst-main1): Likewise. (LDFLAGS-tst-main1): Likewise. (LDLIBS-tst-main1): Likewise. (tst-main1mod.so-no-z-defs): Likewise. * elf/tst-main1.c: New file. * elf/tst-main1mod.c: Likewise.
2017-10-03ld.so: Replace (&bootstrap_map) with BOOTSTRAP_MAPH.J. Lu
(&_dl_main_map) is used instead of (&bootstrap_map) to bootstrap static PIE. Define BOOTSTRAP_MAP with (&_dl_main_map) to avoid hardcode to (&bootstrap_map). * elf/rtld.c (BOOTSTRAP_MAP): New. (RESOLVE_MAP): Replace (&bootstrap_map) with BOOTSTRAP_MAP. * sysdeps/hppa/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC): Likewise. * sysdeps/ia64/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC): Likewise. * sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC): Likewise.
2017-10-01Move hidden_proto (__dl_iterate_phdr) to include/link.h [BZ #18822]H.J. Lu
__dl_iterate_phdr is hidden and should be accessed directly within libc.so and libc.a without using GOT nor PLT. [BZ #18822] * elf/dl-iteratephdr.c (hidden_proto (__dl_iterate_phdr)): Moved to ... * include/link.h (hidden_proto (__dl_iterate_phdr)): Here.
2017-09-30Add a test for non-PIE static executableH.J. Lu
tst-tls1-static-non-pie is built with $(no-pie-ldflag) to make it a non-PIE static executable, regardless if --enable-static-pie is used to configure glibc. * elf/Makefile (tests-static-internal): Add tst-tls1-static-non-pie. (LDFLAGS-tst-tls1-static-non-pie): New. * elf/tst-tls1-static-non-pie.c: New file.
2017-09-27Fix range check in do_tunable_update_valAlexey Makhalov
Current implementation of tunables does not set arena_max and arena_test values. Any value provided by glibc.malloc.arena_max and glibc.malloc.arena_test parameters is ignored. These tunables have minval value set to 1 (see elf/dl-tunables.list file) and undefined maxval value. In that case default value (which is 0. see scripts/gen-tunables.awk) is being used to set maxval. For instance, generated tunable_list[] entry for arena_max is: (gdb) p *cur $1 = {name = 0x7ffff7df6217 "glibc.malloc.arena_max", type = {type_code = TUNABLE_TYPE_SIZE_T, min = 1, max = 0}, val = {numval = 0, strval = 0x0}, initialized = false, security_level = TUNABLE_SECLEVEL_SXID_IGNORE, env_alias = 0x7ffff7df622e "MALLOC_ARENA_MAX"} As a result, any value of glibc.malloc.arena_max is ignored by TUNABLE_SET_VAL_IF_VALID_RANGE macro __type min = (__cur)->type.min; <- initialized to 1 __type max = (__cur)->type.max; <- initialized to 0! if (min == max) <- false { min = __default_min; max = __default_max; } if ((__type) (__val) >= min && (__type) (val) <= max) <- false { (__cur)->val.numval = val; (__cur)->initialized = true; } Assigning correct min/max values at a build time fixes a problem. Plus, a bit of optimization: Setting of default min/max values for the given type at a run time might be eliminated. * elf/dl-tunables.c (do_tunable_update_val): Range checking fix. * scripts/gen-tunables.awk: Set unspecified minval and/or maxval values to correct default value for given type.
2017-09-26Skip PT_DYNAMIC segment with p_filesz == 0 [BZ #22101]H.J. Lu
ELF objects generated with "objcopy --only-keep-debug" have Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align DYNAMIC 0x0+e28 0x0+200e40 0x0+200e40 0x0+ 0x0+1a0 RW 0x8 with 0 file size. ld.so should skip such PT_DYNAMIC segments. Without a PT_DYNAMIC segment the loading of the shared object will fail, and therefore ldd on such objects will also fail instead of crashing. This provides better diagnostics for tooling that is attempting to inspect the invalid shared objects which may just contain debug information. [BZ #22101] * elf/Makefile (tests): Add tst-debug1. ($(objpfx)tst-debug1): New. ($(objpfx)tst-debug1.out): Likewise. ($(objpfx)tst-debug1mod1.so): Likewise. * elf/dl-load.c (_dl_map_object_from_fd): Skip PT_DYNAMIC segment with p_filesz == 0. * elf/tst-debug1.c: New file. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2017-09-10Fix $(error) use in MakefileSamuel Thibault
* elf/rtld-Rules: Fix $(error) use.
2017-08-31elf: Remove internal_function attributeFlorian Weimer
2017-08-31dlfcn: Remove internal_function attributeFlorian Weimer
2017-08-21Don't compile non-lib modules as lib modules [BZ #21864]H.J. Lu
Some programs have more than one source files. These non-lib modules should not be compiled with -DMODULE_NAME=libc. This patch puts these non-lib modules in $(others-extras) and adds $(others-extras) to all-nonlib. [BZ #21864] * Makerules (all-nonlib): Add $(others-extras). * catgets/Makefile (others-extras): New. * elf/Makefile (others-extras): Likewise. * nss/Makefile (others-extras): Likewise.
2017-08-21Mark __libc_multiple_libcs with attribute_hidden [BZ #18822]H.J. Lu
Since __libc_multiple_libcs is defined as hidden symbol in init-first.c, it should be always marked with attribute_hidden. [BZ #18822] * csu/libc-start.c (__libc_multiple_libcs): Removed. * elf/dl-open.c: Include <libc-internal.h>. (__libc_multiple_libcs): Removed. * elf/dl-sysdep.c: Include <libc-internal.h> instead of <hp-timing.h>. * include/libc-internal.h (__libc_multiple_libcs): New. * misc/sbrk.c: Include <libc-internal.h>. (__libc_multiple_libcs): Removed.
2017-08-18Add NT_GNU_PROPERTY_TYPE_0 macrosH.J. Lu
Add macros used in GNU .note.gnu.property notes (NT_GNU_PROPERTY_TYPE_0). * elf/elf.h (NT_GNU_PROPERTY_TYPE_0): New. (NOTE_GNU_PROPERTY_SECTION_NAME): Likewise. (GNU_PROPERTY_STACK_SIZE): Likewie. (GNU_PROPERTY_NO_COPY_ON_PROTECTED): Likewie. (GNU_PROPERTY_LOPROC): Likewise. (GNU_PROPERTY_HIPROC): Likewise. (GNU_PROPERTY_LOUSER): Likewise. (GNU_PROPERTY_HIUSER): Likewise. (GNU_PROPERTY_X86_ISA_1_USED): Likwise. (GNU_PROPERTY_X86_ISA_1_NEEDED): Likwise. (GNU_PROPERTY_X86_FEATURE_1_AND): Likwise. (GNU_PROPERTY_X86_ISA_1_486): Likwise. (GNU_PROPERTY_X86_ISA_1_586): Likwise. (GNU_PROPERTY_X86_ISA_1_686): Likwise. (GNU_PROPERTY_X86_ISA_1_SSE): Likwise. (GNU_PROPERTY_X86_ISA_1_SSE2): Likwise. (GNU_PROPERTY_X86_ISA_1_SSE3): Likwise. (GNU_PROPERTY_X86_ISA_1_SSSE3): Likwise. (GNU_PROPERTY_X86_ISA_1_SSE4_1): Likwise. (GNU_PROPERTY_X86_ISA_1_SSE4_2): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX2): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512F): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512CD): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512ER): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512PF): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512VL): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512DQ): Likwise. (GNU_PROPERTY_X86_ISA_1_AVX512BW): Likwise. (GNU_PROPERTY_X86_FEATURE_1_IBT): Likwise. (GNU_PROPERTY_X86_FEATURE_1_SHSTK): Likwise.
2017-08-16ldd: never run file directlyAndreas Schwab
2017-08-15powerpc: Add values from Linux 4.8 to <elf.h>Gustavo Romero
Add powerpc specific note sections available since Linux v4.8. * elf/elf.h A (NT_PPC_TAR): New macro. (NT_PPC_PPR): Likewise. (NT_PPC_DSCR): Likewise. (NT_PPC_EBB): Likewise. (NT_PPC_PMU): Likewise. (NT_PPC_TM_CGPR): Likewise. (NT_PPC_TM_CFPR): Likewise. (NT_PPC_TM_CVMX): Likewise. (NT_PPC_TM_CVSX): Likewise. (NT_PPC_TM_SPR): Likewise. (NT_PPC_TM_CTAR): Likewise. (NT_PPC_TM_CPPR): Likewise. (NT_PPC_TM_CDSCR): Likewise.
2017-08-14_dl_init: Remove internal_function attributeFlorian Weimer
The function is called from the i386 startup code, which needs minor adjustments due to the changed ABI.
2017-08-14_dl_start: Remove internal_function attributeFlorian Weimer
The i386 startup code needs adjusting because it calls the function and the ABI has changed.
2017-08-14_dl_fini: Remove internal_function attributeFlorian Weimer
Assembler code passes the address of _dl_fini to __libc_start_main, whose function pointer argument lacks the attribute. This means that calls could use the wrong ABI. Fortunately, for zero-parameter void-returning functions, internal_function does not change ABI on i386 (the only architecture which uses internal_function), so this inconsistency was harmless (which is why it had not been noticed so far).
2017-08-13ld.so: Remove internal_function attribute from various functionsFlorian Weimer
These functions are invoked from other DSOs and should therefore use the standard calling convention.
2017-08-13NPTL: Remove internal_function from stack marking functionsFlorian Weimer
These are called across DSO boundaries and therefore should use the ABI calling convention.
2017-08-10ld.so: Introduce struct dl_exceptionFlorian Weimer
This commit separates allocating and raising exceptions. This simplifies catching and re-raising them because it is no longer necessary to make a temporary, on-stack copy of the exception message.
2017-08-08i386: Add <startup.h> [BZ #21913]H.J. Lu
On Linux/i386, there are 3 ways to make a system call: 1. call *%gs:SYSINFO_OFFSET. This requires TLS initialization. 2. call *_dl_sysinfo. This requires relocation of _dl_sysinfo. 3. int $0x80. This is slower than #2 and #3, but works everywhere. When an object file is compiled with PIC, #1 is prefered since it is faster than #3 and doesn't require relocation of _dl_sysinfo. For dynamic executables, ld.so initializes TLS. However, for static executables, before TLS is initialized by __libc_setup_tls, #3 should be used for system calls. This patch adds <startup.h> which defines _startup_fatal and defaults it to __libc_fatal. It replaces __libc_fatal with _startup_fatal in static executables where it is called before __libc_setup_tls is called. This header file is included in all files containing functions which are called before __libc_setup_tls is called. On Linux/i386, when PIE is enabled by default, _startup_fatal is turned into ABORT_INSTRUCTION and I386_USE_SYSENTER is defined to 0 so that "int $0x80" is used for system calls before __libc_setup_tls is called. Tested on i686 and x86-64. Without this patch, all statically-linked tests will fail on i686 when the compiler defaults to -fPIE. [BZ #21913] * csu/libc-tls.c: Include <startup.h> first. (__libc_setup_tls): Call _startup_fatal instead of __libc_fatal. * elf/dl-tunables.c: Include <startup.h> first. * include/libc-symbols.h (BUILD_PIE_DEFAULT): New. * sysdeps/generic/startup.h: New file. * sysdeps/unix/sysv/linux/i386/startup.h: Likewise. * sysdeps/unix/sysv/linux/i386/brk.c [BUILD_PIE_DEFAULT != 0] (I386_USE_SYSENTER): New. Defined to 0.
2017-08-07Fix missing redirects in testsuite targetsAndreas Schwab
2017-08-04Compile tst-prelink.c without PIE [BZ #21815]H.J. Lu
tst-prelink.c checks for conflict with GLOB_DAT relocation against stdio. On i386, there is no GLOB_DAT relocation against stdio with PIE. We should compile tst-prelink.c without PIE. [BZ #21815] * elf/Makefile (CFLAGS-tst-prelink.c): New. (LDFLAGS-tst-prelink): Likewise.
2017-08-04Run vismain only if linker supports protected data symbolH.J. Lu
Gold doesn't support protected data symbol: configure:5672: checking linker support for protected data symbol configure:5682: gcc -fuse-ld=gold -nostdlib -nostartfiles -fno-stack-protector -fPIC -shared conftest.c -o conftest.so configure:5685: $? = 0 configure:5692: gcc -fuse-ld=gold -nostdlib -nostartfiles -fno-stack-protector conftest.c -o conftest conftest.so /usr/local/bin/ld.gold: error: /tmp/ccXWoofs.o: cannot make copy relocation for protected symbol 'bar', defined in conftest.so collect2: error: ld returned 1 exit status Run vismain only if linker supports protected data symbol. * elf/Makefile (tests): Add vismain only if $(have-protected-data) == yes. (tests-pie): Likewise.
2017-07-24tunables: Use direct syscall for access (BZ#21744)Adhemerval Zanella
The function maybe_enable_malloc_check, which is called by __tunables_init, calls __access_noerrno. It isn't problem when symbol is is in ld.so, which has a special version of __access_noerrno without stack protector. But when glibc is built with stack protector, maybe_enable_malloc_check in libc.a can't call the regular version of __access_noerrno with stack protector. This patch changes how Linux defines the __access_noerrno to be an inline call instead and thus preventing defining different build rules for ld/static and shared. H.J. Lu <hongjiu.lu@intel.com> Adhemerval Zanella <adhemerval.zanella@linaro.org> [BZ #21744] * elf/dl-tunables.c: Include not-errno.h header. * include/unistd.h (__access_noerrno): Remove definition. * sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise. * sysdeps/generic/not-errno.h: New file. * sysdeps/unix/sysv/linux/not-errno.h: Likewise.
2017-07-17powerpc: Fix float128 IFUNC relocations [BZ #21707]Tulio Magno Quites Machado Filho
The patch proposed by Peter Bergner [1] to libgcc in order to fix [BZ #21707] adds a dependency on a symbol provided by the loader, forcing the loader to be linked to tests after libgcc was linked. It also requires to read the thread pointer during IRELA relocations. Tested on powerpc, powerpc64, powerpc64le, s390x and x86_64. [1] https://sourceware.org/ml/libc-alpha/2017-06/msg01383.html [BZ #21707] * csu/libc-start.c (LIBC_START_MAIN): Perform IREL{,A} relocations before or after initializing the TCB on statically linked executables. That's a per-architecture definition. * elf/rtld.c (dl_main): Add a comment about thread-local variables initialization. * sysdeps/generic/libc-start.h: New file. Define ARCH_APPLY_IREL and ARCH_SETUP_IREL. * sysdeps/powerpc/Makefile: [$(subdir) = elf && $(multi-arch) != no] (tests-static-internal): Add tst-tlsifunc-static. [$(subdir) = elf && $(multi-arch) != no && $(build-shared) == yes] (tests-internal): Add tst-tlsifunc. * sysdeps/powerpc/tst-tlsifunc.c: New file. * sysdeps/powerpc/tst-tlsifunc-static.c: Likewise. * sysdeps/powerpc/powerpc64le/Makefile (f128-loader-link): New variable. [$(subdir) = math] (test-float128% test-ifloat128%): Force linking to the loader after linking to libgcc. [$(subdir) = wcsmbs || $(subdir) = stdlib] (bug-strtod bug-strtod2) (bug-strtod2 tst-strtod-round tst-wcstod-round tst-strtod6 tst-strrom) (tst-strfrom-locale strfrom-skeleton): Likewise. * sysdeps/unix/sysv/linux/powerpc/libc-start.h: New file. Define ARCH_APPLY_IREL and ARCH_SETUP_IREL.
2017-07-10Don't include _dl_resolve_conflicts in libc.a [BZ #21742]H.J. Lu
Since _dl_resolve_conflicts is only used in elf/rtld.c, don't include it in libc.a. [BZ #21742] * elf/Makefile (dl-routines): Move dl-conflict to ... (rtld-routines): Here.
2017-07-06Add per-thread cache to mallocDJ Delorie
* config.make.in: Enable experimental malloc option. * configure.ac: Likewise. * configure: Regenerate. * manual/install.texi: Document it. * INSTALL: Regenerate. * malloc/Makefile: Likewise. * malloc/malloc.c: Add per-thread cache (tcache). (tcache_put): New. (tcache_get): New. (tcache_thread_freeres): New. (tcache_init): New. (__libc_malloc): Use cached chunks if available. (__libc_free): Initialize tcache if needed. (__libc_realloc): Likewise. (__libc_calloc): Likewise. (_int_malloc): Prefill tcache when appropriate. (_int_free): Likewise. (do_set_tcache_max): New. (do_set_tcache_count): New. (do_set_tcache_unsorted_limit): New. * manual/probes.texi: Document new probes. * malloc/arena.c: Add new tcache tunables. * elf/dl-tunables.list: Likewise. * manual/tunables.texi: Document them. * NEWS: Mention the per-thread cache.
2017-06-30tunables, aarch64: New tunable to override cpuSiddhesh Poyarekar
Add a new tunable (glibc.tune.cpu) to override CPU identification on aarch64. This is useful in two cases: one where it is desirable to pretend to be another CPU for purposes of testing or because routines written for that CPU are beneficial for specific workloads and second where the underlying kernel does not support emulation of MRS to get the MIDR of the CPU. * elf/dl-tunables.h (tunable_is_name): Move from... * elf/dl-tunables.c (is_name): ... here. (parse_tunables, __tunables_init): Adjust. * manual/tunables.texi: Document glibc.tune.cpu. * sysdeps/aarch64/dl-tunables.list: New file. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (struct cpu_list): New type. (cpu_list): New list of CPU names and their MIDR. (get_midr_from_mcpu): New function. (init_cpu_features): Override MIDR if necessary.
2017-06-27Fix elf/loadtest.c build with GCC 8.Joseph Myers
Building the testsuite with current GCC mainline fails with: loadtest.c: In function 'main': loadtest.c:76:3: error: macro expands to multiple statements [-Werror=multistatement-macros] for (map = MAPS; map != NULL; map = map->l_next) \ ^ loadtest.c:165:2: note: in expansion of macro 'OUT' OUT; ^~~ loadtest.c:164:7: note: some parts of macro expansion are not guarded by this 'if' clause if (debug) ^~ This seems like a genuine bug, although fairly harmless; it means the fflush call in the OUT macro is unconditional instead of being inside the conditional as presumably intended. This patch makes this macro use do { } while (0) to avoid the problem. Tested for x86_64 (testsuite), and with build-many-glibcs.py for aarch64-linux-gnu with GCC mainline. * elf/loadtest.c (OUT): Define using do { } while (0).
2017-06-21x86: Rename glibc.tune.ifunc to glibc.tune.hwcapsH.J. Lu
Rename glibc.tune.ifunc to glibc.tune.hwcaps and move it to sysdeps/x86/dl-tunables.list since it is x86 specicifc. Also change type of data_cache_size, data_cache_size and non_temporal_threshold to unsigned long int to match size_t. Remove usage DEFAULT_STRLEN from cpu-tunables.c. * elf/dl-tunables.list (glibc.tune.ifunc): Removed. * sysdeps/x86/dl-tunables.list (glibc.tune.hwcaps): New. Remove security_level on all fields. * manual/tunables.texi: Replace ifunc with hwcaps. * sysdeps/x86/cpu-features.c (TUNABLE_CALLBACK (set_ifunc)): Renamed to .. (TUNABLE_CALLBACK (set_hwcaps)): This. (init_cpu_features): Updated. * sysdeps/x86/cpu-features.h (cpu_features): Change type of data_cache_size, data_cache_size and non_temporal_threshold to unsigned long int. * sysdeps/x86/cpu-tunables.c (DEFAULT_STRLEN): Removed. (TUNABLE_CALLBACK (set_ifunc)): Renamed to ... (TUNABLE_CALLBACK (set_hwcaps)): This. Update comments. Don't use DEFAULT_STRLEN.
2017-06-20Move x86 specific tunables to x86/dl-tunables.listH.J. Lu
* elf/dl-tunables.list: Move x86 specific tunables to ... * sysdeps/x86/dl-tunables.list: Here. New file.
2017-06-20tunables: Add IFUNC selection and cache sizesH.J. Lu
The current IFUNC selection is based on microbenchmarks in glibc. It should give the best performance for most workloads. But other choices may have better performance for a particular workload or on the hardware which wasn't available at the selection was made. The environment variable, GLIBC_TUNABLES=glibc.tune.ifunc=-xxx,yyy,-zzz...., can be used to enable CPU/ARCH feature yyy, disable CPU/ARCH feature yyy and zzz, where the feature name is case-sensitive and has to match the ones in cpu-features.h. It can be used by glibc developers to override the IFUNC selection to tune for a new processor or improve performance for a particular workload. It isn't intended for normal end users. NOTE: the IFUNC selection may change over time. Please check all multiarch implementations when experimenting. Also, GLIBC_TUNABLES=glibc.tune.x86_non_temporal_threshold=NUMBER is provided to set threshold to use non temporal store to NUMBER, GLIBC_TUNABLES=glibc.tune.x86_data_cache_size=NUMBER to set data cache size, GLIBC_TUNABLES=glibc.tune.x86_shared_cache_size=NUMBER to set shared cache size. * elf/dl-tunables.list (tune): Add ifunc, x86_non_temporal_threshold, x86_data_cache_size and x86_shared_cache_size. * manual/tunables.texi: Document glibc.tune.ifunc, glibc.tune.x86_data_cache_size, glibc.tune.x86_shared_cache_size and glibc.tune.x86_non_temporal_threshold. * sysdeps/unix/sysv/linux/x86/dl-sysdep.c: New file. * sysdeps/x86/cpu-tunables.c: Likewise. * sysdeps/x86/cacheinfo.c (init_cacheinfo): Check and get data cache size, shared cache size and non temporal threshold from cpu_features. * sysdeps/x86/cpu-features.c [HAVE_TUNABLES] (TUNABLE_NAMESPACE): New. [HAVE_TUNABLES] Include <unistd.h>. [HAVE_TUNABLES] Include <elf/dl-tunables.h>. [HAVE_TUNABLES] (TUNABLE_CALLBACK (set_ifunc)): Likewise. [HAVE_TUNABLES] (init_cpu_features): Use TUNABLE_GET to set IFUNC selection, data cache size, shared cache size and non temporal threshold. * sysdeps/x86/cpu-features.h (cpu_features): Add data_cache_size, shared_cache_size and non_temporal_threshold.
2017-06-19ld.so: Reject overly long LD_AUDIT path elementsFlorian Weimer
Also only process the last LD_AUDIT entry.
2017-06-19ld.so: Reject overly long LD_PRELOAD path elementsFlorian Weimer
2017-06-19CVE-2017-1000366: Ignore LD_LIBRARY_PATH for AT_SECURE=1 programs [BZ #21624]Florian Weimer
LD_LIBRARY_PATH can only be used to reorder system search paths, which is not useful functionality. This makes an exploitable unbounded alloca in _dl_init_paths unreachable for AT_SECURE=1 programs.
2017-06-16Remove _dl_out_of_memory from elf/VersionsH.J. Lu
Since _dl_out_of_memory is static in elf/dl-error-skeleton.c: static const char _dl_out_of_memory[] = "out of memory"; remove _dl_out_of_memory from elf/Versions. * elf/Versions (ld): Remove _dl_out_of_memory.
2017-06-14PowerPC64 ELFv2 PPC64_OPT_LOCALENTRYAlan Modra
ELFv2 functions with localentry:0 are those with a single entry point, ie. global entry == local entry, that have no requirement on r2 or r12 and guarantee r2 is unchanged on return. Such an external function can be called via the PLT without saving r2 or restoring it on return, avoiding a common load-hit-store for small functions. This patch implements the ld.so changes necessary for this optimization. ld.so needs to check that an optimized plt call sequence is in fact calling a function implemented with localentry:0, end emit a fatal error otherwise. The elf/testobj6.c change is to stop "error while loading shared libraries: expected localentry:0 `preload'" when running elf/preloadtest, which we'd get otherwise. * elf/elf.h (PPC64_OPT_LOCALENTRY): Define. * sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add refsym and sym parameters. Adjust callers. * sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise. * sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New. (_dl_reloc_overflow): Increase buffser size. Formatting. * sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset): Delete reloc param, add refsym and sym. Check optimized plt call stubs for localentry:0 functions. Adjust callers. (elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym and sym parameters. Adjust callers. (_dl_reloc_overflow): Move attribute. (_dl_error_localentry): Declare. * elf/dl-runtime.c (_dl_fixup): Save original sym. Pass refsym and sym to elf_machine_fixup_plt. * elf/testobj6.c (preload): Call printf.
2017-06-08ld.so: Consolidate 2 strtouls into _dl_strtoul [BZ #21528]H.J. Lu
There are 2 minimal strtoul implementations in ld.so: 1. __strtoul_internal in elf/dl-minimal.c. 2. tunables_strtoul in elf/dl-tunables.c. This patch adds _dl_strtoul to replace them. Tested builds with and without --enable-tunables. [BZ #21528] * elf/dl-minimal.c (__strtoul_internal): Removed. (strtoul): Likewise. * elf/dl-misc.c (_dl_strtoul): New function. * elf/dl-tunables.c (tunables_strtoul): Removed. (tunable_initialize): Replace tunables_strtoul with _dl_strtoul. * elf/rtld.c (process_envvars): Likewise. * sysdeps/unix/sysv/linux/dl-librecon.h (_dl_osversion_init): Likewise. * sysdeps/generic/ldsodefs.h (_dl_strtoul): New prototype.
2017-06-07Make LD_HWCAP_MASK usable for static binariesSiddhesh Poyarekar
The LD_HWCAP_MASK environment variable was ignored in static binaries, which is inconsistent with the behaviour of dynamically linked binaries. This seems to have been because of the inability of ld_hwcap_mask being read early enough to influence anything but now that it is in tunables, the mask is usable in static binaries as well. This feature is important for aarch64, which relies on HWCAP_CPUID being masked out to disable multiarch. A sanity test on x86_64 shows that there are no failures. Likewise for aarch64. * elf/dl-hwcaps.h [HAVE_TUNABLES]: Always read hwcap_mask. * sysdeps/sparc/sparc32/dl-machine.h [HAVE_TUNABLES]: Likewise. * sysdeps/x86/cpu-features.c (init_cpu_features): Always set up hwcap and hwcap_mask.
2017-06-07tunables: Use glibc.tune.hwcap_mask tunable instead of _dl_hwcap_maskSiddhesh Poyarekar
Drop _dl_hwcap_mask when building with tunables. This completes the transition of hwcap_mask reading from _dl_hwcap_mask to tunables. * elf/dl-hwcaps.h: New file. * elf/dl-hwcaps.c: Include it. (_dl_important_hwcaps)[HAVE_TUNABLES]: Read and update glibc.tune.hwcap_mask. * elf/dl-cache.c: Include dl-hwcaps.h. (_dl_load_cache_lookup)[HAVE_TUNABLES]: Read glibc.tune.hwcap_mask. * sysdeps/sparc/sparc32/dl-machine.h: Likewise. * elf/dl-support.c (_dl_hwcap2)[HAVE_TUNABLES]: Drop _dl_hwcap_mask. * elf/rtld.c (rtld_global_ro)[HAVE_TUNABLES]: Drop _dl_hwcap_mask. (process_envvars)[HAVE_TUNABLES]: Likewise. * sysdeps/generic/ldsodefs.h (rtld_global_ro)[HAVE_TUNABLES]: Likewise. * sysdeps/x86/cpu-features.c (init_cpu_features): Don't initialize dl_hwcap_mask when tunables are enabled.
2017-06-07tunables: Add LD_HWCAP_MASK to tunablesSiddhesh Poyarekar
Add LD_HWCAP_MASK to tunables in preparation of it being removed from rtld.c. This allows us to read LD_HWCAP_MASK much earlier so that it can influence IFUNC resolution in aarch64. This patch does not actually do anything other than read the LD_HWCAP_MASK variable and add the tunables way to set the LD_HWCAP_MASK, i.e. via the glibc.tune.hwcap_mask tunable. In a follow-up patch, the _dl_hwcap_mask will be replaced with glibc.tune.hwcap_mask to complete the transition. * elf/dl-tunables.list: Add glibc.tune.hwcap_mask. * scripts/gen-tunables.awk: Include dl-procinfo.h. * manual/tunables.texi: Document glibc.tune.hwcap_mask.
2017-06-07tunables: Clean up hooks to get and set tunablesSiddhesh Poyarekar
The TUNABLE_SET_VALUE and family of macros (and my later attempt to add a TUNABLE_GET) never quite went together very well because the overall interface was not clearly defined. This patch is an attempt to do just that. This patch consolidates the API to two simple sets of macros, TUNABLE_GET* and TUNABLE_SET*. If TUNABLE_NAMESPACE is defined, TUNABLE_GET takes just the tunable name, type and a (optionally NULL) callback function to get the value of the tunable. The callback function, if non-NULL, is called if the tunable was externally set (i.e. via GLIBC_TUNABLES or any future mechanism). For example: val = TUNABLE_GET (check, int32_t, check_callback) returns the value of the glibc.malloc.check tunable (assuming TUNABLE_NAMESPACE is set to malloc) as an int32_t into VAL after calling check_callback. Likewise, TUNABLE_SET can be used to set the value of the tunable, although this is currently possible only in the dynamic linker before it relocates itself. For example: TUNABLE_SET (check, int32_t, 2) will set glibc.malloc.check to 2. Of course, this is not possible since we set (or read) glibc.malloc.check long after it is relocated. To access or set a tunable outside of TUNABLE_NAMESPACE, use the TUNABLE_GET_FULL and TUNABLE_SET_FULL macros, which have the following prototype: TUNABLE_GET_FULL (glibc, tune, hwcap_mask, uint64_t, NULL) TUNABLE_SET_FULL (glibc, tune, hwcap_mask, uint64_t, 0xffff) In future the tunable list may get split into mutable and immutable tunables where mutable tunables can be modified by the library and userspace after relocation as well and TUNABLE_SET will be more useful than it currently is. However whenever we actually do that split, we will have to ensure that the mutable tunables are protected with locks. * elf/Versions (__tunable_set_val): Rename to __tunable_get_val. * elf/dl-tunables.c: Likewise. (do_tunable_update_val): New function. (__tunable_set_val): New function. (__tunable_get_val): Call CB only if the tunable was externally initialized. (tunables_strtoul): Replace strval with initialized. * elf/dl-tunables.h (strval): Replace with a bool initialized. (TUNABLE_ENUM_NAME, TUNABLE_ENUM_NAME1): Adjust names to prevent collision. (__tunable_set_val): New function. (TUNABLE_GET, TUNABLE_GET_FULL): New macros. (TUNABLE_SET, TUNABLE_SET_FULL): Likewise. (TUNABLE_SET_VAL): Remove. (TUNABLE_SET_VAL_WITH_CALLBACK): Likewise. * README.tunables: Document the new macros. * malloc/arena.c (ptmalloc_init): Adjust.
2017-05-25Make __tunables_init hidden and avoid PLTH.J. Lu
Since __tunables_init is internal to ld.so, we should mark it hidden to avoid PLT. We should also avoid PLT when calling __tunable_set_val within ld.so. 2017-05-25 Siddhesh Poyarekar <siddhesh@sourceware.org> H.J. Lu <hongjiu.lu@intel.com> * elf/dl-tunables.c (__tunable_set_val): Make a hidden alias. * elf/dl-tunables.h (__tunables_init): Mark it hidden in rtld. (__tunable_set_val): Likewise.