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2018-11-30Fix _dl_profile_fixup data-dependency issue (Bug 23690)Tulio Magno Quites Machado Filho1-5/+43
There is a data-dependency between the fields of struct l_reloc_result and the field used as the initialization guard. Users of the guard expect writes to the structure to be observable when they also observe the guard initialized. The solution for this problem is to use an acquire and release load and store to ensure previous writes to the structure are observable if the guard is initialized. The previous implementation used DL_FIXUP_VALUE_ADDR (l_reloc_result->addr) as the initialization guard, making it impossible for some architectures to load and store it atomically, i.e. hppa and ia64, due to its larger size. This commit adds an unsigned int to l_reloc_result to be used as the new initialization guard of the struct, making it possible to load and store it atomically in all architectures. The fix ensures that the values observed in l_reloc_result are consistent and do not lead to crashes. The algorithm is documented in the code in elf/dl-runtime.c (_dl_profile_fixup). Not all data races have been eliminated. Tested with build-many-glibcs and on powerpc, powerpc64, and powerpc64le. [BZ #23690] * elf/dl-runtime.c (_dl_profile_fixup): Guarantee memory modification order when accessing reloc_result->addr. * include/link.h (reloc_result): Add field init. * nptl/Makefile (tests): Add tst-audit-threads. (modules-names): Add tst-audit-threads-mod1 and tst-audit-threads-mod2. Add rules to build tst-audit-threads. * nptl/tst-audit-threads-mod1.c: New file. * nptl/tst-audit-threads-mod2.c: Likewise. * nptl/tst-audit-threads.c: Likewise. * nptl/tst-audit-threads.h: Likewise. Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com> Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2018-11-29elf/dl-exception.c: Include <_itoa.h> for _itoa prototypeH.J. Lu1-0/+1
Tested with build-many-glibcs.py. * elf/dl-exception.c: Include <_itoa.h>.
2018-11-29_dl_exception_create_format: Support %x/%lx/%zxH.J. Lu3-1/+145
Add support for %x, %lx and %zx to _dl_exception_create_format and pad to the full width with 0. * elf/Makefile (tests-internal): Add tst-create_format1. * elf/dl-exception.c (_dl_exception_create_format): Support %x, %lx and %zx. * elf/tst-create_format1.c: New file.
2018-11-29C-SKY: Add dynamic relocations to elf.hMao Han1-1/+66
* elf/elf.h (EM_CSKY, R_CKCORE_NONE, R_CKCORE_ADDR32) (R_CKCORE_PCRELIMM8BY4, R_CKCORE_PCRELIMM11BY2, R_CKCORE_PCREL32) (R_CKCORE_PCRELJSR_IMM11BY2, R_CKCORE_RELATIVE, R_CKCORE_COPY) (R_CKCORE_GLOB_DAT, R_CKCORE_JUMP_SLOT, R_CKCORE_GOTOFF) (R_CKCORE_GOTPC, R_CKCORE_GOT32, R_CKCORE_PLT32, R_CKCORE_ADDRGOT) (R_CKCORE_ADDRPLT, R_CKCORE_PCREL_IMM26BY2, R_CKCORE_PCREL_IMM16BY2) (R_CKCORE_PCREL_IMM16BY4, R_CKCORE_PCREL_IMM10BY2) (R_CKCORE_PCREL_IMM10BY4, R_CKCORE_ADDR_HI16, R_CKCORE_ADDR_LO16) (R_CKCORE_GOTPC_HI16, R_CKCORE_GOTPC_LO16, R_CKCORE_GOTOFF_HI16) (R_CKCORE_GOTOFF_LO16, R_CKCORE_GOT12, R_CKCORE_GOT_HI16) (R_CKCORE_GOT_LO16, R_CKCORE_PLT12, R_CKCORE_PLT_HI16) (R_CKCORE_PLT_LO16, R_CKCORE_ADDRGOT_HI16, R_CKCORE_ADDRGOT_LO16) (R_CKCORE_ADDRPLT_HI16, R_CKCORE_ADDRPLT_LO16) (R_CKCORE_PCREL_JSR_IMM26BY2, R_CKCORE_TOFFSET_LO16) (R_CKCORE_DOFFSET_LO16, R_CKCORE_PCREL_IMM18BY2) (R_CKCORE_DOFFSET_IMM18, R_CKCORE_DOFFSET_IMM18BY2) (R_CKCORE_DOFFSET_IMM18BY4, R_CKCORE_GOT_IMM18BY4) (R_CKCORE_PLT_IMM18BY4, R_CKCORE_PCREL_IMM7BY4, R_CKCORE_TLS_LE32) (R_CKCORE_TLS_IE32, R_CKCORE_TLS_GD32, R_CKCORE_TLS_LDM32) (R_CKCORE_TLS_LDO32, R_CKCORE_TLS_DTPMOD32, R_CKCORE_TLS_DTPOFF32) (R_CKCORE_TLS_TPOFF32): New defines.
2018-10-30RISC-V: properly terminate call chain (bug 23125)Andreas Schwab2-1/+41
Mark the ra register as undefined in _start, so that unwinding through main works correctly. Also, don't use a tail call so that ra points after the call to __libc_start_main, not after the previous call.
2018-10-25Add new ELF note types from Linux 4.19 to elf.h.Joseph Myers1-0/+2
This patch adds NT_MIPS_DSP and NT_MIPS_FP_MODE from Linux 4.19 to elf.h. Tested for x86_64. * elf/elf.h (NT_MIPS_DSP): New macro. (NT_MIPS_FP_MODE): Likewise.
2018-10-25elf: Fix the ld flags not be applied to tst-execstack-mod.soZong Li1-1/+1
The Makefile variable name lacked the file extension (.so). As a result, tst-execstack-mod.so was not linked with the -z execstack flag.
2018-10-24Add more checks for valid ld.so.cache file (bug 18093)Andreas Schwab2-1/+9
2018-09-26Add missing unwind information to ld.so on powerpc32 (bug 23707)Andreas Schwab3-2/+74
2018-09-25Fix ifunc support with DT_TEXTREL segments (BZ#20480)Adhemerval Zanella3-12/+57
Currently, DT_TEXTREL is incompatible with IFUNC. When DT_TEXTREL or DF_TEXTREL is seen, the dynamic linker calls __mprotect on the segments with PROT_READ|PROT_WRITE before applying dynamic relocations. It leads to segfault when performing IFUNC resolution (which requires PROT_EXEC as well for the IFUNC resolver). This patch makes it call __mprotect with extra PROT_WRITE bit, which will keep the PROT_EXEC bit if exists, and thus fixes the segfault. FreeBSD rtld libexec/rtld-elf/rtld.c (reloc_textrel_prot) does the same. Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, sparc64-linux-gnu, sparcv9-linux-gnu, and armv8-linux-gnueabihf. Adam J. Richte <adam_richter2004@yahoo.com> Adhemerval Zanella <adhemerval.zanella@linaro.org> Fangrui Song <maskray@google.com> [BZ #20480] * config.h.in (CAN_TEXTREL_IFUNC): New define. * configure.ac: Add check if linker supports textrel relocation with ifunc. * elf/dl-reloc.c (_dl_relocate_object): Use all required flags on DT_TEXTREL segments, not only PROT_READ and PROT_WRITE. * elf/Makefile (ifunc-pie-tests): Add tst-ifunc-textrel. (CFLAGS-tst-ifunc-textrel.c): New rule. * elf/tst-ifunc-textrel.c: New file.
2018-09-12Include most of elf/ modules-names in modules-names-tests.Joseph Myers1-0/+4
I'm testing a patch to let the compiler expand calls to floor in libm as built-in function calls as much as possible, instead of calling __floor, so that no architecture-specific __floor inlines are needed, and then to arrange for non-inlined calls to end up calling __floor, as done with sqrt and __ieee754_sqrt. This shows up elf/tst-relsort1mod2.c calling floor, which must not be converted to a call to __floor. Now, while an IS_IN (libm) conditional could be added to the existing conditionals on such redirections in include/math.h, the _ISOMAC conditional ought to suffice (code in other glibc libraries shouldn't be calling floor or sqrt anyway, as they aren't provided in libc and the other libraries don't link with libm). But while tests are mostly now built with _ISOMAC defined, test modules in modules-names aren't unless also listed in modules-names-tests. As far as I can see, all the modules in modules-names in elf/ are in fact parts of tests and so listing them in modules-names-tests is appropriate, so they get built with something closer to the headers used for user code, except in a few cases that actually rely on something from internal headers. This patch duly sets modules-names-tests there accordingly (filtering out those tests that fail to build without internal headers). Tested for x86_64, and with build-many-glibcs.py. * elf/Makefile (modules-names-tests): New variable.
2018-08-30Fix test failure with -DNDEBUG.Carlos O'Donell1-6/+6
The elf/tst-dlopen-aout.c test uses asserts to verify properties of the test execution. Instead of using assert it should use xpthread_create and xpthread_join to catch errors starting the threads and fail the test. This shows up in Fedora 28 when building for i686-pc-linux-gnu and using gcc 8.1.1. Tested on i686, and fixes a check failure with -DNDEBUG. Signed-off-by: Carlos O'Donell <carlos@redhat.com>
2018-08-20Add NT_VMCOREDD, AT_MINSIGSTKSZ from Linux 4.18 to elf.h.Joseph Myers1-0/+4
This patch adds two new constants from Linux 4.18 to elf.h, NT_VMCOREDD and AT_MINSIGSTKSZ. Tested for x86_64. * elf/elf.c (NT_VMCOREDD): New macro. (AT_MINSIGSTKSZ): Likewise.
2018-08-02Rename the glibc.tune namespace to glibc.cpuSiddhesh Poyarekar3-3/+3
The glibc.tune namespace is vaguely named since it is a 'tunable', so give it a more specific name that describes what it refers to. Rename the tunable namespace to 'cpu' to more accurately reflect what it encompasses. Also rename glibc.tune.cpu to glibc.cpu.name since glibc.cpu.cpu is weird. * NEWS: Mention the change. * elf/dl-tunables.list: Rename tune namespace to cpu. * sysdeps/powerpc/dl-tunables.list: Likewise. * sysdeps/x86/dl-tunables.list: Likewise. * sysdeps/aarch64/dl-tunables.list: Rename tune.cpu to cpu.name. * elf/dl-hwcaps.c (_dl_important_hwcaps): Adjust. * elf/dl-hwcaps.h (GET_HWCAP_MASK): Likewise. * manual/README.tunables: Likewise. * manual/tunables.texi: Likewise. * sysdeps/powerpc/cpu-features.c: Likewise. * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Likewise. * sysdeps/x86/cpu-features.c: Likewise. * sysdeps/x86/cpu-features.h: Likewise. * sysdeps/x86/cpu-tunables.c: Likewise. * sysdeps/x86_64/Makefile: Likewise. * sysdeps/x86/dl-cet.c: Likewise. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2018-07-20check-execstack: Permit sysdeps to xfail some libsSamuel Thibault1-1/+1
* scripts/check-execstack.awk: Consider `xfail' variable containing a list of libraries whose stack executability is expected. * elf/Makefile ($(objpfx)check-execstack.out): Pass $(check-execstack-xfail) to check-execstack.awk through `xfail' variable. * sysdeps/mach/hurd/i386/Makefile (check-execstack-xfail): Set to ld.so libc.so libpthread.so.
2018-07-16x86: Support IBT and SHSTK in Intel CET [BZ #21598]H.J. Lu4-25/+49
Intel Control-flow Enforcement Technology (CET) instructions: https://software.intel.com/sites/default/files/managed/4d/2a/control-flow-en forcement-technology-preview.pdf includes Indirect Branch Tracking (IBT) and Shadow Stack (SHSTK). GNU_PROPERTY_X86_FEATURE_1_IBT is added to GNU program property to indicate that all executable sections are compatible with IBT when ENDBR instruction starts each valid target where an indirect branch instruction can land. Linker sets GNU_PROPERTY_X86_FEATURE_1_IBT on output only if it is set on all relocatable inputs. On an IBT capable processor, the following steps should be taken: 1. When loading an executable without an interpreter, enable IBT and lock IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the executable. 2. When loading an executable with an interpreter, enable IBT if GNU_PROPERTY_X86_FEATURE_1_IBT is set on the interpreter. a. If GNU_PROPERTY_X86_FEATURE_1_IBT isn't set on the executable, disable IBT. b. Lock IBT. 3. If IBT is enabled, when loading a shared object without GNU_PROPERTY_X86_FEATURE_1_IBT: a. If legacy interwork is allowed, then mark all pages in executable PT_LOAD segments in legacy code page bitmap. Failure of legacy code page bitmap allocation causes an error. b. If legacy interwork isn't allowed, it causes an error. GNU_PROPERTY_X86_FEATURE_1_SHSTK is added to GNU program property to indicate that all executable sections are compatible with SHSTK where return address popped from shadow stack always matches return address popped from normal stack. Linker sets GNU_PROPERTY_X86_FEATURE_1_SHSTK on output only if it is set on all relocatable inputs. On a SHSTK capable processor, the following steps should be taken: 1. When loading an executable without an interpreter, enable SHSTK if GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on the executable. 2. When loading an executable with an interpreter, enable SHSTK if GNU_PROPERTY_X86_FEATURE_1_SHSTK is set on interpreter. a. If GNU_PROPERTY_X86_FEATURE_1_SHSTK isn't set on the executable or any shared objects loaded via the DT_NEEDED tag, disable SHSTK. b. Otherwise lock SHSTK. 3. After SHSTK is enabled, it is an error to load a shared object without GNU_PROPERTY_X86_FEATURE_1_SHSTK. To enable CET support in glibc, --enable-cet is required to configure glibc. When CET is enabled, both compiler and assembler must support CET. Otherwise, it is a configure-time error. To support CET run-time control, 1. _dl_x86_feature_1 is added to the writable ld.so namespace to indicate if IBT or SHSTK are enabled at run-time. It should be initialized by init_cpu_features. 2. For dynamic executables: a. A l_cet field is added to struct link_map to indicate if IBT or SHSTK is enabled in an ELF module. _dl_process_pt_note or _rtld_process_pt_note is called to process PT_NOTE segment for GNU program property and set l_cet. b. _dl_open_check is added to check IBT and SHSTK compatibilty when dlopening a shared object. 3. Replace i386 _dl_runtime_resolve and _dl_runtime_profile with _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk, respectively if SHSTK is enabled. CET run-time control can be changed via GLIBC_TUNABLES with $ export GLIBC_TUNABLES=glibc.tune.x86_shstk=[permissive|on|off] $ export GLIBC_TUNABLES=glibc.tune.x86_ibt=[permissive|on|off] 1. permissive: SHSTK is disabled when dlopening a legacy ELF module. 2. on: IBT or SHSTK are always enabled, regardless if there are IBT or SHSTK bits in GNU program property. 3. off: IBT or SHSTK are always disabled, regardless if there are IBT or SHSTK bits in GNU program property. <cet.h> from CET-enabled GCC is automatically included by assembly codes to add GNU_PROPERTY_X86_FEATURE_1_IBT and GNU_PROPERTY_X86_FEATURE_1_SHSTK to GNU program property. _CET_ENDBR is added at the entrance of all assembly functions whose address may be taken. _CET_NOTRACK is used to insert NOTRACK prefix with indirect jump table to support IBT. It is defined as notrack when _CET_NOTRACK is defined in <cet.h>. [BZ #21598] * configure.ac: Add --enable-cet. * configure: Regenerated. * elf/Makefille (all-built-dso): Add a comment. * elf/dl-load.c (filebuf): Moved before "dynamic-link.h". Include <dl-prop.h>. (_dl_map_object_from_fd): Call _dl_process_pt_note on PT_NOTE segment. * elf/dl-open.c: Include <dl-prop.h>. (dl_open_worker): Call _dl_open_check. * elf/rtld.c: Include <dl-prop.h>. (dl_main): Call _rtld_process_pt_note on PT_NOTE segment. Call _rtld_main_check. * sysdeps/generic/dl-prop.h: New file. * sysdeps/i386/dl-cet.c: Likewise. * sysdeps/unix/sysv/linux/x86/cpu-features.c: Likewise. * sysdeps/unix/sysv/linux/x86/dl-cet.h: Likewise. * sysdeps/x86/cet-tunables.h: Likewise. * sysdeps/x86/check-cet.awk: Likewise. * sysdeps/x86/configure: Likewise. * sysdeps/x86/configure.ac: Likewise. * sysdeps/x86/dl-cet.c: Likewise. * sysdeps/x86/dl-procruntime.c: Likewise. * sysdeps/x86/dl-prop.h: Likewise. * sysdeps/x86/libc-start.h: Likewise. * sysdeps/x86/link_map.h: Likewise. * sysdeps/i386/dl-trampoline.S (_dl_runtime_resolve): Add _CET_ENDBR. (_dl_runtime_profile): Likewise. (_dl_runtime_resolve_shstk): New. (_dl_runtime_profile_shstk): Likewise. * sysdeps/linux/x86/Makefile (sysdep-dl-routines): Add dl-cet if CET is enabled. (CFLAGS-.o): Add -fcf-protection if CET is enabled. (CFLAGS-.os): Likewise. (CFLAGS-.op): Likewise. (CFLAGS-.oS): Likewise. (asm-CPPFLAGS): Add -fcf-protection -include cet.h if CET is enabled. (tests-special): Add $(objpfx)check-cet.out. (cet-built-dso): New. (+$(cet-built-dso:=.note)): Likewise. (common-generated): Add $(cet-built-dso:$(common-objpfx)%=%.note). ($(objpfx)check-cet.out): New. (generated): Add check-cet.out. * sysdeps/x86/cpu-features.c: Include <dl-cet.h> and <cet-tunables.h>. (TUNABLE_CALLBACK (set_x86_ibt)): New prototype. (TUNABLE_CALLBACK (set_x86_shstk)): Likewise. (init_cpu_features): Call get_cet_status to check CET status and update dl_x86_feature_1 with CET status. Call TUNABLE_CALLBACK (set_x86_ibt) and TUNABLE_CALLBACK (set_x86_shstk). Disable and lock CET in libc.a. * sysdeps/x86/cpu-tunables.c: Include <cet-tunables.h>. (TUNABLE_CALLBACK (set_x86_ibt)): New function. (TUNABLE_CALLBACK (set_x86_shstk)): Likewise. * sysdeps/x86/sysdep.h (_CET_NOTRACK): New. (_CET_ENDBR): Define if not defined. (ENTRY): Add _CET_ENDBR. * sysdeps/x86/dl-tunables.list (glibc.tune): Add x86_ibt and x86_shstk. * sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve): Add _CET_ENDBR. (_dl_runtime_profile): Likewise.
2018-06-29elf: Accept absolute (SHN_ABS) symbols whose value is zero [BZ #23307]Maciej W. Rozycki5-2/+71
We have this condition in `check_match' (in elf/dl-lookup.c): if (__glibc_unlikely ((sym->st_value == 0 /* No value. */ && stt != STT_TLS) || ELF_MACHINE_SYM_NO_MATCH (sym) || (type_class & (sym->st_shndx == SHN_UNDEF)))) return NULL; which causes all !STT_TLS symbols whose value is zero to be silently ignored in lookup. This may make sense for regular symbols, however not for absolute (SHN_ABS) ones, where zero is like any value, there's no special meaning attached to it. Consequently legitimate programs fail, for example taking the `elf/tst-absolute-sym' test case, substituting 0 for 0x55aa in `elf/tst-absolute-sym-lib.lds' and then trying to run the resulting program we get this: $ .../elf/tst-absolute-sym .../elf/tst-absolute-sym: symbol lookup error: .../elf/tst-absolute-sym-lib.so: undefined symbol: absolute $ even though the symbol clearly is there: $ readelf --dyn-syms .../elf/tst-absolute-sym-lib.so | grep '\babsolute\b' 7: 00000000 0 NOTYPE GLOBAL DEFAULT ABS absolute $ The check for the zero value has been there since forever or commit d66e34cd4234/08162fa88891 ("Implemented runtime dynamic linker to support ELF shared libraries.") dating back to May 2nd 1995, and the problem triggers regardless of commit e7feec374c63 ("elf: Correct absolute (SHN_ABS) symbol run-time calculation [BZ #19818]") being present or not. Fix the issue then, by permitting `sym->st_value' to be 0 for SHN_ABS symbols in lookup. [BZ #23307] * elf/dl-lookup.c (check_match): Do not reject a symbol whose `st_value' is 0 if `st_shndx' is SHN_ABS. * elf/tst-absolute-zero.c: New file. * elf/tst-absolute-zero-lib.c: New file. * elf/tst-absolute-zero-lib.lds: New file. * elf/Makefile (tests): Add `tst-absolute-zero'. (modules-names): Add `tst-absolute-zero-lib'. (LDLIBS-tst-absolute-zero-lib.so): New variable. ($(objpfx)tst-absolute-zero-lib.so): New dependency. ($(objpfx)tst-absolute-zero: New dependency.
2018-06-29New configure option --disable-crypt.Zack Weinberg2-9/+22
Some Linux distributions are experimenting with a new, separately maintained and hopefully more agile implementation of the crypt API. To facilitate this, add a configure option which disables glibc's embedded libcrypt. When this option is given, libcrypt.* and crypt.h will not be built nor installed.
2018-06-27_dl_map_object_deps: Use struct scratch_buffer [BZ #18023]Florian Weimer1-12/+16
The function comment suggests that _dl_map_object_deps cannot use malloc, but it already allocates the l_initfini array on the heap, so the additional allocation should be acceptable.
2018-06-21Add Andes nds32 dynamic relocations to elf.hVincent Chen1-0/+10
* elf/elf.h (R_NDS32_NONE): New define. (R_NDS32_32_RELA): Likewise. (R_NDS32_COPY): Likewise. (R_NDS32_GLOB_DAT): Likewise. (R_NDS32_JUMP_SLOT): Likewise. (R_NDS32_RELATIVE): Likewise. (R_NDS32_TLS_TPOFF): Likewise. (R_NDS32_TLS_DESC): Likewise.
2018-06-21elf.h: Add BPF relocation types.Mark Wielaard1-1/+2
The BPF ELF format has new relocation types R_BPF_64_64 and R_BPF_64_32. The existing R_BPF_MAP_FD was an extension that never got implemented. Remove it, because the constant conflicts with the official R_BPF_64_64. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2018-06-12Fix comments in _dl_dst_count and _dl_dst_substitute.Carlos O'Donell1-6/+8
The comments in _dl_dst_count is adjusted to match what the code does which is count DSTs from the start of the string. With the removal of DL_DST_COUNT we no longer accept an input that starts at the first $. In _dl_dst_substitute we adjust the comment to indicate that both conditions must be true for the SUID/SGID $ORIGIN exception.
2018-06-12Improve DST handling (Bug 23102, Bug 21942, Bug 18018, Bug 23259).Carlos O'Donell3-93/+135
This commit improves DST handling significantly in the following ways: firstly is_dst () is overhauled to correctly process DST sequences that would be accepted given the ELF gABI. This means that we actually now accept slightly more sequences than before. Now we accept $ORIGIN$ORIGIN, but in the past we accepted only $ORIGIN\0 or $ORIGIN/..., but this kind of behaviour results in unexpected and uninterpreted DST sequences being used as literal search paths leading to security defects. Therefore the first step in correcting this defect is making is_dst () properly account for all DSTs and making the function context free in the sense that it counts DSTs without knowledge of path, or AT_SECURE. Next, _dl_dst_count () is also simplified to count all DSTs regardless of context. Then in _dl_dst_substitute () we reintroduce context-dependent processing for such things as AT_SECURE handling. At the level of _dl_dst_substitute we can have access to things like the true start of the string sequence to validate $ORIGIN-based paths rooted in trusted directories. Lastly, we tighten up the accepted sequences in AT_SECURE, and avoid leaving known unexpanded DSTs, this is noted in the NEWS entry. Verified with a sequence of 68 tests on x86_64 that cover non-AT_SECURE and AT_SECURE testing using a sysroot (requires root to run). The tests cover cases for bug 23102, bug 21942, bug 18018, and bug 23259. These tests are not yet appropriate for the glibc regression testsuite, but with the upcoming test-in-container testing framework it should be possible to include these tests upstream soon. See the mailing list for the tests: https://www.sourceware.org/ml/libc-alpha/2018-06/msg00251.html
2018-06-12Avoid cancellable I/O primitives in ld.so.Zack Weinberg4-28/+30
Neither the <dlfcn.h> entry points, nor lazy symbol resolution, nor initial shared library load-up, are cancellation points, so ld.so should exclusively use I/O primitives that are not cancellable. We currently achieve this by having the cancellation hooks compile as no-ops when IS_IN(rtld); this patch changes to using exclusively _nocancel primitives in the source code instead, which makes the intent clearer and significantly reduces the amount of code compiled under IS_IN(rtld) as well as IS_IN(libc) -- in particular, elf/Makefile no longer thinks we require a copy of unwind.c in rtld-libc.a. (The older mechanism is preserved as a backstop.) The bulk of the change is splitting up the files that define the _nocancel I/O functions, so they don't also define the variants that *are* cancellation points; after which, the existing logic for picking out the bits of libc that need to be recompiled as part of ld.so Just Works. I did this for all of the _nocancel functions, not just the ones used by ld.so, for consistency. fcntl was a little tricky because it's only a cancellation point for certain opcodes (F_SETLKW(64), which can block), and the existing __fcntl_nocancel wasn't applying the FCNTL_ADJUST_CMD hook, which strikes me as asking for trouble, especially as the only nontrivial definition of FCNTL_ADJUST_CMD (for powerpc64) changes F_*LK* opcodes. To fix this, fcntl_common moves to fcntl_nocancel.c along with __fcntl_nocancel, and changes its name to the extern (but hidden) symbol __fcntl_nocancel_adjusted, so that regular fcntl can continue calling it. __fcntl_nocancel now applies FCNTL_ADJUST_CMD; so that both both fcntl.c and fcntl_nocancel.c can see it, the only nontrivial definition moves from sysdeps/u/s/l/powerpc/powerpc64/fcntl.c to .../powerpc64/sysdep.h and becomes entirely a macro, instead of a macro that calls an inline function. The nptl version of libpthread also changes a little, because its "compat-routines" formerly included files that defined all the _nocancel functions it uses; instead of continuing to duplicate them, I exported the relevant ones from libc.so as GLIBC_PRIVATE. Since the Linux fcntl.c calls a function defined by fcntl_nocancel.c, it can no longer be used from libpthread.so; instead, introduce a custom forwarder, pt-fcntl.c, and export __libc_fcntl from libc.so as GLIBC_PRIVATE. The nios2-linux ABI doesn't include a copy of vfork() in libpthread, and it was handling that by manipulating libpthread-routines in .../linux/nios2/Makefile; it is cleaner to do what other such ports do, and have a pt-vfork.S that defines no symbols. Right now, it appears that Hurd does not implement _nocancel I/O, so sysdeps/generic/not-cancel.h will forward everything back to the regular functions. This changed the names of some of the functions that sysdeps/mach/hurd/dl-sysdep.c needs to interpose. * elf/dl-load.c, elf/dl-misc.c, elf/dl-profile.c, elf/rtld.c * sysdeps/unix/sysv/linux/dl-sysdep.c Include not-cancel.h. Use __close_nocancel instead of __close, __open64_nocancel instead of __open, __read_nocancel instead of __libc_read, and __write_nocancel instead of __libc_write. * csu/check_fds.c (check_one_fd) * sysdeps/posix/fdopendir.c (__fdopendir) * sysdeps/posix/opendir.c (__alloc_dir): Use __fcntl_nocancel instead of __fcntl and/or __libc_fcntl. * sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np) * sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np) * sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system): Use __open64_nocancel instead of __open_nocancel. * sysdeps/unix/sysv/linux/not-cancel.h: Move all of the hidden_proto declarations to the end and issue them if either IS_IN(libc) or IS_IN(rtld). * sysdeps/unix/sysv/linux/Makefile [subdir=io] (sysdep_routines): Add close_nocancel, fcntl_nocancel, nanosleep_nocancel, open_nocancel, open64_nocancel, openat_nocancel, pause_nocancel, read_nocancel, waitpid_nocancel, write_nocancel. * io/Versions [GLIBC_PRIVATE]: Add __libc_fcntl, __fcntl_nocancel, __open64_nocancel, __write_nocancel. * posix/Versions: Add __nanosleep_nocancel, __pause_nocancel. * nptl/pt-fcntl.c: New file. * nptl/Makefile (pthread-compat-wrappers): Remove fcntl. (libpthread-routines): Add pt-fcntl. * include/fcntl.h (__fcntl_nocancel_adjusted): New function. (__libc_fcntl): Remove attribute_hidden. * sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Call __fcntl_nocancel_adjusted, not fcntl_common. (__fcntl_nocancel): Move to new file fcntl_nocancel.c. (fcntl_common): Rename to __fcntl_nocancel_adjusted; also move to fcntl_nocancel.c. * sysdeps/unix/sysv/linux/fcntl_nocancel.c: New file. * sysdeps/unix/sysv/linux/powerpc/powerpc64/fcntl.c: Remove file. * sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h: Define FCNTL_ADJUST_CMD here, as a self-contained macro. * sysdeps/unix/sysv/linux/close.c: Move __close_nocancel to... * sysdeps/unix/sysv/linux/close_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/nanosleep.c: Move __nanosleep_nocancel to... * sysdeps/unix/sysv/linux/nanosleep_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/open.c: Move __open_nocancel to... * sysdeps/unix/sysv/linux/open_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/open64.c: Move __open64_nocancel to... * sysdeps/unix/sysv/linux/open64_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/openat.c: Move __openat_nocancel to... * sysdeps/unix/sysv/linux/openat_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/openat64.c: Move __openat64_nocancel to... * sysdeps/unix/sysv/linux/openat64_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/pause.c: Move __pause_nocancel to... * sysdeps/unix/sysv/linux/pause_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/read.c: Move __read_nocancel to... * sysdeps/unix/sysv/linux/read_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/waitpid.c: Move __waitpid_nocancel to... * sysdeps/unix/sysv/linux/waitpid_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/write.c: Move __write_nocancel to... * sysdeps/unix/sysv/linux/write_nocancel.c: ...this new file. * sysdeps/unix/sysv/linux/nios2/Makefile: Don't override libpthread-routines. * sysdeps/unix/sysv/linux/nios2/pt-vfork.S: New file which defines nothing. * sysdeps/mach/hurd/dl-sysdep.c: Define __read instead of __libc_read, and __write instead of __libc_write. Define __open64 in addition to __open.
2018-06-08Mark _init and _fini as hidden [BZ #23145]H.J. Lu1-1/+14
_init and _fini are special functions provided by glibc for linker to define DT_INIT and DT_FINI in executable and shared library. They should never be put in dynamic symbol table. This patch marks them as hidden to remove them from dynamic symbol table. Tested with build-many-glibcs.py. [BZ #23145] * elf/Makefile (tests-special): Add $(objpfx)check-initfini.out. ($(all-built-dso:=.dynsym): New target. (common-generated): Add $(all-built-dso:$(common-objpfx)%=%.dynsym). ($(objpfx)check-initfini.out): New target. (generated): Add check-initfini.out. * scripts/check-initfini.awk: New file. * sysdeps/aarch64/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/alpha/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/arm/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/hppa/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/i386/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/ia64/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/m68k/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/microblaze/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/mips/mips32/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/mips/mips64/n32/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/mips/mips64/n64/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/nios2/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/powerpc/powerpc32/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/powerpc/powerpc64/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/s390/s390-32/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/s390/s390-64/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/sh/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/sparc/crti.S (_init): Mark as hidden. (_fini): Likewise. * sysdeps/x86_64/crti.S (_init): Mark as hidden. (_fini): Likewise.
2018-05-29static-PIE: Update DT_DEBUG for debugger [BZ #23206]H.J. Lu1-0/+16
This is needed to support debugging dlopened shared libraries in static PIE. [BZ #23206] * elf/dl-reloc-static-pie.c (_dl_relocate_static_pie): Initialize _r_debug and update DT_DEBUG for debugger. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2018-05-05Fix BZ 20419. A PT_NOTE in a binary could be arbitratily large, so usingPaul Pluzhnikov4-4/+77
alloca for it may cause stack overflow. If the note is larger than __MAX_ALLOCA_CUTOFF, use dynamically allocated memory to read it in. 2018-05-05 Paul Pluzhnikov <ppluzhnikov@google.com> [BZ #20419] * elf/dl-load.c (open_verify): Fix stack overflow. * elf/Makefile (tst-big-note): New test. * elf/tst-big-note-lib.S: New. * elf/tst-big-note.c: New.
2018-04-23Add NT_PPC_PKEY from Linux 4.16 to elf.h.Joseph Myers1-0/+2
This patch adds the NT_PPC_PKEY macro from Linux 4.16 to elf.h. Tested for x86_64. * elf/elf.h (NT_PPC_PKEY): New macro.
2018-04-04elf: Correct absolute (SHN_ABS) symbol run-time calculation [BZ #19818]Maciej W. Rozycki5-2/+90
Do not relocate ab