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* ia64: Work around incorrect type of IA64 uc_sigmaskH.J. Lu2018-07-251-0/+26
| | | | | | | | Work around: https://sourceware.org/bugzilla/show_bug.cgi?id=21634 * sysdeps/unix/sysv/linux/ia64/tst-setcontext4.c: New file.
* Fix ISO C threads installed header and HURD assumptionAdhemerval Zanella2018-07-252-1/+270
| | | | | | | | | | | | | Set installed NPTL header as the expected one (instead of an internal one for glibc testsuite) and add a hurd specific stdc-predef with __STDC_NO_THREADS__. Checked on both i686-linux-gnu and i686-gnu that both threads.h and stdc-predef.h are the expected ones. * nptl/threads.h: Move to ... * sysdeps/nptl/threads.h: ... here. * sysdeps/hurd/stdc-predef.h: New file.
* x86/CET: Add a setcontext test for CETH.J. Lu2018-07-252-0/+134
| | | | | | | | | | Verify that setcontext works with gaps above and below the newly allocated shadow stack. * sysdeps/unix/sysv/linux/x86/Makefile (tests): Add tst-cet-setcontext-1 if CET is enabled. (CFLAGS-tst-cet-setcontext-1.c): Add -mshstk. * sysdeps/unix/sysv/linux/x86/tst-cet-setcontext-1.c: New file.
* Fix C11 conformance issuesAdhemerval Zanella2018-07-252-0/+2
| | | | | | | | | | | | | | | | | | | | | | | Remove conformace assumption of NPTL implementation for ISO C threads and revert wrong libcrypt addition on linknamespace-libs-XPG4. The i686-gnu target now shows two new conformance failures: FAIL: conform/ISO11/threads.h/conform FAIL: conform/ISO11/threads.h/linknamespace It is expected due missing HTL ISO C threads support and both conformance .out files indicates the reason ("#error "HTL does not implement ISO C threads"). Checked on i686-linux-gnu and i686-gnu. * include/threads.h: Move to ... * sysdeps/nptl/threads.h: ... here. * sysdeps/htl/threads.h: New file. * conform/Makefile (linknamespace-libs-ISO11): Use static-thread-library instead of linking libpthread. (linknamespace-libs-XPG4): Revert wrong libcrypt.a addition.
* x86-64/CET: Extend ucontext_t to save shadow stackH.J. Lu2018-07-258-1/+391
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a field to ucontext_t to save shadow stack: 1. getcontext and swapcontext are updated to save the caller's shadow stack pointer and return addresses. 2. setcontext and swapcontext are updated to restore shadow stack and jump to new context directly. 3. makecontext is updated to allocate a new shadow stack and set the caller's return address to __start_context. Since makecontext allocates a new shadow stack when making a new context and kernel allocates a new shadow stack for clone/fork/vfork syscalls, we track the current shadow stack base. In setcontext and swapcontext, if the target shadow stack base is the same as the current shadow stack base, we unwind the shadow stack. Otherwise it is a stack switch and we look for a restore token. We enable shadow stack at run-time only if program and all used shared objects, including dlopened ones, are shadow stack enabled, which means that they must be compiled with GCC 8 or above and glibc 2.28 or above. We need to save and restore shadow stack only if shadow stack is enabled. When caller of getcontext, setcontext, swapcontext and makecontext is compiled with smaller ucontext_t, shadow stack won't be enabled at run-time. We check if shadow stack is enabled before accessing the extended field in ucontext_t. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/unix/sysv/linux/x86/sys/ucontext.h (ucontext_t): Add __ssp. * sysdeps/unix/sysv/linux/x86_64/__start_context.S: Include <asm/prctl.h> and "ucontext_i.h" when shadow stack is enabled. (__push___start_context): New. * sysdeps/unix/sysv/linux/x86_64/getcontext.S: Include <asm/prctl.h>. (__getcontext): Record the current shadow stack base. Save the caller's shadow stack pointer and base. * sysdeps/unix/sysv/linux/x86_64/makecontext.c: Include <pthread.h>, <libc-pointer-arith.h> and <sys/prctl.h>. (__push___start_context): New prototype. (__makecontext): Call __push___start_context to allocate a new shadow stack, push __start_context onto the new stack as well as the new shadow stack. * sysdeps/unix/sysv/linux/x86_64/setcontext.S: Include <asm/prctl.h>. (__setcontext): Restore the target shadow stack. * sysdeps/unix/sysv/linux/x86_64/swapcontext.S: Include <asm/prctl.h>. (__swapcontext): Record the current shadow stack base. Save the caller's shadow stack pointer and base. Restore the target shadow stack. * sysdeps/unix/sysv/linux/x86_64/sysdep.h (STACK_SIZE_TO_SHADOW_STACK_SIZE_SHIFT): New. * sysdeps/unix/sysv/linux/x86_64/ucontext_i.sym (oSSP): New.
* x86/CET: Add tests with legacy non-CET shared objectsH.J. Lu2018-07-2512-0/+293
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Check binary compatibility of CET-enabled executables: 1. When CET-enabled executable is used with legacy non-CET shared object at run-time, ld.so should disable SHSTK and put legacy non-CET shared objects in legacy bitmap. 2. When IBT-enabled executable dlopens legacy non-CET shared object, ld.so should put legacy shared object in legacy bitmap. 3. Use GLIBC_TUNABLES=glibc.tune.x86_shstk=[on|off|permissive] to control how SHSTK is enabled. * sysdeps/x86/Makefile (tests): Add tst-cet-legacy-1, tst-cet-legacy-2, tst-cet-legacy-2a, tst-cet-legacy-3, tst-cet-legacy-4, tst-cet-legacy-4a, tst-cet-legacy-4b and tst-cet-legacy-4c. (modules-names): Add tst-cet-legacy-mod-1, tst-cet-legacy-mod-2 and tst-cet-legacy-mod-4. (CFLAGS-tst-cet-legacy-2.c): New. (CFLAGS-tst-cet-legacy-mod-1.c): Likewise. (CFLAGS-tst-cet-legacy-mod-2.c): Likewise. (CFLAGS-tst-cet-legacy-3.c): Likewise. (CFLAGS-tst-cet-legacy-4.c): Likewise. (CFLAGS-tst-cet-legacy-mod-4.c): Likewise. ($(objpfx)tst-cet-legacy-1): Likewise. ($(objpfx)tst-cet-legacy-2): Likewise. ($(objpfx)tst-cet-legacy-2.out): Likewise. ($(objpfx)tst-cet-legacy-2a): Likewise. ($(objpfx)tst-cet-legacy-2a.out): Likewise. ($(objpfx)tst-cet-legacy-4): Likewise. ($(objpfx)tst-cet-legacy-4.out): Likewise. ($(objpfx)tst-cet-legacy-4a): Likewise. ($(objpfx)tst-cet-legacy-4a.out): Likewise. (tst-cet-legacy-4a-ENV): Likewise. ($(objpfx)tst-cet-legacy-4b): Likewise. ($(objpfx)tst-cet-legacy-4b.out): Likewise. (tst-cet-legacy-4b-ENV): Likewise. ($(objpfx)tst-cet-legacy-4c): Likewise. ($(objpfx)tst-cet-legacy-4c.out): Likewise. (tst-cet-legacy-4c-ENV): Likewise. * sysdeps/x86/tst-cet-legacy-1.c: New file. * sysdeps/x86/tst-cet-legacy-2.c: Likewise. * sysdeps/x86/tst-cet-legacy-2a.c: Likewise. * sysdeps/x86/tst-cet-legacy-3.c: Likewise. * sysdeps/x86/tst-cet-legacy-4.c: Likewise. * sysdeps/x86/tst-cet-legacy-4a.c: Likewise. * sysdeps/x86/tst-cet-legacy-4b.c: Likewise. * sysdeps/x86/tst-cet-legacy-4c.c: Likewise. * sysdeps/x86/tst-cet-legacy-mod-1.c: Likewise. * sysdeps/x86/tst-cet-legacy-mod-2.c: Likewise. * sysdeps/x86/tst-cet-legacy-mod-4.c: Likewise.
* x86: Rename __glibc_reserved2 to ssp_base in tcbhead_tH.J. Lu2018-07-254-2/+13
| | | | | | | | | | | | | | | This will be used to record the current shadow stack base for shadow stack switching by getcontext, makecontext, setcontext and swapcontext. If the target shadow stack base is the same as the current shadow stack base, we unwind the shadow stack. Otherwise it is a stack switch and we look for a restore token to restore the target shadow stack. * sysdeps/i386/nptl/tcb-offsets.sym (SSP_BASE_OFFSET): New. * sysdeps/i386/nptl/tls.h (tcbhead_t): Replace __glibc_reserved2 with ssp_base. * sysdeps/x86_64/nptl/tcb-offsets.sym (SSP_BASE_OFFSET): New. * sysdeps/x86_64/nptl/tls.h (tcbhead_t): Replace __glibc_reserved2 with ssp_base.
* alpha: mlock2, copy_file_range syscalls were introduced in kernel 4.13Florian Weimer2018-07-241-1/+3
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* x86/CET: Extend arch_prctl syscall for CET controlH.J. Lu2018-07-244-6/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CET arch_prctl bits should be defined in <asm/prctl.h> from Linux kernel header files. Add x86 <include/asm/prctl.h> for pre-CET kernel header files. Note: sysdeps/unix/sysv/linux/x86/include/asm/prctl.h should be removed if <asm/prctl.h> from the required kernel header files contains CET arch_prctl bits. /* CET features: IBT: GNU_PROPERTY_X86_FEATURE_1_IBT SHSTK: GNU_PROPERTY_X86_FEATURE_1_SHSTK */ /* Return CET features in unsigned long long *addr: features: addr[0]. shadow stack base address: addr[1]. shadow stack size: addr[2]. */ # define ARCH_CET_STATUS 0x3001 /* Disable CET features in unsigned int features. */ # define ARCH_CET_DISABLE 0x3002 /* Lock all CET features. */ # define ARCH_CET_LOCK 0x3003 /* Allocate a new shadow stack with unsigned long long *addr: IN: requested shadow stack size: *addr. OUT: allocated shadow stack address: *addr. */ # define ARCH_CET_ALLOC_SHSTK 0x3004 /* Return legacy region bitmap info in unsigned long long *addr: address: addr[0]. size: addr[1]. */ # define ARCH_CET_LEGACY_BITMAP 0x3005 Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/unix/sysv/linux/x86/include/asm/prctl.h: New file. * sysdeps/unix/sysv/linux/x86/cpu-features.c: Include <sys/prctl.h> and <asm/prctl.h>. (get_cet_status): Call arch_prctl with ARCH_CET_STATUS. * sysdeps/unix/sysv/linux/x86/dl-cet.h: Include <sys/prctl.h> and <asm/prctl.h>. (dl_cet_allocate_legacy_bitmap): Call arch_prctl with ARCH_CET_LEGACY_BITMAP. (dl_cet_disable_cet): Call arch_prctl with ARCH_CET_DISABLE. (dl_cet_lock_cet): Call arch_prctl with ARCH_CET_LOCK. * sysdeps/x86/libc-start.c: Include <startup.h>.
* sh: Do not define __ASSUME_STATXFlorian Weimer2018-07-241-0/+3
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* nptl: Add abilist symbols for C11 threadsAdhemerval Zanella2018-07-2449-0/+587
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the required abilist symbols for C11 thread support. Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu, powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu, and x86_64-linux-gnu). Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu, arm-linux-gnueabhf, and powerpc64le-linux-gnu. [BZ #14092] * sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.28] (thrd_current, thrd_equal, thrd_sleep, thrd_yield): Add C11 thread symbols. * sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/aarch64/libpthread.abilist [[GLIBC_2.28] (call_once, cnd_broadcast, cnd_destroy, cnd_init, cnd_signal, cnd_timedwait, cnd_wait, mtx_destroy, mtx_init, mtx_lock, mtx_timedlock, mtx_trylock, mtx_unlokc, thrd_create, thrd_detach, thrd_exit, thrd_join, tss_create, tss_delete, tss_get, tss_set): Likewise. * sysdeps/unix/sysv/linux/aarch64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/alpha/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/arm/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/hppa/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/i386/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/ia64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/coldfire/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/m68k/m680x0/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/microblaze/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips32/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/mips/mips64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/nios2/libpthread.abilist: Likewise. ikewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/libpthread.abilist: * sysdeps/unix/sysv/linux/powerpc/powerpc64/libpthread-le.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/sh/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libpthread.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libpthread.abilist: Likewise.
* nptl: Add C11 threads thrd_* functionsAdhemerval Zanella2018-07-241-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the thrd_* definitions from C11 threads (ISO/IEC 9899:2011), more specifically thrd_create, thrd_curent, rhd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, thrd_yield, and required types. Mostly of the definitions are composed based on POSIX conterparts, such as thrd_t (using pthread_t). For thrd_* function internally direct POSIX pthread call are used with the exceptions: 1. thrd_start uses pthread_create internal implementation, but changes how to actually calls the start routine. This is due the difference in signature between POSIX and C11, where former return a 'void *' and latter 'int'. To avoid calling convention issues due 'void *' to int cast, routines from C11 threads are started slight different than default pthread one. Explicit cast to expected return are used internally on pthread_create and the result is stored back to void also with an explicit cast. 2. thrd_sleep uses nanosleep internal direct syscall to avoid clobbering errno and to handle expected standard return codes. It is a cancellation entrypoint to be consistent with both thrd_join and cnd_{timed}wait. 3. thrd_yield also uses internal direct syscall to avoid errno clobbering. Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu, powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu, and x86_64-linux-gnu). Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu, arm-linux-gnueabhf, and powerpc64le-linux-gnu. [BZ #14092] * conform/Makefile (conformtest-headers-ISO11): Add threads.h. (linknamespace-libs-ISO11): Add libpthread.a. * conform/data/threads.h-data: New file: add C11 thrd_* types and functions. * include/stdc-predef.h (__STDC_NO_THREADS__): Remove definition. * nptl/Makefile (headers): Add threads.h. (libpthread-routines): Add new C11 thread thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, and thrd_yield. * nptl/Versions (libpthread) [GLIBC_2.28]): Add new C11 thread thrd_create, thrd_current, thrd_detach, thrd_equal, thrd_exit, thrd_join, thrd_sleep, and thrd_yield symbols. * nptl/descr.h (struct pthread): Add c11 field. * nptl/pthreadP.h (ATTR_C11_THREAD): New define. * nptl/pthread_create.c (START_THREAD_DEFN): Call C11 thread start routine with expected function prototype. (__pthread_create_2_1): Add C11 threads check based on attribute value. * sysdeps/unix/sysdep.h (INTERNAL_SYSCALL_CANCEL): New macro. * nptl/thrd_create.c: New file. * nptl/thrd_current.c: Likewise. * nptl/thrd_detach.c: Likewise. * nptl/thrd_equal.c: Likewise. * nptl/thrd_exit.c: Likewise. * nptl/thrd_join.c: Likewise. * nptl/thrd_priv.h: Likewise. * nptl/thrd_sleep.c: Likewise. * nptl/thrd_yield.c: Likewise. * include/threads.h: Likewise.
* Add <bits/indirect-return.h>H.J. Lu2018-07-241-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add <bits/indirect-return.h> and include it in <ucontext.h>. __INDIRECT_RETURN defined in <bits/indirect-return.h> indicates if swapcontext requires special compiler treatment. The default __INDIRECT_RETURN is empty. On x86, when shadow stack is enabled, __INDIRECT_RETURN is defined with indirect_return attribute, which has been added to GCC 9, to indicate that swapcontext returns via indirect branch. Otherwise __INDIRECT_RETURN is defined with returns_twice attribute. When shadow stack is enabled, remove always_inline attribute from prepare_test_buffer in string/tst-xbzero-opt.c to avoid: tst-xbzero-opt.c: In function ‘prepare_test_buffer’: tst-xbzero-opt.c:105:1: error: function ‘prepare_test_buffer’ can never be inlined because it uses setjmp prepare_test_buffer (unsigned char *buf) when indirect_return attribute isn't available. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * bits/indirect-return.h: New file. * misc/sys/cdefs.h (__glibc_has_attribute): New. * sysdeps/x86/bits/indirect-return.h: Likewise. * stdlib/Makefile (headers): Add bits/indirect-return.h. * stdlib/ucontext.h: Include <bits/indirect-return.h>. (swapcontext): Add __INDIRECT_RETURN. * string/tst-xbzero-opt.c (ALWAYS_INLINE): New. (prepare_test_buffer): Use it.
* x86: Update vfork to pop shadow stackH.J. Lu2018-07-242-0/+95
| | | | | | | | | | | | | | | | | | | | | The shadow stack prevents us from pushing the saved return PC onto the stack and returning normally. Instead we pop the shadow stack and return directly. This is the safest way to return and ensures any stack manipulations done by the vfork'd child doesn't cause the parent to terminate when CET is enabled. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/unix/sysv/linux/i386/vfork.S (SYSCALL_ERROR_HANDLER): Redefine if shadow stack is enabled. (SYSCALL_ERROR_LABEL): Likewise. (__vfork): Pop shadow stack and jump back to to caller directly when shadow stack is in use. * sysdeps/unix/sysv/linux/x86_64/vfork.S (SYSCALL_ERROR_HANDLER): Redefine if shadow stack is enabled. (SYSCALL_ERROR_LABEL): Likewise. (__vfork): Pop shadow stack and jump back to to caller directly when shadow stack is in use.
* x86-64: Add endbr64 to tst-quadmod[12].SH.J. Lu2018-07-242-0/+12
| | | | | | | | | | | | | Add endbr64 to tst-quadmod1.S and tst-quadmod2.S so that func and foo can be called indirectly. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/x86_64/tst-quadmod1.S (func): Add endbr64 if IBT is enabled. (foo): Likewise. * sysdeps/x86_64/tst-quadmod2.S (func) : Likewise. (foo): Likewise.
* check-execstack: Permit sysdeps to xfail some libsSamuel Thibault2018-07-201-0/+6
| | | | | | | | | | | * 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.
* hurd: Fix installed-headers testsSamuel Thibault2018-07-203-0/+6
| | | | | | * sysdeps/mach/include/mach-shortcuts-hidden.h [!_ISOMAC]: Do not declare libc hidden prototypes. * sysdeps/mach/include/mach/mach_traps.h [!_ISOMAC]: Likewise.
* Fix new file headerSamuel Thibault2018-07-201-4/+3
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* hurd: Implement pipe2Thomas Schwinge2018-07-202-20/+61
| | | | | | * sysdeps/mach/hurd/pipe2.c: New file, copy from pipe.c. Evolve it to implement __pipe2. * sysdeps/mach/hurd/pipe.c (__pipe): Reimplement using __pipe2.
* hurd: SOCK_CLOEXEC and SOCK_NONBLOCK for socketpairThomas Schwinge2018-07-201-3/+22
| | | | | * sysdeps/mach/hurd/socketpair.c (__socketpair): Handle SOCK_CLOEXEC and SOCK_NONBLOCK.
* hurd: SOCK_CLOEXEC and SOCK_NONBLOCK for socketThomas Schwinge2018-07-201-1/+14
| | | | | * sysdeps/mach/hurd/socket.c (__socket): Handle SOCK_CLOEXEC and SOCK_NONBLOCK.
* hurd: Enable thread-safe i386 atomic instructionsSamuel Thibault2018-07-201-0/+2
| | | | | * sysdeps/mach/hurd/i386/tls.h (_hurd_tls_init): Set multiple_threads to 1.
* x86-64: Use _CET_NOTRACK in memcmp-sse4.SH.J. Lu2018-07-181-1/+1
| | | | | * sysdeps/x86_64/multiarch/memcmp-sse4.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in memset-sse2-rep.SH.J. Lu2018-07-181-2/+2
| | | | | | * sysdeps/i386/i686/multiarch/memset-sse2-rep.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in strcat-sse2.SH.J. Lu2018-07-181-2/+2
| | | | | | * sysdeps/i386/i686/multiarch/strcat-sse2.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in strcpy-sse2.SH.J. Lu2018-07-181-2/+2
| | | | | | * sysdeps/i386/i686/multiarch/strcpy-sse2.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in memcpy-ssse3.SH.J. Lu2018-07-181-2/+2
| | | | | | * sysdeps/i386/i686/multiarch/memcpy-ssse3.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in memcpy-ssse3-rep.SH.J. Lu2018-07-181-4/+4
| | | | | | | * sysdeps/i386/i686/multiarch/memcpy-ssse3-rep.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table. (BRANCH_TO_JMPTBL_ENTRY_TAIL): Likewise.
* i386: Use _CET_NOTRACK in memcmp-sse4.SH.J. Lu2018-07-181-2/+2
| | | | | | * sysdeps/i386/i686/multiarch/memcmp-sse4.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in memset-sse2.SH.J. Lu2018-07-181-2/+2
| | | | | | * sysdeps/i386/i686/multiarch/memset-sse2.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Use _CET_NOTRACK in i686/memcmp.SH.J. Lu2018-07-181-2/+2
| | | | | * sysdeps/i386/i686/memcmp.S (memcmp): Add _CET_NOTRACK before indirect jump to jump table.
* x86-64: Use _CET_NOTRACK in memcpy-ssse3.SH.J. Lu2018-07-181-62/+62
| | | | | | | * sysdeps/x86_64/multiarch/memcpy-ssse3.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table. (MEMCPY): Likewise.
* x86-64: Use _CET_NOTRACK in memcpy-ssse3-back.SH.J. Lu2018-07-181-3/+3
| | | | | | | * sysdeps/x86_64/multiarch/memcpy-ssse3-back.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table. (MEMCPY): Likewise.
* x86-64: Use _CET_NOTRACK in strcmp-sse42.SH.J. Lu2018-07-181-1/+1
| | | | | * sysdeps/x86_64/multiarch/strcmp-sse42.S (STRCMP_SSE42): Add _CET_NOTRACK before indirect jump to jump table.
* x86-64: Use _CET_NOTRACK in strcpy-sse2-unaligned.SH.J. Lu2018-07-181-1/+1
| | | | | | * sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S (BRANCH_TO_JMPTBL_ENTRY): Add _CET_NOTRACK before indirect jump to jump table.
* x86_64: Use _CET_NOTRACK in strcmp.SH.J. Lu2018-07-181-1/+1
| | | | | * sysdeps/x86_64/strcmp.S (STRCMP): Add _CET_NOTRACK before indirect jump to jump table.
* i386: Add _CET_ENDBR to indirect jump targets in add_n.S/sub_n.SH.J. Lu2018-07-173-3/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | i386 add_n.S and sub_n.S use a trick to implment jump tables with LEA. We can't use conditional branches nor normal jump tables since jump table entries use EFLAGS set by jump table index. This patch adds _CET_ENDBR to indirect jump targets and adjust destination for _CET_ENDBR. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/i386/add_n.S: Include <sysdep.h>, instead of "sysdep.h". (__mpn_add_n): Save and restore %ebx if IBT is enabed. Add _CET_ENDBR to indirect jump targets and adjust jump destination for _CET_ENDBR. * sysdeps/i386/i686/add_n.S: Include <sysdep.h>, instead of "sysdep.h". (__mpn_add_n): Save and restore %ebx if IBT is enabed. Add _CET_ENDBR to indirect jump targets and adjust jump destination for _CET_ENDBR. * sysdeps/i386/sub_n.S: Include <sysdep.h>, instead of "sysdep.h". (__mpn_sub_n): Save and restore %ebx if IBT is enabed. Add _CET_ENDBR to indirect jump targets and adjust jump destination for _CET_ENDBR.
* x86-64: Add _CET_ENDBR to STRCMP_SSE42H.J. Lu2018-07-171-0/+1
| | | | | | | | | | Add _CET_ENDBR to STRCMP_SSE42, which is called indirectly, to support IBT. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/x86_64/multiarch/strcmp-sse42.S (STRCMP_SSE42): Add _CET_ENDBR.
* x86: Add _CET_ENDBR to functions in dl-tlsdesc.SH.J. Lu2018-07-172-0/+12
| | | | | | | | | | | | | | | | | | | | | | | Add _CET_ENDBR to functions in dl-tlsdesc.S, which are called indirectly, to support IBT. Tested on i686 and x86-64. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/i386/dl-tlsdesc.S (_dl_tlsdesc_return): Add _CET_ENDBR. (_dl_tlsdesc_undefweak): Likewise. (_dl_tlsdesc_dynamic): Likewise. (_dl_tlsdesc_resolve_abs_plus_addend): Likewise. (_dl_tlsdesc_resolve_rel): Likewise. (_dl_tlsdesc_resolve_rela): Likewise. (_dl_tlsdesc_resolve_hold): Likewise. * sysdeps/x86_64/dl-tlsdesc.S (_dl_tlsdesc_return): Likewise. (_dl_tlsdesc_undefweak): Likewise. (_dl_tlsdesc_dynamic): Likewise. (_dl_tlsdesc_resolve_rela): Likewise. (_dl_tlsdesc_resolve_hold): Likewise.
* x86: Add _CET_ENDBR to functions in crti.SH.J. Lu2018-07-172-0/+4
| | | | | | | | | | | | | | Add _CET_ENDBR to functions in crti.S, which are called indirectly, to support IBT. Tested on i686 and x86-64. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/i386/crti.S (_init): Add _CET_ENDBR. (_fini): Likewise. * sysdeps/x86_64/crti.S (_init): Likewise. (_fini): Likewise.
* x86: Always include <dl-cet.h>/cet-tunables.h> for --enable-cetH.J. Lu2018-07-171-2/+5
| | | | | | | | | Always include <dl-cet.h> and cet-tunables.h> when CET is enabled. Otherwise, configure glibc with --enable-cet --disable-tunables will fail to build. * sysdeps/x86/cpu-features.c: Always include <dl-cet.h> and cet-tunables.h> when CET is enabled.
* x86: Support IBT and SHSTK in Intel CET [BZ #21598]H.J. Lu2018-07-1620-0/+1249
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* powerpc64: Always restore TOC on longjmp [BZ #21895]Rogerio Alves2018-07-164-4/+139
| | | | | | | | | | | | | | | | | | | This patch changes longjmp to always restore the TOC pointer (r2 register) to the caller frame on powerpc64 and powerpc64le. This is related to bug 21895 that reports a situation where you have a static longjmp to a shared object file. [BZ #21895] * sysdeps/powerpc/powerpc64/__longjmp-common.S: Remove condition code for restoring r2 in longjmp. * sysdeps/powerpc/powerpc64/Makefile: Added tst-setjmp-bug21895-static to test list. Added rules to build test tst-setjmp-bug21895-static. Added module setjmp-bug21895 and rules to build a shared object from it. * sysdeps/powerpc/powerpc64/setjmp-bug21895.c: New test file. * sysdeps/powerpc/powerpc64/tst-setjmp-bug21895-static.c: New test file. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
* x86_64: Undef SHADOW_STACK_POINTER_OFFSET lastH.J. Lu2018-07-151-3/+2
| | | | | | | | Since SHADOW_STACK_POINTER_OFFSET is defined in jmp_buf-ssp.h, we must undef SHADOW_STACK_POINTER_OFFSET after including <jmp_buf-ssp.h>. * sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Undef SHADOW_STACK_POINTER_OFFSET after including <jmp_buf-ssp.h>.
* x86: Support shadow stack pointer in setjmp/longjmpH.J. Lu2018-07-1411-1/+278
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Save and restore shadow stack pointer in setjmp and longjmp to support shadow stack in Intel CET. Use feature_1 in tcbhead_t to check if shadow stack is enabled before saving and restoring shadow stack pointer. Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/i386/__longjmp.S: Include <jmp_buf-ssp.h>. (__longjmp): Restore shadow stack pointer if shadow stack is enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp isn't defined for __longjmp_cancel. * sysdeps/i386/bsd-_setjmp.S: Include <jmp_buf-ssp.h>. (_setjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/i386/bsd-setjmp.S: Include <jmp_buf-ssp.h>. (setjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/i386/setjmp.S: Include <jmp_buf-ssp.h>. (__sigsetjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/unix/sysv/linux/i386/____longjmp_chk.S: Include <jmp_buf-ssp.h>. (____longjmp_chk): Restore shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/unix/sysv/linux/x86/Makefile (gen-as-const-headers): Remove jmp_buf-ssp.sym. * sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Include <jmp_buf-ssp.h>. (____longjmp_chk): Restore shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined. * sysdeps/x86/Makefile (gen-as-const-headers): Add jmp_buf-ssp.sym. * sysdeps/x86/jmp_buf-ssp.sym: New dummy file. * sysdeps/x86_64/__longjmp.S: Include <jmp_buf-ssp.h>. (__longjmp): Restore shadow stack pointer if shadow stack is enabled, SHADOW_STACK_POINTER_OFFSET is defined and __longjmp isn't defined for __longjmp_cancel. * sysdeps/x86_64/setjmp.S: Include <jmp_buf-ssp.h>. (__sigsetjmp): Save shadow stack pointer if shadow stack is enabled and SHADOW_STACK_POINTER_OFFSET is defined.
* x86: Rename __glibc_reserved1 to feature_1 in tcbhead_t [BZ #22563]H.J. Lu2018-07-147-2/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | feature_1 has X86_FEATURE_1_IBT and X86_FEATURE_1_SHSTK bits for CET run-time control. CET_ENABLED, IBT_ENABLED and SHSTK_ENABLED are defined to 1 or 0 to indicate that if CET, IBT and SHSTK are enabled. <tls-setup.h> is added to set up thread-local data. Reviewed-by: Carlos O'Donell <carlos@redhat.com> [BZ #22563] * nptl/pthread_create.c: Include <tls-setup.h>. (__pthread_create_2_1): Call tls_setup_tcbhead. * sysdeps/generic/tls-setup.h: New file. * sysdeps/x86/nptl/tls-setup.h: Likewise. * sysdeps/i386/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): New. * sysdeps/x86_64/nptl/tcb-offsets.sym (FEATURE_1_OFFSET): Likewise. * sysdeps/i386/nptl/tls.h (tcbhead_t): Rename __glibc_reserved1 to feature_1. * sysdeps/x86_64/nptl/tls.h (tcbhead_t): Likewise. * sysdeps/x86/sysdep.h (X86_FEATURE_1_IBT): New. (X86_FEATURE_1_SHSTK): Likewise. (CET_ENABLED): Likewise. (IBT_ENABLED): Likewise. (SHSTK_ENABLED): Likewise.
* Add the statx functionFlorian Weimer2018-07-1032-0/+86
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* Comment tst-ofdlocks-compat expected failure in some Linux releasesAdhemerval Zanella2018-07-101-0/+8
| | | | | | | | | | | | | As pointed out in a libc-alpha thread [1], the misc/tst-ofdlocks-compat may fail in some specific Linux releases. This patch adds a comment along with a link to discussion in the test source code. No changes are expected. * sysdeps/unix/sysv/linux/tst-ofdlocks-compat.c: Add a comment about a kernel issue which lead to test failure in some cases. [1] https://sourceware.org/ml/libc-alpha/2018-07/msg00243.html
* aarch64: add HWCAP_ATOMICS to HWCAP_IMPORTANTSzabolcs Nagy2018-07-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables searching shared libraries in atomics/ when the hardware supports LSE atomics of armv8.1 so one can provide optimized variants of libraries in a portable way. LSE atomics does not affect library abi, the new instructions can interoperate with old ones. I considered the earlier comments on the patch https://sourceware.org/ml/libc-alpha/2018-04/msg00400.html https://sourceware.org/ml/libc-alpha/2018-04/msg00625.html It turns out that the way glibc dynamic linker decides on the search path is not very flexible: it wants to use hwcap bits and associated strings. So some targets reuse hwcap bits for glibc internal purposes to affect the search logic. But hwcap is an interface with the kernel, glibc should not allocate bits in it for its internal logic as that limits future hwcap extensions and confusing to users who expect to see hwcap bits in ifunc resolvers. Instead of rewriting the dynamic linker path logic (which affects all targets) this patch just uses the existing mechanism, however this means that the path name has to be the hwcap name "atomics" and cannot be changed to something more meaningful to users. It is hard to tell how much performance benefit this can give, in principle armv8.1 atomics can be better optimized in the hardware, so it can make a difference for synchronization heavy code. On some systems such multilib setup may be the only viable way to get optimized libraries used. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (HWCAP_IMPORTANT): Add HWCAP_ATOMICS.
* aarch64: Remove HWCAP_CPUID from HWCAP_IMPORTANTSzabolcs Nagy2018-07-062-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This partially reverts commit f82e9672ad89ea1ef40bbe1af71478e255e87c5e Author: Siddhesh Poyarekar <siddhesh@sourceware.org> aarch64: Allow overriding HWCAP_CPUID feature check using HWCAP_MASK The idea was to make it possible to disable cpuid based ifunc resolution in glibc by changing the hwcap mask which the user could already control. However the hwcap mask has an orthogonal role: it specifies additional library search paths for the dynamic linker. So "cpuid" got added to the search paths when it was set in the default mask (HWCAP_IMPORTANT), which is not useful behaviour, the hwcap masking should not be reused in the cpu features code. Meanwhile there is a tunable to set the cpu explicitly so it is possible to disable the cpuid based dispatch without using a hwcap mask: GLIBC_TUNABLES=glibc.tune.cpu=generic * sysdeps/unix/sysv/linux/aarch64/cpu-features.c (init_cpu_features): Use dl_hwcap without masking. * sysdeps/unix/sysv/linux/aarch64/dl-procinfo.h (HWCAP_IMPORTANT): Remove HWCAP_CPUID.