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* posix: Remove ununsed posix_spawn internal assignmentAdhemerval Zanella2017-04-251-16/+14
| | | | | | | | | | The internal 'ret' variable in '__spawni_child' function is not used after assignment in most cases. Checked on x86_64-linux-gnu. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Remove ununsed assignment.
* [BZ 21340] add support for POSIX_SPAWN_SETSIDAdhemerval Zanella2017-04-251-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for the POSIX_SPAWN_SETSID flag. It was recently accepted by the Austin Group: http://austingroupbugs.net/view.php?id=1044 Checked on x86_64 Daurnimator <quae@daurnimator.com> Adhemerval Zanella <adhemerval.zanella@linaro.org> [BZ #21340] * posix/Makefile (tests): Add tst-posix_spawn-setsid to list of tests. * posix/spawn.h: define POSIX_SPAWN_SETSID flag. * posix/spawnattr_setflags.c (ALL_FLAGS): Add POSIX_SPAWN_SETSID to valid flags. * posix/tst-posix_spawn-setsid.c: Add test for POSIX_SPAWN_SETSID. * sysdeps/mach/hurd/spawni.c (__spawni): Implementation of POSIX_SPAWN_SETSID. * sysdeps/posix/spawni.c (__spawni): Likewise. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Likewise. * NEWS: Add note about POSIX_SPAWN_SETSID support.
* posix_spawn: use a larger min stack for -fstack-check [BZ #21253]Mike Frysinger2017-04-031-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | When glibc is built with -fstack-check, trying to use posix_spawn can lead to segfaults due to gcc internally probing stack memory too far. The new spawn API will allocate a minimum of 1 page, but the stack checking logic might probe a couple of pages. When it tries to walk them, everything falls apart. The gcc internal docs [1] state the default interval checking is one page. Which means we need two pages (the current one, and the next probed). No target currently defines it larger. Further, it mentions that the default minimum stack size needed to recover from an overflow is 4/8KiB for sjlj or 8/12KiB for others. But some Linux targets (like mips and ppc) go up to 16KiB (and some non-Linux targets go up to 24KiB). Let's create each child with a minimum of 32KiB slack space to support them all, and give us future breathing room. No test is added as existing ones crash. Even a simple call is enough to trigger the problem: char *argv[] = { "/bin/ls", NULL }; posix_spawn(NULL, "/bin/ls", NULL, NULL, argv, NULL); [1] https://gcc.gnu.org/onlinedocs/gcc-6.3.0/gccint/Stack-Checking.html
* posix_spawn: fix stack setup on ia64 [BZ #21275]Mike Frysinger2017-03-201-5/+6
| | | | | | | | | The ia64-specific clone2 call expects the base of the stack mapping and the stack size as sep arguments, not an initial stack value as on other stack-grows-down architectures. Reuse the stack-grows-up macro so we pass in the right stack base. Reported-by: Matt Turner <mattst88@gentoo.org>
* Narrowing the visibility of libc-internal.h even further.Zack Weinberg2017-03-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar to what was done with libc-diag.h, I have split the definitions of cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN to a new header, libc-pointer-arith.h. It then occurred to me that the remaining declarations in libc-internal.h are mostly to do with early initialization, and probably most of the files including it, even in the core code, don't need it anymore. Indeed, only 19 files actually need what remains of libc-internal.h. 23 others need libc-diag.h instead, and 12 need libc-pointer-arith.h instead. No file needs more than one of them, and 16 don't need any of them! So, with this patch, libc-internal.h stops including libc-diag.h as well as losing the pointer arithmetic macros, and all including files are adjusted. * include/libc-pointer-arith.h: New file. Define cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN here. * include/libc-internal.h: Definitions of above macros moved from here. Don't include libc-diag.h anymore either. * posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h. Don't include libc-internal.h. * debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c * io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c * nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c * string/strcoll_l.c, sysdeps/nacl/brk.c * sysdeps/unix/clock_settime.c * sysdeps/unix/sysv/linux/i386/get_clockfreq.c * sysdeps/unix/sysv/linux/ia64/get_clockfreq.c * sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c * sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c: Don't include libc-internal.h. * elf/get-dynamic-info.h, iconv/loop.c * iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h * misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h * nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c * soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c * sysdeps/ieee754/dbl-64/e_lgamma_r.c * sysdeps/ieee754/dbl-64/k_rem_pio2.c * sysdeps/ieee754/flt-32/e_lgammaf_r.c * sysdeps/ieee754/flt-32/k_rem_pio2f.c * sysdeps/ieee754/ldbl-128/k_tanl.c * sysdeps/ieee754/ldbl-128ibm/k_tanl.c * sysdeps/ieee754/ldbl-96/e_lgammal_r.c * sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h: Include libc-diag.h instead of libc-internal.h. * elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c * nptl/nptl-init.c, string/strcspn.c, string/strspn.c * malloc/malloc.c, sysdeps/i386/nptl/tls.h * sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h * sysdeps/unix/sysv/linux/spawni.c * sysdeps/x86_64/nptl/tls.h: Include libc-pointer-arith.h instead of libc-internal.h. * elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h * sysdeps/x86_64/atomic-machine.h: Add multiple include guard.
* Update copyright dates with scripts/update-copyrights.Joseph Myers2017-01-011-1/+1
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* posix: Fix open file action for posix_spawn on LinuxAdhemerval Zanella2016-09-281-0/+8
| | | | | | | | | | | | | | | | | | | | | On posix_spawn open file action (issued by posix_spawn_file_actions_addopen) POSIX states that if fildes was already an open file descriptor, it shall be closed before the new file is openedi [1]. This avoid pontential issues when posix_spawn plus addopen action is called with the process already at maximum number of file descriptor opened and also for multiple actions on single-open special paths (like /dev/watchdog). This fixes its behavior on Linux posix_spawn implementation and also adds a tests to check for its behavior. Checked on x86_64. * posix/Makefile (tests): Add tst-spawn3. * posix/tst-spawn3.c: New file. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Close file descriptor if it is already opened for open action. [1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_addclose.html
* linux: spawni.c: simplify error reporting to parentRasmus Villemoes2016-09-281-46/+25
| | | | | | | | | | | | | | | | | | | | | | | | | Using CLONE_VFORK already ensures that the parent does not run until the child has either exec'ed succesfully or called _exit. Hence we don't need to read from a CLOEXEC pipe to ensure proper synchronization - we just make explicit use of the fact the the child and parent run in the same VM, so the child can write an error code to a field of the posix_spawn_args struct instead of sending it through a pipe. To ensure that this mechanism really works, the parent initializes the field to -1 and the child writes 0 before execing. This eliminates some annoying bookkeeping that is necessary to avoid the file actions from clobbering the write end of the pipe, and getting rid of the pipe creation in the first place means fewer system calls (four in the parent, usually one in the child) and fewer chanches for the spawn to fail (e.g. if we're close to EMFILE). Checked on x86_64 and i686. * sysdeps/unix/sysv/linux/spawni.c (posix_spawn_args): Remove pipe field, add err field. (__spawni_child): Report error through err member instead of pipe. (__spawnix): Likewise.
* posix: Correctly block/unblock all signals on Linux posix_spawnAdhemerval Zanella2016-09-201-6/+2
| | | | | | | | | | | | | This patch correctly block and unblocks all signals when executing Linux posix_spawn by using the __libc_signal_{un}block_all functions instead of default sigprocmask. The latter might remove both SIGCANCEL and SIGSETXID from the blocked signal list. Checked on x86_64, i686, powerpc64le, and aarch64. * sysdeps/unix/sysv/linux/spawni.c (__spawnix): Correctly block and unblock all signals when executing the clone vfork child. (SIGALL_SET): Remove macro.
* posix: Correctly enable/disable cancellation on Linux posix_spawnAdhemerval Zanella2016-09-201-2/+4
| | | | | | | | | | | | | | This patch correctly enable and disable asynchronous cancellation on Linux posix_spawn. Current code invert the logic by enabling and disabling instead. It also adds a new test to check if posix_spawn is not a cancellation entrypoint. Checked on x86_64, i686, powerpc64le, and aarch64. * nptl/Makefile (tests): Add tst-exec5. * nptl/tst-exec5.c: New file. * sysdeps/unix/sysv/linux/spawni.c (__spawni): Correctly enable and disable asynchronous cancellation.
* posix: Call _exit in failure case for posix_spawn{p} (BZ#20178)Adhemerval Zanella2016-05-301-1/+1
| | | | | | | | | | | This patch call _exit instead of exit in failure case for the spawned child in Linux posix_spawn{p} implementation. Tested on x86_64. [BZ #20178] * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Call _exit on failure instead of exit.
* posix: Fix posix_spawn implict check styleAdhemerval Zanella2016-03-211-1/+1
| | | | | | | | | | This patch fixes the implicit check style add in 2a69f853c for the general convention one. Checked on x86_64. * sysdeps/unix/sysv/linux/spawni.c (__spawnix): Fix implict checks style.
* posix: Fix posix_spawn invalid memory accessAdhemerval Zanella2016-03-201-1/+1
| | | | | | | | | | | | | Current Linux posix_spawn spawn do not test if the pid argument is valid before trying to update it for success case. This patch fixes it. Tested on x86_64 and i686. * sysdeps/unix/sysv/linux/spawni.c (__spawnix): Fix invalid memory access where posix_spawn success and pid argument is null. * posix/tst-spawn.c (do_test): Add posix_spawn null pid argument for success case.
* posix: New Linux posix_spawn{p} implementationAdhemerval Zanella2016-03-071-0/+404
This patch implements a new posix_spawn{p} implementation for Linux. The main difference is it uses the clone syscall directly with CLONE_VM and CLONE_VFORK flags and a direct allocated stack. The new stack and start function solves most the vfork limitation (possible parent clobber due stack spilling). The remaning issue are related to signal handling: 1. That no signal handlers must run in child context, to avoid corrupt parent's state. 2. Child must synchronize with parent to enforce stack deallocation and to possible return execv issues. The first one is solved by blocking all signals in child, even NPTL-internal ones (SIGCANCEL and SIGSETXID). The second issue is done by a stack allocation in parent and a synchronization with using a pipe or waitpid (in case or error). The pipe has the advantage of allowing the child signal an exec error (checked with new tst-spawn2 test). There is an inherent race condition in pipe2 usage for architectures that do not support the syscall directly. In such cases the a pipe plus fctnl is used instead and it may lead to file descriptor leak in parent (as decribed by fcntl documentation). The child process stack is allocate with a mmap with MAP_STACK flag using default architecture stack size. Although it is slower than use a stack buffer from parent, it allows some slack for the compatibility code to run scripts with no shebang (which may use a buffer with size depending of argument list count). Performance should be similar to the vfork default posix implementation and way faster than fork path (vfork on mostly linux ports are basically clone with CLONE_VM plus CLONE_VFORK). The only difference is the syscalls required for the stack allocation/deallocation. It fixes BZ#10354, BZ#14750, and BZ#18433. Tested on i386, x86_64, powerpc64le, and aarch64. [BZ #14750] [BZ #10354] [BZ #18433] * include/sched.h (__clone): Add hidden prototype. (__clone2): Likewise. * include/unistd.h (__dup): Likewise. * posix/Makefile (tests): Add tst-spawn2. * posix/tst-spawn2.c: New file. * sysdeps/posix/dup.c (__dup): Add hidden definition. * sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/alpha/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/arm/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/hppa/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/i386/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/ia64/clone2.S (__clone): Likewise. * sysdeps/unix/sysv/linux/m68k/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/microblaze/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/mips/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/nios2/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/sh/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/tile/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/x86_64/clone.S (__clone): Likewise. * sysdeps/unix/sysv/linux/nptl-signals.h (____nptl_is_internal_signal): New function. * sysdeps/unix/sysv/linux/spawni.c: New file.