glibc/sysdeps/nptl
Adhemerval Zanella d2dc5467c6 Filter out NPTL internal signals (BZ #22391)
This patch filters out the internal NPTL signals (SIGCANCEL/SIGTIMER and
SIGSETXID) from signal functions.  GLIBC on Linux requires both signals to
proper implement pthread cancellation, posix timers, and set*id posix
thread synchronization.

And not filtering out the internal signal is troublesome:

  - A conformant program on a architecture that does not filter out the
    signals might inadvertently disable pthread asynchronous cancellation,
    set*id synchronization or posix timers.

  - It might also to security issues if SIGSETXID is masked and set*id
    functions are called (some threads might have effective user or group
    id different from the rest).

The changes are basically:

  - Change __is_internal_signal to bool and used on all signal function
    that has a signal number as input.  Also for signal function which accepts
    signals sets (sigset_t) it assumes that canonical function were used to
    add/remove signals which lead to some input simplification.

  - Fix tst-sigset.c to avoid check for SIGCANCEL/SIGTIMER and SIGSETXID.
    It is rewritten to check each signal indidually and to check realtime
    signals using canonical macros.

  - Add generic __clear_internal_signals and __is_internal_signal
    version since both symbols are used on generic implementations.

  - Remove superflous sysdeps/nptl/sigfillset.c.

  - Remove superflous SIGTIMER handling on Linux __is_internal_signal
    since it is the same of SIGCANCEL.

  - Remove dangling define and obvious comment on nptl/sigaction.c.

Checked on x86_64-linux-gnu.

	[BZ #22391]
	* nptl/sigaction.c (__sigaction): Use __is_internal_signal to
	check for internal nptl signals.
	* nptl/sigaction.c (__sigaction): Likewise.
	* signal/sigaddset.c (sigaddset): Likewise.
	* signal/sigdelset.c (sigdelset): Likewise.
	* sysdeps/posix/signal.c (__bsd_signal): Likewise.
	* sysdeps/posix/sigset.c (sigset): Call and check sigaddset return
	value.
	* signal/sigfillset.c (sigfillset): User __clear_internal_signals
	to filter out internal nptl signals.
	* signal/tst-sigset.c (do_test): Check ech signal indidually and
	also check realtime signals using standard macros.
	* sysdeps/generic/internal-signals.h (__clear_internal_signals,
	__is_internal_signal, __libc_signal_block_all,
	__libc_signal_block_app, __libc_signal_restore_set): New functions.
	* sysdeps/nptl/sigfillset.c: Remove file.
	* sysdeps/unix/sysv/linux/internal-signals.h (__is_internal_signal):
	Change return to bool.
	(__clear_internal_signals): Remove SIGTIMER clean since it is
	equal to SIGCANEL on Linux.
	* sysdeps/unix/sysv/linux/sigtimedwait.c (__sigtimedwait): Assume
	signal set was constructed using standard functions.

Reported-by: Yury Norov <ynorov@caviumnetworks.com>
2018-04-03 13:30:49 -03:00
..
bits Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
sys Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
aio_misc.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
allocrtsig.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
fork.c Refactor Linux ARCH_FORK implementation 2018-03-07 17:39:40 -03:00
fork.h Refactor atfork handlers 2018-02-22 16:43:59 -03:00
futex-internal.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
gai_misc.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Implies
internaltypes.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
jmp-unwind.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
libc-lock.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
libc-lockP.h Refactor atfork handlers 2018-02-22 16:43:59 -03:00
librt-cancellation.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
lowlevellock-futex.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
lowlevellock.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Makeconfig nptl: Move pthread_atfork to libc_nonshared.a 2018-03-01 08:18:48 +01:00
Makefile Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
malloc-machine.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
pthread-functions.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
pthread.h Revert Intel CET changes to __jmp_buf_tag (Bug 22743) 2018-01-25 23:43:46 -08:00
setxid.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
shm-directory.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
stdio-lock.h Mechanically remove _IO_ name aliases for types and constants. 2018-02-21 14:11:05 -05:00
Subdirs
tcb-offsets.h
timer_routines.h Move NPTL-specific code to NPTL-specific header 2018-02-27 00:48:24 +01:00
tst-mqueue8x.c
unwind-forcedunwind.c nptl: Open libgcc.so with RTLD_NOW during pthread_cancel [BZ #22636] 2018-01-10 13:18:04 +01:00