glibc/signal/tst-sigset.c
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

86 lines
1.9 KiB
C

/* Test sig*set functions. */
#include <signal.h>
#include <support/check.h>
static int
do_test (void)
{
sigset_t set;
TEST_VERIFY (sigemptyset (&set) == 0);
#define VERIFY(set, sig) \
TEST_VERIFY (sigismember (&set, sig) == 0); \
TEST_VERIFY (sigaddset (&set, sig) == 0); \
TEST_VERIFY (sigismember (&set, sig) != 0); \
TEST_VERIFY (sigdelset (&set, sig) == 0); \
TEST_VERIFY (sigismember (&set, sig) == 0)
/* ISO C99 signals. */
VERIFY (set, SIGINT);
VERIFY (set, SIGILL);
VERIFY (set, SIGABRT);
VERIFY (set, SIGFPE);
VERIFY (set, SIGSEGV);
VERIFY (set, SIGTERM);
/* Historical signals specified by POSIX. */
VERIFY (set, SIGHUP);
VERIFY (set, SIGQUIT);
VERIFY (set, SIGTRAP);
VERIFY (set, SIGKILL);
VERIFY (set, SIGBUS);
VERIFY (set, SIGSYS);
VERIFY (set, SIGPIPE);
VERIFY (set, SIGALRM);
/* New(er) POSIX signals (1003.1-2008, 1003.1-2013). */
VERIFY (set, SIGURG);
VERIFY (set, SIGSTOP);
VERIFY (set, SIGTSTP);
VERIFY (set, SIGCONT);
VERIFY (set, SIGCHLD);
VERIFY (set, SIGTTIN);
VERIFY (set, SIGTTOU);
VERIFY (set, SIGPOLL);
VERIFY (set, SIGXCPU);
VERIFY (set, SIGXFSZ);
VERIFY (set, SIGVTALRM);
VERIFY (set, SIGPROF);
VERIFY (set, SIGUSR1);
VERIFY (set, SIGUSR2);
/* Nonstandard signals found in all modern POSIX systems
(including both BSD and Linux). */
VERIFY (set, SIGWINCH);
/* Arch-specific signals. */
#ifdef SIGEMT
VERIFY (set, SIGEMT);
#endif
#ifdef SIGLOST
VERIFY (set, SIGLOST);
#endif
#ifdef SIGINFO
VERIFY (set, SIGINFO);
#endif
#ifdef SIGSTKFLT
VERIFY (set, SIGSTKFLT);
#endif
#ifdef SIGPWR
VERIFY (set, SIGPWR);
#endif
/* Read-time signals (POSIX.1b real-time extensions). If they are
supported SIGRTMAX value is greater than SIGRTMIN. */
for (int rtsig = SIGRTMIN; rtsig <= SIGRTMAX; rtsig++)
{
VERIFY (set, rtsig);
}
return 0;
}
#include <support/test-driver.c>