Differential D12773 Diff 65838 lib/libthr/thread/thr_sig.c

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lib/libthr/thread/thr_sig.c

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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.		* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/		*/

#include <sys/cdefs.h>		#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");		__FBSDID("$FreeBSD$");

#include "namespace.h"		#include "namespace.h"
#include <sys/param.h>		#include <sys/param.h>
#include <sys/types.h>		#include <sys/auxv.h>
		#include <sys/elf.h>
#include <sys/signalvar.h>		#include <sys/signalvar.h>
#include <sys/syscall.h>		#include <sys/syscall.h>
#include <signal.h>		#include <signal.h>
#include <errno.h>		#include <errno.h>
#include <stdlib.h>		#include <stdlib.h>
#include <string.h>		#include <string.h>
#include <pthread.h>		#include <pthread.h>
#include "un-namespace.h"		#include "un-namespace.h"
▲ Show 20 Lines • Show All 44 Lines • ▼ Show 20 Lines	static const sigset_t _thr_deferset={{
0xffffffff}};		0xffffffff}};

static const sigset_t _thr_maskset={{		static const sigset_t _thr_maskset={{
0xffffffff,		0xffffffff,
0xffffffff,		0xffffffff,
0xffffffff,		0xffffffff,
0xffffffff}};		0xffffffff}};

void		static void
_thr_signal_block(struct pthread *curthread)		thr_signal_block_slow(struct pthread *curthread)
{		{

if (curthread->sigblock > 0) {		if (curthread->sigblock > 0) {
curthread->sigblock++;		curthread->sigblock++;
return;		return;
}		}
__sys_sigprocmask(SIG_BLOCK, &_thr_maskset, &curthread->sigmask);		__sys_sigprocmask(SIG_BLOCK, &_thr_maskset, &curthread->sigmask);
curthread->sigblock++;		curthread->sigblock++;
}		}

void		static void
_thr_signal_unblock(struct pthread *curthread)		thr_signal_unblock_slow(struct pthread *curthread)
{		{
if (--curthread->sigblock == 0)		if (--curthread->sigblock == 0)
__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);		__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
		}

		static void
		thr_signal_block_fast(struct pthread *curthread)
		{
		atomic_add_32(&curthread->fsigblock, FAST_SIGBLOCK_INC);
		jillesUnsubmitted Not Done Inline Actions It would be nice if this mechanism can also replace the userspace signal handler defer mechanism, but that need not be in this review. jilles: It would be nice if this mechanism can also replace the userspace signal handler defer…
		kibAuthorUnsubmitted Done Inline Actions I considered this, and I decided that it is not enough to stop redirecting the signal handlers to libthr. libthr needs to delay cancellation while executing signal handlers, in other words, libthr wrappers around syscalls should be made inactive. kib: I considered this, and I decided that it is not enough to stop redirecting the signal handlers…
		jillesUnsubmitted Not Done Inline Actions Right, libthr needs to wrap signal handlers for disabling cancellation and for something related to sigsuspend(2), but the postpone part can probably be replaced by fast sigblock (not in this review though). jilles: Right, libthr needs to wrap signal handlers for disabling cancellation and for something…
		}

		static void
		thr_signal_unblock_fast(struct pthread *curthread)
		{
		uint32_t oldval;

		oldval = atomic_fetchadd_32(&curthread->fsigblock, -FAST_SIGBLOCK_INC);
		if (oldval == (FAST_SIGBLOCK_PEND \| FAST_SIGBLOCK_INC))
		__sys_fast_sigblock(FAST_SIGBLOCK_UNBLOCK, NULL);
		}

		static bool fast_sigblock;

		void
		_thr_signal_block(struct pthread *curthread)
		{
		if (fast_sigblock)
		thr_signal_block_fast(curthread);
		else
		thr_signal_block_slow(curthread);
		}

		void
		_thr_signal_unblock(struct pthread *curthread)
		{
		if (fast_sigblock)
		thr_signal_unblock_fast(curthread);
		else
		thr_signal_unblock_slow(curthread);
		}

		void
		_thr_signal_block_check_fast(void)
		{
		int bsdflags, error;

		error = elf_aux_info(AT_BSDFLAGS, &bsdflags, sizeof(bsdflags));
		if (error != 0)
		return;
		fast_sigblock = (bsdflags & ELF_BSDF_FASTSIGBLK) != 0;
		}

		void
		_thr_signal_block_setup(struct pthread *curthread)
		{
		if (!fast_sigblock)
		return;
		__sys_fast_sigblock(FAST_SIGBLOCK_SETPTR, &curthread->fsigblock);
}		}

int		int
_thr_send_sig(struct pthread *thread, int sig)		_thr_send_sig(struct pthread *thread, int sig)
{		{
return thr_kill(thread->tid, sig);		return thr_kill(thread->tid, sig);
}		}

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