transition to using functions for internal signal blocking/restoring

there are several reasons for this change. one is getting rid of the
repetition of the syscall signature all over the place. another is
sharing the constant masks without costly GOT accesses in PIC.

the main motivation, however, is accurately representing whether we
want to block signals that might be handled by the application, or all
signals.

3 files changed, 48 insertions, 4 deletions

diff --git a/src/signal/block.c b/src/signal/block.c
new file mode 100644
index 00000000..d7f61001
--- /dev/null
+++ b/src/signal/block.c
@@ -0,0 +1,44 @@
+#include "pthread_impl.h"
+#include "syscall.h"
+#include <signal.h>
+
+static const unsigned long all_mask[] = {
+#if ULONG_MAX == 0xffffffff && _NSIG == 129
+	-1UL, -1UL, -1UL, -1UL
+#elif ULONG_MAX == 0xffffffff
+	-1UL, -1UL
+#else
+	-1UL
+#endif
+};
+
+static const unsigned long app_mask[] = {
+#if ULONG_MAX == 0xffffffff
+#if _NSIG == 65
+	0x7fffffff, 0xfffffffc
+#else
+	0x7fffffff, 0xfffffffc, -1UL, -1UL
+#endif
+#else
+#if _NSIG == 65
+	0xfffffffc7fffffff
+#else
+	0xfffffffc7fffffff, -1UL
+#endif
+#endif
+};
+
+void __block_all_sigs(void *set)
+{
+	__syscall(SYS_rt_sigprocmask, SIG_BLOCK, &all_mask, set, _NSIG/8);
+}
+
+void __block_app_sigs(void *set)
+{
+	__syscall(SYS_rt_sigprocmask, SIG_BLOCK, &app_mask, set, _NSIG/8);
+}
+
+void __restore_sigs(void *set)
+{
+	__syscall(SYS_rt_sigprocmask, SIG_SETMASK, set, 0, _NSIG/8);
+}
diff --git a/src/signal/raise.c b/src/signal/raise.c
index b24dc741..6fa43bef 100644
--- a/src/signal/raise.c
+++ b/src/signal/raise.c
@@ -8,10 +8,10 @@ int raise(int sig)
 {
 	int pid, tid, ret;
 	sigset_t set;
-	__syscall(SYS_rt_sigprocmask, SIG_BLOCK, SIGALL_SET, &set, _NSIG/8);
+	__block_app_sigs(&set);
 	tid = __syscall(SYS_gettid);
 	pid = __syscall(SYS_getpid);
 	ret = syscall(SYS_tgkill, pid, tid, sig);
-	__syscall(SYS_rt_sigprocmask, SIG_SETMASK, &set, 0, _NSIG/8);
+	__restore_sigs(&set);
 	return ret;
 }
diff --git a/src/signal/siglongjmp.c b/src/signal/siglongjmp.c
index bbdde796..a7bcca24 100644
--- a/src/signal/siglongjmp.c
+++ b/src/signal/siglongjmp.c
@@ -2,10 +2,10 @@
 #include <signal.h>
 #include <stdlib.h>
 #include "syscall.h"
+#include "pthread_impl.h"
 
 _Noreturn void siglongjmp(sigjmp_buf buf, int ret)
 {
-	if (buf->__fl) __syscall(SYS_rt_sigprocmask, SIG_SETMASK,
-		buf->__ss, 0, _NSIG/8);
+	if (buf->__fl) __restore_sigs(buf->__ss);
 	longjmp(buf->__jb, ret);
 }