sparc/sigaction.c: note possible bugs by comments. style fixes

no code is actually changed

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

libc/sysdeps/linux/sparc/sigaction.c

@@ -31,48 +31,52 @@
 
 
 _syscall5(int, rt_sigaction, int, a, int, b, int, c, int, d, int, e);
-static void __rt_sigreturn_stub (void);
-static void __sigreturn_stub (void);
+static void __rt_sigreturn_stub(void);
+static void __sigreturn_stub(void);
 
-int
-__libc_sigaction (int sig, __const struct sigaction *act, struct sigaction *oact)
+int __libc_sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
 {
-    int ret;
-    struct old_kernel_sigaction kact, koact;
-    unsigned long stub = 0;
-    int saved_errno = errno;
-    
-    if (act)
-    {
-        kact.k_sa_handler = act->sa_handler;
-        memcpy (&kact.sa_mask, &act->sa_mask, sizeof(sigset_t));
-        if (((kact.sa_flags = act->sa_flags) & SA_SIGINFO)!= 0)
-            stub = (unsigned long) &__rt_sigreturn_stub;
-        else
-            stub = (unsigned long) &__sigreturn_stub;
-        stub -= 8;
-        kact.sa_restorer = NULL;
-    }
-    /* XXX The size argument hopefully will have to be changed to the real size of the user-level sigset_t.  */
-    ret = rt_sigaction(sig, 
-	(int)(act ? &kact : NULL), 
-	(int)(oact ? &koact : NULL), 
-	stub, 
-	_NSIG / 8);
+	int ret;
+	struct old_kernel_sigaction kact, koact;
+	unsigned long stub = 0;
+	int saved_errno = errno;
 
-    if (ret >= 0 || errno != ENOSYS)
-    {
-        if (oact && ret >= 0)
-        {
-            oact->sa_handler = koact.k_sa_handler;
-            memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t));
-            oact->sa_flags = koact.sa_flags;
-            oact->sa_restorer = koact.sa_restorer;
-        }
-        return ret;
-    }
-    __set_errno (saved_errno);
-    return -1;
+	if (act) {
+		kact.k_sa_handler = act->sa_handler;
+		// BUG?! kact.sa_mask is a long, but sigset_t is a vector
+		// of longs and it may be bigger (in glibc, it _is_ bigger).
+		// Should we do this instead?
+		// kact.sa_mask = act->sa_mask.__val[0];
+		memcpy(&kact.sa_mask, &act->sa_mask, sizeof(sigset_t));
+		kact.sa_flags = act->sa_flags;
+		if (kact.sa_flags & SA_SIGINFO)
+			stub = (unsigned long) &__rt_sigreturn_stub;
+		else
+			stub = (unsigned long) &__sigreturn_stub;
+		stub -= 8;
+		kact.sa_restorer = NULL;
+	}
+	/* NB: kernel (as of 2.6.25) will return EINVAL
+	 * if _NSIG / 8 does not match kernel's sizeof(sigset_t) */
+	ret = rt_sigaction(sig,
+		(int)(act ? &kact : NULL),
+		(int)(oact ? &koact : NULL),
+		stub,
+		_NSIG / 8);
+
+	// BUG?! if ret == -1, we return -1 but do not set errno?!
+	if (ret >= 0 || errno != ENOSYS) {
+		if (oact && ret >= 0) {
+			oact->sa_handler = koact.k_sa_handler;
+			// maybe oact->sa_mask.__val[0] = koact.sa_mask; ?
+			memcpy(&oact->sa_mask, &koact.sa_mask, sizeof(sigset_t));
+			oact->sa_flags = koact.sa_flags;
+			oact->sa_restorer = koact.sa_restorer;
+		}
+		return ret;
+	}
+	__set_errno(saved_errno);
+	return -1;
 }
 
 #ifndef LIBC_SIGACTION
@@ -81,18 +85,22 @@ libc_hidden_weak(sigaction)
 #endif
 
 static void
-__rt_sigreturn_stub (void)
+__rt_sigreturn_stub(void)
 {
-  __asm__ ("mov %0, %%g1\n\t"
-          "ta  0x10\n\t"
-          : /* no outputs */
-          : "i" (__NR_rt_sigreturn));
+	__asm__(
+		"mov %0, %%g1\n\t"
+		"ta  0x10\n\t"
+		: /* no outputs */
+		: "i" (__NR_rt_sigreturn)
+	);
 }
 static void
-__sigreturn_stub (void)
+__sigreturn_stub(void)
 {
-  __asm__ ("mov %0, %%g1\n\t"
-          "ta  0x10\n\t"
-          : /* no outputs */
-          : "i" (__NR_sigreturn));
+	__asm__(
+		"mov %0, %%g1\n\t"
+		"ta  0x10\n\t"
+		: /* no outputs */
+		: "i" (__NR_sigreturn)
+	);
 }