[PATCH]: Fix N32 sigsuspend syscall that causes non-fatal oopses

[Kumba <kumba@xxxxxxxxxx>]

When using an N32 userland, it was discovered that a specific configure test in glib triggered a non-fatal oops, as 
well as killing the build.  Daniel Jacobwitz just happened to have the patch that fixed this issue, and with a small 
#ifdef tweak to make it build for 32bit systems, it fixed the problem and allowed glib to build properly.

The patch is attached for comment, however we've been using it in our kernel patchset for sometime now with no 
observable ill effect.


--Kumba


--
Gentoo/MIPS Team Lead
Gentoo Foundation Board of Trustees

"Such is oft the course of deeds that move the wheels of the world: small hands do them because they must, while the
eyes of the great are elsewhere." --Elrond

diff -Naurp linux-2.6.13.3.orig/arch/mips/kernel/linux32.c linux-2.6.13.3/arch/mips/kernel/linux32.c
--- linux-2.6.13.3.orig/arch/mips/kernel/linux32.c	2005-10-05 22:46:31.000000000 -0400
+++ linux-2.6.13.3/arch/mips/kernel/linux32.c	2005-10-05 22:34:45.000000000 -0400
@@ -1453,25 +1453,6 @@ sys32_timer_create(u32 clock, struct sig
 	return sys_timer_create(clock, p, timer_id);
 }
 
-asmlinkage long
-sysn32_rt_sigtimedwait(const sigset_t __user *uthese,
-		       siginfo_t __user *uinfo,
-		       const struct compat_timespec __user *uts32,
-		       size_t sigsetsize)
-{
-	struct timespec __user *uts = NULL;
-
-	if (uts32) {
-		struct timespec ts;
-		uts = compat_alloc_user_space(sizeof(struct timespec));
-		if (get_user(ts.tv_sec, &uts32->tv_sec) ||
-		    get_user(ts.tv_nsec, &uts32->tv_nsec) ||
-		    copy_to_user (uts, &ts, sizeof (ts)))
-			return -EFAULT;
-	}
-	return sys_rt_sigtimedwait(uthese, uinfo, uts, sigsetsize);
-}
-
 save_static_function(sys32_clone);
 __attribute_used__ noinline static int
 _sys32_clone(nabi_no_regargs struct pt_regs regs)
diff -Naurp linux-2.6.13.3.orig/arch/mips/kernel/scall64-n32.S linux-2.6.13.3/arch/mips/kernel/scall64-n32.S
--- linux-2.6.13.3.orig/arch/mips/kernel/scall64-n32.S	2005-10-05 22:46:31.000000000 -0400
+++ linux-2.6.13.3/arch/mips/kernel/scall64-n32.S	2005-10-05 22:34:45.000000000 -0400
@@ -243,9 +243,9 @@ EXPORT(sysn32_call_table)
 	PTR	sys_capget
 	PTR	sys_capset
 	PTR	sys32_rt_sigpending		/* 6125 */
-	PTR	sysn32_rt_sigtimedwait
+	PTR	compat_sys_rt_sigtimedwait
 	PTR	sys_rt_sigqueueinfo
-	PTR	sys32_rt_sigsuspend
+	PTR	sysn32_rt_sigsuspend
 	PTR	sys32_sigaltstack
 	PTR	compat_sys_utime		/* 6130 */
 	PTR	sys_mknod
diff -Naurp linux-2.6.13.3.orig/arch/mips/kernel/signal.c linux-2.6.13.3/arch/mips/kernel/signal.c
--- linux-2.6.13.3.orig/arch/mips/kernel/signal.c	2005-10-05 22:46:31.000000000 -0400
+++ linux-2.6.13.3/arch/mips/kernel/signal.c	2005-10-05 22:47:07.000000000 -0400
@@ -21,6 +21,7 @@
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/compiler.h>
+#include <linux/compat.h>
 
 #include <asm/abi.h>
 #include <asm/asm.h>
@@ -39,6 +40,10 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
+#ifdef CONFIG_MIPS32_N32
+extern void sigset_from_compat (sigset_t *set, compat_sigset_t *compat);
+#endif
+
 int do_signal(sigset_t *oldset, struct pt_regs *regs);
 
 /*
@@ -109,6 +114,43 @@ _sys_rt_sigsuspend(nabi_no_regargs struc
 	}
 }
 
+#ifdef CONFIG_MIPS32_N32
+save_static_function(sysn32_rt_sigsuspend);
+__attribute_used__ noinline static int
+_sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
+{
+	sigset_t saveset, newset;
+	compat_sigset_t __user *unewset, uset;
+	size_t sigsetsize;
+
+	/* XXX Don't preclude handling different sized sigset_t's.  */
+	sigsetsize = regs.regs[5];
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	unewset = (compat_sigset_t __user *) regs.regs[4];
+	if (copy_from_user(&uset, unewset, sizeof(uset)))
+		return -EFAULT;
+	sigset_from_compat (&newset, &uset);
+	sigdelsetmask(&newset, ~_BLOCKABLE);
+
+	spin_lock_irq(&current->sighand->siglock);
+	saveset = current->blocked;
+	current->blocked = newset;
+        recalc_sigpending();
+	spin_unlock_irq(&current->sighand->siglock);
+
+	regs.regs[2] = EINTR;
+	regs.regs[7] = 1;
+	while (1) {
+		current->state = TASK_INTERRUPTIBLE;
+		schedule();
+		if (do_signal(&saveset, &regs))
+			return -EINTR;
+	}
+}
+#endif
+
 #ifdef CONFIG_TRAD_SIGNALS
 asmlinkage int sys_sigaction(int sig, const struct sigaction *act,
 	struct sigaction *oact)