[PATCH 1/2] ia64: add TIF_RESTORE_SIGMASK

[Alexey Dobriyan <adobriyan@openvz.org>]

ia32 compat code not tested. :-(
please, point fingers if I broke something. --adobriyan
---------------------------------------
[PATCH] ia64: add TIF_RESTORE_SIGMASK

From: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>

Signed-off-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
---

 arch/ia64/ia32/ia32_entry.S    |   39 ----------------------
 arch/ia64/ia32/ia32_signal.c   |   59 +++++-----------------------------
 arch/ia64/kernel/entry.S       |   26 ---------------
 arch/ia64/kernel/process.c     |    6 +--
 arch/ia64/kernel/sigframe.h    |    2 -
 arch/ia64/kernel/signal.c      |   71 +++++++++++++----------------------------
 include/asm-ia64/thread_info.h |    4 +-
 include/asm-ia64/unistd.h      |    2 +
 8 files changed, 43 insertions(+), 166 deletions(-)

--- a/arch/ia64/ia32/ia32_entry.S
+++ b/arch/ia64/ia32/ia32_entry.S
@@ -52,43 +52,6 @@ ENTRY(ia32_clone)
 	br.ret.sptk.many rp
 END(ia32_clone)
 
-ENTRY(sys32_rt_sigsuspend)
-	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
-	alloc loc1=ar.pfs,8,2,3,0		// preserve all eight input regs
-	mov loc0=rp
-	mov out0=in0				// mask
-	mov out1=in1				// sigsetsize
-	mov out2=sp				// out2 = &sigscratch
-	.fframe 16
-	adds sp=-16,sp				// allocate dummy "sigscratch"
-	;;
-	.body
-	br.call.sptk.many rp=ia32_rt_sigsuspend
-1:	.restore sp
-	adds sp\x16,sp
-	mov rp=loc0
-	mov ar.pfs=loc1
-	br.ret.sptk.many rp
-END(sys32_rt_sigsuspend)
-
-ENTRY(sys32_sigsuspend)
-	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
-	alloc loc1=ar.pfs,8,2,3,0		// preserve all eight input regs
-	mov loc0=rp
-	mov out0=in2				// mask (first two args are ignored)
-	;;
-	mov out1=sp				// out1 = &sigscratch
-	.fframe 16
-	adds sp=-16,sp				// allocate dummy "sigscratch"
-	.body
-	br.call.sptk.many rp=ia32_sigsuspend
-1:	.restore sp
-	adds sp\x16,sp
-	mov rp=loc0
-	mov ar.pfs=loc1
-	br.ret.sptk.many rp
-END(sys32_sigsuspend)
-
 GLOBAL_ENTRY(ia32_ret_from_clone)
 	PT_REGS_UNWIND_INFO(0)
 {	/*
@@ -389,7 +352,7 @@ ia32_syscall_table:
 	data8 sys_rt_sigpending
 	data8 compat_sys_rt_sigtimedwait
 	data8 sys32_rt_sigqueueinfo
-	data8 sys32_rt_sigsuspend
+	data8 compat_sys_rt_sigsuspend
 	data8 sys32_pread	  /* 180 */
 	data8 sys32_pwrite
 	data8 sys_chown	/* 16-bit version */
--- a/arch/ia64/ia32/ia32_signal.c
+++ b/arch/ia64/ia32/ia32_signal.c
@@ -452,59 +452,20 @@ sigact_set_handler (struct k_sigaction *
 		sa->sa.sa_handler = (__sighandler_t) (((unsigned long) restorer << 32) | handler);
 }
 
-long
-__ia32_rt_sigsuspend (compat_sigset_t *sset, unsigned int sigsetsize, struct sigscratch *scr)
+asmlinkage long
+sys32_sigsuspend (int history0, int history1, old_sigset_t mask)
 {
-	extern long ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall);
-	sigset_t oldset, set;
-
-	scr->scratch_unat = 0;	/* avoid leaking kernel bits to user level */
-	memset(&set, 0, sizeof(set));
-
-	memcpy(&set.sig, &sset->sig, sigsetsize);
-
-	sigdelsetmask(&set, ~_BLOCKABLE);
-
+	mask &= _BLOCKABLE;
 	spin_lock_irq(&current->sighand->siglock);
-	{
-		oldset = current->blocked;
-		current->blocked = set;
-		recalc_sigpending();
-	}
+	current->saved_sigmask = current->blocked;
+	siginitset(&current->blocked, mask);
+	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	/*
-	 * The return below usually returns to the signal handler.  We need to pre-set the
-	 * correct error code here to ensure that the right values get saved in sigcontext
-	 * by ia64_do_signal.
-	 */
-	scr->pt.r8 = -EINTR;
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (ia64_do_signal(&oldset, scr, 1))
-			return -EINTR;
-	}
-}
-
-asmlinkage long
-ia32_rt_sigsuspend (compat_sigset_t __user *uset, unsigned int sigsetsize, struct sigscratch *scr)
-{
-	compat_sigset_t set;
-
-	if (sigsetsize > sizeof(compat_sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&set.sig, &uset->sig, sigsetsize))
-		return -EFAULT;
-
-	return __ia32_rt_sigsuspend(&set, sigsetsize, scr);
-}
-
-asmlinkage long
-ia32_sigsuspend (unsigned int mask, struct sigscratch *scr)
-{
-	return __ia32_rt_sigsuspend((compat_sigset_t *) &mask, sizeof(mask), scr);
+	current->state = TASK_INTERRUPTIBLE;
+	schedule();
+	set_thread_flag(TIF_RESTORE_SIGMASK);
+	return -ERESTARTNOHAND;
 }
 
 asmlinkage long
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -1202,32 +1202,6 @@ (pNonSys) mov out2=0				// out2=0 => no
 	br.ret.sptk.many rp
 END(notify_resume_user)
 
-GLOBAL_ENTRY(sys_rt_sigsuspend)
-	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
-	alloc loc1=ar.pfs,8,2,3,0 // preserve all eight input regs in case of syscall restart!
-	mov r9=ar.unat
-	mov loc0=rp				// save return address
-	mov out0=in0				// mask
-	mov out1=in1				// sigsetsize
-	adds out2=8,sp				// out2=&sigscratch->ar_pfs
-	;;
-	.fframe 16
-	.spillsp ar.unat, 16
-	st8 [sp]=r9,-16				// allocate space for ar.unat and save it
-	st8 [out2]=loc1,-8			// save ar.pfs, out2=&sigscratch
-	.body
-	br.call.sptk.many rp=ia64_rt_sigsuspend
-.ret17:	.restore sp
-	adds sp\x16,sp				// pop scratch stack space
-	;;
-	ld8 r9=[sp]				// load new unat from sw->caller_unat
-	mov rp=loc0
-	;;
-	mov ar.unat=r9
-	mov ar.pfs=loc1
-	br.ret.sptk.many rp
-END(sys_rt_sigsuspend)
-
 ENTRY(sys_rt_sigreturn)
 	PT_REGS_UNWIND_INFO(0)
 	/*
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -155,7 +155,7 @@ show_regs (struct pt_regs *regs)
 }
 
 void
-do_notify_resume_user (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
+do_notify_resume_user (sigset_t *unused, struct sigscratch *scr, long in_syscall)
 {
 	if (fsys_mode(current, &scr->pt)) {
 		/* defer signal-handling etc. until we return to privilege-level 0.  */
@@ -170,8 +170,8 @@ #ifdef CONFIG_PERFMON
 #endif
 
 	/* deal with pending signal delivery */
-	if (test_thread_flag(TIF_SIGPENDING))
-		ia64_do_signal(oldset, scr, in_syscall);
+	if (test_thread_flag(TIF_SIGPENDING)||test_thread_flag(TIF_RESTORE_SIGMASK))
+		ia64_do_signal(scr, in_syscall);
 }
 
 static int pal_halt        = 1;
--- a/arch/ia64/kernel/sigframe.h
+++ b/arch/ia64/kernel/sigframe.h
@@ -22,4 +22,4 @@ struct sigframe {
 	struct sigcontext sc;
 };
 
-extern long ia64_do_signal (sigset_t *, struct sigscratch *, long);
+extern void ia64_do_signal (struct sigscratch *, long);
--- a/arch/ia64/kernel/signal.c
+++ b/arch/ia64/kernel/signal.c
@@ -41,47 +41,6 @@ # define PUT_SIGSET(k,u)	__put_user((k)-
 # define GET_SIGSET(k,u)	__get_user((k)->sig[0], &(u)->sig[0])
 #endif
 
-long
-ia64_rt_sigsuspend (sigset_t __user *uset, size_t sigsetsize, struct sigscratch *scr)
-{
-	sigset_t oldset, set;
-
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (!access_ok(VERIFY_READ, uset, sigsetsize))
-		return -EFAULT;
-
-	if (GET_SIGSET(&set, uset))
-		return -EFAULT;
-
-	sigdelsetmask(&set, ~_BLOCKABLE);
-
-	spin_lock_irq(&current->sighand->siglock);
-	{
-		oldset = current->blocked;
-		current->blocked = set;
-		recalc_sigpending();
-	}
-	spin_unlock_irq(&current->sighand->siglock);
-
-	/*
-	 * The return below usually returns to the signal handler.  We need to
-	 * pre-set the correct error code here to ensure that the right values
-	 * get saved in sigcontext by ia64_do_signal.
-	 */
-	scr->pt.r8 = EINTR;
-	scr->pt.r10 = -1;
-
-	while (1) {
-		current->state = TASK_INTERRUPTIBLE;
-		schedule();
-		if (ia64_do_signal(&oldset, scr, 1))
-			return -EINTR;
-	}
-}
-
 asmlinkage long
 sys_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, long arg2,
 		 long arg3, long arg4, long arg5, long arg6, long arg7,
@@ -478,10 +437,11 @@ handle_signal (unsigned long sig, struct
  * Note that `init' is a special process: it doesn't get signals it doesn't want to
  * handle.  Thus you cannot kill init even with a SIGKILL even by mistake.
  */
-long
-ia64_do_signal (sigset_t *oldset, struct sigscratch *scr, long in_syscall)
+void
+ia64_do_signal (struct sigscratch *scr, long in_syscall)
 {
 	struct k_sigaction ka;
+	sigset_t *oldset;
 	siginfo_t info;
 	long restart = in_syscall;
 	long errno = scr->pt.r8;
@@ -493,9 +453,11 @@ #	define ERR_CODE(c)	(IS_IA32_PROCESS(&s
 	 * doing anything if so.
 	 */
 	if (!user_mode(&scr->pt))
-		return 0;
+		return;
 
-	if (!oldset)
+	if (test_thread_flag(TIF_RESTORE_SIGMASK))
+		oldset = &current->saved_sigmask;
+	else
 		oldset = &current->blocked;
 
 	/*
@@ -558,8 +520,15 @@ #	define ERR_CODE(c)	(IS_IA32_PROCESS(&s
 		 * Whee!  Actually deliver the signal.  If the delivery failed, we need to
 		 * continue to iterate in this loop so we can deliver the SIGSEGV...
 		 */
-		if (handle_signal(signr, &ka, &info, oldset, scr))
-			return 1;
+		if (handle_signal(signr, &ka, &info, oldset, scr)) {
+			/* a signal was successfully delivered; the saved
+			 * sigmask will have been stored in the signal frame,
+			 * and will be restored by sigreturn, so we can simply
+			 * clear the TIF_RESTORE_SIGMASK flag */
+			if (test_thread_flag(TIF_RESTORE_SIGMASK))
+				clear_thread_flag(TIF_RESTORE_SIGMASK);
+			return;
+		}
 	}
 
 	/* Did we come from a system call? */
@@ -585,5 +554,11 @@ #	define ERR_CODE(c)	(IS_IA32_PROCESS(&s
 			}
 		}
 	}
-	return 0;
+
+	/* if there's no signal to deliver, we just put the saved sigmask
+	 * back */
+	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+		clear_thread_flag(TIF_RESTORE_SIGMASK);
+		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+	}
 }
--- a/include/asm-ia64/thread_info.h
+++ b/include/asm-ia64/thread_info.h
@@ -84,6 +84,7 @@ #define TIF_SIGPENDING		1	/* signal pend
 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
 #define TIF_SYSCALL_TRACE	3	/* syscall trace active */
 #define TIF_SYSCALL_AUDIT	4	/* syscall auditing active */
+#define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
 #define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		17
 #define TIF_MCA_INIT		18	/* this task is processing MCA or INIT */
@@ -94,6 +95,7 @@ #define _TIF_SYSCALL_TRACE	(1 << TIF_SYS
 #define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
 #define _TIF_SYSCALL_TRACEAUDIT	(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
+#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
@@ -102,7 +104,7 @@ #define _TIF_DB_DISABLED	(1 << TIF_DB_DI
 #define _TIF_FREEZE		(1 << TIF_FREEZE)
 
 /* "work to do on user-return" bits */
-#define TIF_ALLWORK_MASK	(_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
+#define TIF_ALLWORK_MASK	(_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_RESTORE_SIGMASK)
 /* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
 #define TIF_WORK_MASK		(TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
 
--- a/include/asm-ia64/unistd.h
+++ b/include/asm-ia64/unistd.h
@@ -298,6 +298,7 @@ #ifdef __KERNEL__
 #define NR_syscalls			279 /* length of syscall table */
 
 #define __ARCH_WANT_SYS_RT_SIGACTION
+#define __ARCH_WANT_SYS_RT_SIGSUSPEND
 
 #ifdef CONFIG_IA32_SUPPORT
 # define __ARCH_WANT_SYS_FADVISE64
@@ -308,6 +309,7 @@ # define __ARCH_WANT_SYS_OLD_GETRLIMIT
 # define __ARCH_WANT_SYS_OLDUMOUNT
 # define __ARCH_WANT_SYS_SIGPENDING
 # define __ARCH_WANT_SYS_SIGPROCMASK
+# define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
 # define __ARCH_WANT_COMPAT_SYS_TIME
 #endif