sh: pselect6 and ppoll, along with signal trampoline rework.

This implements support for ppoll() and pselect6()..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

3 files changed, 85 insertions, 91 deletions

diff --git a/arch/sh/kernel/entry.S b/arch/sh/kernel/entry.S
index fcbf50d4ee10..fd5fe2349f20 100644
--- a/arch/sh/kernel/entry.S
+++ b/arch/sh/kernel/entry.S
@@ -371,12 +371,12 @@ work_pending:
         ! r8: current_thread_info
         ! t:  result of "tst    #_TIF_NEED_RESCHED, r0"
         bf/s    work_resched
-         tst    #_TIF_SIGPENDING, r0
+         tst    #(_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), r0
 work_notifysig:
         bt/s    restore_all
          mov    r15, r4
-        mov     #0, r5
-        mov     r12, r6         ! set arg2(save_r0)
+        mov     r12, r5         ! set arg1(save_r0)
+        mov     r0, r6
         mov.l   2f, r1
         mova    restore_all, r0
         jmp     @r1
@@ -414,7 +414,7 @@ work_resched:
 
         .align  2
 1:      .long   schedule
-2:      .long   do_signal
+2:      .long   do_notify_resume
 
         .align  2
 syscall_exit_work:
diff --git a/arch/sh/kernel/signal.c b/arch/sh/kernel/signal.c
index eb6a3b97e46c..2f1c9545b49f 100644
--- a/arch/sh/kernel/signal.c
+++ b/arch/sh/kernel/signal.c
@@ -29,13 +29,10 @@
 #include <asm/pgtable.h>
 #include <asm/cacheflush.h>
 
-#define DEBUG_SIG 0
+#undef DEBUG
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset,
-                         unsigned int save_r0);
-
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
@@ -44,51 +41,17 @@ sys_sigsuspend(old_sigset_t mask,
                unsigned long r5, unsigned long r6, unsigned long r7,
                struct pt_regs regs)
 {
-        sigset_t saveset;
-
         mask &= _BLOCKABLE;
         spin_lock_irq(&current->sighand->siglock);
-        saveset = current->blocked;
+        current->saved_sigmask = current->blocked;
         siginitset(&current->blocked, mask);
         recalc_sigpending();
         spin_unlock_irq(&current->sighand->siglock);
 
-        regs.regs[0] = -EINTR;
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                if (do_signal(&regs, &saveset, regs.regs[0]))
-                        return -EINTR;
-        }
-}
-
-asmlinkage int
-sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
-                  unsigned long r6, unsigned long r7,
-                  struct pt_regs regs)
-{
-        sigset_t saveset, newset;
-
-        /* XXX: Don't preclude handling different sized sigset_t's.  */
-        if (sigsetsize != sizeof(sigset_t))
-                return -EINVAL;
-
-        if (copy_from_user(&newset, unewset, sizeof(newset)))
-                return -EFAULT;
-        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[0] = -EINTR;
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                if (do_signal(&regs, &saveset, regs.regs[0]))
-                        return -EINTR;
-        }
+        current->state = TASK_INTERRUPTIBLE;
+        schedule();
+        set_thread_flag(TIF_RESTORE_SIGMASK);
+        return -ERESTARTNOHAND;
 }
 
 asmlinkage int 
@@ -349,7 +312,7 @@ get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
         return (void __user *)((sp - frame_size) & -8ul);
 }
 
-static void setup_frame(int sig, struct k_sigaction *ka,
+static int setup_frame(int sig, struct k_sigaction *ka,
                         sigset_t *set, struct pt_regs *regs)
 {
         struct sigframe __user *frame;
@@ -369,10 +332,9 @@ static void setup_frame(int sig, struct k_sigaction *ka,
 
         err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
 
-        if (_NSIG_WORDS > 1) {
+        if (_NSIG_WORDS > 1)
                 err |= __copy_to_user(frame->extramask, &set->sig[1],
                                       sizeof(frame->extramask));
-        }
 
         /* Set up to return from userspace.  If provided, use a stub
            already in userspace.  */
@@ -403,21 +365,22 @@ static void setup_frame(int sig, struct k_sigaction *ka,
 
         set_fs(USER_DS);
 
-#if DEBUG_SIG
-        printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
-                current->comm, current->pid, frame, regs->pc, regs->pr);
-#endif
+        pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
+                 current->comm, current->pid, frame, regs->pc, regs->pr);
 
         flush_cache_sigtramp(regs->pr);
+
         if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode))
                 flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES);
-        return;
+
+        return 0;
 
 give_sigsegv:
         force_sigsegv(sig, current);
+        return -EFAULT;
 }
 
-static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                            sigset_t *set, struct pt_regs *regs)
 {
         struct rt_sigframe __user *frame;
@@ -478,28 +441,31 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 
         set_fs(USER_DS);
 
-#if DEBUG_SIG
-        printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
-                current->comm, current->pid, frame, regs->pc, regs->pr);
-#endif
+        pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
+                 current->comm, current->pid, frame, regs->pc, regs->pr);
 
         flush_cache_sigtramp(regs->pr);
+
         if ((-regs->pr & (L1_CACHE_BYTES-1)) < sizeof(frame->retcode))
                 flush_cache_sigtramp(regs->pr + L1_CACHE_BYTES);
-        return;
+
+        return 0;
 
 give_sigsegv:
         force_sigsegv(sig, current);
+        return -EFAULT;
 }
 
 /*
  * OK, we're invoking a handler
  */
 
-static void
+static int
 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
               sigset_t *oldset, struct pt_regs *regs)
 {
+        int ret;
+
         /* Are we from a system call? */
         if (regs->tra >= 0) {
                 /* If so, check system call restarting.. */
@@ -540,19 +506,23 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 
         /* Set up the stack frame */
         if (ka->sa.sa_flags & SA_SIGINFO)
-                setup_rt_frame(sig, ka, info, oldset, regs);
+                ret = setup_rt_frame(sig, ka, info, oldset, regs);
         else
-                setup_frame(sig, ka, oldset, regs);
+                ret = setup_frame(sig, ka, oldset, regs);
 
         if (ka->sa.sa_flags & SA_ONESHOT)
                 ka->sa.sa_handler = SIG_DFL;
 
-        spin_lock_irq(&current->sighand->siglock);
-        sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-        if (!(ka->sa.sa_flags & SA_NODEFER))
-                sigaddset(&current->blocked,sig);
-        recalc_sigpending();
-        spin_unlock_irq(&current->sighand->siglock);
+        if (ret == 0) {
+                spin_lock_irq(&current->sighand->siglock);
+                sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
+                if (!(ka->sa.sa_flags & SA_NODEFER))
+                        sigaddset(&current->blocked,sig);
+                recalc_sigpending();
+                spin_unlock_irq(&current->sighand->siglock);
+        }
+
+        return ret;
 }
 
 /*
@@ -564,11 +534,12 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-int do_signal(struct pt_regs *regs, sigset_t *oldset, unsigned int save_r0)
+static void do_signal(struct pt_regs *regs, unsigned int save_r0)
 {
         siginfo_t info;
         int signr;
         struct k_sigaction ka;
+        sigset_t *oldset;
 
         /*
          * We want the common case to go fast, which
@@ -577,19 +548,27 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, unsigned int save_r0)
          * if so.
          */
         if (!user_mode(regs))
-                return 1;
+                return;
 
         if (try_to_freeze())
                 goto no_signal;
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
         if (signr > 0) {
                 /* Whee!  Actually deliver the signal.  */
-                handle_signal(signr, &ka, &info, oldset, regs);
-                return 1;
+                if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
+                        /* 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);
+                }
         }
 
  no_signal:
@@ -606,5 +585,19 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, unsigned int save_r0)
                         regs->regs[3] = __NR_restart_syscall;
                 }
         }
-        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);
+        }
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
+                                 __u32 thread_info_flags)
+{
+        /* deal with pending signal delivery */
+        if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+                do_signal(regs, save_r0);
 }
diff --git a/arch/sh/kernel/syscalls.S b/arch/sh/kernel/syscalls.S
index ea23b213c77f..768334e95075 100644
--- a/arch/sh/kernel/syscalls.S
+++ b/arch/sh/kernel/syscalls.S
@@ -319,34 +319,35 @@ ENTRY(sys_call_table)
         .long sys_mq_getsetattr
         .long sys_kexec_load
         .long sys_waitid
-        .long sys_add_key               /* 285 */
+        .long sys_ni_syscall            /* 285 */
+        .long sys_add_key
         .long sys_request_key
         .long sys_keyctl
         .long sys_ioprio_set
-        .long sys_ioprio_get
-        .long sys_inotify_init          /* 290 */
+        .long sys_ioprio_get            /* 290 */
+        .long sys_inotify_init
         .long sys_inotify_add_watch
         .long sys_inotify_rm_watch
         .long sys_migrate_pages
-        .long sys_openat
-        .long sys_mkdirat               /* 295 */
+        .long sys_openat                /* 295 */
+        .long sys_mkdirat
         .long sys_mknodat
         .long sys_fchownat
         .long sys_futimesat
-        .long sys_fstatat64
-        .long sys_unlinkat              /* 300 */
+        .long sys_fstatat64             /* 300 */
+        .long sys_unlinkat
         .long sys_renameat
         .long sys_linkat
         .long sys_symlinkat
-        .long sys_readlinkat
-        .long sys_fchmodat              /* 305 */
+        .long sys_readlinkat            /* 305 */
+        .long sys_fchmodat
         .long sys_faccessat
-        .long sys_ni_syscall            /* Reserved for pselect6 */
-        .long sys_ni_syscall            /* Reserved for ppoll */
-        .long sys_unshare
-        .long sys_set_robust_list       /* 310 */
+        .long sys_pselect6
+        .long sys_ppoll
+        .long sys_unshare               /* 310 */
+        .long sys_set_robust_list
         .long sys_get_robust_list
         .long sys_splice
         .long sys_sync_file_range
-        .long sys_tee
-        .long sys_vmsplice              /* 315 */
+        .long sys_tee                   /* 315 */
+        .long sys_vmsplice