Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull first series of signal handling cleanups from Al Viro:
 "This is just the first part of the queue (about a half of it);
  assorted fixes all over the place in signal handling.

  This one ends with all sigsuspend() implementations switched to
  generic one (->saved_sigmask-based).

  With this, a bunch of assorted old buglets are fixed and most of the
  missing bits of NOTIFY_RESUME hookup are in place.  Two more fixes sit
  in arm and um trees respectively, and there's a couple of broken ones
  that need obvious fixes - parisc and avr32 check TIF_NOTIFY_RESUME
  only on one of two codepaths; fixes for that will happen in the next
  series"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (55 commits)
  unicore32: if there's no handler we need to restore sigmask, syscall or no syscall
  xtensa: add handling of TIF_NOTIFY_RESUME
  microblaze: drop 'oldset' argument of do_notify_resume()
  microblaze: handle TIF_NOTIFY_RESUME
  score: add handling of NOTIFY_RESUME to do_notify_resume()
  m68k: add TIF_NOTIFY_RESUME and handle it.
  sparc: kill ancient comment in sparc_sigaction()
  h8300: missing checks of __get_user()/__put_user() return values
  frv: missing checks of __get_user()/__put_user() return values
  cris: missing checks of __get_user()/__put_user() return values
  powerpc: missing checks of __get_user()/__put_user() return values
  sh: missing checks of __get_user()/__put_user() return values
  sparc: missing checks of __get_user()/__put_user() return values
  avr32: struct old_sigaction is never used
  m32r: struct old_sigaction is never used
  xtensa: xtensa_sigaction doesn't exist
  alpha: tidy signal delivery up
  score: don't open-code force_sigsegv()
  cris: don't open-code force_sigsegv()
  blackfin: don't open-code force_sigsegv()
  ...

2 files changed, 39 insertions, 98 deletions

diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c
index 5901fba3176..cb4172c8af7 100644
--- a/arch/sh/kernel/signal_32.c
+++ b/arch/sh/kernel/signal_32.c
@@ -53,23 +53,11 @@ struct fdpic_func_descriptor {
  * Atomically swap in the new signal mask, and wait for a signal.
  */
 asmlinkage int
-sys_sigsuspend(old_sigset_t mask,
-               unsigned long r5, unsigned long r6, unsigned long r7,
-               struct pt_regs __regs)
+sys_sigsuspend(old_sigset_t mask)
 {
         sigset_t blocked;
-
-        current->saved_sigmask = current->blocked;
-
-        mask &= _BLOCKABLE;
         siginitset(&blocked, mask);
-        set_current_blocked(&blocked);
-
-        current->state = TASK_INTERRUPTIBLE;
-        schedule();
-        set_restore_sigmask();
-
-        return -ERESTARTNOHAND;
+        return sigsuspend(&blocked);
 }
 
 asmlinkage int
@@ -83,10 +71,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
                 old_sigset_t mask;
                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+                    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+                    __get_user(mask, &act->sa_mask))
                         return -EFAULT;
-                __get_user(new_ka.sa.sa_flags, &act->sa_flags);
-                __get_user(mask, &act->sa_mask);
                 siginitset(&new_ka.sa.sa_mask, mask);
         }
 
@@ -95,10 +83,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
         if (!ret && oact) {
                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+                    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+                    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
                         return -EFAULT;
-                __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-                __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
         }
 
         return ret;
@@ -162,12 +150,11 @@ static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
         if (!(boot_cpu_data.flags & CPU_HAS_FPU))
                 return 0;
 
-        if (!used_math()) {
-                __put_user(0, &sc->sc_ownedfp);
-                return 0;
-        }
+        if (!used_math())
+                return __put_user(0, &sc->sc_ownedfp);
 
-        __put_user(1, &sc->sc_ownedfp);
+        if (__put_user(1, &sc->sc_ownedfp))
+                return -EFAULT;
 
         /* This will cause a "finit" to be triggered by the next
            attempted FPU operation by the 'current' process.
@@ -207,7 +194,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p
                 regs->sr |= SR_FD; /* Release FPU */
                 clear_fpu(tsk, regs);
                 clear_used_math();
-                __get_user (owned_fp, &sc->sc_ownedfp);
+                err |= __get_user (owned_fp, &sc->sc_ownedfp);
                 if (owned_fp)
                         err |= restore_sigcontext_fpu(sc);
         }
@@ -398,11 +385,14 @@ static int setup_frame(int sig, struct k_sigaction *ka,
                 struct fdpic_func_descriptor __user *funcptr =
                         (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 
-                __get_user(regs->pc, &funcptr->text);
-                __get_user(regs->regs[12], &funcptr->GOT);
+                err |= __get_user(regs->pc, &funcptr->text);
+                err |= __get_user(regs->regs[12], &funcptr->GOT);
         } else
                 regs->pc = (unsigned long)ka->sa.sa_handler;
 
+        if (err)
+                goto give_sigsegv;
+
         set_fs(USER_DS);
 
         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
@@ -482,11 +472,14 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 struct fdpic_func_descriptor __user *funcptr =
                         (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
 
-                __get_user(regs->pc, &funcptr->text);
-                __get_user(regs->regs[12], &funcptr->GOT);
+                err |= __get_user(regs->pc, &funcptr->text);
+                err |= __get_user(regs->regs[12], &funcptr->GOT);
         } else
                 regs->pc = (unsigned long)ka->sa.sa_handler;
 
+        if (err)
+                goto give_sigsegv;
+
         set_fs(USER_DS);
 
         pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
diff --git a/arch/sh/kernel/signal_64.c b/arch/sh/kernel/signal_64.c
index 3c9a6f7dcdc..b589a354c06 100644
--- a/arch/sh/kernel/signal_64.c
+++ b/arch/sh/kernel/signal_64.c
@@ -83,11 +83,12 @@ handle_syscall_restart(struct pt_regs *regs, struct sigaction *sa)
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
-static int do_signal(struct pt_regs *regs, sigset_t *oldset)
+static void do_signal(struct pt_regs *regs)
 {
         siginfo_t info;
         int signr;
         struct k_sigaction ka;
+        sigset_t *oldset;
 
         /*
          * We want the common case to go fast, which
@@ -96,11 +97,11 @@ static int do_signal(struct pt_regs *regs, sigset_t *oldset)
          * if so.
          */
         if (!user_mode(regs))
-                return 1;
+                return;
 
         if (current_thread_info()->status & TS_RESTORE_SIGMASK)
                 oldset = &current->saved_sigmask;
-        else if (!oldset)
+        else
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, 0);
@@ -118,7 +119,7 @@ static int do_signal(struct pt_regs *regs, sigset_t *oldset)
 
                         tracehook_signal_handler(signr, &info, &ka, regs,
                                         test_thread_flag(TIF_SINGLESTEP));
-                        return 1;
+                        return;
                 }
         }
 
@@ -147,71 +148,18 @@ static int do_signal(struct pt_regs *regs, sigset_t *oldset)
                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
         }
 
-        return 0;
+        return;
 }
 
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
 asmlinkage int
-sys_sigsuspend(old_sigset_t mask,
-               unsigned long r3, unsigned long r4, unsigned long r5,
-               unsigned long r6, unsigned long r7,
-               struct pt_regs * regs)
+sys_sigsuspend(old_sigset_t mask)
 {
-        sigset_t saveset, blocked;
-
-        saveset = current->blocked;
-
-        mask &= _BLOCKABLE;
+        sigset_t blocked;
         siginitset(&blocked, mask);
-        set_current_blocked(&blocked);
-
-        REF_REG_RET = -EINTR;
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                set_restore_sigmask();
-                regs->pc += 4;    /* because sys_sigreturn decrements the pc */
-                if (do_signal(regs, &saveset)) {
-                        /* pc now points at signal handler. Need to decrement
-                           it because entry.S will increment it. */
-                        regs->pc -= 4;
-                        return -EINTR;
-                }
-        }
-}
-
-asmlinkage int
-sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
-                  unsigned long r4, unsigned long r5, 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);
-        saveset = current->blocked;
-        set_current_blocked(&newset);
-
-        REF_REG_RET = -EINTR;
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                regs->pc += 4;    /* because sys_sigreturn decrements the pc */
-                if (do_signal(regs, &saveset)) {
-                        /* pc now points at signal handler. Need to decrement
-                           it because entry.S will increment it. */
-                        regs->pc -= 4;
-                        return -EINTR;
-                }
-        }
+        return sigsuspend(&blocked);
 }
 
 asmlinkage int
@@ -225,10 +173,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
                 old_sigset_t mask;
                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+                    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+                    __get_user(mask, &act->sa_mask))
                         return -EFAULT;
-                __get_user(new_ka.sa.sa_flags, &act->sa_flags);
-                __get_user(mask, &act->sa_mask);
                 siginitset(&new_ka.sa.sa_mask, mask);
         }
 
@@ -237,10 +185,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
         if (!ret && oact) {
                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+                    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+                    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
                         return -EFAULT;
-                __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-                __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
         }
 
         return ret;
@@ -732,7 +680,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 {
         if (thread_info_flags & _TIF_SIGPENDING)
-                do_signal(regs, 0);
+                do_signal(regs);
 
         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
                 clear_thread_flag(TIF_NOTIFY_RESUME);