2 files changed, 139 insertions, 118 deletions

diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index d8a455ede5a7..fec8bf97d806 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -853,37 +853,44 @@ UNHANDLED_EXCEPTION(_vector_0x1f00,0x1f00)
 
 /* ========================================================[ return ] === */
 
+_resume_userspace:
+        DISABLE_INTERRUPTS(r3,r4)
+        l.lwz   r4,TI_FLAGS(r10)
+        l.andi  r13,r4,_TIF_WORK_MASK
+        l.sfeqi r13,0
+        l.bf    _restore_all
+         l.nop
+
 _work_pending:
-        /*
-         * if (current_thread_info->flags & _TIF_NEED_RESCHED)
-         *     schedule();
-         */
-        l.lwz   r5,TI_FLAGS(r10)
-        l.andi  r3,r5,_TIF_NEED_RESCHED
-        l.sfnei r3,0
-        l.bnf   _work_notifysig
+        l.lwz   r5,PT_ORIG_GPR11(r1)
+        l.sfltsi r5,0
+        l.bnf   1f
          l.nop
-        l.jal   schedule
+        l.andi  r5,r5,0
+1:
+        l.jal   do_work_pending
+         l.ori  r3,r1,0                 /* pt_regs */
+
+        l.sfeqi r11,0
+        l.bf    _restore_all
          l.nop
-        l.j     _resume_userspace
+        l.sfltsi r11,0
+        l.bnf   1f
          l.nop
-
-/* Handle pending signals and notify-resume requests.
- * do_notify_resume must be passed the latest pushed pt_regs, not
- * necessarily the "userspace" ones.  Also, pt_regs->syscallno
- * must be set so that the syscall restart functionality works.
- */
-_work_notifysig:
-        l.jal   do_notify_resume
-         l.ori  r3,r1,0           /* pt_regs */
-
-_resume_userspace:
-        DISABLE_INTERRUPTS(r3,r4)
-        l.lwz   r3,TI_FLAGS(r10)
-        l.andi  r3,r3,_TIF_WORK_MASK
-        l.sfnei r3,0
-        l.bf    _work_pending
+        l.and   r11,r11,r0
+        l.ori   r11,r11,__NR_restart_syscall
+        l.j     _syscall_check_trace_enter
          l.nop
+1:
+        l.lwz   r11,PT_ORIG_GPR11(r1)
+        /* Restore arg registers */
+        l.lwz   r3,PT_GPR3(r1)
+        l.lwz   r4,PT_GPR4(r1)
+        l.lwz   r5,PT_GPR5(r1)
+        l.lwz   r6,PT_GPR6(r1)
+        l.lwz   r7,PT_GPR7(r1)
+        l.j     _syscall_check_trace_enter
+         l.lwz  r8,PT_GPR8(r1)
 
 _restore_all:
         RESTORE_ALL
diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c
index ae167f7e081a..c277ec82783d 100644
--- a/arch/openrisc/kernel/signal.c
+++ b/arch/openrisc/kernel/signal.c
@@ -28,24 +28,24 @@
 #include <linux/tracehook.h>
 
 #include <asm/processor.h>
+#include <asm/syscall.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
 
 #define DEBUG_SIG 0
 
 struct rt_sigframe {
-        struct siginfo *pinfo;
-        void *puc;
         struct siginfo info;
         struct ucontext uc;
         unsigned char retcode[16];      /* trampoline code */
 };
 
-static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
+static int restore_sigcontext(struct pt_regs *regs,
+                              struct sigcontext __user *sc)
 {
-        unsigned int err = 0;
+        int err = 0;
 
-        /* Alwys make any pending restarted system call return -EINTR */
+        /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
         /*
@@ -53,25 +53,21 @@ static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
          * (sc is already checked for VERIFY_READ since the sigframe was
          *  checked in sys_sigreturn previously)
          */
-        if (__copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long)))
-                goto badframe;
-        if (__copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long)))
-                goto badframe;
-        if (__copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long)))
-                goto badframe;
+        err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long));
+        err |= __copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long));
+        err |= __copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long));
 
         /* make sure the SM-bit is cleared so user-mode cannot fool us */
         regs->sr &= ~SPR_SR_SM;
 
+        regs->orig_gpr11 = -1;  /* Avoid syscall restart checks */
+
         /* TODO: the other ports use regs->orig_XX to disable syscall checks
          * after this completes, but we don't use that mechanism. maybe we can
          * use it now ?
          */
 
         return err;
-
-badframe:
-        return 1;
 }
 
 asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
@@ -111,21 +107,18 @@ badframe:
  * Set up a signal frame.
  */
 
-static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
-                            unsigned long mask)
+static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
         int err = 0;
 
         /* copy the regs */
-
+        /* There should be no need to save callee-saved registers here...
+         * ...but we save them anyway.  Revisit this
+         */
         err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
         err |= __copy_to_user(&sc->regs.pc, &regs->pc, sizeof(unsigned long));
         err |= __copy_to_user(&sc->regs.sr, &regs->sr, sizeof(unsigned long));
 
-        /* then some other stuff */
-
-        err |= __put_user(mask, &sc->oldmask);
-
         return err;
 }
 
@@ -181,24 +174,18 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
         int err = 0;
 
         frame = get_sigframe(ka, regs, sizeof(*frame));
-
         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
                 goto give_sigsegv;
 
-        err |= __put_user(&frame->info, &frame->pinfo);
-        err |= __put_user(&frame->uc, &frame->puc);
-
+        /* Create siginfo.  */
         if (ka->sa.sa_flags & SA_SIGINFO)
                 err |= copy_siginfo_to_user(&frame->info, info);
-        if (err)
-                goto give_sigsegv;
 
-        /* Clear all the bits of the ucontext we don't use.  */
-        err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
+        /* Create the ucontext.  */
         err |= __put_user(0, &frame->uc.uc_flags);
         err |= __put_user(NULL, &frame->uc.uc_link);
         err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
-        err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
+        err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
 
         err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 
@@ -207,9 +194,12 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 
         /* trampoline - the desired return ip is the retcode itself */
         return_ip = (unsigned long)&frame->retcode;
-        /* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
-        err |= __put_user(0xa960, (short *)(frame->retcode + 0));
-        err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2));
+        /* This is:
+                l.ori r11,r0,__NR_sigreturn
+                l.sys 1
+         */
+        err |= __put_user(0xa960,             (short *)(frame->retcode + 0));
+        err |= __put_user(__NR_rt_sigreturn,  (short *)(frame->retcode + 2));
         err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
         err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
 
@@ -262,82 +252,106 @@ handle_signal(unsigned long sig,
  * mode below.
  */
 
-void do_signal(struct pt_regs *regs)
+int do_signal(struct pt_regs *regs, int syscall)
 {
         siginfo_t info;
         int signr;
         struct k_sigaction ka;
-
-        /*
-         * We want the common case to go fast, which
-         * is why we may in certain cases get here from
-         * kernel mode. Just return without doing anything
-         * if so.
-         */
-        if (!user_mode(regs))
-                return;
-
-        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
-
-        /* If we are coming out of a syscall then we need
-         * to check if the syscall was interrupted and wants to be
-         * restarted after handling the signal.  If so, the original
-         * syscall number is put back into r11 and the PC rewound to
-         * point at the l.sys instruction that resulted in the
-         * original syscall.  Syscall results other than the four
-         * below mean that the syscall executed to completion and no
-         * restart is necessary.
-         */
-        if (regs->orig_gpr11) {
-                int restart = 0;
-
-                switch (regs->gpr[11]) {
+        unsigned long continue_addr = 0;
+        unsigned long restart_addr = 0;
+        unsigned long retval = 0;
+        int restart = 0;
+
+        if (syscall) {
+                continue_addr = regs->pc;
+                restart_addr = continue_addr - 4;
+                retval = regs->gpr[11];
+
+                /*
+                 * Setup syscall restart here so that a debugger will
+                 * see the already changed PC.
+                 */
+                switch (retval) {
                 case -ERESTART_RESTARTBLOCK:
+                        restart = -2;
+                        /* Fall through */
                 case -ERESTARTNOHAND:
-                        /* Restart if there is no signal handler */
-                        restart = (signr <= 0);
-                        break;
                 case -ERESTARTSYS:
-                        /* Restart if there no signal handler or
-                         * SA_RESTART flag is set */
-                        restart = (signr <= 0 || (ka.sa.sa_flags & SA_RESTART));
-                        break;
                 case -ERESTARTNOINTR:
-                        /* Always restart */
-                        restart = 1;
+                        restart++;
+                        regs->gpr[11] = regs->orig_gpr11;
+                        regs->pc = restart_addr;
                         break;
                 }
+        }
 
-                if (restart) {
-                        if (regs->gpr[11] == -ERESTART_RESTARTBLOCK)
-                                regs->gpr[11] = __NR_restart_syscall;
-                        else
-                                regs->gpr[11] = regs->orig_gpr11;
-                        regs->pc -= 4;
-                } else {
-                        regs->gpr[11] = -EINTR;
+        /*
+         * Get the signal to deliver.  When running under ptrace, at this
+         * point the debugger may change all our registers ...
+         */
+        signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+        /*
+         * Depending on the signal settings we may need to revert the
+         * decision to restart the system call.  But skip this if a
+         * debugger has chosen to restart at a different PC.
+         */
+        if (signr > 0) {
+                if (unlikely(restart) && regs->pc == restart_addr) {
+                        if (retval == -ERESTARTNOHAND ||
+                            retval == -ERESTART_RESTARTBLOCK
+                            || (retval == -ERESTARTSYS
+                                && !(ka.sa.sa_flags & SA_RESTART))) {
+                                /* No automatic restart */
+                                regs->gpr[11] = -EINTR;
+                                regs->pc = continue_addr;
+                        }
                 }
-        }
 
-        if (signr <= 0) {
-                /* no signal to deliver so we just put the saved sigmask
-                 * back */
-                restore_saved_sigmask();
-        } else {                /* signr > 0 */
-                /* Whee!  Actually deliver the signal.  */
                 handle_signal(signr, &info, &ka, regs);
+        } else {
+                /* no handler */
+                restore_saved_sigmask();
+                /*
+                 * Restore pt_regs PC as syscall restart will be handled by
+                 * kernel without return to userspace
+                 */
+                if (unlikely(restart) && regs->pc == restart_addr) {
+                        regs->pc = continue_addr;
+                        return restart;
+                }
         }
 
-        return;
+        return 0;
 }
 
-asmlinkage void do_notify_resume(struct pt_regs *regs)
+asmlinkage int
+do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 {
-        if (current_thread_info()->flags & _TIF_SIGPENDING)
-                do_signal(regs);
-
-        if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) {
-                clear_thread_flag(TIF_NOTIFY_RESUME);
-                tracehook_notify_resume(regs);
-        }
+        do {
+                if (likely(thread_flags & _TIF_NEED_RESCHED)) {
+                        schedule();
+                } else {
+                        if (unlikely(!user_mode(regs)))
+                                return 0;
+                        local_irq_enable();
+                        if (thread_flags & _TIF_SIGPENDING) {
+                                int restart = do_signal(regs, syscall);
+                                if (unlikely(restart)) {
+                                        /*
+                                         * Restart without handlers.
+                                         * Deal with it without leaving
+                                         * the kernel space.
+                                         */
+                                        return restart;
+                                }
+                                syscall = 0;
+                        } else {
+                                clear_thread_flag(TIF_NOTIFY_RESUME);
+                                tracehook_notify_resume(regs);
+                        }
+                }
+                local_irq_disable();
+                thread_flags = current_thread_info()->flags;
+        } while (thread_flags & _TIF_WORK_MASK);
+        return 0;
 }