Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / arch / x86 / kernel / signal.c

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 5ddc7ec..f980408 100644 (file)
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -61,8 +61,7 @@
        regs->seg = GET_SEG(seg) | 3;                   \
 } while (0)
 
-int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
-                      unsigned long *pax)
+int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
        void __user *buf;
        unsigned int tmpflags;
@@ -81,7 +80,7 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 #endif /* CONFIG_X86_32 */
 
                COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
-               COPY(dx); COPY(cx); COPY(ip);
+               COPY(dx); COPY(cx); COPY(ip); COPY(ax);
 
 #ifdef CONFIG_X86_64
                COPY(r8);
@@ -94,27 +93,20 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
                COPY(r15);
 #endif /* CONFIG_X86_64 */
 
-#ifdef CONFIG_X86_32
                COPY_SEG_CPL3(cs);
                COPY_SEG_CPL3(ss);
-#else /* !CONFIG_X86_32 */
-               /* Kernel saves and restores only the CS segment register on signals,
-                * which is the bare minimum needed to allow mixed 32/64-bit code.
-                * App's signal handler can save/restore other segments if needed. */
-               COPY_SEG_CPL3(cs);
-#endif /* CONFIG_X86_32 */
 
                get_user_ex(tmpflags, &sc->flags);
                regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
                regs->orig_ax = -1;             /* disable syscall checks */
 
                get_user_ex(buf, &sc->fpstate);
-
-               get_user_ex(*pax, &sc->ax);
        } get_user_catch(err);
 
        err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32));
 
+       force_iret();
+
        return err;
 }
 
@@ -162,8 +154,9 @@ int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
 #else /* !CONFIG_X86_32 */
                put_user_ex(regs->flags, &sc->flags);
                put_user_ex(regs->cs, &sc->cs);
-               put_user_ex(0, &sc->gs);
-               put_user_ex(0, &sc->fs);
+               put_user_ex(0, &sc->__pad2);
+               put_user_ex(0, &sc->__pad1);
+               put_user_ex(regs->ss, &sc->ss);
 #endif /* CONFIG_X86_32 */
 
                put_user_ex(fpstate, &sc->fpstate);
@@ -457,9 +450,19 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
 
        regs->sp = (unsigned long)frame;
 
-       /* Set up the CS register to run signal handlers in 64-bit mode,
-          even if the handler happens to be interrupting 32-bit code. */
+       /*
+        * Set up the CS and SS registers to run signal handlers in
+        * 64-bit mode, even if the handler happens to be interrupting
+        * 32-bit or 16-bit code.
+        *
+        * SS is subtle.  In 64-bit mode, we don't need any particular
+        * SS descriptor, but we do need SS to be valid.  It's possible
+        * that the old SS is entirely bogus -- this can happen if the
+        * signal we're trying to deliver is #GP or #SS caused by a bad
+        * SS value.
+        */
        regs->cs = __USER_CS;
+       regs->ss = __USER_DS;
 
        return 0;
 }
@@ -539,7 +542,6 @@ asmlinkage unsigned long sys_sigreturn(void)
 {
        struct pt_regs *regs = current_pt_regs();
        struct sigframe __user *frame;
-       unsigned long ax;
        sigset_t set;
 
        frame = (struct sigframe __user *)(regs->sp - 8);
@@ -553,9 +555,9 @@ asmlinkage unsigned long sys_sigreturn(void)
 
        set_current_blocked(&set);
 
-       if (restore_sigcontext(regs, &frame->sc, &ax))
+       if (restore_sigcontext(regs, &frame->sc))
                goto badframe;
-       return ax;
+       return regs->ax;
 
 badframe:
        signal_fault(regs, frame, "sigreturn");
@@ -568,7 +570,6 @@ asmlinkage long sys_rt_sigreturn(void)
 {
        struct pt_regs *regs = current_pt_regs();
        struct rt_sigframe __user *frame;
-       unsigned long ax;
        sigset_t set;
 
        frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
@@ -579,13 +580,13 @@ asmlinkage long sys_rt_sigreturn(void)
 
        set_current_blocked(&set);
 
-       if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
+       if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
                goto badframe;
 
        if (restore_altstack(&frame->uc.uc_stack))
                goto badframe;
 
-       return ax;
+       return regs->ax;
 
 badframe:
        signal_fault(regs, frame, "rt_sigreturn");
@@ -665,7 +666,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
                 * Ensure the signal handler starts with the new fpu state.
                 */
                if (used_math())
-                       drop_init_fpu(current);
+                       fpu_reset_state(current);
        }
        signal_setup_done(failed, ksig, test_thread_flag(TIF_SINGLESTEP));
 }
@@ -766,7 +767,6 @@ asmlinkage long sys32_x32_rt_sigreturn(void)
        struct pt_regs *regs = current_pt_regs();
        struct rt_sigframe_x32 __user *frame;
        sigset_t set;
-       unsigned long ax;
 
        frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
 
@@ -777,13 +777,13 @@ asmlinkage long sys32_x32_rt_sigreturn(void)
 
        set_current_blocked(&set);
 
-       if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
+       if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
                goto badframe;
 
        if (compat_restore_altstack(&frame->uc.uc_stack))
                goto badframe;
 
-       return ax;
+       return regs->ax;
 
 badframe:
        signal_fault(regs, frame, "x32 rt_sigreturn");