This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / arch / i386 / kernel / signal.c

diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
index a9b33b1..ab606b5 100644 (file)
--- a/arch/i386/kernel/signal.c
+++ b/arch/i386/kernel/signal.c
@@ -190,6 +190,12 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax
                        if (verify_area(VERIFY_READ, buf, sizeof(*buf)))
                                goto badframe;
                        err |= restore_i387(buf);
+               } else {
+                       struct task_struct *me = current;
+                       if (me->used_math) {
+                               clear_fpu(me);
+                               me->used_math = 0;
+                       }
                }
        }
 
@@ -292,10 +298,15 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
        err |= __put_user(current->thread.error_code, &sc->err);
        err |= __put_user(regs->eip, &sc->eip);
        err |= __put_user(regs->xcs, (unsigned int __user *)&sc->cs);
+
+       /*
+        * Iff TF was set because the program is being single-stepped by a
+        * debugger, don't save that information on the signal stack.. We
+        * don't want debugging to change state.
+        */
        eflags = regs->eflags;
-       if (current->ptrace & PT_PTRACED) {
+       if (current->ptrace & PT_DTRACE)
                eflags &= ~TF_MASK;
-       }
        err |= __put_user(eflags, &sc->eflags);
        err |= __put_user(regs->esp, &sc->esp_at_signal);
        err |= __put_user(regs->xss, (unsigned int __user *)&sc->ss);
@@ -379,7 +390,7 @@ static void setup_frame(int sig, struct k_sigaction *ka,
        if (err)
                goto give_sigsegv;
 
-       restorer = &__kernel_sigreturn;
+       restorer = current->mm->context.vdso + (long)&__kernel_sigreturn;
        if (ka->sa.sa_flags & SA_RESTORER)
                restorer = ka->sa.sa_restorer;
 
@@ -412,12 +423,17 @@ static void setup_frame(int sig, struct k_sigaction *ka,
        regs->xes = __USER_DS;
        regs->xss = __USER_DS;
        regs->xcs = __USER_CS;
+
+       /*
+        * Clear TF when entering the signal handler, but
+        * notify any tracer that was single-stepping it.
+        * The tracer may want to single-step inside the
+        * handler too.
+        */
        if (regs->eflags & TF_MASK) {
-               if (current->ptrace & PT_PTRACED) {
+               regs->eflags &= ~TF_MASK;
+               if (current->ptrace & PT_DTRACE)
                        ptrace_notify(SIGTRAP);
-               } else {
-                       regs->eflags &= ~TF_MASK;
-               }
        }
 
 #if DEBUG_SIG
@@ -471,9 +487,10 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                goto give_sigsegv;
 
        /* Set up to return from userspace.  */
-       restorer = &__kernel_rt_sigreturn;
+       restorer = current->mm->context.vdso + (long)&__kernel_rt_sigreturn;
        if (ka->sa.sa_flags & SA_RESTORER)
                restorer = ka->sa.sa_restorer;
+
        err |= __put_user(restorer, &frame->pretcode);
         
        /*
@@ -502,12 +519,17 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        regs->xes = __USER_DS;
        regs->xss = __USER_DS;
        regs->xcs = __USER_CS;
+
+       /*
+        * Clear TF when entering the signal handler, but
+        * notify any tracer that was single-stepping it.
+        * The tracer may want to single-step inside the
+        * handler too.
+        */
        if (regs->eflags & TF_MASK) {
-               if (current->ptrace & PT_PTRACED) {
+               regs->eflags &= ~TF_MASK;
+               if (current->ptrace & PT_DTRACE)
                        ptrace_notify(SIGTRAP);
-               } else {
-                       regs->eflags &= ~TF_MASK;
-               }
        }
 
 #if DEBUG_SIG
@@ -600,7 +622,9 @@ int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
                 * have been cleared if the watchpoint triggered
                 * inside the kernel.
                 */
-               __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7]));
+               if (unlikely(current->thread.debugreg[7])) {
+                       __asm__("movl %0,%%db7" : : "r" (current->thread.debugreg[7]));
+               }
 
                /* Whee!  Actually deliver the signal.  */
                handle_signal(signr, &info, &ka, oldset, regs);