powerpc/booke64: Fix kernel hangs at kernel_dbg_exc

[linux-2.6-microblaze.git] / arch / powerpc / kernel / process.c

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 16e77a8..a902723 100644 (file)
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -339,6 +339,13 @@ static void set_debug_reg_defaults(struct thread_struct *thread)
 
 static void prime_debug_regs(struct thread_struct *thread)
 {
+       /*
+        * We could have inherited MSR_DE from userspace, since
+        * it doesn't get cleared on exception entry.  Make sure
+        * MSR_DE is clear before we enable any debug events.
+        */
+       mtmsr(mfmsr() & ~MSR_DE);
+
        mtspr(SPRN_IAC1, thread->iac1);
        mtspr(SPRN_IAC2, thread->iac2);
 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
@@ -831,6 +838,8 @@ void show_regs(struct pt_regs * regs)
 {
        int i, trap;
 
+       show_regs_print_info(KERN_DEFAULT);
+
        printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
               regs->nip, regs->link, regs->ctr);
        printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
@@ -850,12 +859,6 @@ void show_regs(struct pt_regs * regs)
 #else
                printk("DAR: "REG", DSISR: %08lx\n", regs->dar, regs->dsisr);
 #endif
-       printk("TASK = %p[%d] '%s' THREAD: %p",
-              current, task_pid_nr(current), current->comm, task_thread_info(current));
-
-#ifdef CONFIG_SMP
-       printk(" CPU: %d", raw_smp_processor_id());
-#endif /* CONFIG_SMP */
 
        for (i = 0;  i < 32;  i++) {
                if ((i % REGS_PER_LINE) == 0)
@@ -912,10 +915,6 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
        flush_altivec_to_thread(src);
        flush_vsx_to_thread(src);
        flush_spe_to_thread(src);
-#ifdef CONFIG_HAVE_HW_BREAKPOINT
-       flush_ptrace_hw_breakpoint(src);
-#endif /* CONFIG_HAVE_HW_BREAKPOINT */
-
        *dst = *src;
        return 0;
 }
@@ -979,6 +978,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
         * do some house keeping and then return from the fork or clone
         * system call, using the stack frame created above.
         */
+       ((unsigned long *)sp)[0] = 0;
        sp -= sizeof(struct pt_regs);
        kregs = (struct pt_regs *) sp;
        sp -= STACK_FRAME_OVERHEAD;
@@ -986,6 +986,10 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
        p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
                                _ALIGN_UP(sizeof(struct thread_info), 16);
 
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+       p->thread.ptrace_bps[0] = NULL;
+#endif
+
 #ifdef CONFIG_PPC_STD_MMU_64
        if (mmu_has_feature(MMU_FTR_SLB)) {
                unsigned long sp_vsid;
@@ -1362,12 +1366,6 @@ void show_stack(struct task_struct *tsk, unsigned long *stack)
        } while (count++ < kstack_depth_to_print);
 }
 
-void dump_stack(void)
-{
-       show_stack(current, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
 #ifdef CONFIG_PPC64
 /* Called with hard IRQs off */
 void __ppc64_runlatch_on(void)