1 files changed, 93 insertions, 17 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9be77e3936fb..e4d71ced97ef 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -245,6 +245,24 @@ void discard_lazy_cpu_state(void)
 }
 #endif /* CONFIG_SMP */
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+void do_send_trap(struct pt_regs *regs, unsigned long address,
+                  unsigned long error_code, int signal_code, int breakpt)
+{
+        siginfo_t info;
+
+        if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+                        11, SIGSEGV) == NOTIFY_STOP)
+                return;
+
+        /* Deliver the signal to userspace */
+        info.si_signo = SIGTRAP;
+        info.si_errno = breakpt;        /* breakpoint or watchpoint id */
+        info.si_code = signal_code;
+        info.si_addr = (void __user *)address;
+        force_sig_info(SIGTRAP, &info, current);
+}
+#else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
 void do_dabr(struct pt_regs *regs, unsigned long address,
                     unsigned long error_code)
 {
@@ -257,12 +275,6 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
         if (debugger_dabr_match(regs))
                 return;
 
-        /* Clear the DAC and struct entries.  One shot trigger */
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-        mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W
-                                                        | DBCR0_IDM));
-#endif
-
         /* Clear the DABR */
         set_dabr(0);
 
@@ -273,9 +285,82 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
         info.si_addr = (void __user *)address;
         force_sig_info(SIGTRAP, &info, current);
 }
+#endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
 
 static DEFINE_PER_CPU(unsigned long, current_dabr);
 
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+/*
+ * Set the debug registers back to their default "safe" values.
+ */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+        thread->iac1 = thread->iac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+        thread->iac3 = thread->iac4 = 0;
+#endif
+        thread->dac1 = thread->dac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+        thread->dvc1 = thread->dvc2 = 0;
+#endif
+        thread->dbcr0 = 0;
+#ifdef CONFIG_BOOKE
+        /*
+         * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
+         */
+        thread->dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |   \
+                        DBCR1_IAC3US | DBCR1_IAC4US;
+        /*
+         * Force Data Address Compare User/Supervisor bits to be User-only
+         * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
+         */
+        thread->dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
+#else
+        thread->dbcr1 = 0;
+#endif
+}
+
+static void prime_debug_regs(struct thread_struct *thread)
+{
+        mtspr(SPRN_IAC1, thread->iac1);
+        mtspr(SPRN_IAC2, thread->iac2);
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+        mtspr(SPRN_IAC3, thread->iac3);
+        mtspr(SPRN_IAC4, thread->iac4);
+#endif
+        mtspr(SPRN_DAC1, thread->dac1);
+        mtspr(SPRN_DAC2, thread->dac2);
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+        mtspr(SPRN_DVC1, thread->dvc1);
+        mtspr(SPRN_DVC2, thread->dvc2);
+#endif
+        mtspr(SPRN_DBCR0, thread->dbcr0);
+        mtspr(SPRN_DBCR1, thread->dbcr1);
+#ifdef CONFIG_BOOKE
+        mtspr(SPRN_DBCR2, thread->dbcr2);
+#endif
+}
+/*
+ * Unless neither the old or new thread are making use of the
+ * debug registers, set the debug registers from the values
+ * stored in the new thread.
+ */
+static void switch_booke_debug_regs(struct thread_struct *new_thread)
+{
+        if ((current->thread.dbcr0 & DBCR0_IDM)
+                || (new_thread->dbcr0 & DBCR0_IDM))
+                        prime_debug_regs(new_thread);
+}
+#else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+        if (thread->dabr) {
+                thread->dabr = 0;
+                set_dabr(0);
+        }
+}
+#endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
+
 int set_dabr(unsigned long dabr)
 {
         __get_cpu_var(current_dabr) = dabr;
@@ -372,9 +457,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
-        /* If new thread DAC (HW breakpoint) is the same then leave it */
-        if (new->thread.dabr)
-                set_dabr(new->thread.dabr);
+        switch_booke_debug_regs(&new->thread);
 #else
         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
                 set_dabr(new->thread.dabr);
@@ -556,14 +639,7 @@ void flush_thread(void)
 {
         discard_lazy_cpu_state();
 
-        if (current->thread.dabr) {
-                current->thread.dabr = 0;
-                set_dabr(0);
-
-#ifdef CONFIG_PPC_ADV_DEBUG_REGS
-                current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W);
-#endif
-        }
+        set_debug_reg_defaults(&current->thread);
 }
 
 void