3 files changed, 83 insertions, 0 deletions

diff --git a/arch/sparc/kernel/helpers.S b/arch/sparc/kernel/helpers.S
index 314dd0c9fc5b..92090cc9e829 100644
--- a/arch/sparc/kernel/helpers.S
+++ b/arch/sparc/kernel/helpers.S
@@ -46,6 +46,81 @@ stack_trace_flush:
          nop
         .size           stack_trace_flush,.-stack_trace_flush
 
+#ifdef CONFIG_PERF_EVENTS
+        .globl          perf_arch_fetch_caller_regs
+        .type           perf_arch_fetch_caller_regs,#function
+perf_arch_fetch_caller_regs:
+        /* We always read the %pstate into %o5 since we will use
+         * that to construct a fake %tstate to store into the regs.
+         */
+        rdpr            %pstate, %o5
+        brz,pn          %o2, 50f
+         mov            %o2, %g7
+
+        /* Turn off interrupts while we walk around the register
+         * window by hand.
+         */
+        wrpr            %o5, PSTATE_IE, %pstate
+
+        /* The %canrestore tells us how many register windows are
+         * still live in the chip above us, past that we have to
+         * walk the frame as saved on the stack.   We stash away
+         * the %cwp in %g1 so we can return back to the original
+         * register window.
+         */
+        rdpr            %cwp, %g1
+        rdpr            %canrestore, %g2
+        sub             %g1, 1, %g3
+
+        /* We have the skip count in %g7, if it hits zero then
+         * %fp/%i7 are the registers we need.  Otherwise if our
+         * %canrestore count maintained in %g2 hits zero we have
+         * to start traversing the stack.
+         */
+10:     brz,pn          %g2, 4f
+         sub            %g2, 1, %g2
+        wrpr            %g3, %cwp
+        subcc           %g7, 1, %g7
+        bne,pt          %xcc, 10b
+         sub            %g3, 1, %g3
+
+        /* We found the values we need in the cpu's register
+         * windows.
+         */
+        mov             %fp, %g3
+        ba,pt           %xcc, 3f
+         mov            %i7, %g2
+
+50:     mov             %fp, %g3
+        ba,pt           %xcc, 2f
+         mov            %i7, %g2
+
+        /* We hit the end of the valid register windows in the
+         * cpu, start traversing the stack frame.
+         */
+4:      mov             %fp, %g3
+
+20:     ldx             [%g3 + STACK_BIAS + RW_V9_I7], %g2
+        subcc           %g7, 1, %g7
+        bne,pn          %xcc, 20b
+         ldx            [%g3 + STACK_BIAS + RW_V9_I6], %g3
+
+        /* Restore the current register window position and
+         * re-enable interrupts.
+         */
+3:      wrpr            %g1, %cwp
+        wrpr            %o5, %pstate
+
+2:      stx             %g3, [%o0 + PT_V9_FP]
+        sllx            %o5, 8, %o5
+        stx             %o5, [%o0 + PT_V9_TSTATE]
+        stx             %g2, [%o0 + PT_V9_TPC]
+        add             %g2, 4, %g2
+        retl
+         stx            %g2, [%o0 + PT_V9_TNPC]
+        .size           perf_arch_fetch_caller_regs,.-perf_arch_fetch_caller_regs
+#endif /* CONFIG_PERF_EVENTS */
+
 #ifdef CONFIG_SMP
         .globl          hard_smp_processor_id
         .type           hard_smp_processor_id,#function
diff --git a/arch/sparc/kernel/ptrace_32.c b/arch/sparc/kernel/ptrace_32.c
index 7e3dfd9bb97e..e608f397e11f 100644
--- a/arch/sparc/kernel/ptrace_32.c
+++ b/arch/sparc/kernel/ptrace_32.c
@@ -65,6 +65,7 @@ static int genregs32_get(struct task_struct *target,
                         *k++ = regs->u_regs[pos++];
 
                 reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 for (; count > 0 && pos < 32; count--) {
                         if (get_user(*k++, &reg_window[pos++]))
                                 return -EFAULT;
@@ -76,6 +77,7 @@ static int genregs32_get(struct task_struct *target,
                 }
 
                 reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 for (; count > 0 && pos < 32; count--) {
                         if (get_user(reg, &reg_window[pos++]) ||
                             put_user(reg, u++))
@@ -141,6 +143,7 @@ static int genregs32_set(struct task_struct *target,
                         regs->u_regs[pos++] = *k++;
 
                 reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 for (; count > 0 && pos < 32; count--) {
                         if (put_user(*k++, &reg_window[pos++]))
                                 return -EFAULT;
@@ -153,6 +156,7 @@ static int genregs32_set(struct task_struct *target,
                 }
 
                 reg_window = (unsigned long __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 for (; count > 0 && pos < 32; count--) {
                         if (get_user(reg, u++) ||
                             put_user(reg, &reg_window[pos++]))
diff --git a/arch/sparc/kernel/ptrace_64.c b/arch/sparc/kernel/ptrace_64.c
index 2f6524d1a817..aa90da08bf61 100644
--- a/arch/sparc/kernel/ptrace_64.c
+++ b/arch/sparc/kernel/ptrace_64.c
@@ -492,6 +492,7 @@ static int genregs32_get(struct task_struct *target,
                         *k++ = regs->u_regs[pos++];
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 if (target == current) {
                         for (; count > 0 && pos < 32; count--) {
                                 if (get_user(*k++, &reg_window[pos++]))
@@ -516,6 +517,7 @@ static int genregs32_get(struct task_struct *target,
                 }
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 if (target == current) {
                         for (; count > 0 && pos < 32; count--) {
                                 if (get_user(reg, &reg_window[pos++]) ||
@@ -599,6 +601,7 @@ static int genregs32_set(struct task_struct *target,
                         regs->u_regs[pos++] = *k++;
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 if (target == current) {
                         for (; count > 0 && pos < 32; count--) {
                                 if (put_user(*k++, &reg_window[pos++]))
@@ -625,6 +628,7 @@ static int genregs32_set(struct task_struct *target,
                 }
 
                 reg_window = (compat_ulong_t __user *) regs->u_regs[UREG_I6];
+                reg_window -= 16;
                 if (target == current) {
                         for (; count > 0 && pos < 32; count--) {
                                 if (get_user(reg, u++) ||