1 files changed, 41 insertions, 33 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 75e0cd847bd6..2941b32ea666 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -593,6 +593,34 @@ static unsigned long ptrace_get_dr7(struct perf_event *bp[])
         return dr7;
 }
 
+static struct perf_event *
+ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
+                         struct task_struct *tsk)
+{
+        int err;
+        int gen_len, gen_type;
+        DEFINE_BREAKPOINT_ATTR(attr);
+
+        /*
+         * We shoud have at least an inactive breakpoint at this
+         * slot. It means the user is writing dr7 without having
+         * written the address register first
+         */
+        if (!bp)
+                return ERR_PTR(-EINVAL);
+
+        err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
+        if (err)
+                return ERR_PTR(err);
+
+        attr = bp->attr;
+        attr.bp_len = gen_len;
+        attr.bp_type = gen_type;
+        attr.disabled = 0;
+
+        return modify_user_hw_breakpoint(bp, &attr, bp->callback, tsk);
+}
+
 /*
  * Handle ptrace writes to debug register 7.
  */
@@ -603,7 +631,6 @@ static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
         int i, orig_ret = 0, rc = 0;
         int enabled, second_pass = 0;
         unsigned len, type;
-        int gen_len, gen_type;
         struct perf_event *bp;
 
         data &= ~DR_CONTROL_RESERVED;
@@ -634,33 +661,12 @@ restore:
                         continue;
                 }
 
-                /*
-                 * We shoud have at least an inactive breakpoint at this
-                 * slot. It means the user is writing dr7 without having
-                 * written the address register first
-                 */
-                if (!bp) {
-                        rc = -EINVAL;
-                        break;
-                }
-
-                rc = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
-                if (rc)
-                        break;
-
-                /*
-                 * This is a temporary thing as bp is unregistered/registered
-                 * to simulate modification
-                 */
-                bp = modify_user_hw_breakpoint(bp, bp->attr.bp_addr, gen_len,
-                                               gen_type, bp->callback,
-                                               tsk, true);
-                thread->ptrace_bps[i] = NULL;
+                bp = ptrace_modify_breakpoint(bp, len, type, tsk);
 
                 /* Incorrect bp, or we have a bug in bp API */
                 if (IS_ERR(bp)) {
                         rc = PTR_ERR(bp);
-                        bp = NULL;
+                        thread->ptrace_bps[i] = NULL;
                         break;
                 }
                 thread->ptrace_bps[i] = bp;
@@ -707,24 +713,26 @@ static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
 {
         struct perf_event *bp;
         struct thread_struct *t = &tsk->thread;
+        DEFINE_BREAKPOINT_ATTR(attr);
 
         if (!t->ptrace_bps[nr]) {
                 /*
                  * Put stub len and type to register (reserve) an inactive but
                  * correct bp
                  */
-                bp = register_user_hw_breakpoint(addr, HW_BREAKPOINT_LEN_1,
-                                                 HW_BREAKPOINT_W,
-                                                 ptrace_triggered, tsk,
-                                                 false);
+                attr.bp_addr = addr;
+                attr.bp_len = HW_BREAKPOINT_LEN_1;
+                attr.bp_type = HW_BREAKPOINT_W;
+                attr.disabled = 1;
+
+                bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
         } else {
                 bp = t->ptrace_bps[nr];
                 t->ptrace_bps[nr] = NULL;
-                bp = modify_user_hw_breakpoint(bp, addr, bp->attr.bp_len,
-                                               bp->attr.bp_type,
-                                               bp->callback,
-                                               tsk,
-                                               bp->attr.disabled);
+
+                attr = bp->attr;
+                attr.bp_addr = addr;
+                bp = modify_user_hw_breakpoint(bp, &attr, bp->callback, tsk);
         }
         /*
          * CHECKME: the previous code returned -EIO if the addr wasn't a