hw-breakpoints: Use struct perf_event_attr to define user breakpoints

[deliverable/linux.git] / arch / x86 / kernel / ptrace.c

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 75e0cd847bd6b20bf8d99a9de3edbdbd92c191b6..2941b32ea666f09d584ef34cb06cde995aa7b89f 100644 (file)
--- 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