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-rw-r--r--arch/x86/kernel/ptrace.c74
1 files changed, 41 insertions, 33 deletions
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 75e0cd847bd..2941b32ea66 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