[PATCH 4/6] hw_breakpoint: Factor out __modify_user_hw_breakpoint function

From: Jiri Olsa
Date: Mon Nov 27 2017 - 11:22:53 EST


Moving out the all the functionality without the events
disabling/enabling calls, because we want to call another
disabling/enabling functions in following change.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
kernel/events/hw_breakpoint.c | 46 +++++++++++++++++++++++++++----------------
1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 776948beb4ac..a556aba223da 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -456,6 +456,33 @@ register_user_hw_breakpoint(struct perf_event_attr *attr,
}
EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);

+static int __modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
+{
+ u64 old_addr = bp->attr.bp_addr;
+ u64 old_len = bp->attr.bp_len;
+ int old_type = bp->attr.bp_type;
+ bool modify = attr->bp_type != old_type;
+ int err = 0;
+
+ bp->attr.bp_addr = attr->bp_addr;
+ bp->attr.bp_type = attr->bp_type;
+ bp->attr.bp_len = attr->bp_len;
+
+ err = validate_hw_breakpoint(bp);
+ if (!err && modify)
+ err = modify_bp_slot(bp, old_type);
+
+ if (err) {
+ bp->attr.bp_addr = old_addr;
+ bp->attr.bp_type = old_type;
+ bp->attr.bp_len = old_len;
+ return err;
+ }
+
+ bp->attr.disabled = attr->disabled;
+ return 0;
+}
+
/**
* modify_user_hw_breakpoint - modify a user-space hardware breakpoint
* @bp: the breakpoint structure to modify
@@ -465,11 +492,7 @@ EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
*/
int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
{
- u64 old_addr = bp->attr.bp_addr;
- u64 old_len = bp->attr.bp_len;
- int old_type = bp->attr.bp_type;
- bool modify = attr->bp_type != old_type;
- int err = 0;
+ int err;

/*
* modify_user_hw_breakpoint can be invoked with IRQs disabled and hence it
@@ -482,18 +505,9 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att
else
perf_event_disable(bp);

- bp->attr.bp_addr = attr->bp_addr;
- bp->attr.bp_type = attr->bp_type;
- bp->attr.bp_len = attr->bp_len;
-
- err = validate_hw_breakpoint(bp);
- if (!err && modify)
- err = modify_bp_slot(bp, old_type);
+ err = __modify_user_hw_breakpoint(bp, attr);

if (err) {
- bp->attr.bp_addr = old_addr;
- bp->attr.bp_type = old_type;
- bp->attr.bp_len = old_len;
if (!bp->attr.disabled)
perf_event_enable(bp);

@@ -502,8 +516,6 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att

if (!attr->disabled)
perf_event_enable(bp);
-
- bp->attr.disabled = attr->disabled;
return 0;
}
EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint);
--
2.13.6