This is a note to let you know that I've just added the patch titled
tracing/cfi: Fix cmp_entries_* functions signature mismatch
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-cfi-fix-cmp_entries_-functions-signature-mis.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fcbb9939926e38f788cdf767d1e214816fc2ee76
Author: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Date: Wed Oct 13 21:52:17 2021 -0700
tracing/cfi: Fix cmp_entries_* functions signature mismatch
[ Upstream commit 7ce1bb83a14019f8c396d57ec704d19478747716 ]
If CONFIG_CFI_CLANG=y, attempting to read an event histogram will cause
the kernel to panic due to failed CFI check.
1. echo 'hist:keys=common_pid' >> events/sched/sched_switch/trigger
2. cat events/sched/sched_switch/hist
3. kernel panics on attempting to read hist
This happens because the sort() function expects a generic
int (*)(const void *, const void *) pointer for the compare function.
To prevent this CFI failure, change tracing map cmp_entries_* function
signatures to match this.
Also, fix the build error reported by the kernel test robot [1].
[1] https://lore.kernel.org/r/202110141140.zzi4dRh4-lkp@xxxxxxxxx/
Link: https://lkml.kernel.org/r/20211014045217.3265162-1-kaleshsingh@xxxxxxxxxx
Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 35b2ba07f3c6f..379db35838b64 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -703,29 +703,35 @@ int tracing_map_init(struct tracing_map *map)
return err;
}
-static int cmp_entries_dup(const struct tracing_map_sort_entry **a,
- const struct tracing_map_sort_entry **b)
+static int cmp_entries_dup(const void *A, const void *B)
{
+ const struct tracing_map_sort_entry *a, *b;
int ret = 0;
- if (memcmp((*a)->key, (*b)->key, (*a)->elt->map->key_size))
+ a = *(const struct tracing_map_sort_entry **)A;
+ b = *(const struct tracing_map_sort_entry **)B;
+
+ if (memcmp(a->key, b->key, a->elt->map->key_size))
ret = 1;
return ret;
}
-static int cmp_entries_sum(const struct tracing_map_sort_entry **a,
- const struct tracing_map_sort_entry **b)
+static int cmp_entries_sum(const void *A, const void *B)
{
const struct tracing_map_elt *elt_a, *elt_b;
+ const struct tracing_map_sort_entry *a, *b;
struct tracing_map_sort_key *sort_key;
struct tracing_map_field *field;
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
- elt_a = (*a)->elt;
- elt_b = (*b)->elt;
+ a = *(const struct tracing_map_sort_entry **)A;
+ b = *(const struct tracing_map_sort_entry **)B;
+
+ elt_a = a->elt;
+ elt_b = b->elt;
sort_key = &elt_a->map->sort_key;
@@ -742,18 +748,21 @@ static int cmp_entries_sum(const struct tracing_map_sort_entry **a,
return ret;
}
-static int cmp_entries_key(const struct tracing_map_sort_entry **a,
- const struct tracing_map_sort_entry **b)
+static int cmp_entries_key(const void *A, const void *B)
{
const struct tracing_map_elt *elt_a, *elt_b;
+ const struct tracing_map_sort_entry *a, *b;
struct tracing_map_sort_key *sort_key;
struct tracing_map_field *field;
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
- elt_a = (*a)->elt;
- elt_b = (*b)->elt;
+ a = *(const struct tracing_map_sort_entry **)A;
+ b = *(const struct tracing_map_sort_entry **)B;
+
+ elt_a = a->elt;
+ elt_b = b->elt;
sort_key = &elt_a->map->sort_key;
@@ -926,10 +935,8 @@ static void sort_secondary(struct tracing_map *map,
struct tracing_map_sort_key *primary_key,
struct tracing_map_sort_key *secondary_key)
{
- int (*primary_fn)(const struct tracing_map_sort_entry **,
- const struct tracing_map_sort_entry **);
- int (*secondary_fn)(const struct tracing_map_sort_entry **,
- const struct tracing_map_sort_entry **);
+ int (*primary_fn)(const void *, const void *);
+ int (*secondary_fn)(const void *, const void *);
unsigned i, start = 0, n_sub = 1;
if (is_key(map, primary_key->field_idx))
@@ -998,8 +1005,7 @@ int tracing_map_sort_entries(struct tracing_map *map,
unsigned int n_sort_keys,
struct tracing_map_sort_entry ***sort_entries)
{
- int (*cmp_entries_fn)(const struct tracing_map_sort_entry **,
- const struct tracing_map_sort_entry **);
+ int (*cmp_entries_fn)(const void *, const void *);
struct tracing_map_sort_entry *sort_entry, **entries;
int i, n_entries, ret;
