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From: Kalesh Singh <kaleshsingh@google.com>
To: unlisted-recipients:; (no To-header on input)
Cc: surenb@google.com, hridya@google.com, namhyung@kernel.org,
samitolvanen@google.com, ndesaulniers@google.com,
kernel-team@android.com, Kalesh Singh <kaleshsingh@google.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] tracing/cfi: Fix cmp_entries_* functions signature mismatch
Date: Thu, 23 Sep 2021 17:09:07 +0000 [thread overview]
Message-ID: <20210923170908.2184404-1-kaleshsingh@google.com> (raw)
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 panices 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.
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
kernel/trace/tracing_map.c | 40 ++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 17 deletions(-)
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index d6bddb157ef2..a8c80ebbf9da 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -834,19 +834,21 @@ 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)
{
int ret = 0;
+ const struct tracing_map_sort_entry *a
+ = *(const struct tracing_map_sort_entry **)__a;
+ const struct tracing_map_sort_entry *b
+ = *(const struct tracing_map_sort_entry **)__b;
- if (memcmp((*a)->key, (*b)->key, (*a)->elt->map->key_size))
+ 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;
struct tracing_map_sort_key *sort_key;
@@ -854,9 +856,13 @@ static int cmp_entries_sum(const struct tracing_map_sort_entry **a,
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
+ const struct tracing_map_sort_entry *a
+ = *(const struct tracing_map_sort_entry **)__a;
+ const struct tracing_map_sort_entry *b
+ = *(const struct tracing_map_sort_entry **)__b;
- elt_a = (*a)->elt;
- elt_b = (*b)->elt;
+ elt_a = a->elt;
+ elt_b = b->elt;
sort_key = &elt_a->map->sort_key;
@@ -873,8 +879,7 @@ 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;
struct tracing_map_sort_key *sort_key;
@@ -882,9 +887,13 @@ static int cmp_entries_key(const struct tracing_map_sort_entry **a,
tracing_map_cmp_fn_t cmp_fn;
void *val_a, *val_b;
int ret = 0;
+ const struct tracing_map_sort_entry *a
+ = *(const struct tracing_map_sort_entry **)__a;
+ const struct tracing_map_sort_entry *b
+ = *(const struct tracing_map_sort_entry **)__b;
- elt_a = (*a)->elt;
- elt_b = (*b)->elt;
+ elt_a = a->elt;
+ elt_b = b->elt;
sort_key = &elt_a->map->sort_key;
@@ -989,10 +998,8 @@ 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))
@@ -1061,8 +1068,7 @@ 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;
base-commit: 58e2cf5d794616b84f591d4d1276c8953278ce24
--
2.33.0.685.g46640cef36-goog
next reply other threads:[~2021-09-23 17:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 17:09 Kalesh Singh [this message]
2021-09-24 15:20 ` Sami Tolvanen
2021-09-27 18:15 ` Kalesh Singh
2021-09-27 21:56 ` Steven Rostedt
2021-10-13 22:08 ` Steven Rostedt
2021-10-14 1:39 ` Kalesh Singh
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