Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4d8a391e authored by Kalesh Singh's avatar Kalesh Singh Committed by Greg Kroah-Hartman
Browse files

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@intel.com/

Link: https://lkml.kernel.org/r/20211014045217.3265162-1-kaleshsingh@google.com



Signed-off-by: default avatarKalesh Singh <kaleshsingh@google.com>
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 01549775

kernel/trace/tracing_map.c

+23 −17
Original line number Diff line number Diff line
@@ -834,29 +834,35 @@ 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;
@@ -873,18 +879,21 @@ 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;
@@ -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;