Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Martin KaFai Lau says:

====================
pull-request: bpf 2023-08-03

We've added 5 non-merge commits during the last 7 day(s) which contain
a total of 3 files changed, 37 insertions(+), 20 deletions(-).

The main changes are:

1) Disable preemption in perf_event_output helpers code,
   from Jiri Olsa

2) Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing,
   from Lin Ma

3) Multiple warning splat fixes in cpumap from Hou Tao

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, cpumap: Handle skb as well when clean up ptr_ring
  bpf, cpumap: Make sure kthread is running before map update returns
  bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing
  bpf: Disable preemption in bpf_event_output
  bpf: Disable preemption in bpf_perf_event_output
====================

Link: https://lore.kernel.org/r/20230803181429.994607-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 12 insertions, 5 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 5f2dcabad202..bd1a42b23f3f 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -661,8 +661,7 @@ static DEFINE_PER_CPU(int, bpf_trace_nest_level);
 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
 	   u64, flags, void *, data, u64, size)
 {
-	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
-	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
+	struct bpf_trace_sample_data *sds;
 	struct perf_raw_record raw = {
 		.frag = {
 			.size = size,
@@ -670,7 +669,11 @@ BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
 		},
 	};
 	struct perf_sample_data *sd;
-	int err;
+	int nest_level, err;
+
+	preempt_disable();
+	sds = this_cpu_ptr(&bpf_trace_sds);
+	nest_level = this_cpu_inc_return(bpf_trace_nest_level);
 
 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
 		err = -EBUSY;
@@ -688,9 +691,9 @@ BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
 	perf_sample_save_raw_data(sd, &raw);
 
 	err = __bpf_perf_event_output(regs, map, flags, sd);
-
 out:
 	this_cpu_dec(bpf_trace_nest_level);
+	preempt_enable();
 	return err;
 }
 
@@ -715,7 +718,6 @@ static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
 u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
 		     void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
 {
-	int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
 	struct perf_raw_frag frag = {
 		.copy		= ctx_copy,
 		.size		= ctx_size,
@@ -732,8 +734,12 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
 	};
 	struct perf_sample_data *sd;
 	struct pt_regs *regs;
+	int nest_level;
 	u64 ret;
 
+	preempt_disable();
+	nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
+
 	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
 		ret = -EBUSY;
 		goto out;
@@ -748,6 +754,7 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
 	ret = __bpf_perf_event_output(regs, map, flags, sd);
 out:
 	this_cpu_dec(bpf_event_output_nest_level);
+	preempt_enable();
 	return ret;
 }