5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Peter Zijlstra peterz@infradead.org
[ Upstream commit 7ed9138a72829d2035ecbd8dbd35b1bc3c137c40 ]
Ravi reported that the bpf_perf_link_attach() usage of perf_event_set_bpf_prog() is not serialized by ctx->mutex, unlike the PERF_EVENT_IOC_SET_BPF case.
Reported-by: Ravi Bangoria ravi.bangoria@amd.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Ravi Bangoria ravi.bangoria@amd.com Link: https://lkml.kernel.org/r/20250307193305.486326750@infradead.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/events/core.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c index cb0c8aa71c98b..dd9ae1cae8e3c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5822,6 +5822,9 @@ static int perf_event_set_output(struct perf_event *event, static int perf_event_set_filter(struct perf_event *event, void __user *arg); static int perf_copy_attr(struct perf_event_attr __user *uattr, struct perf_event_attr *attr); +static int __perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie);
static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned long arg) { @@ -5890,7 +5893,7 @@ static long _perf_ioctl(struct perf_event *event, unsigned int cmd, unsigned lon if (IS_ERR(prog)) return PTR_ERR(prog);
- err = perf_event_set_bpf_prog(event, prog, 0); + err = __perf_event_set_bpf_prog(event, prog, 0); if (err) { bpf_prog_put(prog); return err; @@ -10360,8 +10363,9 @@ static inline bool perf_event_is_tracing(struct perf_event *event) return false; }
-int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, - u64 bpf_cookie) +static int __perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) { bool is_kprobe, is_tracepoint, is_syscall_tp;
@@ -10395,6 +10399,20 @@ int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, return perf_event_attach_bpf_prog(event, prog, bpf_cookie); }
+int perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) +{ + struct perf_event_context *ctx; + int ret; + + ctx = perf_event_ctx_lock(event); + ret = __perf_event_set_bpf_prog(event, prog, bpf_cookie); + perf_event_ctx_unlock(event, ctx); + + return ret; +} + void perf_event_free_bpf_prog(struct perf_event *event) { if (!perf_event_is_tracing(event)) { @@ -10414,7 +10432,15 @@ static void perf_event_free_filter(struct perf_event *event) { }
-int perf_event_set_bpf_prog(struct perf_event *event, struct bpf_prog *prog, +static int __perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, + u64 bpf_cookie) +{ + return -ENOENT; +} + +int perf_event_set_bpf_prog(struct perf_event *event, + struct bpf_prog *prog, u64 bpf_cookie) { return -ENOENT;