6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Josh Poimboeuf jpoimboe@kernel.org
[ Upstream commit e649bcda25b5ae1a30a182cc450f928a0b282c93 ]
The 'init_nr' argument has double duty: it's used to initialize both the number of contexts and the number of stack entries. That's confusing and the callers always pass zero anyway. Hard code the zero.
Signed-off-by: Josh Poimboeuf jpoimboe@kernel.org Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Namhyung Kim Namhyung@kernel.org Acked-by: Alexei Starovoitov ast@kernel.org Link: https://lore.kernel.org/r/20250820180428.259565081@kernel.org Stable-dep-of: 23f852daa4ba ("bpf: Fix stackmap overflow check in __bpf_get_stackid()") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/perf_event.h | 2 +- kernel/bpf/stackmap.c | 4 ++-- kernel/events/callchain.c | 12 ++++++------ kernel/events/core.c | 2 +- 4 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index ce64b4b937f06..c2bd4bc45a27b 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1602,7 +1602,7 @@ DECLARE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry); extern void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs); extern void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs); extern struct perf_callchain_entry * -get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, +get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, u32 max_stack, bool crosstask, bool add_mark); extern int get_callchain_buffers(int max_stack); extern void put_callchain_buffers(void); diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 3615c06b7dfa9..ec3a57a5fba1f 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -314,7 +314,7 @@ BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, if (max_depth > sysctl_perf_event_max_stack) max_depth = sysctl_perf_event_max_stack;
- trace = get_perf_callchain(regs, 0, kernel, user, max_depth, + trace = get_perf_callchain(regs, kernel, user, max_depth, false, false);
if (unlikely(!trace)) @@ -451,7 +451,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, else if (kernel && task) trace = get_callchain_entry_for_task(task, max_depth); else - trace = get_perf_callchain(regs, 0, kernel, user, max_depth, + trace = get_perf_callchain(regs, kernel, user, max_depth, crosstask, false);
if (unlikely(!trace) || trace->nr < skip) { diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c index 49d87e6db553f..677901f456a94 100644 --- a/kernel/events/callchain.c +++ b/kernel/events/callchain.c @@ -216,7 +216,7 @@ static void fixup_uretprobe_trampoline_entries(struct perf_callchain_entry *entr }
struct perf_callchain_entry * -get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, +get_perf_callchain(struct pt_regs *regs, bool kernel, bool user, u32 max_stack, bool crosstask, bool add_mark) { struct perf_callchain_entry *entry; @@ -231,11 +231,11 @@ get_perf_callchain(struct pt_regs *regs, u32 init_nr, bool kernel, bool user, if (!entry) return NULL;
- ctx.entry = entry; - ctx.max_stack = max_stack; - ctx.nr = entry->nr = init_nr; - ctx.contexts = 0; - ctx.contexts_maxed = false; + ctx.entry = entry; + ctx.max_stack = max_stack; + ctx.nr = entry->nr = 0; + ctx.contexts = 0; + ctx.contexts_maxed = false;
if (kernel && !user_mode(regs)) { if (add_mark) diff --git a/kernel/events/core.c b/kernel/events/core.c index d6a86d8e9e59b..6bc8b84f12156 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7860,7 +7860,7 @@ perf_callchain(struct perf_event *event, struct pt_regs *regs) if (!kernel && !user) return &__empty_callchain;
- callchain = get_perf_callchain(regs, 0, kernel, user, + callchain = get_perf_callchain(regs, kernel, user, max_stack, crosstask, true); return callchain ?: &__empty_callchain; }