From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24D953AC0F3; Sat, 17 Oct 2026 16:39:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255154; cv=none; b=YYAfKmSLbLkIdllO5vXaUEetVh73B9M6cm6sX0tol0ABk/QeUqZvUu1ackFfpu5UhUrp0xS8WT7JTIMRFRJjUOwDVyuHI7/CijWoblJSx9Dr264xGkcoboPSVFb4e17WG7Va6+Y1ukS1rsi9P3j91lrT68pXOkLXzo9OS2F0w88= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255154; c=relaxed/simple; bh=xu+swF2kLEe09kqDcf/HejtARdP6JN7BpXv1P7JzUY0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Em2cjQVFrGCPjqPnAvczjFjmKMUvS4iGCTqBe5M67l/XYBeB/udJMFCCpdMyAMnOOjw5YlYy3qm12H1P5RWDeKe57qYomo9UWODB79uw32Qv0Hs/KbQ/USjuXrAzciQhPkXXfBMn5putXw0QuoedV/8ut0CAuPI3ltcEFZ01L8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LadfUH5V; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LadfUH5V" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 398121F000C4; Sat, 17 Oct 2026 16:39:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792255152; bh=ktynenPazvLSslV/su1/OpibAVXjLWDqHrCeOZ5SgO8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LadfUH5VsoVEAJuF+6zMX2Euj7EuJBFdr+DXGWWjigx82QlfQ6oGIKUVorrMJXvop gLDyukF44tSm7PasjyA1hMyztCB0bFGi+0BJwcpTEdbO8p0C84XX4RNbSqrnYBVHg4 R0W5w5oid4Pm18Q48h1JgNd8YxyfwShjCPgmVU3c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiri Olsa , Andrii Nakryiko , Sasha Levin Subject: [PATCH 6.12 655/869] bpf: Remove trace_in argument from __bpf_get_stack Date: Sat, 17 Oct 2026 17:58:16 +0200 Message-ID: <20261017160053.794952987@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160036.979869304@linuxfoundation.org> References: <20261017160036.979869304@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa [ Upstream commit 58cfc2201d964163fe9c4a703136eb64db799f08 ] Now with the new callchain_* helper functions we can process trace_in case directly in bpf_get_stack_pe function and remove it from __bpf_get_stack which makes things easier for preemption fix in following change. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20260803210149.296496-9-jolsa@kernel.org Stable-dep-of: f5d242825ca4 ("bpf: Clear buf on error in __bpf_get_task_stack") Signed-off-by: Sasha Levin --- kernel/bpf/stackmap.c | 49 ++++++++++++++++++++++++++++++------------- 1 file changed, 35 insertions(+), 14 deletions(-) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index 7818b124d9d6e..49f724e63e38a 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -527,7 +527,6 @@ static long callchain_finalize(void *buf, u32 size, u32 trace_nr, u32 elem_size, } static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, - struct perf_callchain_entry *trace_in, void *buf, u32 size, u64 flags, bool may_fault) { bool user_build_id = flags & BPF_F_USER_BUILD_ID; @@ -567,10 +566,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, if (may_fault) rcu_read_lock(); /* need RCU for perf's callchain below */ - if (trace_in) { - trace = trace_in; - trace->nr = min_t(u32, trace->nr, max_depth); - } else if (kernel && task) { + if (kernel && task) { trace = get_callchain_entry_for_task(task, max_depth); } else { trace = get_perf_callchain(regs, kernel, user, max_depth, @@ -603,7 +599,7 @@ static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size, u64, flags) { - return __bpf_get_stack(regs, NULL, NULL, buf, size, flags, false /* !may_fault */); + return __bpf_get_stack(regs, NULL, buf, size, flags, false /* !may_fault */); } const struct bpf_func_proto bpf_get_stack_proto = { @@ -619,7 +615,7 @@ const struct bpf_func_proto bpf_get_stack_proto = { BPF_CALL_4(bpf_get_stack_sleepable, struct pt_regs *, regs, void *, buf, u32, size, u64, flags) { - return __bpf_get_stack(regs, NULL, NULL, buf, size, flags, true /* may_fault */); + return __bpf_get_stack(regs, NULL, buf, size, flags, true /* may_fault */); } const struct bpf_func_proto bpf_get_stack_sleepable_proto = { @@ -644,7 +640,7 @@ static long __bpf_get_task_stack(struct task_struct *task, void *buf, u32 size, regs = task_pt_regs(task); if (regs) - res = __bpf_get_stack(regs, task, NULL, buf, size, flags, may_fault); + res = __bpf_get_stack(regs, task, buf, size, flags, may_fault); put_task_stack(task); return res; @@ -685,6 +681,32 @@ const struct bpf_func_proto bpf_get_task_stack_sleepable_proto = { .arg4_type = ARG_ANYTHING, }; +static int __bpf_get_stack_pe(struct perf_callchain_entry *trace, void *buf, u32 size, + u64 flags) +{ + bool user_build_id = flags & BPF_F_USER_BUILD_ID; + u64 skip = flags & BPF_F_SKIP_FIELD_MASK; + bool user = flags & BPF_F_USER_STACK; + u32 elem_size, max_depth, nr_trace; + bool kernel = !user; + + if (kernel && user_build_id) + return -EINVAL; + + elem_size = user_build_id ? sizeof(struct bpf_stack_build_id) : sizeof(u64); + if (unlikely(size % elem_size)) + return -EINVAL; + + max_depth = stack_map_calculate_max_depth(size, elem_size, flags); + trace->nr = min_t(u32, trace->nr, max_depth); + + if (trace->nr < skip) + return -EFAULT; + + nr_trace = callchain_store(trace, buf, elem_size, flags); + return callchain_finalize(buf, size, nr_trace, elem_size, flags, false /* !may_fault */); +} + BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx, void *, buf, u32, size, u64, flags) { @@ -696,7 +718,7 @@ BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx, __u64 nr_kernel; if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) - return __bpf_get_stack(regs, NULL, NULL, buf, size, flags, false /* !may_fault */); + return __bpf_get_stack(regs, NULL, buf, size, flags, false /* !may_fault */); if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | BPF_F_USER_BUILD_ID))) @@ -716,7 +738,7 @@ BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx, __u64 nr = trace->nr; trace->nr = nr_kernel; - err = __bpf_get_stack(regs, NULL, trace, buf, size, flags, false /* !may_fault */); + err = __bpf_get_stack_pe(trace, buf, size, flags); /* restore nr */ trace->nr = nr; @@ -726,14 +748,13 @@ BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx, skip += nr_kernel; if (skip > BPF_F_SKIP_FIELD_MASK) goto clear; - flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; - err = __bpf_get_stack(regs, NULL, trace, buf, size, flags, false /* !may_fault */); + err = __bpf_get_stack_pe(trace, buf, size, flags); } - return err; clear: - memset(buf, 0, size); + if (err < 0) + memset(buf, 0, size); return err; } -- 2.53.0