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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Eelco Chaudron <echaudro@redhat.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andriin@fb.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.7 247/376] libbpf: Fix perf_buffer__free() API for sparse allocs
Date:   Fri, 19 Jun 2020 16:32:45 +0200
Message-Id: <20200619141722.017192577@linuxfoundation.org>
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From: Eelco Chaudron <echaudro@redhat.com>

[ Upstream commit 601b05ca6edb0422bf6ce313fbfd55ec7bbbc0fd ]

In case the cpu_bufs are sparsely allocated they are not all
free'ed. These changes will fix this.

Fixes: fb84b8224655 ("libbpf: add perf buffer API")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/159056888305.330763.9684536967379110349.stgit@ebuild
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/lib/bpf/libbpf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index cd53204d33f0..0c5b4fb553fb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7809,9 +7809,12 @@ void perf_buffer__free(struct perf_buffer *pb)
 	if (!pb)
 		return;
 	if (pb->cpu_bufs) {
-		for (i = 0; i < pb->cpu_cnt && pb->cpu_bufs[i]; i++) {
+		for (i = 0; i < pb->cpu_cnt; i++) {
 			struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i];
 
+			if (!cpu_buf)
+				continue;
+
 			bpf_map_delete_elem(pb->map_fd, &cpu_buf->map_key);
 			perf_buffer__free_cpu_buf(pb, cpu_buf);
 		}
-- 
2.25.1