From: Hou Tao <houtao1@huawei.com>
Date: Wed, 18 Jan 2023 08:46:30 +0000 (+0800)
Subject: bpf: Fix off-by-one error in bpf_mem_cache_idx()
X-Git-Tag: v6.6.17~5654^2~35^2~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=36024d023d139a0c8b552dc3b7f4dc7b4c139e8f;p=platform%2Fkernel%2Flinux-rpi.git

bpf: Fix off-by-one error in bpf_mem_cache_idx()

According to the definition of sizes[NUM_CACHES], when the size passed
to bpf_mem_cache_size() is 256, it should return 6 instead 7.

Fixes: 7c8199e24fa0 ("bpf: Introduce any context BPF specific memory allocator.")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230118084630.3750680-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---

diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index ebcc3dd..1db1564 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -71,7 +71,7 @@ static int bpf_mem_cache_idx(size_t size)
 	if (size <= 192)
 		return size_index[(size - 1) / 8] - 1;
 
-	return fls(size - 1) - 1;
+	return fls(size - 1) - 2;
 }
 
 #define NUM_CACHES 11