Messages in this thread Patch in this message | | | From | Yuntao Wang <> | Subject | [PATCH] bpf: Fix incorrect memory charge cost calculation in stack_map_alloc() | Date | Tue, 14 Jun 2022 22:26:22 +0800 |
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commit b45043192b3e481304062938a6561da2ceea46a6 upstream.
This is a backport of the original upstream patch for 5.4/5.10.
The original upstream patch has been applied to 5.4/5.10 branches, which simply removed the line:
cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));
This is correct for upstream branch but incorrect for 5.4/5.10 branches, as the 5.4/5.10 branches do not have the commit 370868107bf6 ("bpf: Eliminate rlimit-based memory accounting for stackmap maps"), so the bpf_map_charge_init() function has not been removed.
Currently the bpf_map_charge_init() function in 5.4/5.10 branches takes a wrong memory charge cost, the
attr->max_entries * (sizeof(struct stack_map_bucket) + (u64)value_size))
part is missing, let's fix it.
Cc: <stable@vger.kernel.org> # 5.4.y Cc: <stable@vger.kernel.org> # 5.10.y Signed-off-by: Yuntao Wang <ytcoode@gmail.com> --- Note that the original upstream patch is currently applied to linux-stable-rc/linux-5.4.y branch, not linux/linux-5.4.y, this patch depends on that patch.
kernel/bpf/stackmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index c19e669afba0..0c5bf98d5576 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -121,7 +121,8 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr) return ERR_PTR(-E2BIG); cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap); - err = bpf_map_charge_init(&mem, cost); + err = bpf_map_charge_init(&mem, cost + attr->max_entries * + (sizeof(struct stack_map_bucket) + (u64)value_size)); if (err) return ERR_PTR(err); -- 2.36.0
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