linux-stable/include/linux/bpf_mem_alloc.h
Hou Tao 63ddf081e1 bpf: Use pcpu_alloc_size() in bpf_mem_free{_rcu}()
[ Upstream commit 3f2189e4f7 ]

For bpf_global_percpu_ma, the pointer passed to bpf_mem_free_rcu() is
allocated by kmalloc() and its size is fixed (16-bytes on x86-64). So
no matter which cache allocates the dynamic per-cpu area, on x86-64
cache[2] will always be used to free the per-cpu area.

Fix the unbalance by checking whether the bpf memory allocator is
per-cpu or not and use pcpu_alloc_size() instead of ksize() to
find the correct cache for per-cpu free.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231020133202.4043247-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 7ac5c53e00 ("bpf: Use c->unit_size to select target cache during free")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:35:28 -08:00

40 lines
1.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#ifndef _BPF_MEM_ALLOC_H
#define _BPF_MEM_ALLOC_H
#include <linux/compiler_types.h>
#include <linux/workqueue.h>
struct bpf_mem_cache;
struct bpf_mem_caches;
struct bpf_mem_alloc {
struct bpf_mem_caches __percpu *caches;
struct bpf_mem_cache __percpu *cache;
bool percpu;
struct work_struct work;
};
/* 'size != 0' is for bpf_mem_alloc which manages fixed-size objects.
* Alloc and free are done with bpf_mem_cache_{alloc,free}().
*
* 'size = 0' is for bpf_mem_alloc which manages many fixed-size objects.
* Alloc and free are done with bpf_mem_{alloc,free}() and the size of
* the returned object is given by the size argument of bpf_mem_alloc().
*/
int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu);
void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma);
/* kmalloc/kfree equivalent: */
void *bpf_mem_alloc(struct bpf_mem_alloc *ma, size_t size);
void bpf_mem_free(struct bpf_mem_alloc *ma, void *ptr);
void bpf_mem_free_rcu(struct bpf_mem_alloc *ma, void *ptr);
/* kmem_cache_alloc/free equivalent: */
void *bpf_mem_cache_alloc(struct bpf_mem_alloc *ma);
void bpf_mem_cache_free(struct bpf_mem_alloc *ma, void *ptr);
void bpf_mem_cache_free_rcu(struct bpf_mem_alloc *ma, void *ptr);
void bpf_mem_cache_raw_free(void *ptr);
void *bpf_mem_cache_alloc_flags(struct bpf_mem_alloc *ma, gfp_t flags);
#endif /* _BPF_MEM_ALLOC_H */