6.6-stable review patch. If anyone has any objections, please let me know.
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From: Lorenzo Bianconi lorenzo@kernel.org
[ Upstream commit 714070c4cb7a10ff57450a618a936775f3036245 ]
In the current implementation if the program is dev-bound to a specific device, it will not be possible to perform XDP_REDIRECT into a DEVMAP or CPUMAP even if the program is running in the driver NAPI context and it is not attached to any map entry. This seems in contrast with the explanation available in bpf_prog_map_compatible routine. Fix the issue introducing __bpf_prog_map_compatible utility routine in order to avoid bpf_prog_is_dev_bound() check running bpf_check_tail_call() at program load time (bpf_prog_select_runtime()). Continue forbidding to attach a dev-bound program to XDP maps (BPF_MAP_TYPE_PROG_ARRAY, BPF_MAP_TYPE_DEVMAP and BPF_MAP_TYPE_CPUMAP).
Fixes: 3d76a4d3d4e59 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Lorenzo Bianconi lorenzo@kernel.org Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Acked-by: Stanislav Fomichev sdf@fomichev.me Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/core.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-)
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 81fd1bb994164..3f140b7527cfc 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2258,8 +2258,8 @@ static unsigned int __bpf_prog_ret0_warn(const void *ctx, } #endif
-bool bpf_prog_map_compatible(struct bpf_map *map, - const struct bpf_prog *fp) +static bool __bpf_prog_map_compatible(struct bpf_map *map, + const struct bpf_prog *fp) { enum bpf_prog_type prog_type = resolve_prog_type(fp); bool ret; @@ -2268,14 +2268,6 @@ bool bpf_prog_map_compatible(struct bpf_map *map, if (fp->kprobe_override) return false;
- /* XDP programs inserted into maps are not guaranteed to run on - * a particular netdev (and can run outside driver context entirely - * in the case of devmap and cpumap). Until device checks - * are implemented, prohibit adding dev-bound programs to program maps. - */ - if (bpf_prog_is_dev_bound(aux)) - return false; - spin_lock(&map->owner.lock); if (!map->owner.type) { /* There's no owner yet where we could check for @@ -2309,6 +2301,19 @@ bool bpf_prog_map_compatible(struct bpf_map *map, return ret; }
+bool bpf_prog_map_compatible(struct bpf_map *map, const struct bpf_prog *fp) +{ + /* XDP programs inserted into maps are not guaranteed to run on + * a particular netdev (and can run outside driver context entirely + * in the case of devmap and cpumap). Until device checks + * are implemented, prohibit adding dev-bound programs to program maps. + */ + if (bpf_prog_is_dev_bound(fp->aux)) + return false; + + return __bpf_prog_map_compatible(map, fp); +} + static int bpf_check_tail_call(const struct bpf_prog *fp) { struct bpf_prog_aux *aux = fp->aux; @@ -2321,7 +2326,7 @@ static int bpf_check_tail_call(const struct bpf_prog *fp) if (!map_type_contains_progs(map)) continue;
- if (!bpf_prog_map_compatible(map, fp)) { + if (!__bpf_prog_map_compatible(map, fp)) { ret = -EINVAL; goto out; }