bpf: Charge modmem for struct_ops trampoline

Current code charges modmem for regular trampoline, but not for struct_ops
trampoline. Add bpf_jit_[charge|uncharge]_modmem() to struct_ops so the
trampoline is charged in both cases.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230914222542.2986059-1-song@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index fdc3e8705a3cb838e82409f0c025b1e39ea4dfec..db6176fb64dc3f4b7cc3a84f935c2b28095ba77e 100644 (file)
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -615,7 +615,10 @@ static void __bpf_struct_ops_map_free(struct bpf_map *map)
        if (st_map->links)
                bpf_struct_ops_map_put_progs(st_map);
        bpf_map_area_free(st_map->links);
-       bpf_jit_free_exec(st_map->image);
+       if (st_map->image) {
+               bpf_jit_free_exec(st_map->image);
+               bpf_jit_uncharge_modmem(PAGE_SIZE);
+       }
        bpf_map_area_free(st_map->uvalue);
        bpf_map_area_free(st_map);
 }
@@ -657,6 +660,7 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
        struct bpf_struct_ops_map *st_map;
        const struct btf_type *t, *vt;
        struct bpf_map *map;
+       int ret;
 
        st_ops = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id);
        if (!st_ops)
@@ -681,12 +685,27 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
        st_map->st_ops = st_ops;
        map = &st_map->map;
 
+       ret = bpf_jit_charge_modmem(PAGE_SIZE);
+       if (ret) {
+               __bpf_struct_ops_map_free(map);
+               return ERR_PTR(ret);
+       }
+
+       st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
+       if (!st_map->image) {
+               /* __bpf_struct_ops_map_free() uses st_map->image as flag
+                * for "charged or not". In this case, we need to unchange
+                * here.
+                */
+               bpf_jit_uncharge_modmem(PAGE_SIZE);
+               __bpf_struct_ops_map_free(map);
+               return ERR_PTR(-ENOMEM);
+       }
        st_map->uvalue = bpf_map_area_alloc(vt->size, NUMA_NO_NODE);
        st_map->links =
                bpf_map_area_alloc(btf_type_vlen(t) * sizeof(struct bpf_links *),
                                   NUMA_NO_NODE);
-       st_map->image = bpf_jit_alloc_exec(PAGE_SIZE);
-       if (!st_map->uvalue || !st_map->links || !st_map->image) {
+       if (!st_map->uvalue || !st_map->links) {
                __bpf_struct_ops_map_free(map);
                return ERR_PTR(-ENOMEM);
        }
@@ -907,4 +926,3 @@ err_out:
        kfree(link);
        return err;
 }
-