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Diffstat (limited to 'kernel/bpf/cgroup.c')
-rw-r--r--kernel/bpf/cgroup.c205
1 files changed, 171 insertions, 34 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 9122c39870bf..180b630279b9 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -658,6 +658,116 @@ static struct bpf_prog_list *find_attach_entry(struct hlist_head *progs,
return NULL;
}
+static struct bpf_link *bpf_get_anchor_link(u32 flags, u32 id_or_fd)
+{
+ struct bpf_link *link = ERR_PTR(-EINVAL);
+
+ if (flags & BPF_F_ID)
+ link = bpf_link_by_id(id_or_fd);
+ else if (id_or_fd)
+ link = bpf_link_get_from_fd(id_or_fd);
+ return link;
+}
+
+static struct bpf_prog *bpf_get_anchor_prog(u32 flags, u32 id_or_fd)
+{
+ struct bpf_prog *prog = ERR_PTR(-EINVAL);
+
+ if (flags & BPF_F_ID)
+ prog = bpf_prog_by_id(id_or_fd);
+ else if (id_or_fd)
+ prog = bpf_prog_get(id_or_fd);
+ return prog;
+}
+
+static struct bpf_prog_list *get_prog_list(struct hlist_head *progs, struct bpf_prog *prog,
+ struct bpf_cgroup_link *link, u32 flags, u32 id_or_fd)
+{
+ bool is_link = flags & BPF_F_LINK, is_id = flags & BPF_F_ID;
+ struct bpf_prog_list *pltmp, *pl = ERR_PTR(-EINVAL);
+ bool preorder = flags & BPF_F_PREORDER;
+ struct bpf_link *anchor_link = NULL;
+ struct bpf_prog *anchor_prog = NULL;
+ bool is_before, is_after;
+
+ is_before = flags & BPF_F_BEFORE;
+ is_after = flags & BPF_F_AFTER;
+ if (is_link || is_id || id_or_fd) {
+ /* flags must have either BPF_F_BEFORE or BPF_F_AFTER */
+ if (is_before == is_after)
+ return ERR_PTR(-EINVAL);
+ if ((is_link && !link) || (!is_link && !prog))
+ return ERR_PTR(-EINVAL);
+ } else if (!hlist_empty(progs)) {
+ /* flags cannot have both BPF_F_BEFORE and BPF_F_AFTER */
+ if (is_before && is_after)
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (is_link) {
+ anchor_link = bpf_get_anchor_link(flags, id_or_fd);
+ if (IS_ERR(anchor_link))
+ return ERR_CAST(anchor_link);
+ } else if (is_id || id_or_fd) {
+ anchor_prog = bpf_get_anchor_prog(flags, id_or_fd);
+ if (IS_ERR(anchor_prog))
+ return ERR_CAST(anchor_prog);
+ }
+
+ if (!anchor_prog && !anchor_link) {
+ /* if there is no anchor_prog/anchor_link, then BPF_F_PREORDER
+ * doesn't matter since either prepend or append to a combined
+ * list of progs will end up with correct result.
+ */
+ hlist_for_each_entry(pltmp, progs, node) {
+ if (is_before)
+ return pltmp;
+ if (pltmp->node.next)
+ continue;
+ return pltmp;
+ }
+ return NULL;
+ }
+
+ hlist_for_each_entry(pltmp, progs, node) {
+ if ((anchor_prog && anchor_prog == pltmp->prog) ||
+ (anchor_link && anchor_link == &pltmp->link->link)) {
+ if (!!(pltmp->flags & BPF_F_PREORDER) != preorder)
+ goto out;
+ pl = pltmp;
+ goto out;
+ }
+ }
+
+ pl = ERR_PTR(-ENOENT);
+out:
+ if (anchor_link)
+ bpf_link_put(anchor_link);
+ else
+ bpf_prog_put(anchor_prog);
+ return pl;
+}
+
+static int insert_pl_to_hlist(struct bpf_prog_list *pl, struct hlist_head *progs,
+ struct bpf_prog *prog, struct bpf_cgroup_link *link,
+ u32 flags, u32 id_or_fd)
+{
+ struct bpf_prog_list *pltmp;
+
+ pltmp = get_prog_list(progs, prog, link, flags, id_or_fd);
+ if (IS_ERR(pltmp))
+ return PTR_ERR(pltmp);
+
+ if (!pltmp)
+ hlist_add_head(&pl->node, progs);
+ else if (flags & BPF_F_BEFORE)
+ hlist_add_before(&pl->node, &pltmp->node);
+ else
+ hlist_add_behind(&pl->node, &pltmp->node);
+
+ return 0;
+}
+
/**
* __cgroup_bpf_attach() - Attach the program or the link to a cgroup, and
* propagate the change to descendants
@@ -667,6 +777,8 @@ static struct bpf_prog_list *find_attach_entry(struct hlist_head *progs,
* @replace_prog: Previously attached program to replace if BPF_F_REPLACE is set
* @type: Type of attach operation
* @flags: Option flags
+ * @id_or_fd: Relative prog id or fd
+ * @revision: bpf_prog_list revision
*
* Exactly one of @prog or @link can be non-null.
* Must be called with cgroup_mutex held.
@@ -674,7 +786,8 @@ static struct bpf_prog_list *find_attach_entry(struct hlist_head *progs,
static int __cgroup_bpf_attach(struct cgroup *cgrp,
struct bpf_prog *prog, struct bpf_prog *replace_prog,
struct bpf_cgroup_link *link,
- enum bpf_attach_type type, u32 flags)
+ enum bpf_attach_type type, u32 flags, u32 id_or_fd,
+ u64 revision)
{
u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI));
struct bpf_prog *old_prog = NULL;
@@ -690,6 +803,9 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp,
((flags & BPF_F_REPLACE) && !(flags & BPF_F_ALLOW_MULTI)))
/* invalid combination */
return -EINVAL;
+ if ((flags & BPF_F_REPLACE) && (flags & (BPF_F_BEFORE | BPF_F_AFTER)))
+ /* only either replace or insertion with before/after */
+ return -EINVAL;
if (link && (prog || replace_prog))
/* only either link or prog/replace_prog can be specified */
return -EINVAL;
@@ -700,6 +816,8 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp,
atype = bpf_cgroup_atype_find(type, new_prog->aux->attach_btf_id);
if (atype < 0)
return -EINVAL;
+ if (revision && revision != cgrp->bpf.revisions[atype])
+ return -ESTALE;
progs = &cgrp->bpf.progs[atype];
@@ -728,22 +846,18 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp,
if (pl) {
old_prog = pl->prog;
} else {
- struct hlist_node *last = NULL;
-
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
if (!pl) {
bpf_cgroup_storages_free(new_storage);
return -ENOMEM;
}
- if (hlist_empty(progs))
- hlist_add_head(&pl->node, progs);
- else
- hlist_for_each(last, progs) {
- if (last->next)
- continue;
- hlist_add_behind(&pl->node, last);
- break;
- }
+
+ err = insert_pl_to_hlist(pl, progs, prog, link, flags, id_or_fd);
+ if (err) {
+ kfree(pl);
+ bpf_cgroup_storages_free(new_storage);
+ return err;
+ }
}
pl->prog = prog;
@@ -753,7 +867,7 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp,
cgrp->bpf.flags[atype] = saved_flags;
if (type == BPF_LSM_CGROUP) {
- err = bpf_trampoline_link_cgroup_shim(new_prog, atype);
+ err = bpf_trampoline_link_cgroup_shim(new_prog, atype, type);
if (err)
goto cleanup;
}
@@ -762,6 +876,7 @@ static int __cgroup_bpf_attach(struct cgroup *cgrp,
if (err)
goto cleanup_trampoline;
+ cgrp->bpf.revisions[atype] += 1;
if (old_prog) {
if (type == BPF_LSM_CGROUP)
bpf_trampoline_unlink_cgroup_shim(old_prog);
@@ -793,12 +908,13 @@ static int cgroup_bpf_attach(struct cgroup *cgrp,
struct bpf_prog *prog, struct bpf_prog *replace_prog,
struct bpf_cgroup_link *link,
enum bpf_attach_type type,
- u32 flags)
+ u32 flags, u32 id_or_fd, u64 revision)
{
int ret;
cgroup_lock();
- ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags);
+ ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags,
+ id_or_fd, revision);
cgroup_unlock();
return ret;
}
@@ -868,7 +984,7 @@ static int __cgroup_bpf_replace(struct cgroup *cgrp,
struct hlist_head *progs;
bool found = false;
- atype = bpf_cgroup_atype_find(link->type, new_prog->aux->attach_btf_id);
+ atype = bpf_cgroup_atype_find(link->link.attach_type, new_prog->aux->attach_btf_id);
if (atype < 0)
return -EINVAL;
@@ -886,6 +1002,7 @@ static int __cgroup_bpf_replace(struct cgroup *cgrp,
if (!found)
return -ENOENT;
+ cgrp->bpf.revisions[atype] += 1;
old_prog = xchg(&link->link.prog, new_prog);
replace_effective_prog(cgrp, atype, link);
bpf_prog_put(old_prog);
@@ -1011,12 +1128,14 @@ found:
* @prog: A program to detach or NULL
* @link: A link to detach or NULL
* @type: Type of detach operation
+ * @revision: bpf_prog_list revision
*
* At most one of @prog or @link can be non-NULL.
* Must be called with cgroup_mutex held.
*/
static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
- struct bpf_cgroup_link *link, enum bpf_attach_type type)
+ struct bpf_cgroup_link *link, enum bpf_attach_type type,
+ u64 revision)
{
enum cgroup_bpf_attach_type atype;
struct bpf_prog *old_prog;
@@ -1034,6 +1153,9 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
if (atype < 0)
return -EINVAL;
+ if (revision && revision != cgrp->bpf.revisions[atype])
+ return -ESTALE;
+
progs = &cgrp->bpf.progs[atype];
flags = cgrp->bpf.flags[atype];
@@ -1059,6 +1181,7 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
/* now can actually delete it from this cgroup list */
hlist_del(&pl->node);
+ cgrp->bpf.revisions[atype] += 1;
kfree(pl);
if (hlist_empty(progs))
@@ -1074,12 +1197,12 @@ static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
}
static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
- enum bpf_attach_type type)
+ enum bpf_attach_type type, u64 revision)
{
int ret;
cgroup_lock();
- ret = __cgroup_bpf_detach(cgrp, prog, NULL, type);
+ ret = __cgroup_bpf_detach(cgrp, prog, NULL, type, revision);
cgroup_unlock();
return ret;
}
@@ -1097,6 +1220,7 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
struct bpf_prog_array *effective;
int cnt, ret = 0, i;
int total_cnt = 0;
+ u64 revision = 0;
u32 flags;
if (effective_query && prog_attach_flags)
@@ -1134,6 +1258,10 @@ static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
return -EFAULT;
if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt)))
return -EFAULT;
+ if (!effective_query && from_atype == to_atype)
+ revision = cgrp->bpf.revisions[from_atype];
+ if (copy_to_user(&uattr->query.revision, &revision, sizeof(revision)))
+ return -EFAULT;
if (attr->query.prog_cnt == 0 || !prog_ids || !total_cnt)
/* return early if user requested only program count + flags */
return 0;
@@ -1216,7 +1344,8 @@ int cgroup_bpf_prog_attach(const union bpf_attr *attr,
}
ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
- attr->attach_type, attr->attach_flags);
+ attr->attach_type, attr->attach_flags,
+ attr->relative_fd, attr->expected_revision);
if (replace_prog)
bpf_prog_put(replace_prog);
@@ -1238,7 +1367,7 @@ int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
if (IS_ERR(prog))
prog = NULL;
- ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type);
+ ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, attr->expected_revision);
if (prog)
bpf_prog_put(prog);
@@ -1267,8 +1396,8 @@ static void bpf_cgroup_link_release(struct bpf_link *link)
}
WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
- cg_link->type));
- if (cg_link->type == BPF_LSM_CGROUP)
+ link->attach_type, 0));
+ if (link->attach_type == BPF_LSM_CGROUP)
bpf_trampoline_unlink_cgroup_shim(cg_link->link.prog);
cg = cg_link->cgroup;
@@ -1310,7 +1439,7 @@ static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
"cgroup_id:\t%llu\n"
"attach_type:\t%d\n",
cg_id,
- cg_link->type);
+ link->attach_type);
}
static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
@@ -1326,7 +1455,7 @@ static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
cgroup_unlock();
info->cgroup.cgroup_id = cg_id;
- info->cgroup.attach_type = cg_link->type;
+ info->cgroup.attach_type = link->attach_type;
return 0;
}
@@ -1339,6 +1468,13 @@ static const struct bpf_link_ops bpf_cgroup_link_lops = {
.fill_link_info = bpf_cgroup_link_fill_link_info,
};
+#define BPF_F_LINK_ATTACH_MASK \
+ (BPF_F_ID | \
+ BPF_F_BEFORE | \
+ BPF_F_AFTER | \
+ BPF_F_PREORDER | \
+ BPF_F_LINK)
+
int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
struct bpf_link_primer link_primer;
@@ -1346,7 +1482,7 @@ int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
struct cgroup *cgrp;
int err;
- if (attr->link_create.flags)
+ if (attr->link_create.flags & (~BPF_F_LINK_ATTACH_MASK))
return -EINVAL;
cgrp = cgroup_get_from_fd(attr->link_create.target_fd);
@@ -1359,9 +1495,8 @@ int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
goto out_put_cgroup;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops,
- prog);
+ prog, attr->link_create.attach_type);
link->cgroup = cgrp;
- link->type = attr->link_create.attach_type;
err = bpf_link_prime(&link->link, &link_primer);
if (err) {
@@ -1370,7 +1505,9 @@ int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
}
err = cgroup_bpf_attach(cgrp, NULL, NULL, link,
- link->type, BPF_F_ALLOW_MULTI);
+ link->link.attach_type, BPF_F_ALLOW_MULTI | attr->link_create.flags,
+ attr->link_create.cgroup.relative_fd,
+ attr->link_create.cgroup.expected_revision);
if (err) {
bpf_link_cleanup(&link_primer);
goto out_put_cgroup;
@@ -2134,7 +2271,7 @@ static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_PTR_TO_MEM | MEM_WRITE,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_ANYTHING,
};
@@ -2440,22 +2577,22 @@ static bool cg_sockopt_is_valid_access(int off, int size,
}
switch (off) {
- case offsetof(struct bpf_sockopt, sk):
+ case bpf_ctx_range_ptr(struct bpf_sockopt, sk):
if (size != sizeof(__u64))
return false;
info->reg_type = PTR_TO_SOCKET;
break;
- case offsetof(struct bpf_sockopt, optval):
+ case bpf_ctx_range_ptr(struct bpf_sockopt, optval):
if (size != sizeof(__u64))
return false;
info->reg_type = PTR_TO_PACKET;
break;
- case offsetof(struct bpf_sockopt, optval_end):
+ case bpf_ctx_range_ptr(struct bpf_sockopt, optval_end):
if (size != sizeof(__u64))
return false;
info->reg_type = PTR_TO_PACKET_END;
break;
- case offsetof(struct bpf_sockopt, retval):
+ case bpf_ctx_range(struct bpf_sockopt, retval):
if (size != size_default)
return false;
return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;
generated by cgit (git 2.34.1) at 2025-07-31 14:22:21 +0000