bpf: Eliminate rlimit-based memory accounting for bpf progs

Do not use rlimit-based memory accounting for bpf progs. It has been
replaced with memcg-based memory accounting.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-34-guro@fb.com

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 61331a1..a9de571 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1202,8 +1202,6 @@ void bpf_prog_sub(struct bpf_prog *prog, int i);
 void bpf_prog_inc(struct bpf_prog *prog);
 struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog);
 void bpf_prog_put(struct bpf_prog *prog);
 void bpf_prog_inc(struct bpf_prog *prog);
 struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog);
 void bpf_prog_put(struct bpf_prog *prog);

-int __bpf_prog_charge(struct user_struct *user, u32 pages);
-void __bpf_prog_uncharge(struct user_struct *user, u32 pages);

 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
                          struct bpf_map **used_maps, u32 len);
 
 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
                          struct bpf_map **used_maps, u32 len);
 


@@ -1512,15 +1510,6 @@ bpf_prog_inc_not_zero(struct bpf_prog *prog)
        return ERR_PTR(-EOPNOTSUPP);
 }
 
        return ERR_PTR(-EOPNOTSUPP);
 }
 

-static inline int __bpf_prog_charge(struct user_struct *user, u32 pages)
-{
-       return 0;
-}
-
-static inline void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
-{
-}
-

 static inline void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
                                 const struct bpf_link_ops *ops,
                                 struct bpf_prog *prog)
 static inline void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
                                 const struct bpf_link_ops *ops,
                                 struct bpf_prog *prog)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 2921f58..261f869 100644 (file)
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -221,23 +221,15 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 {
        gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
        struct bpf_prog *fp;
 {
        gfp_t gfp_flags = GFP_KERNEL_ACCOUNT | __GFP_ZERO | gfp_extra_flags;
        struct bpf_prog *fp;

-       u32 pages, delta;
-       int ret;
+       u32 pages;

 
        size = round_up(size, PAGE_SIZE);
        pages = size / PAGE_SIZE;
        if (pages <= fp_old->pages)
                return fp_old;
 
 
        size = round_up(size, PAGE_SIZE);
        pages = size / PAGE_SIZE;
        if (pages <= fp_old->pages)
                return fp_old;
 

-       delta = pages - fp_old->pages;
-       ret = __bpf_prog_charge(fp_old->aux->user, delta);
-       if (ret)
-               return NULL;
-

        fp = __vmalloc(size, gfp_flags);
        fp = __vmalloc(size, gfp_flags);

-       if (fp == NULL) {
-               __bpf_prog_uncharge(fp_old->aux->user, delta);
-       } else {
+       if (fp) {

                memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
                fp->pages = pages;
                fp->aux->prog = fp;
                memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
                fp->pages = pages;
                fp->aux->prog = fp;

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 29096d9..d16dd49 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1632,51 +1632,6 @@ static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
        audit_log_end(ab);
 }
 
        audit_log_end(ab);
 }
 

-int __bpf_prog_charge(struct user_struct *user, u32 pages)
-{
-       unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-       unsigned long user_bufs;
-
-       if (user) {
-               user_bufs = atomic_long_add_return(pages, &user->locked_vm);
-               if (user_bufs > memlock_limit) {
-                       atomic_long_sub(pages, &user->locked_vm);
-                       return -EPERM;
-               }
-       }
-
-       return 0;
-}
-
-void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
-{
-       if (user)
-               atomic_long_sub(pages, &user->locked_vm);
-}
-
-static int bpf_prog_charge_memlock(struct bpf_prog *prog)
-{
-       struct user_struct *user = get_current_user();
-       int ret;
-
-       ret = __bpf_prog_charge(user, prog->pages);
-       if (ret) {
-               free_uid(user);
-               return ret;
-       }
-
-       prog->aux->user = user;
-       return 0;
-}
-
-static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
-{
-       struct user_struct *user = prog->aux->user;
-
-       __bpf_prog_uncharge(user, prog->pages);
-       free_uid(user);
-}
-

 static int bpf_prog_alloc_id(struct bpf_prog *prog)
 {
        int id;
 static int bpf_prog_alloc_id(struct bpf_prog *prog)
 {
        int id;


@@ -1726,7 +1681,7 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu)
 
        kvfree(aux->func_info);
        kfree(aux->func_info_aux);
 
        kvfree(aux->func_info);
        kfree(aux->func_info_aux);

-       bpf_prog_uncharge_memlock(aux->prog);
+       free_uid(aux->user);

        security_bpf_prog_free(aux);
        bpf_prog_free(aux->prog);
 }
        security_bpf_prog_free(aux);
        bpf_prog_free(aux->prog);
 }


@@ -2164,7 +2119,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
                dst_prog = bpf_prog_get(attr->attach_prog_fd);
                if (IS_ERR(dst_prog)) {
                        err = PTR_ERR(dst_prog);
                dst_prog = bpf_prog_get(attr->attach_prog_fd);
                if (IS_ERR(dst_prog)) {
                        err = PTR_ERR(dst_prog);

-                       goto free_prog_nouncharge;
+                       goto free_prog;

                }
                prog->aux->dst_prog = dst_prog;
        }
                }
                prog->aux->dst_prog = dst_prog;
        }


@@ -2174,18 +2129,15 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 
        err = security_bpf_prog_alloc(prog->aux);
        if (err)
 
        err = security_bpf_prog_alloc(prog->aux);
        if (err)

-               goto free_prog_nouncharge;
-
-       err = bpf_prog_charge_memlock(prog);
-       if (err)
-               goto free_prog_sec;
+               goto free_prog;

 
 

+       prog->aux->user = get_current_user();

        prog->len = attr->insn_cnt;
 
        err = -EFAULT;
        if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
                           bpf_prog_insn_size(prog)) != 0)
        prog->len = attr->insn_cnt;
 
        err = -EFAULT;
        if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
                           bpf_prog_insn_size(prog)) != 0)

-               goto free_prog;
+               goto free_prog_sec;

 
        prog->orig_prog = NULL;
        prog->jited = 0;
 
        prog->orig_prog = NULL;
        prog->jited = 0;


@@ -2196,19 +2148,19 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
        if (bpf_prog_is_dev_bound(prog->aux)) {
                err = bpf_prog_offload_init(prog, attr);
                if (err)
        if (bpf_prog_is_dev_bound(prog->aux)) {
                err = bpf_prog_offload_init(prog, attr);
                if (err)

-                       goto free_prog;
+                       goto free_prog_sec;

        }
 
        /* find program type: socket_filter vs tracing_filter */
        err = find_prog_type(type, prog);
        if (err < 0)
        }
 
        /* find program type: socket_filter vs tracing_filter */
        err = find_prog_type(type, prog);
        if (err < 0)

-               goto free_prog;
+               goto free_prog_sec;

 
        prog->aux->load_time = ktime_get_boottime_ns();
        err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
                               sizeof(attr->prog_name));
        if (err < 0)
 
        prog->aux->load_time = ktime_get_boottime_ns();
        err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
                               sizeof(attr->prog_name));
        if (err < 0)

-               goto free_prog;
+               goto free_prog_sec;

 
        /* run eBPF verifier */
        err = bpf_check(&prog, attr, uattr);
 
        /* run eBPF verifier */
        err = bpf_check(&prog, attr, uattr);


@@ -2253,11 +2205,10 @@ free_used_maps:
         */
        __bpf_prog_put_noref(prog, prog->aux->func_cnt);
        return err;
         */
        __bpf_prog_put_noref(prog, prog->aux->func_cnt);
        return err;

-free_prog:
-       bpf_prog_uncharge_memlock(prog);

 free_prog_sec:
 free_prog_sec:

+       free_uid(prog->aux->user);

        security_bpf_prog_free(prog->aux);
        security_bpf_prog_free(prog->aux);

-free_prog_nouncharge:
+free_prog:

        bpf_prog_free(prog);
        return err;
 }
        bpf_prog_free(prog);
        return err;
 }