On Tue, Apr 19, 2022 at 3:23 PM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote:
>
> Rename bpf_prog_run_array_cg_flags to bpf_prog_run_array_cg and
> use it everywhere. check_return_code already enforces sane
> return ranges for all cgroup types. (only egress and bind hooks have
> uncanonical return ranges, the rest is using [0, 1])
>
> No functional changes.
>
> Suggested-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> ---
> include/linux/bpf-cgroup.h | 8 ++---
> kernel/bpf/cgroup.c | 70 ++++++++++++--------------------------
> 2 files changed, 24 insertions(+), 54 deletions(-)
>
> diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
> index 88a51b242adc..669d96d074ad 100644
> --- a/include/linux/bpf-cgroup.h
> +++ b/include/linux/bpf-cgroup.h
> @@ -225,24 +225,20 @@ static inline bool cgroup_bpf_sock_enabled(struct sock *sk,
>
> #define BPF_CGROUP_RUN_SA_PROG(sk, uaddr, atype) \
> ({ \
> - u32 __unused_flags; \
> int __ret = 0; \
> if (cgroup_bpf_enabled(atype)) \
> __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, atype, \
> - NULL, \
> - &__unused_flags); \
> + NULL, NULL); \
> __ret; \
> })
>
> #define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, atype, t_ctx) \
> ({ \
> - u32 __unused_flags; \
> int __ret = 0; \
> if (cgroup_bpf_enabled(atype)) { \
> lock_sock(sk); \
> __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, atype, \
> - t_ctx, \
> - &__unused_flags); \
> + t_ctx, NULL); \
> release_sock(sk); \
> } \
> __ret; \
> diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
> index 0cb6211fcb58..f61eca32c747 100644
> --- a/kernel/bpf/cgroup.c
> +++ b/kernel/bpf/cgroup.c
> @@ -25,50 +25,18 @@ EXPORT_SYMBOL(cgroup_bpf_enabled_key);
> /* __always_inline is necessary to prevent indirect call through run_prog
> * function pointer.
> */
> -static __always_inline int
> -bpf_prog_run_array_cg_flags(const struct cgroup_bpf *cgrp,
> - enum cgroup_bpf_attach_type atype,
> - const void *ctx, bpf_prog_run_fn run_prog,
> - int retval, u32 *ret_flags)
> -{
> - const struct bpf_prog_array_item *item;
> - const struct bpf_prog *prog;
> - const struct bpf_prog_array *array;
> - struct bpf_run_ctx *old_run_ctx;
> - struct bpf_cg_run_ctx run_ctx;
> - u32 func_ret;
> -
> - run_ctx.retval = retval;
> - migrate_disable();
> - rcu_read_lock();
> - array = rcu_dereference(cgrp->effective[atype]);
> - item = &array->items[0];
> - old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
> - while ((prog = READ_ONCE(item->prog))) {
> - run_ctx.prog_item = item;
> - func_ret = run_prog(prog, ctx);
> - if (!(func_ret & 1) && !IS_ERR_VALUE((long)run_ctx.retval))
> - run_ctx.retval = -EPERM;
> - *(ret_flags) |= (func_ret >> 1);
> - item++;
> - }
> - bpf_reset_run_ctx(old_run_ctx);
> - rcu_read_unlock();
> - migrate_enable();
> - return run_ctx.retval;
> -}
> -
> static __always_inline int
> bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
> enum cgroup_bpf_attach_type atype,
> const void *ctx, bpf_prog_run_fn run_prog,
> - int retval)
> + int retval, u32 *ret_flags)
> {
> const struct bpf_prog_array_item *item;
> const struct bpf_prog *prog;
> const struct bpf_prog_array *array;
> struct bpf_run_ctx *old_run_ctx;
> struct bpf_cg_run_ctx run_ctx;
> + u32 func_ret;
>
> run_ctx.retval = retval;
> migrate_disable();
> @@ -78,8 +46,11 @@ bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
> old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
> while ((prog = READ_ONCE(item->prog))) {
> run_ctx.prog_item = item;
> - if (!run_prog(prog, ctx) && !IS_ERR_VALUE((long)run_ctx.retval))
> + func_ret = run_prog(prog, ctx);
> + if (!(func_ret & 1) && !IS_ERR_VALUE((long)run_ctx.retval))
to be completely true to previous behavior, shouldn't there be
if (ret_flags)
func_ret &= 1;
if (!func_ret && !IS_ERR_VALUE(...))
here?
This might have been discussed previously and I missed it. If that's
so, please ignore.
> run_ctx.retval = -EPERM;
> + if (ret_flags)
> + *(ret_flags) |= (func_ret >> 1);
> item++;
> }
> bpf_reset_run_ctx(old_run_ctx);
[..]
