linux/kernel/bpf
Chuyi Zhou 0de4f50de2 bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg
BTF_TYPE_SAFE_TRUSTED(struct bpf_iter__task) in verifier.c wanted to
teach BPF verifier that bpf_iter__task -> task is a trusted ptr. But it
doesn't work well.

The reason is, bpf_iter__task -> task would go through btf_ctx_access()
which enforces the reg_type of 'task' is ctx_arg_info->reg_type, and in
task_iter.c, we actually explicitly declare that the
ctx_arg_info->reg_type is PTR_TO_BTF_ID_OR_NULL.

Actually we have a previous case like this[1] where PTR_TRUSTED is added to
the arg flag for map_iter.

This patch sets ctx_arg_info->reg_type is PTR_TO_BTF_ID_OR_NULL |
PTR_TRUSTED in task_reg_info.

Similarly, bpf_cgroup_reg_info -> cgroup is also PTR_TRUSTED since we are
under the protection of cgroup_mutex and we would check cgroup_is_dead()
in __cgroup_iter_seq_show().

This patch is to improve the user experience of the newly introduced
bpf_iter_css_task kfunc before hitting the mainline. The Fixes tag is
pointing to the commit introduced the bpf_iter_css_task kfunc.

Link[1]:https://lore.kernel.org/all/20230706133932.45883-3-aspsk@isovalent.com/

Fixes: 9c66dc94b6 ("bpf: Introduce css_task open-coded iterator kfuncs")
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231107132204.912120-2-zhouchuyi@bytedance.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-11-07 15:24:25 -08:00
..
preload bpf: make preloaded map iterators to display map elements count 2023-07-06 12:42:25 -07:00
arraymap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
bloom_filter.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
bpf_cgrp_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
bpf_inode_storage.c Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
bpf_iter.c bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
bpf_local_storage.c bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc 2023-09-06 11:08:14 +02:00
bpf_lru_list.c bpf: Address KCSAN report on bpf_lru_list 2023-05-12 12:01:03 -07:00
bpf_lru_list.h bpf: lru: Remove unused declaration bpf_lru_promote() 2023-08-08 17:21:42 -07:00
bpf_lsm.c bpf: Fix the kernel crash caused by bpf_setsockopt(). 2023-01-26 23:26:40 -08:00
bpf_struct_ops_types.h bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpf_struct_ops.c bpf: Charge modmem for struct_ops trampoline 2023-09-14 15:30:45 -07:00
bpf_task_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
btf.c bpf: Add bpf_sock_addr_set_sun_path() to allow writing unix sockaddr from bpf 2023-10-11 16:29:25 -07:00
cgroup_iter.c bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg 2023-11-07 15:24:25 -08:00
cgroup.c for-6.7/io_uring-sockopt-2023-10-30 2023-11-01 11:16:34 -10:00
core.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2023-09-17 15:12:06 +01:00
cpumap.c net, bpf: Add a warning if NAPI cb missed xdp_do_flush(). 2023-10-17 15:02:03 +02:00
cpumask.c bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
devmap.c net, bpf: Add a warning if NAPI cb missed xdp_do_flush(). 2023-10-17 15:02:03 +02:00
disasm.c bpf: change bpf_alu_sign_string and bpf_movsx_string to static 2023-08-04 16:15:50 -07:00
disasm.h bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
dispatcher.c bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func 2022-12-14 12:02:14 -08:00
hashtab.c bpf: Fix unnecessary -EBUSY from htab_lock_bucket 2023-10-24 14:25:55 +02:00
helpers.c bpf: Check map->usercnt after timer->timer is assigned 2023-11-01 22:37:31 -07:00
inode.c bpf: convert to new timestamp accessors 2023-10-18 14:08:30 +02:00
Kconfig bpf: Add fd-based tcx multi-prog infra with link support 2023-07-19 10:07:27 -07:00
link_iter.c bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
local_storage.c cgroup changes for v6.4-rc1 2023-04-29 10:05:22 -07:00
log.c bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log 2023-05-16 22:34:50 -07:00
lpm_trie.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
Makefile bpf: Add fd-based tcx multi-prog infra with link support 2023-07-19 10:07:27 -07:00
map_in_map.c bpf: Fix elem_size not being set for inner maps 2023-06-02 16:22:12 -07:00
map_in_map.h
map_iter.c bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
memalloc.c bpf: Add more WARN_ON_ONCE checks for mismatched alloc and free 2023-10-26 14:23:33 +02:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
mprog.c bpf: Handle bpf_mprog_query with NULL entry 2023-10-06 17:11:20 -07:00
net_namespace.c net: Add includes masked by netdevice.h including uapi/bpf.h 2021-12-29 20:03:05 -08:00
offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-09-21 21:49:45 +02:00
percpu_freelist.c bpf: Initialize same number of free nodes for each pcpu_freelist 2022-11-11 12:05:14 -08:00
percpu_freelist.h
prog_iter.c
queue_stack_maps.c bpf: Avoid deadlock when using queue and stack maps from NMI 2023-09-11 19:04:49 -07:00
reuseport_array.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
ringbuf.c bpf: Fold smp_mb__before_atomic() into atomic_set_release() 2023-10-24 14:26:07 +02:00
stackmap.c bpf: Annotate struct bpf_stack_map with __counted_by 2023-10-06 23:44:35 +02:00
syscall.c netkit, bpf: Add bpf programmable net device 2023-10-24 16:06:03 -07:00
sysfs_btf.c
task_iter.c bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg 2023-11-07 15:24:25 -08:00
tcx.c bpf, tcx: Get rid of tcx_link_const 2023-10-23 15:01:53 -07:00
tnum.c bpf, tnums: Provably sound, faster, and more precise algorithm for tnum_mul 2021-06-01 13:34:15 +02:00
trampoline.c bpf, x64: Fix tailcall infinite loop 2023-09-12 13:06:12 -07:00
verifier.c bpf: Fix precision tracking for BPF_ALU | BPF_TO_BE | BPF_END 2023-11-01 22:54:27 -07:00