linux/kernel/bpf
Kumar Kartikeya Dwivedi aaa619ebcc bpf: Refactor check_btf_func and split into two phases
This patch splits the check_btf_info's check_btf_func check into two
separate phases.  The first phase sets up the BTF and prepares
func_info, but does not perform any validation of required invariants
for subprogs just yet. This is left to the second phase, which happens
where check_btf_info executes currently, and performs the line_info and
CO-RE relocation.

The reason to perform this split is to obtain the userspace supplied
func_info information before we perform the add_subprog call, where we
would now require finding and adding subprogs that may not have a
bpf_pseudo_call or bpf_pseudo_func instruction in the program.

We require this as we want to enable userspace to supply exception
callbacks that can override the default hidden subprogram generated by
the verifier (which performs a hardcoded action). In such a case, the
exception callback may never be referenced in an instruction, but will
still be suitably annotated (by way of BTF declaration tags). For
finding this exception callback, we would require the program's BTF
information, and the supplied func_info information which maps BTF type
IDs to subprograms.

Since the exception callback won't actually be referenced through
instructions, later checks in check_cfg and do_check_subprogs will not
verify the subprog. This means that add_subprog needs to add them in the
add_subprog_and_kfunc phase before we move forward, which is why the BTF
and func_info are required at that point.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
..
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: implement numbers iterator 2023-03-08 16:19:51 -08:00
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_KPTR_PERCPU as a field type 2023-09-08 08:42:17 -07:00
cgroup_iter.c cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers 2023-03-17 12:07:13 -10:00
cgroup.c bpf-next-for-netdev 2023-05-16 19:50:05 -07:00
core.c bpf: Implement BPF exceptions 2023-09-16 09:34:21 -07:00
cpumap.c bpf, cpumask: Clean up bpf_cpu_map_entry directly in cpu_map_free 2023-08-21 15:21:16 -07:00
cpumask.c bpf: Convert bpf_cpumask to bpf_mem_cache_free_rcu. 2023-07-12 23:45:23 +02:00
devmap.c bpf, devmap: Remove unused dtab field from bpf_dtab_netdev 2023-07-31 18:26:08 -07:00
disasm.c bpf: change bpf_alu_sign_string and bpf_movsx_string to static 2023-08-04 16:15:50 -07:00
disasm.h
dispatcher.c bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func 2022-12-14 12:02:14 -08:00
hashtab.c bpf: populate the per-cpu insertions/deletions counters for hashmaps 2023-07-06 12:42:25 -07:00
helpers.c bpf: Implement BPF exceptions 2023-09-16 09:34:21 -07:00
inode.c bpf: convert to ctime accessor functions 2023-07-24 10:30:07 +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: allow any program to use the bpf_map_sum_elem_count kfunc 2023-07-19 09:48:53 -07:00
memalloc.c bpf: Enable IRQ after irq_work_raise() completes in unit_free{_rcu}() 2023-09-08 08:42:19 -07:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
mprog.c bpf: Fix mprog detachment for empty mprog entry 2023-08-04 09:35:39 -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 bpf: Allow to use kfunc XDP hints and frags together 2023-09-15 11:39:46 -07:00
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: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
reuseport_array.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
ringbuf.c bpf: Remove unnecessary ring buffer size check 2023-07-05 14:09:45 +02:00
stackmap.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
syscall.c bpf: Implement support for adding hidden subprogs 2023-09-16 09:34:21 -07:00
sysfs_btf.c
task_iter.c bpf: task_group_seq_get_next: simplify the "next tid" logic 2023-09-08 08:42:19 -07:00
tcx.c tcx: Fix splat during dev unregister 2023-07-31 14:44:02 -07:00
tnum.c
trampoline.c bpf, x64: Fix tailcall infinite loop 2023-09-12 13:06:12 -07:00
verifier.c bpf: Refactor check_btf_func and split into two phases 2023-09-16 09:34:21 -07:00