linux/kernel/bpf
Ilya Leoshkevich 1cf3bfc60f bpf: Support 64-bit pointers to kfuncs
test_ksyms_module fails to emit a kfunc call targeting a module on
s390x, because the verifier stores the difference between kfunc
address and __bpf_call_base in bpf_insn.imm, which is s32, and modules
are roughly (1 << 42) bytes away from the kernel on s390x.

Fix by keeping BTF id in bpf_insn.imm for BPF_PSEUDO_KFUNC_CALLs,
and storing the absolute address in bpf_kfunc_desc.

Introduce bpf_jit_supports_far_kfunc_call() in order to limit this new
behavior to the s390x JIT. Otherwise other JITs need to be modified,
which is not desired.

Introduce bpf_get_kfunc_addr() instead of exposing both
find_kfunc_desc() and struct bpf_kfunc_desc.

In addition to sorting kfuncs by imm, also sort them by offset, in
order to handle conflicting imms from different modules. Do this on
all architectures in order to simplify code.

Factor out resolving specialized kfuncs (XPD and dynptr) from
fixup_kfunc_call(). This was required in the first place, because
fixup_kfunc_call() uses find_kfunc_desc(), which returns a const
pointer, so it's not possible to modify kfunc addr without stripping
const, which is not nice. It also removes repetition of code like:

	if (bpf_jit_supports_far_kfunc_call())
		desc->addr = func;
	else
		insn->imm = BPF_CALL_IMM(func);

and separates kfunc_desc_tab fixups from kfunc_call fixups.

Suggested-by: Jiri Olsa <olsajiri@gmail.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230412230632.885985-1-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-13 21:36:41 -07:00
..
preload bpf: iterators: Split iterators.lskel.h into little- and big- endian versions 2023-01-28 12:45:15 -08:00
arraymap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
bloom_filter.c bpf: compute hashes in bloom filter similar to hashmap 2023-04-02 08:44:49 -07:00
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 bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
bpf_iter.c bpf: implement numbers iterator 2023-03-08 16:19:51 -08:00
bpf_local_storage.c bpf: Handle NULL in bpf_local_storage_free. 2023-04-12 10:27:50 -07:00
bpf_lru_list.c
bpf_lru_list.h
bpf_lsm.c bpf: Fix the kernel crash caused by bpf_setsockopt(). 2023-01-26 23:26:40 -08:00
bpf_struct_ops.c bpf: Check IS_ERR for the bpf_map_get() return value 2023-03-24 12:40:47 -07:00
bpf_struct_ops_types.h
bpf_task_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
btf.c bpf-next-for-netdev 2023-04-13 16:43:38 -07:00
cgroup.c bpf: allow ctx writes using BPF_ST_MEM instruction 2023-03-03 21:41:46 -08:00
cgroup_iter.c bpf: Pin the start cgroup in cgroup_iter_seq_init() 2022-11-21 17:40:42 +01:00
core.c bpf: Support 64-bit pointers to kfuncs 2023-04-13 21:36:41 -07:00
cpumap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
cpumask.c bpf: Treat KF_RELEASE kfuncs as KF_TRUSTED_ARGS 2023-03-25 16:56:22 -07:00
devmap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
disasm.c
disasm.h
dispatcher.c bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func 2022-12-14 12:02:14 -08:00
hashtab.c bpf: optimize hashmap lookups when key_size is divisible by 4 2023-04-01 15:08:19 -07:00
helpers.c bpf: Remove bpf_cgroup_kptr_get() kfunc 2023-04-12 12:57:54 -07:00
inode.c fs: port inode_init_owner() to mnt_idmap 2023-01-19 09:24:28 +01:00
Kconfig
link_iter.c
local_storage.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
log.c bpf: Relax log_buf NULL conditions when log_level>0 is requested 2023-04-11 18:05:44 +02:00
lpm_trie.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
Makefile bpf: Split off basic BPF verifier log into separate file 2023-04-11 18:05:42 +02:00
map_in_map.c
map_in_map.h
map_iter.c
memalloc.c bpf: Add a few bpf mem allocator functions 2023-03-25 19:52:51 -07:00
mmap_unlock_work.h
net_namespace.c
offload.c bpf: offload map memory usage 2023-03-07 09:33:43 -08:00
percpu_freelist.c
percpu_freelist.h
prog_iter.c
queue_stack_maps.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
reuseport_array.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
ringbuf.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
stackmap.c bpf: return long from bpf_map_ops funcs 2023-03-22 15:11:30 -07:00
syscall.c bpf: Add log_true_size output field to return necessary log buffer size 2023-04-11 18:05:43 +02:00
sysfs_btf.c
task_iter.c bpf: keep a reference to the mm, in case the task is dead. 2022-12-28 14:11:48 -08:00
tnum.c
trampoline.c bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules 2023-03-15 18:38:21 -07:00
verifier.c bpf: Support 64-bit pointers to kfuncs 2023-04-13 21:36:41 -07:00