linux/kernel/bpf
Puranjay Mohan f7f5d1808b bpf: verifier: fix addr_space_cast from as(1) to as(0)
The verifier currently converts addr_space_cast from as(1) to as(0) that
is: BPF_ALU64 | BPF_MOV | BPF_X with off=1 and imm=1
to
BPF_ALU | BPF_MOV | BPF_X with imm=1 (32-bit mov)

Because of this imm=1, the JITs that have bpf_jit_needs_zext() == true,
interpret the converted instruction as BPF_ZEXT_REG(DST) which is a
special form of mov32, used for doing explicit zero extension on dst.
These JITs will just zero extend the dst reg and will not move the src to
dst before the zext.

Fix do_misc_fixups() to set imm=0 when converting addr_space_cast to a
normal mov32.

The JITs that have bpf_jit_needs_zext() == true rely on the verifier to
emit zext instructions. Mark dst_reg as subreg when doing cast from
as(1) to as(0) so the verifier emits a zext instruction after the mov.

Fixes: 6082b6c328 ("bpf: Recognize addr_space_cast instruction in the verifier.")
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20240321153939.113996-1-puranjay12@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-22 20:36:36 -07:00
..
preload bpf: make preloaded map iterators to display map elements count 2023-07-06 12:42:25 -07:00
arena.c bpf: Clarify bpf_arena comments. 2024-03-15 14:23:45 -07:00
arraymap.c bpf: Consistently use BPF token throughout BPF verifier logic 2024-01-24 16:21:01 -08:00
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: Enable bpf_cgrp_storage for cgroup1 non-attach case 2023-12-08 17:08:18 -08:00
bpf_inode_storage.c Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
bpf_iter.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
bpf_local_storage.c bpf: Allow compiler to inline most of bpf_local_storage_lookup() 2024-02-11 14:06:24 -08:00
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: Minor clean-up to sleepable_lsm_hooks BTF set 2024-02-01 18:37:45 +01:00
bpf_struct_ops.c bpf: struct_ops supports more than one page for trampolines. 2024-03-04 14:09:20 -08:00
bpf_task_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
btf.c bpf: Recognize btf_decl_tag("arg: Arena") as PTR_TO_ARENA. 2024-03-11 15:37:24 -07:00
cgroup.c net: adopt skb_network_offset() and similar helpers 2024-03-04 08:47:06 +00:00
cgroup_iter.c bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg 2023-11-07 15:24:25 -08:00
core.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
cpumap.c net: move skbuff_cache(s) to net_hotdata 2024-03-07 21:12:42 -08:00
cpumask.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
devmap.c bpf: Fix DEVMAP_HASH overflow check on 32-bit arches 2024-03-07 20:02:38 -08:00
disasm.c bpf: Disasm support for addr_space_cast instruction. 2024-03-11 15:37:24 -07:00
disasm.h
dispatcher.c bpf: Use arch_bpf_trampoline_size 2023-12-06 17:17:20 -08:00
hashtab.c bpf: Fix hashtab overflow check on 32-bit arches 2024-03-07 20:05:56 -08:00
helpers.c bpf-next-for-netdev 2024-03-02 20:50:59 -08:00
inode.c bpf: Support symbolic BPF FS delegation mount options 2024-01-24 16:21:02 -08:00
Kconfig bpf: Merge two CONFIG_BPF entries 2024-02-07 16:38:20 -08:00
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: Recognize addr_space_cast instruction in the verifier. 2024-03-11 15:37:24 -07:00
lpm_trie.c bpf: Replace bpf_lpm_trie_key 0-length array with flexible array 2024-02-29 22:52:43 +01:00
Makefile bpf: Introduce bpf_arena. 2024-03-11 15:37:23 -07:00
map_in_map.c bpf: Optimize the free of inner map 2023-12-04 17:50:26 -08:00
map_in_map.h bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2023-12-04 17:50:26 -08:00
map_iter.c bpf: treewide: Annotate BPF kfuncs in BTF 2024-01-31 20:40:56 -08:00
memalloc.c bpf: Remove unnecessary cpu == 0 check in memalloc 2024-01-04 10:18:14 -08:00
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: Fix stackmap overflow check on 32-bit arches 2024-03-07 20:06:25 -08:00
syscall.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
sysfs_btf.c
task_iter.c bpf: Fix an issue due to uninitialized bpf_iter_task 2024-02-19 12:28:15 +01:00
tcx.c bpf, tcx: Get rid of tcx_link_const 2023-10-23 15:01:53 -07:00
tnum.c bpf: simplify tnum output if a fully known constant 2023-12-02 11:36:51 -08:00
token.c bpf,token: Use BIT_ULL() to convert the bit mask 2024-01-29 20:04:55 -08:00
trampoline.c bpf: move sleepable flag from bpf_prog_aux to bpf_prog 2024-03-11 16:41:25 -07:00
verifier.c bpf: verifier: fix addr_space_cast from as(1) to as(0) 2024-03-22 20:36:36 -07:00