Ilya Leoshkevich f4a5c7ff2a bpf: Clear subreg_def for global function return values ... [ Upstream commit 45159b27637b0fef6d5ddb86fc7c46b13c77960f ] test_global_func4 fails on s390 as reported by Yauheni in [1]. The immediate problem is that the zext code includes the instruction, whose result needs to be zero-extended, into the zero-extension patchlet, and if this instruction happens to be a branch, then its delta is not adjusted. As a result, the verifier rejects the program later. However, according to [2], as far as the verifier's algorithm is concerned and as specified by the insn_no_def() function, branching insns do not define anything. This includes call insns, even though one might argue that they define %r0. This means that the real problem is that zero extension kicks in at all. This happens because clear_caller_saved_regs() sets BPF_REG_0's subreg_def after global function calls. This can be fixed in many ways; this patch mimics what helper function call handling already does. [1] https://lore.kernel.org/bpf/20200903140542.156624-1-yauheni.kaliuta@redhat.com/ [2] https://lore.kernel.org/bpf/CAADnVQ+2RPKcftZw8d+B1UwB35cpBhpF5u3OocNh90D9pETPwg@mail.gmail.com/ Fixes: 51c39bb1d5 ("bpf: Introduce function-by-function verification") Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210212040408.90109-1-iii@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-03-04 11:37:34 +01:00
..
preload	bpf, preload: Fix build when $(O) points to a relative path	2021-02-10 09:29:13 +01:00
arraymap.c	bpf: Allow for map-in-map with dynamic inner array map entries	2020-10-11 10:21:04 -07:00
bpf_inode_storage.c	bpf, inode_storage: Put file handler if no storage was found	2021-02-10 09:29:12 +01:00
bpf_iter.c	bpf: Fix an unitialized value in bpf_iter	2021-03-04 11:37:33 +01:00
bpf_local_storage.c
bpf_lru_list.c	bpf_lru_list: Read double-checked variable once without lock	2021-03-04 11:37:29 +01:00
bpf_lru_list.h
bpf_lsm.c	bpf: Update verification logic for LSM programs	2020-11-06 13:15:21 -08:00
bpf_struct_ops_types.h
bpf_struct_ops.c
btf.c
cgroup.c	bpf, cgroup: Fix problematic bounds check	2021-02-10 09:29:12 +01:00
core.c	bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE	2020-10-29 20:01:46 -07:00
cpumap.c
devmap.c	bpf, devmap: Use GFP_KERNEL for xdp bulk queue allocation	2021-03-04 11:37:33 +01:00
disasm.c
disasm.h
dispatcher.c
hashtab.c	bpf: Zero-fill re-used per-cpu map element	2020-11-05 19:55:57 -08:00
helpers.c	bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback	2021-01-23 16:03:59 +01:00
inode.c
local_storage.c
lpm_trie.c
Makefile	bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE	2020-10-29 20:01:46 -07:00
map_in_map.c
map_in_map.h
map_iter.c
net_namespace.c
offload.c
percpu_freelist.c	bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI	2020-10-06 00:04:11 +02:00
percpu_freelist.h	bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI	2020-10-06 00:04:11 +02:00
prog_iter.c
queue_stack_maps.c
reuseport_array.c
ringbuf.c
stackmap.c	bpf: Check for integer overflow when using roundup_pow_of_two()	2021-02-17 11:02:25 +01:00
syscall.c	bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach	2021-01-27 11:55:07 +01:00
sysfs_btf.c
task_iter.c	bpf: Save correct stopping point in file seq iteration	2021-01-19 18:27:28 +01:00
tnum.c
trampoline.c
verifier.c	bpf: Clear subreg_def for global function return values	2021-03-04 11:37:34 +01:00