diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2023-01-29 22:04:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 11:32:57 +0300 |
| commit | 24f105f90ad3e2e2e5349789c12da9ca71145093 (patch) | |
| tree | e2ebb0758fa9ce3581ee998f6af2ce5df638da85 /arch/s390 | |
| parent | bddd22cf5cc2ef6f0f4ce73986bed20443c54af7 (diff) | |
| download | linux-24f105f90ad3e2e2e5349789c12da9ca71145093.tar.xz | |
s390/bpf: Add expoline to tail calls
[ Upstream commit bb4ef8fc3d193ed8d5583fb47cbeff5d8fb8302f ]
All the indirect jumps in the eBPF JIT already use expolines, except
for the tail call one.
Fixes: de5cb6eb514e ("s390: use expoline thunks in the BPF JIT")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230129190501.1624747-3-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index af35052d06ed..fbdba4c306be 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1393,8 +1393,16 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, /* lg %r1,bpf_func(%r1) */ EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0, offsetof(struct bpf_prog, bpf_func)); - /* bc 0xf,tail_call_start(%r1) */ - _EMIT4(0x47f01000 + jit->tail_call_start); + if (nospec_uses_trampoline()) { + jit->seen |= SEEN_FUNC; + /* aghi %r1,tail_call_start */ + EMIT4_IMM(0xa70b0000, REG_1, jit->tail_call_start); + /* brcl 0xf,__s390_indirect_jump_r1 */ + EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->r1_thunk_ip); + } else { + /* bc 0xf,tail_call_start(%r1) */ + _EMIT4(0x47f01000 + jit->tail_call_start); + } /* out: */ if (jit->prg_buf) { *(u16 *)(jit->prg_buf + patch_1_clrj + 2) = |