From: Ilya Leoshkevich <iii@linux.ibm.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org, Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH bpf-next 24/24] s390/bpf: Implement bpf_jit_supports_kfunc_call()
Date: Wed, 25 Jan 2023 22:38:17 +0100 [thread overview]
Message-ID: <20230125213817.1424447-25-iii@linux.ibm.com> (raw)
In-Reply-To: <20230125213817.1424447-1-iii@linux.ibm.com>
Implement calling kernel functions from eBPF. In general, the eBPF ABI
is fairly close to that of s390x, with one important difference: on
s390x callers should sign-extend signed arguments. Handle that by using
information returned by bpf_jit_find_kfunc_model().
At the moment bpf_jit_find_kfunc_model() does not seem to play nicely
with XDP metadata functions: add_kfunc_call() adds an "abstract" bpf_*()
version to kfunc_btf_tab, but then fixup_kfunc_call() puts the concrete
version into insn->imm, which bpf_jit_find_kfunc_model() cannot find.
But this seems to be a common code problem.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
arch/s390/net/bpf_jit_comp.c | 25 +++++++++++++++++++++++--
1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index f4cdecb32629..74b38e817bd8 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -1401,9 +1401,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
*/
case BPF_JMP | BPF_CALL:
{
- u64 func;
+ const struct btf_func_model *m;
bool func_addr_fixed;
- int ret;
+ int j, ret;
+ u64 func;
ret = bpf_jit_get_func_addr(fp, insn, extra_pass,
&func, &func_addr_fixed);
@@ -1425,6 +1426,21 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
/* mvc STK_OFF_TCCNT(4,%r15),N(%r15) */
_EMIT6(0xd203f000 | STK_OFF_TCCNT,
0xf000 | (STK_OFF_TCCNT + STK_OFF + stack_depth));
+
+ /* Sign-extend the kfunc arguments. */
+ if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) {
+ m = bpf_jit_find_kfunc_model(fp, insn);
+ if (!m)
+ return -1;
+
+ for (j = 0; j < m->nr_args; j++) {
+ if (sign_extend(jit, BPF_REG_1 + j,
+ m->arg_size[j],
+ m->arg_flags[j]))
+ return -1;
+ }
+ }
+
/* lgrl %w1,func */
EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func));
/* %r1() */
@@ -1980,6 +1996,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
return fp;
}
+bool bpf_jit_supports_kfunc_call(void)
+{
+ return true;
+}
+
int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
void *old_addr, void *new_addr)
{
--
2.39.1
next prev parent reply other threads:[~2023-01-25 21:40 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-25 21:37 [PATCH bpf-next 00/24] Support bpf trampoline for s390x Ilya Leoshkevich
2023-01-25 21:37 ` [PATCH bpf-next 01/24] selftests/bpf: Fix liburandom_read.so linker error Ilya Leoshkevich
2023-01-26 1:07 ` Andrii Nakryiko
2023-01-26 13:30 ` Ilya Leoshkevich
2023-01-25 21:37 ` [PATCH bpf-next 02/24] selftests/bpf: Fix symlink creation error Ilya Leoshkevich
2023-01-25 21:37 ` [PATCH bpf-next 03/24] selftests/bpf: Fix fexit_stress on s390x Ilya Leoshkevich
2023-01-25 21:37 ` [PATCH bpf-next 04/24] selftests/bpf: Fix trampoline_count " Ilya Leoshkevich
2023-01-25 21:37 ` [PATCH bpf-next 05/24] selftests/bpf: Fix kfree_skb " Ilya Leoshkevich
2023-01-25 21:37 ` [PATCH bpf-next 06/24] selftests/bpf: Set errno when urand_spawn() fails Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 07/24] selftests/bpf: Fix decap_sanity_ns cleanup Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 08/24] selftests/bpf: Fix verify_pkcs7_sig on s390x Ilya Leoshkevich
2023-01-26 1:06 ` Andrii Nakryiko
2023-01-27 12:36 ` Ilya Leoshkevich
2023-01-27 17:26 ` Andrii Nakryiko
2023-01-25 21:38 ` [PATCH bpf-next 09/24] selftests/bpf: Fix xdp_do_redirect " Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 10/24] selftests/bpf: Fix cgrp_local_storage " Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 11/24] selftests/bpf: Check stack_mprotect() return value Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 12/24] selftests/bpf: Increase SIZEOF_BPF_LOCAL_STORAGE_ELEM on s390x Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 13/24] selftests/bpf: Add a sign-extension test for kfuncs Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 14/24] selftests/bpf: Fix test_lsm on s390x Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 15/24] selftests/bpf: Fix test_xdp_adjust_tail_grow2 " Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 16/24] selftests/bpf: Fix vmlinux test " Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 17/24] libbpf: Read usdt arg spec with bpf_probe_read_kernel() Ilya Leoshkevich
2023-01-26 0:26 ` Andrii Nakryiko
2023-01-26 11:41 ` Ilya Leoshkevich
2023-01-26 19:03 ` Andrii Nakryiko
2023-01-27 11:01 ` Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 18/24] s390/bpf: Fix a typo in a comment Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 19/24] s390/bpf: Add expoline to tail calls Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 20/24] s390/bpf: Implement bpf_arch_text_poke() Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 21/24] bpf: btf: Add BTF_FMODEL_SIGNED_ARG flag Ilya Leoshkevich
2023-01-25 21:38 ` [PATCH bpf-next 22/24] s390/bpf: Implement arch_prepare_bpf_trampoline() Ilya Leoshkevich
2023-01-26 1:15 ` Andrii Nakryiko
2023-01-26 14:30 ` Ilya Leoshkevich
2023-01-26 19:06 ` Andrii Nakryiko
2023-01-27 11:15 ` Ilya Leoshkevich
2023-01-27 17:30 ` Andrii Nakryiko
2023-01-25 21:38 ` [PATCH bpf-next 23/24] s390/bpf: Implement bpf_jit_supports_subprog_tailcalls() Ilya Leoshkevich
2023-01-25 21:38 ` Ilya Leoshkevich [this message]
2023-01-26 1:28 ` [PATCH bpf-next 24/24] s390/bpf: Implement bpf_jit_supports_kfunc_call() Alexei Starovoitov
2023-01-27 11:36 ` Ilya Leoshkevich
2023-01-27 16:04 ` Alexei Starovoitov
2023-01-26 0:45 ` [PATCH bpf-next 00/24] Support bpf trampoline for s390x Andrii Nakryiko
2023-01-27 16:51 ` Ilya Leoshkevich
2023-01-27 17:24 ` Andrii Nakryiko
2023-01-27 22:50 ` Ilya Leoshkevich
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