From: Eduard Zingerman <eddyz87@gmail.com>
To: Yonghong Song <yhs@fb.com>, bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Fangrui Song <maskray@google.com>,
kernel-team@fb.com
Subject: Re: [PATCH bpf-next v2 04/15] bpf: Support new unconditional bswap instruction
Date: Mon, 17 Jul 2023 04:42:03 +0300 [thread overview]
Message-ID: <cb9ba725b54fb02a5a552d46043a8e90c6f7b85a.camel@gmail.com> (raw)
In-Reply-To: <20230713060739.390659-1-yhs@fb.com>
On Wed, 2023-07-12 at 23:07 -0700, Yonghong Song wrote:
> > The existing 'be' and 'le' insns will do conditional bswap
> > depends on host endianness. This patch implements
> > unconditional bswap insns.
> >
> > Signed-off-by: Yonghong Song <yhs@fb.com>
Note sure if this is important, but here is an observation:
function is_reg64() has the following code:
...
if (class == BPF_ALU64 || class == BPF_JMP ||
/* BPF_END always use BPF_ALU class. */
(class == BPF_ALU && op == BPF_END && insn->imm == 64))
return true;
...
It probably has to be updated but I'm not sure how:
- either check insn->imm == 64 for ALU64 as well;
- or just update the comment, given that instruction always sets all 64-bits.
> > ---
> > arch/x86/net/bpf_jit_comp.c | 1 +
> > kernel/bpf/core.c | 14 ++++++++++++++
> > kernel/bpf/verifier.c | 2 +-
> > 3 files changed, 16 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
> > index a740a1a6e71d..adda5e7626b4 100644
> > --- a/arch/x86/net/bpf_jit_comp.c
> > +++ b/arch/x86/net/bpf_jit_comp.c
> > @@ -1322,6 +1322,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
> > break;
> >
> > case BPF_ALU | BPF_END | BPF_FROM_BE:
> > + case BPF_ALU64 | BPF_END | BPF_FROM_LE:
> > switch (imm32) {
> > case 16:
> > /* Emit 'ror %ax, 8' to swap lower 2 bytes */
> > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> > index fe648a158c9e..86bb412fee39 100644
> > --- a/kernel/bpf/core.c
> > +++ b/kernel/bpf/core.c
> > @@ -1524,6 +1524,7 @@ EXPORT_SYMBOL_GPL(__bpf_call_base);
> > INSN_3(ALU64, DIV, X), \
> > INSN_3(ALU64, MOD, X), \
> > INSN_2(ALU64, NEG), \
> > + INSN_3(ALU64, END, TO_LE), \
> > /* Immediate based. */ \
> > INSN_3(ALU64, ADD, K), \
> > INSN_3(ALU64, SUB, K), \
> > @@ -1845,6 +1846,19 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
> > break;
> > }
> > CONT;
> > + ALU64_END_TO_LE:
> > + switch (IMM) {
> > + case 16:
> > + DST = (__force u16) __swab16(DST);
> > + break;
> > + case 32:
> > + DST = (__force u32) __swab32(DST);
> > + break;
> > + case 64:
> > + DST = (__force u64) __swab64(DST);
> > + break;
> > + }
> > + CONT;
> >
> > /* CALL */
> > JMP_CALL:
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index 5fee9f24cb5e..22ba0744547b 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -13036,7 +13036,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
> > } else {
> > if (insn->src_reg != BPF_REG_0 || insn->off != 0 ||
> > (insn->imm != 16 && insn->imm != 32 && insn->imm != 64) ||
> > - BPF_CLASS(insn->code) == BPF_ALU64) {
> > + (BPF_CLASS(insn->code) == BPF_ALU64 && BPF_SRC(insn->code) != BPF_K)) {
> > verbose(env, "BPF_END uses reserved fields\n");
> > return -EINVAL;
> > }
next prev parent reply other threads:[~2023-07-17 1:42 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-13 6:07 [PATCH bpf-next v2 00/15] bpf: Support new insns from cpu v4 Yonghong Song
2023-07-13 6:07 ` [PATCH bpf-next v2 01/15] bpf: Support new sign-extension load insns Yonghong Song
2023-07-14 18:13 ` Alexei Starovoitov
2023-07-14 23:22 ` Yonghong Song
2023-07-17 1:39 ` Eduard Zingerman
2023-07-19 0:15 ` Eduard Zingerman
2023-07-19 2:28 ` Yonghong Song
2023-07-13 6:07 ` [PATCH bpf-next v2 02/15] bpf: Fix sign-extension ctx member accesses Yonghong Song
2023-07-17 1:40 ` Eduard Zingerman
2023-07-19 0:40 ` Yonghong Song
2023-07-13 6:07 ` [PATCH bpf-next v2 03/15] bpf: Support new sign-extension mov insns Yonghong Song
2023-07-17 1:41 ` Eduard Zingerman
2023-07-19 1:17 ` Yonghong Song
2023-07-19 12:53 ` Eduard Zingerman
2023-07-19 15:59 ` Fangrui Song
2023-07-19 16:57 ` Eduard Zingerman
2023-07-13 6:07 ` [PATCH bpf-next v2 04/15] bpf: Support new unconditional bswap instruction Yonghong Song
2023-07-17 1:42 ` Eduard Zingerman [this message]
2023-07-19 1:22 ` Yonghong Song
2023-07-13 6:07 ` [PATCH bpf-next v2 05/15] bpf: Support new signed div/mod instructions Yonghong Song
2023-07-18 23:00 ` Eduard Zingerman
2023-07-19 2:30 ` Yonghong Song
2023-07-19 2:44 ` Alexei Starovoitov
2023-07-19 6:57 ` Yonghong Song
2023-07-13 6:07 ` [PATCH bpf-next v2 06/15] bpf: Fix jit blinding with new sdiv/smov insns Yonghong Song
2023-07-13 6:07 ` [PATCH bpf-next v2 07/15] bpf: Support new 32bit offset jmp instruction Yonghong Song
2023-07-13 6:08 ` [PATCH bpf-next v2 08/15] selftests/bpf: Add a cpuv4 test runner for cpu=v4 testing Yonghong Song
2023-07-13 6:18 ` Fangrui Song
2023-07-13 6:25 ` Yonghong Song
2023-07-13 6:08 ` [PATCH bpf-next v2 09/15] selftests/bpf: Add unit tests for new sign-extension load insns Yonghong Song
2023-07-18 23:06 ` Eduard Zingerman
2023-07-13 6:08 ` [PATCH bpf-next v2 10/15] selftests/bpf: Add unit tests for new sign-extension mov insns Yonghong Song
2023-07-13 6:08 ` [PATCH bpf-next v2 11/15] selftests/bpf: Add unit tests for new bswap insns Yonghong Song
2023-07-13 6:08 ` [PATCH bpf-next v2 12/15] selftests/bpf: Add unit tests for new sdiv/smod insns Yonghong Song
2023-07-18 23:10 ` Eduard Zingerman
2023-07-13 6:08 ` [PATCH bpf-next v2 13/15] selftests/bpf: Add unit tests for new gotol insn Yonghong Song
2023-07-13 6:08 ` [PATCH bpf-next v2 14/15] selftests/bpf: Test ldsx with more complex cases Yonghong Song
2023-07-13 6:08 ` [PATCH bpf-next v2 15/15] docs/bpf: Add documentation for new instructions Yonghong Song
2023-07-14 18:28 ` Alexei Starovoitov
2023-07-14 23:26 ` Yonghong Song
2023-07-14 23:33 ` Dave Thaler
2023-07-14 23:33 ` [Bpf] " Dave Thaler
2023-07-15 0:23 ` Alexei Starovoitov
2023-07-15 0:23 ` [Bpf] " Alexei Starovoitov
2023-07-14 23:34 ` Dave Thaler
2023-07-14 23:34 ` [Bpf] " Dave Thaler
2023-07-17 1:39 ` [PATCH bpf-next v2 00/15] bpf: Support new insns from cpu v4 Eduard Zingerman
2023-07-17 16:56 ` Alexei Starovoitov
2023-07-17 17:04 ` Eduard Zingerman
2023-07-17 21:52 ` Yonghong Song
2023-07-21 14:56 ` Jose E. Marchesi
2023-07-24 0:17 ` Jose E. Marchesi
2023-07-24 1:04 ` Jose E. Marchesi
2023-07-24 2:35 ` Yonghong Song
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