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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>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH bpf-next 06/11] s390/bpf: Implement BPF_MEMSX
Date: Wed, 30 Aug 2023 03:07:47 +0200	[thread overview]
Message-ID: <20230830011128.1415752-7-iii@linux.ibm.com> (raw)
In-Reply-To: <20230830011128.1415752-1-iii@linux.ibm.com>

Implement the cpuv4 load with sign-extension, which is encoded as
BPF_MEMSX (and, for internal uses cases only, BPF_PROBE_MEMSX).

This is the same as BPF_MEM and BPF_PROBE_MEM, but with sign
extension instead of zero extension, and s390x has the necessary
instructions: lgb, lgh and lgf.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/net/bpf_jit_comp.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index da6fb4669973..841c5f8ead15 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -670,15 +670,18 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
 static int get_probe_mem_regno(const u8 *insn)
 {
 	/*
-	 * insn must point to llgc, llgh, llgf or lg, which have destination
-	 * register at the same position.
+	 * insn must point to llgc, llgh, llgf, lg, lgb, lgh or lgf, which have
+	 * destination register at the same position.
 	 */
-	if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */
+	if (insn[0] != 0xe3) /* common prefix */
 		return -1;
 	if (insn[5] != 0x90 && /* llgc */
 	    insn[5] != 0x91 && /* llgh */
 	    insn[5] != 0x16 && /* llgf */
-	    insn[5] != 0x04) /* lg */
+	    insn[5] != 0x04 && /* lg */
+	    insn[5] != 0x77 && /* lgb */
+	    insn[5] != 0x15 && /* lgh */
+	    insn[5] != 0x14) /* lgf */
 		return -1;
 	return insn[1] >> 4;
 }
@@ -788,7 +791,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 	int err;
 
 	if (BPF_CLASS(insn->code) == BPF_LDX &&
-	    BPF_MODE(insn->code) == BPF_PROBE_MEM)
+	    (BPF_MODE(insn->code) == BPF_PROBE_MEM ||
+	     BPF_MODE(insn->code) == BPF_PROBE_MEMSX))
 		probe_prg = jit->prg;
 
 	switch (insn->code) {
@@ -1406,6 +1410,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
+	case BPF_LDX | BPF_MEMSX | BPF_B: /* dst = *(s8 *)(ul) (src + off) */
+	case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
+		/* lgb %dst,0(off,%src) */
+		EMIT6_DISP_LH(0xe3000000, 0x0077, dst_reg, src_reg, REG_0, off);
+		jit->seen |= SEEN_MEM;
+		break;
 	case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
 	case BPF_LDX | BPF_PROBE_MEM | BPF_H:
 		/* llgh %dst,0(off,%src) */
@@ -1414,6 +1424,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
+	case BPF_LDX | BPF_MEMSX | BPF_H: /* dst = *(s16 *)(ul) (src + off) */
+	case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
+		/* lgh %dst,0(off,%src) */
+		EMIT6_DISP_LH(0xe3000000, 0x0015, dst_reg, src_reg, REG_0, off);
+		jit->seen |= SEEN_MEM;
+		break;
 	case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
 	case BPF_LDX | BPF_PROBE_MEM | BPF_W:
 		/* llgf %dst,off(%src) */
@@ -1422,6 +1438,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
 		if (insn_is_zext(&insn[1]))
 			insn_count = 2;
 		break;
+	case BPF_LDX | BPF_MEMSX | BPF_W: /* dst = *(s32 *)(ul) (src + off) */
+	case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
+		/* lgf %dst,off(%src) */
+		jit->seen |= SEEN_MEM;
+		EMIT6_DISP_LH(0xe3000000, 0x0014, dst_reg, src_reg, REG_0, off);
+		break;
 	case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
 	case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
 		/* lg %dst,0(off,%src) */
-- 
2.41.0


  parent reply	other threads:[~2023-08-30  1:12 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-30  1:07 [PATCH bpf-next 00/11] Implement cpuv4 support for s390x Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 01/11] bpf: Disable zero-extension for BPF_MEMSX Ilya Leoshkevich
2023-09-01 10:40   ` Yonghong Song
2023-09-01 14:19   ` Puranjay Mohan
2023-09-01 14:56     ` Puranjay Mohan
2023-09-07  0:39       ` Alexei Starovoitov
2023-09-07  7:33         ` Puranjay Mohan
2023-09-07 15:36           ` Alexei Starovoitov
2023-09-07 16:39             ` Puranjay Mohan
2023-09-07 22:45               ` Alexei Starovoitov
2023-09-07 22:57                 ` Puranjay Mohan
2023-09-12 22:49                 ` Puranjay Mohan
2023-09-13  0:09                   ` Alexei Starovoitov
2023-09-13  0:22                     ` Puranjay Mohan
2023-09-13  1:49                       ` Alexei Starovoitov
2023-09-13  6:10                       ` Christophe Leroy
2023-09-03  8:16     ` Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 02/11] net: netfilter: Adjust timeouts of non-confirmed CTs in bpf_ct_insert_entry() Ilya Leoshkevich
2023-08-31 15:30   ` Daniel Borkmann
2023-09-03  8:23     ` Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 03/11] selftests/bpf: Unmount the cgroup2 work directory Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 04/11] selftests/bpf: Add big-endian support to the ldsx test Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 05/11] s390/bpf: Implement BPF_MOV | BPF_X with sign-extension Ilya Leoshkevich
2023-08-30  1:07 ` Ilya Leoshkevich [this message]
2023-08-30  1:07 ` [PATCH bpf-next 07/11] s390/bpf: Implement unconditional byte swap Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 08/11] s390/bpf: Implement unconditional jump with 32-bit offset Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 09/11] s390/bpf: Implement signed division Ilya Leoshkevich
2023-08-30  1:07 ` [PATCH bpf-next 10/11] selftests/bpf: Enable the cpuv4 tests for s390x Ilya Leoshkevich
2023-09-01 10:41   ` Yonghong Song
2023-08-30  1:07 ` [PATCH bpf-next 11/11] selftests/bpf: Trim DENYLIST.s390x Ilya Leoshkevich
2023-09-14 13:00 ` [PATCH bpf-next 00/11] Implement cpuv4 support for s390x patchwork-bot+netdevbpf

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