All of lore.kernel.org
 help / color / mirror / Atom feed
From: Daniel Borkmann <daniel@iogearbox.net>
To: ast@kernel.org
Cc: netdev@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next v2 07/13] bpf, sparc64: remove ld_abs/ld_ind
Date: Fri,  4 May 2018 01:08:18 +0200	[thread overview]
Message-ID: <20180503230824.3462-8-daniel@iogearbox.net> (raw)
In-Reply-To: <20180503230824.3462-1-daniel@iogearbox.net>

Since LD_ABS/LD_IND instructions are now removed from the core and
reimplemented through a combination of inlined BPF instructions and
a slow-path helper, we can get rid of the complexity from sparc64 JIT.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc/net/Makefile          |   5 +-
 arch/sparc/net/bpf_jit_64.h      |  29 -------
 arch/sparc/net/bpf_jit_asm_64.S  | 162 ---------------------------------------
 arch/sparc/net/bpf_jit_comp_64.c |  79 +------------------
 4 files changed, 6 insertions(+), 269 deletions(-)
 delete mode 100644 arch/sparc/net/bpf_jit_asm_64.S

diff --git a/arch/sparc/net/Makefile b/arch/sparc/net/Makefile
index 76fa8e9..d32aac3 100644
--- a/arch/sparc/net/Makefile
+++ b/arch/sparc/net/Makefile
@@ -1,4 +1,7 @@
 #
 # Arch-specific network modules
 #
-obj-$(CONFIG_BPF_JIT) += bpf_jit_asm_$(BITS).o bpf_jit_comp_$(BITS).o
+obj-$(CONFIG_BPF_JIT) += bpf_jit_comp_$(BITS).o
+ifeq ($(BITS),32)
+obj-$(CONFIG_BPF_JIT) += bpf_jit_asm_32.o
+endif
diff --git a/arch/sparc/net/bpf_jit_64.h b/arch/sparc/net/bpf_jit_64.h
index 428f7fd..fbc836f 100644
--- a/arch/sparc/net/bpf_jit_64.h
+++ b/arch/sparc/net/bpf_jit_64.h
@@ -33,35 +33,6 @@
 #define I5		0x1d
 #define FP		0x1e
 #define I7		0x1f
-
-#define r_SKB		L0
-#define r_HEADLEN	L4
-#define r_SKB_DATA	L5
-#define r_TMP		G1
-#define r_TMP2		G3
-
-/* assembly code in arch/sparc/net/bpf_jit_asm_64.S */
-extern u32 bpf_jit_load_word[];
-extern u32 bpf_jit_load_half[];
-extern u32 bpf_jit_load_byte[];
-extern u32 bpf_jit_load_byte_msh[];
-extern u32 bpf_jit_load_word_positive_offset[];
-extern u32 bpf_jit_load_half_positive_offset[];
-extern u32 bpf_jit_load_byte_positive_offset[];
-extern u32 bpf_jit_load_byte_msh_positive_offset[];
-extern u32 bpf_jit_load_word_negative_offset[];
-extern u32 bpf_jit_load_half_negative_offset[];
-extern u32 bpf_jit_load_byte_negative_offset[];
-extern u32 bpf_jit_load_byte_msh_negative_offset[];
-
-#else
-#define r_RESULT	%o0
-#define r_SKB		%o0
-#define r_OFF		%o1
-#define r_HEADLEN	%l4
-#define r_SKB_DATA	%l5
-#define r_TMP		%g1
-#define r_TMP2		%g3
 #endif
 
 #endif /* _BPF_JIT_H */
diff --git a/arch/sparc/net/bpf_jit_asm_64.S b/arch/sparc/net/bpf_jit_asm_64.S
deleted file mode 100644
index 7177867..0000000
--- a/arch/sparc/net/bpf_jit_asm_64.S
+++ /dev/null
@@ -1,162 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm/ptrace.h>
-
-#include "bpf_jit_64.h"
-
-#define SAVE_SZ		176
-#define SCRATCH_OFF	STACK_BIAS + 128
-#define BE_PTR(label)	be,pn %xcc, label
-#define SIGN_EXTEND(reg)	sra reg, 0, reg
-
-#define SKF_MAX_NEG_OFF	(-0x200000) /* SKF_LL_OFF from filter.h */
-
-	.text
-	.globl	bpf_jit_load_word
-bpf_jit_load_word:
-	cmp	r_OFF, 0
-	bl	bpf_slow_path_word_neg
-	 nop
-	.globl	bpf_jit_load_word_positive_offset
-bpf_jit_load_word_positive_offset:
-	sub	r_HEADLEN, r_OFF, r_TMP
-	cmp	r_TMP, 3
-	ble	bpf_slow_path_word
-	 add	r_SKB_DATA, r_OFF, r_TMP
-	andcc	r_TMP, 3, %g0
-	bne	load_word_unaligned
-	 nop
-	retl
-	 ld	[r_TMP], r_RESULT
-load_word_unaligned:
-	ldub	[r_TMP + 0x0], r_OFF
-	ldub	[r_TMP + 0x1], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	or	r_OFF, r_TMP2, r_OFF
-	ldub	[r_TMP + 0x2], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	or	r_OFF, r_TMP2, r_OFF
-	ldub	[r_TMP + 0x3], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	retl
-	 or	r_OFF, r_TMP2, r_RESULT
-
-	.globl	bpf_jit_load_half
-bpf_jit_load_half:
-	cmp	r_OFF, 0
-	bl	bpf_slow_path_half_neg
-	 nop
-	.globl	bpf_jit_load_half_positive_offset
-bpf_jit_load_half_positive_offset:
-	sub	r_HEADLEN, r_OFF, r_TMP
-	cmp	r_TMP, 1
-	ble	bpf_slow_path_half
-	 add	r_SKB_DATA, r_OFF, r_TMP
-	andcc	r_TMP, 1, %g0
-	bne	load_half_unaligned
-	 nop
-	retl
-	 lduh	[r_TMP], r_RESULT
-load_half_unaligned:
-	ldub	[r_TMP + 0x0], r_OFF
-	ldub	[r_TMP + 0x1], r_TMP2
-	sll	r_OFF, 8, r_OFF
-	retl
-	 or	r_OFF, r_TMP2, r_RESULT
-
-	.globl	bpf_jit_load_byte
-bpf_jit_load_byte:
-	cmp	r_OFF, 0
-	bl	bpf_slow_path_byte_neg
-	 nop
-	.globl	bpf_jit_load_byte_positive_offset
-bpf_jit_load_byte_positive_offset:
-	cmp	r_OFF, r_HEADLEN
-	bge	bpf_slow_path_byte
-	 nop
-	retl
-	 ldub	[r_SKB_DATA + r_OFF], r_RESULT
-
-#define bpf_slow_path_common(LEN)	\
-	save	%sp, -SAVE_SZ, %sp;	\
-	mov	%i0, %o0;		\
-	mov	%i1, %o1;		\
-	add	%fp, SCRATCH_OFF, %o2;	\
-	call	skb_copy_bits;		\
-	 mov	(LEN), %o3;		\
-	cmp	%o0, 0;			\
-	restore;
-
-bpf_slow_path_word:
-	bpf_slow_path_common(4)
-	bl	bpf_error
-	 ld	[%sp + SCRATCH_OFF], r_RESULT
-	retl
-	 nop
-bpf_slow_path_half:
-	bpf_slow_path_common(2)
-	bl	bpf_error
-	 lduh	[%sp + SCRATCH_OFF], r_RESULT
-	retl
-	 nop
-bpf_slow_path_byte:
-	bpf_slow_path_common(1)
-	bl	bpf_error
-	 ldub	[%sp + SCRATCH_OFF], r_RESULT
-	retl
-	 nop
-
-#define bpf_negative_common(LEN)			\
-	save	%sp, -SAVE_SZ, %sp;			\
-	mov	%i0, %o0;				\
-	mov	%i1, %o1;				\
-	SIGN_EXTEND(%o1);				\
-	call	bpf_internal_load_pointer_neg_helper;	\
-	 mov	(LEN), %o2;				\
-	mov	%o0, r_TMP;				\
-	cmp	%o0, 0;					\
-	BE_PTR(bpf_error);				\
-	 restore;
-
-bpf_slow_path_word_neg:
-	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
-	cmp	r_OFF, r_TMP
-	bl	bpf_error
-	 nop
-	.globl	bpf_jit_load_word_negative_offset
-bpf_jit_load_word_negative_offset:
-	bpf_negative_common(4)
-	andcc	r_TMP, 3, %g0
-	bne	load_word_unaligned
-	 nop
-	retl
-	 ld	[r_TMP], r_RESULT
-
-bpf_slow_path_half_neg:
-	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
-	cmp	r_OFF, r_TMP
-	bl	bpf_error
-	 nop
-	.globl	bpf_jit_load_half_negative_offset
-bpf_jit_load_half_negative_offset:
-	bpf_negative_common(2)
-	andcc	r_TMP, 1, %g0
-	bne	load_half_unaligned
-	 nop
-	retl
-	 lduh	[r_TMP], r_RESULT
-
-bpf_slow_path_byte_neg:
-	sethi	%hi(SKF_MAX_NEG_OFF), r_TMP
-	cmp	r_OFF, r_TMP
-	bl	bpf_error
-	 nop
-	.globl	bpf_jit_load_byte_negative_offset
-bpf_jit_load_byte_negative_offset:
-	bpf_negative_common(1)
-	retl
-	 ldub	[r_TMP], r_RESULT
-
-bpf_error:
-	/* Make the JIT program itself return zero. */
-	ret
-	restore	%g0, %g0, %o0
diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c
index 48a2586..9f5918e 100644
--- a/arch/sparc/net/bpf_jit_comp_64.c
+++ b/arch/sparc/net/bpf_jit_comp_64.c
@@ -48,10 +48,6 @@ static void bpf_flush_icache(void *start_, void *end_)
 	}
 }
 
-#define SEEN_DATAREF 1 /* might call external helpers */
-#define SEEN_XREG    2 /* ebx is used */
-#define SEEN_MEM     4 /* use mem[] for temporary storage */
-
 #define S13(X)		((X) & 0x1fff)
 #define S5(X)		((X) & 0x1f)
 #define IMMED		0x00002000
@@ -198,7 +194,6 @@ struct jit_ctx {
 	bool 			tmp_1_used;
 	bool 			tmp_2_used;
 	bool 			tmp_3_used;
-	bool			saw_ld_abs_ind;
 	bool			saw_frame_pointer;
 	bool			saw_call;
 	bool			saw_tail_call;
@@ -207,9 +202,7 @@ struct jit_ctx {
 
 #define TMP_REG_1	(MAX_BPF_JIT_REG + 0)
 #define TMP_REG_2	(MAX_BPF_JIT_REG + 1)
-#define SKB_HLEN_REG	(MAX_BPF_JIT_REG + 2)
-#define SKB_DATA_REG	(MAX_BPF_JIT_REG + 3)
-#define TMP_REG_3	(MAX_BPF_JIT_REG + 4)
+#define TMP_REG_3	(MAX_BPF_JIT_REG + 2)
 
 /* Map BPF registers to SPARC registers */
 static const int bpf2sparc[] = {
@@ -238,9 +231,6 @@ static const int bpf2sparc[] = {
 	[TMP_REG_1] = G1,
 	[TMP_REG_2] = G2,
 	[TMP_REG_3] = G3,
-
-	[SKB_HLEN_REG] = L4,
-	[SKB_DATA_REG] = L5,
 };
 
 static void emit(const u32 insn, struct jit_ctx *ctx)
@@ -800,25 +790,6 @@ static int emit_compare_and_branch(const u8 code, const u8 dst, u8 src,
 	return 0;
 }
 
-static void load_skb_regs(struct jit_ctx *ctx, u8 r_skb)
-{
-	const u8 r_headlen = bpf2sparc[SKB_HLEN_REG];
-	const u8 r_data = bpf2sparc[SKB_DATA_REG];
-	const u8 r_tmp = bpf2sparc[TMP_REG_1];
-	unsigned int off;
-
-	off = offsetof(struct sk_buff, len);
-	emit(LD32I | RS1(r_skb) | S13(off) | RD(r_headlen), ctx);
-
-	off = offsetof(struct sk_buff, data_len);
-	emit(LD32I | RS1(r_skb) | S13(off) | RD(r_tmp), ctx);
-
-	emit(SUB | RS1(r_headlen) | RS2(r_tmp) | RD(r_headlen), ctx);
-
-	off = offsetof(struct sk_buff, data);
-	emit(LDPTRI | RS1(r_skb) | S13(off) | RD(r_data), ctx);
-}
-
 /* Just skip the save instruction and the ctx register move.  */
 #define BPF_TAILCALL_PROLOGUE_SKIP	16
 #define BPF_TAILCALL_CNT_SP_OFF		(STACK_BIAS + 128)
@@ -857,9 +828,6 @@ static void build_prologue(struct jit_ctx *ctx)
 
 	emit_reg_move(I0, O0, ctx);
 	/* If you add anything here, adjust BPF_TAILCALL_PROLOGUE_SKIP above. */
-
-	if (ctx->saw_ld_abs_ind)
-		load_skb_regs(ctx, bpf2sparc[BPF_REG_1]);
 }
 
 static void build_epilogue(struct jit_ctx *ctx)
@@ -1225,16 +1193,11 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 		u8 *func = ((u8 *)__bpf_call_base) + imm;
 
 		ctx->saw_call = true;
-		if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
-			emit_reg_move(bpf2sparc[BPF_REG_1], L7, ctx);
 
 		emit_call((u32 *)func, ctx);
 		emit_nop(ctx);
 
 		emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
-
-		if (ctx->saw_ld_abs_ind && bpf_helper_changes_pkt_data(func))
-			load_skb_regs(ctx, L7);
 		break;
 	}
 
@@ -1412,43 +1375,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
 		emit_nop(ctx);
 		break;
 	}
-#define CHOOSE_LOAD_FUNC(K, func) \
-		((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset)
-
-	/* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */
-	case BPF_LD | BPF_ABS | BPF_W:
-		func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_word);
-		goto common_load;
-	case BPF_LD | BPF_ABS | BPF_H:
-		func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_half);
-		goto common_load;
-	case BPF_LD | BPF_ABS | BPF_B:
-		func = CHOOSE_LOAD_FUNC(imm, bpf_jit_load_byte);
-		goto common_load;
-	/* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */
-	case BPF_LD | BPF_IND | BPF_W:
-		func = bpf_jit_load_word;
-		goto common_load;
-	case BPF_LD | BPF_IND | BPF_H:
-		func = bpf_jit_load_half;
-		goto common_load;
-
-	case BPF_LD | BPF_IND | BPF_B:
-		func = bpf_jit_load_byte;
-	common_load:
-		ctx->saw_ld_abs_ind = true;
-
-		emit_reg_move(bpf2sparc[BPF_REG_6], O0, ctx);
-		emit_loadimm(imm, O1, ctx);
-
-		if (BPF_MODE(code) == BPF_IND)
-			emit_alu(ADD, src, O1, ctx);
-
-		emit_call(func, ctx);
-		emit_alu_K(SRA, O1, 0, ctx);
-
-		emit_reg_move(O0, bpf2sparc[BPF_REG_0], ctx);
-		break;
 
 	default:
 		pr_err_once("unknown opcode %02x\n", code);
@@ -1583,12 +1509,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 		build_epilogue(&ctx);
 
 		if (bpf_jit_enable > 1)
-			pr_info("Pass %d: shrink = %d, seen = [%c%c%c%c%c%c%c]\n", pass,
+			pr_info("Pass %d: shrink = %d, seen = [%c%c%c%c%c%c]\n", pass,
 				image_size - (ctx.idx * 4),
 				ctx.tmp_1_used ? '1' : ' ',
 				ctx.tmp_2_used ? '2' : ' ',
 				ctx.tmp_3_used ? '3' : ' ',
-				ctx.saw_ld_abs_ind ? 'L' : ' ',
 				ctx.saw_frame_pointer ? 'F' : ' ',
 				ctx.saw_call ? 'C' : ' ',
 				ctx.saw_tail_call ? 'T' : ' ');
-- 
2.9.5

  parent reply	other threads:[~2018-05-03 23:08 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-03 23:08 [PATCH bpf-next v2 00/13] Move ld_abs/ld_ind to native BPF Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 01/13] bpf: prefix cbpf internal helpers with bpf_ Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 02/13] bpf: migrate ebpf ld_abs/ld_ind tests to test_verifier Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 03/13] bpf: implement ld_abs/ld_ind in native bpf Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 04/13] bpf: add skb_load_bytes_relative helper Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 05/13] bpf, x64: remove ld_abs/ld_ind Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 06/13] bpf, arm64: " Daniel Borkmann
2018-05-03 23:08 ` Daniel Borkmann [this message]
2018-05-03 23:08 ` [PATCH bpf-next v2 08/13] bpf, arm32: " Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 09/13] bpf, mips64: " Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 10/13] bpf, ppc64: " Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 11/13] bpf, s390x: " Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 12/13] bpf, x32: " Daniel Borkmann
2018-05-03 23:08 ` [PATCH bpf-next v2 13/13] bpf: sync tools bpf.h uapi header Daniel Borkmann
2018-05-04  0:02 ` [PATCH bpf-next v2 00/13] Move ld_abs/ld_ind to native BPF Alexei Starovoitov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180503230824.3462-8-daniel@iogearbox.net \
    --to=daniel@iogearbox.net \
    --cc=ast@kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.