Module Name: src
Committed By: alnsn
Date: Sun Jul 13 21:54:46 UTC 2014
Modified Files:
src/sys/net: bpfjit.c
Log Message:
Refactor BPF_COPX code. New version doesn't load buf and buflen after copx call.
To generate a diff of this commit:
cvs rdiff -u -r1.27 -r1.28 src/sys/net/bpfjit.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/bpfjit.c
diff -u src/sys/net/bpfjit.c:1.27 src/sys/net/bpfjit.c:1.28
--- src/sys/net/bpfjit.c:1.27 Sun Jul 13 18:48:27 2014
+++ src/sys/net/bpfjit.c Sun Jul 13 21:54:46 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: bpfjit.c,v 1.27 2014/07/13 18:48:27 alnsn Exp $ */
+/* $NetBSD: bpfjit.c,v 1.28 2014/07/13 21:54:46 alnsn Exp $ */
/*-
* Copyright (c) 2011-2014 Alexander Nasonov.
@@ -31,9 +31,9 @@
#include <sys/cdefs.h>
#ifdef _KERNEL
-__KERNEL_RCSID(0, "$NetBSD: bpfjit.c,v 1.27 2014/07/13 18:48:27 alnsn Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bpfjit.c,v 1.28 2014/07/13 21:54:46 alnsn Exp $");
#else
-__RCSID("$NetBSD: bpfjit.c,v 1.27 2014/07/13 18:48:27 alnsn Exp $");
+__RCSID("$NetBSD: bpfjit.c,v 1.28 2014/07/13 21:54:46 alnsn Exp $");
#endif
#include <sys/types.h>
@@ -95,13 +95,6 @@ __RCSID("$NetBSD: bpfjit.c,v 1.27 2014/0
#define BJ_XREG SLJIT_TEMPORARY_EREG1
#define BJ_TMP3REG SLJIT_TEMPORARY_EREG2
-/*
- * EREG registers can't be used for indirect calls, reuse BJ_BUF and
- * BJ_BUFLEN registers. They can be easily restored from BJ_ARGS.
- */
-#define BJ_COPF_PTR SLJIT_SAVED_REG1
-#define BJ_COPF_IDX SLJIT_SAVED_REG3
-
#ifdef _KERNEL
#define MAX_MEMWORDS BPF_MAX_MEMWORDS
#else
@@ -123,11 +116,12 @@ __RCSID("$NetBSD: bpfjit.c,v 1.27 2014/0
* Optimization hints.
*/
typedef unsigned int bpfjit_hint_t;
-#define BJ_HINT_ABS 0x01 /* packet read at absolute offset */
-#define BJ_HINT_IND 0x02 /* packet read at variable offset */
-#define BJ_HINT_COP 0x04 /* BPF_COP or BPF_COPX instruction */
-#define BJ_HINT_XREG 0x08 /* BJ_XREG is needed */
-#define BJ_HINT_LDX 0x10 /* BPF_LDX instruction */
+#define BJ_HINT_ABS 0x01 /* packet read at absolute offset */
+#define BJ_HINT_IND 0x02 /* packet read at variable offset */
+#define BJ_HINT_COP 0x04 /* BPF_COP or BPF_COPX instruction */
+#define BJ_HINT_COPX 0x08 /* BPF_COPX instruction */
+#define BJ_HINT_XREG 0x10 /* BJ_XREG is needed */
+#define BJ_HINT_LDX 0x20 /* BPF_LDX instruction */
#define BJ_HINT_PKT (BJ_HINT_ABS|BJ_HINT_IND) /* packet read */
/*
@@ -271,6 +265,9 @@ nscratches(bpfjit_hint_t hints)
rv = 5; /* uses BJ_TMP3REG */
#endif
+ if (hints & BJ_HINT_COPX)
+ rv = 5; /* uses BJ_TMP3REG */
+
return rv;
}
@@ -649,26 +646,31 @@ emit_xcall(struct sljit_compiler *compil
* Emit code for BPF_COP and BPF_COPX instructions.
*/
static int
-emit_cop(struct sljit_compiler *compiler, const bpf_ctx_t *bc,
- const struct bpf_insn *pc, struct sljit_jump **ret0_jump)
+emit_cop(struct sljit_compiler *compiler,
+ const bpf_ctx_t *bc, const struct bpf_insn *pc,
+ struct sljit_jump ***ret0, size_t *ret0_size, size_t *ret0_maxsize)
{
-#if BJ_XREG == SLJIT_RETURN_REG || \
- BJ_XREG == SLJIT_SCRATCH_REG1 || \
- BJ_XREG == SLJIT_SCRATCH_REG2 || \
- BJ_XREG == SLJIT_SCRATCH_REG3 || \
- BJ_COPF_PTR == BJ_ARGS || \
- BJ_COPF_IDX == BJ_ARGS
+#if BJ_XREG == SLJIT_RETURN_REG || \
+ BJ_XREG == SLJIT_SCRATCH_REG1 || \
+ BJ_XREG == SLJIT_SCRATCH_REG2 || \
+ BJ_XREG == SLJIT_SCRATCH_REG3 || \
+ BJ_TMP3REG == SLJIT_SCRATCH_REG1 || \
+ BJ_TMP3REG == SLJIT_SCRATCH_REG2 || \
+ BJ_TMP3REG == SLJIT_SCRATCH_REG3
#error "Not supported assignment of registers."
#endif
struct sljit_jump *jump;
+ sljit_si call_reg;
+ sljit_sw call_off;
int status;
- jump = NULL;
-
BJ_ASSERT(bc != NULL && bc->copfuncs != NULL);
- if (BPF_MISCOP(pc->code) == BPF_COPX) {
+ if (BPF_MISCOP(pc->code) == BPF_COP) {
+ call_reg = SLJIT_IMM;
+ call_off = SLJIT_FUNC_OFFSET(bc->copfuncs[pc->k]);
+ } else {
/* if (X >= bc->nfuncs) return 0; */
jump = sljit_emit_cmp(compiler,
SLJIT_C_GREATER_EQUAL,
@@ -676,10 +678,46 @@ emit_cop(struct sljit_compiler *compiler
SLJIT_IMM, bc->nfuncs);
if (jump == NULL)
return SLJIT_ERR_ALLOC_FAILED;
- }
+ if (!append_jump(jump, ret0, ret0_size, ret0_maxsize))
+ return SLJIT_ERR_ALLOC_FAILED;
+
+ /* tmp1 = ctx; */
+ status = sljit_emit_op1(compiler,
+ SLJIT_MOV_P,
+ BJ_TMP1REG, 0,
+ SLJIT_MEM1(SLJIT_LOCALS_REG),
+ offsetof(struct bpfjit_stack, ctx));
+ if (status != SLJIT_SUCCESS)
+ return status;
+
+ /* tmp1 = ctx->copfuncs; */
+ status = sljit_emit_op1(compiler,
+ SLJIT_MOV_P,
+ BJ_TMP1REG, 0,
+ SLJIT_MEM1(BJ_TMP1REG),
+ offsetof(struct bpf_ctx, copfuncs));
+ if (status != SLJIT_SUCCESS)
+ return status;
+
+ /* tmp2 = X; */
+ status = sljit_emit_op1(compiler,
+ SLJIT_MOV,
+ BJ_TMP2REG, 0,
+ BJ_XREG, 0);
+ if (status != SLJIT_SUCCESS)
+ return status;
- if (jump != NULL)
- *ret0_jump = jump;
+ /* tmp3 = ctx->copfuncs[tmp2]; */
+ call_reg = BJ_TMP3REG;
+ call_off = 0;
+ status = sljit_emit_op1(compiler,
+ SLJIT_MOV_P,
+ call_reg, call_off,
+ SLJIT_MEM2(BJ_TMP1REG, BJ_TMP2REG),
+ SLJIT_WORD_SHIFT);
+ if (status != SLJIT_SUCCESS)
+ return status;
+ }
/*
* Copy bpf_copfunc_t arguments to registers.
@@ -708,44 +746,10 @@ emit_cop(struct sljit_compiler *compiler
if (status != SLJIT_SUCCESS)
return status;
- if (BPF_MISCOP(pc->code) == BPF_COP) {
- status = sljit_emit_ijump(compiler,
- SLJIT_CALL3,
- SLJIT_IMM, SLJIT_FUNC_OFFSET(bc->copfuncs[pc->k]));
- if (status != SLJIT_SUCCESS)
- return status;
- } else if (BPF_MISCOP(pc->code) == BPF_COPX) {
- /* load ctx->copfuncs */
- status = sljit_emit_op1(compiler,
- SLJIT_MOV_P,
- BJ_COPF_PTR, 0,
- SLJIT_MEM1(SLJIT_SCRATCH_REG1),
- offsetof(struct bpf_ctx, copfuncs));
- if (status != SLJIT_SUCCESS)
- return status;
-
- /*
- * Load X to a register that can be used for
- * memory addressing.
- */
- status = sljit_emit_op1(compiler,
- SLJIT_MOV,
- BJ_COPF_IDX, 0,
- BJ_XREG, 0);
- if (status != SLJIT_SUCCESS)
- return status;
-
- status = sljit_emit_ijump(compiler,
- SLJIT_CALL3,
- SLJIT_MEM2(BJ_COPF_PTR, BJ_COPF_IDX),
- SLJIT_WORD_SHIFT);
- if (status != SLJIT_SUCCESS)
- return status;
-
- status = load_buf_buflen(compiler);
- if (status != SLJIT_SUCCESS)
- return status;
- }
+ status = sljit_emit_ijump(compiler,
+ SLJIT_CALL3, call_reg, call_off);
+ if (status != SLJIT_SUCCESS)
+ return status;
#if BJ_AREG != SLJIT_RETURN_REG
status = sljit_emit_op1(compiler,
@@ -1328,7 +1332,7 @@ optimize_pass1(const bpf_ctx_t *bc, cons
continue;
case BPF_COPX:
- *hints |= BJ_HINT_XREG;
+ *hints |= BJ_HINT_XREG | BJ_HINT_COPX;
/* FALLTHROUGH */
case BPF_COP:
@@ -2019,15 +2023,11 @@ generate_insn_code(struct sljit_compiler
goto fail;
}
- jump = NULL;
- status = emit_cop(compiler, bc, pc, &jump);
+ status = emit_cop(compiler, bc, pc,
+ &ret0, &ret0_size, &ret0_maxsize);
if (status != SLJIT_SUCCESS)
goto fail;
- if (jump != NULL && !append_jump(jump,
- &ret0, &ret0_size, &ret0_maxsize))
- goto fail;
-
continue;
}
