This is in preparation of bpf_jit support for seccomp filters.
Signed-off-by: Nicolas Schichan <nschic...@freebox.fr>
---
arch/arm/net/bpf_jit_32.c | 46 ++++++++++++++++++++++++++++-----------------
1 file changed, 29 insertions(+), 17 deletions(-)
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 6828ef6..0ea29e0 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -55,7 +55,8 @@
#define FLAG_NEED_X_RESET (1 << 0)
struct jit_ctx {
- const struct sk_filter *skf;
+ unsigned short prog_len;
+ struct sock_filter *prog_insns;
unsigned idx;
unsigned prologue_bytes;
int ret0_fp_idx;
@@ -131,8 +132,8 @@ static u16 saved_regs(struct jit_ctx *ctx)
{
u16 ret = 0;
- if ((ctx->skf->len > 1) ||
- (ctx->skf->insns[0].code == BPF_S_RET_A))
+ if ((ctx->prog_len > 1) ||
+ (ctx->prog_insns[0].code == BPF_S_RET_A))
ret |= 1 << r_A;
#ifdef CONFIG_FRAME_POINTER
@@ -181,7 +182,7 @@ static inline bool is_load_to_a(u16 inst)
static void build_prologue(struct jit_ctx *ctx)
{
u16 reg_set = saved_regs(ctx);
- u16 first_inst = ctx->skf->insns[0].code;
+ u16 first_inst = ctx->prog_insns[0].code;
u16 off;
#ifdef CONFIG_FRAME_POINTER
@@ -279,7 +280,7 @@ static u16 imm_offset(u32 k, struct jit_ctx *ctx)
ctx->imms[i] = k;
/* constants go just after the epilogue */
- offset = ctx->offsets[ctx->skf->len];
+ offset = ctx->offsets[ctx->prog_len];
offset += ctx->prologue_bytes;
offset += ctx->epilogue_bytes;
offset += i * 4;
@@ -419,7 +420,7 @@ static inline void emit_err_ret(u8 cond, struct jit_ctx
*ctx)
emit(ARM_MOV_R(ARM_R0, ARM_R0), ctx);
} else {
_emit(cond, ARM_MOV_I(ARM_R0, 0), ctx);
- _emit(cond, ARM_B(b_imm(ctx->skf->len, ctx)), ctx);
+ _emit(cond, ARM_B(b_imm(ctx->prog_len, ctx)), ctx);
}
}
@@ -469,14 +470,13 @@ static inline void update_on_xread(struct jit_ctx *ctx)
static int build_body(struct jit_ctx *ctx)
{
void *load_func[] = {jit_get_skb_b, jit_get_skb_h, jit_get_skb_w};
- const struct sk_filter *prog = ctx->skf;
const struct sock_filter *inst;
unsigned i, load_order, off, condt;
int imm12;
u32 k;
- for (i = 0; i < prog->len; i++) {
- inst = &(prog->insns[i]);
+ for (i = 0; i < ctx->prog_len; i++) {
+ inst = &(ctx->prog_insns[i]);
/* K as an immediate value operand */
k = inst->k;
@@ -769,8 +769,8 @@ cmp_x:
ctx->ret0_fp_idx = i;
emit_mov_i(ARM_R0, k, ctx);
b_epilogue:
- if (i != ctx->skf->len - 1)
- emit(ARM_B(b_imm(prog->len, ctx)), ctx);
+ if (i != ctx->prog_len - 1)
+ emit(ARM_B(b_imm(ctx->prog_len, ctx)), ctx);
break;
case BPF_S_MISC_TAX:
/* X = A */
@@ -858,7 +858,7 @@ b_epilogue:
}
-void bpf_jit_compile(struct sk_filter *fp)
+static void __bpf_jit_compile(struct jit_ctx *out_ctx)
{
struct jit_ctx ctx;
unsigned tmp_idx;
@@ -867,11 +867,10 @@ void bpf_jit_compile(struct sk_filter *fp)
if (!bpf_jit_enable)
return;
- memset(&ctx, 0, sizeof(ctx));
- ctx.skf = fp;
+ ctx = *out_ctx;
ctx.ret0_fp_idx = -1;
- ctx.offsets = kzalloc(4 * (ctx.skf->len + 1), GFP_KERNEL);
+ ctx.offsets = kzalloc(4 * (ctx.prog_len + 1), GFP_KERNEL);
if (ctx.offsets == NULL)
return;
@@ -921,13 +920,26 @@ void bpf_jit_compile(struct sk_filter *fp)
print_hex_dump(KERN_INFO, "BPF JIT code: ",
DUMP_PREFIX_ADDRESS, 16, 4, ctx.target,
alloc_size, false);
-
- fp->bpf_func = (void *)ctx.target;
out:
kfree(ctx.offsets);
+
+ *out_ctx = ctx;
return;
}
+void bpf_jit_compile(struct sk_filter *fp)
+{
+ struct jit_ctx ctx;
+
+ memset(&ctx, 0, sizeof(ctx));
+ ctx.prog_len = fp->len;
+ ctx.prog_insns = fp->insns;
+
+ __bpf_jit_compile(&ctx);
+ if (ctx.target)
+ fp->bpf_func = (void*)ctx.target;
+}
+
static void bpf_jit_free_worker(struct work_struct *work)
{
module_free(NULL, work);
--
1.7.10.4
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