From 0d2d0cedc0814edaa2b6cb290c78ec333b3eed71 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Fri, 4 May 2018 01:08:19 +0200
Subject: bpf, arm32: remove ld_abs/ld_ind
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 arm32 JIT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
arch/arm/net/bpf_jit_32.c | 77 -----------------------------------------------
1 file changed, 77 deletions(-)
(limited to 'arch/arm')
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index b5030e1a41d8..82689b999257 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -1452,83 +1452,6 @@ exit:
emit(ARM_LDR_I(rn, ARM_SP, STACK_VAR(src_lo)), ctx);
emit_ldx_r(dst, rn, dstk, off, ctx, BPF_SIZE(code));
break;
- /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + imm)) */
- case BPF_LD | BPF_ABS | BPF_W:
- case BPF_LD | BPF_ABS | BPF_H:
- case BPF_LD | BPF_ABS | BPF_B:
- /* R0 = ntohx(*(size *)(((struct sk_buff *)R6)->data + src + imm)) */
- case BPF_LD | BPF_IND | BPF_W:
- case BPF_LD | BPF_IND | BPF_H:
- case BPF_LD | BPF_IND | BPF_B:
- {
- const u8 r4 = bpf2a32[BPF_REG_6][1]; /* r4 = ptr to sk_buff */
- const u8 r0 = bpf2a32[BPF_REG_0][1]; /*r0: struct sk_buff *skb*/
- /* rtn value */
- const u8 r1 = bpf2a32[BPF_REG_0][0]; /* r1: int k */
- const u8 r2 = bpf2a32[BPF_REG_1][1]; /* r2: unsigned int size */
- const u8 r3 = bpf2a32[BPF_REG_1][0]; /* r3: void *buffer */
- const u8 r6 = bpf2a32[TMP_REG_1][1]; /* r6: void *(*func)(..) */
- int size;
-
- /* Setting up first argument */
- emit(ARM_MOV_R(r0, r4), ctx);
-
- /* Setting up second argument */
- emit_a32_mov_i(r1, imm, false, ctx);
- if (BPF_MODE(code) == BPF_IND)
- emit_a32_alu_r(r1, src_lo, false, sstk, ctx,
- false, false, BPF_ADD);
-
- /* Setting up third argument */
- switch (BPF_SIZE(code)) {
- case BPF_W:
- size = 4;
- break;
- case BPF_H:
- size = 2;
- break;
- case BPF_B:
- size = 1;
- break;
- default:
- return -EINVAL;
- }
- emit_a32_mov_i(r2, size, false, ctx);
-
- /* Setting up fourth argument */
- emit(ARM_ADD_I(r3, ARM_SP, imm8m(SKB_BUFFER)), ctx);
-
- /* Setting up function pointer to call */
- emit_a32_mov_i(r6, (unsigned int)bpf_load_pointer, false, ctx);
- emit_blx_r(r6, ctx);
-
- emit(ARM_EOR_R(r1, r1, r1), ctx);
- /* Check if return address is NULL or not.
- * if NULL then jump to epilogue
- * else continue to load the value from retn address
- */
- emit(ARM_CMP_I(r0, 0), ctx);
- jmp_offset = epilogue_offset(ctx);
- check_imm24(jmp_offset);
- _emit(ARM_COND_EQ, ARM_B(jmp_offset), ctx);
-
- /* Load value from the address */
- switch (BPF_SIZE(code)) {
- case BPF_W:
- emit(ARM_LDR_I(r0, r0, 0), ctx);
- emit_rev32(r0, r0, ctx);
- break;
- case BPF_H:
- emit(ARM_LDRH_I(r0, r0, 0), ctx);
- emit_rev16(r0, r0, ctx);
- break;
- case BPF_B:
- emit(ARM_LDRB_I(r0, r0, 0), ctx);
- /* No need to reverse */
- break;
- }
- break;
- }
/* ST: *(size *)(dst + off) = imm */
case BPF_ST | BPF_MEM | BPF_W:
case BPF_ST | BPF_MEM | BPF_H:
--
cgit v1.2.3
From 38ca930601631585fbd7826f8f6908055a8dbc9e Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Mon, 14 May 2018 23:22:30 +0200
Subject: bpf, arm32: save 4 bytes of unneeded stack space
The extra skb_copy_bits() buffer is not used anymore, therefore
remove the extra 4 byte stack space requirement.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
arch/arm/net/bpf_jit_32.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
(limited to 'arch/arm')
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 82689b999257..d3ea6454e775 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -234,18 +234,11 @@ static void jit_fill_hole(void *area, unsigned int size)
#define SCRATCH_SIZE 80
/* total stack size used in JITed code */
-#define _STACK_SIZE \
- (ctx->prog->aux->stack_depth + \
- + SCRATCH_SIZE + \
- + 4 /* extra for skb_copy_bits buffer */)
-
-#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT)
+#define _STACK_SIZE (ctx->prog->aux->stack_depth + SCRATCH_SIZE)
+#define STACK_SIZE ALIGN(_STACK_SIZE, STACK_ALIGNMENT)
/* Get the offset of eBPF REGISTERs stored on scratch space. */
-#define STACK_VAR(off) (STACK_SIZE-off-4)
-
-/* Offset of skb_copy_bits buffer */
-#define SKB_BUFFER STACK_VAR(SCRATCH_SIZE)
+#define STACK_VAR(off) (STACK_SIZE - off)
#if __LINUX_ARM_ARCH__ < 7
--
cgit v1.2.3
From 2b589a7e2bd3eb610a4b7f5e61393481755a4de9 Mon Sep 17 00:00:00 2001
From: Wang YanQing <udknight@gmail.com>
Date: Fri, 11 May 2018 11:06:34 +0800
Subject: bpf, arm32: correct check_imm24
imm24 is signed, so the right range is:
[-(1<<(24 - 1)), (1<<(24 - 1)) - 1]
Note: this patch also fix a typo.
Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Wang YanQing <udknight@gmail.com>
Cc: Shubham Bansal <illusionist.neo@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux@armlinux.org.uk
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
arch/arm/net/bpf_jit_32.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
(limited to 'arch/arm')
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index d3ea6454e775..0d542007b49d 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -84,7 +84,7 @@
*
* 1. First argument is passed using the arm 32bit registers and rest of the
* arguments are passed on stack scratch space.
- * 2. First callee-saved arugument is mapped to arm 32 bit registers and rest
+ * 2. First callee-saved argument is mapped to arm 32 bit registers and rest
* arguments are mapped to scratch space on stack.
* 3. We need two 64 bit temp registers to do complex operations on eBPF
* registers.
@@ -1192,8 +1192,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
s32 jmp_offset;
#define check_imm(bits, imm) do { \
- if ((((imm) > 0) && ((imm) >> (bits))) || \
- (((imm) < 0) && (~(imm) >> (bits)))) { \
+ if ((imm) >= (1 << ((bits) - 1)) || \
+ (imm) < -(1 << ((bits) - 1))) { \
pr_info("[%2d] imm=%d(0x%x) out of range\n", \
i, imm, imm); \
return -EINVAL; \
--
cgit v1.2.3
From 68565a1af9f7012e6f2fe2bdd612f67d2d830c28 Mon Sep 17 00:00:00 2001
From: Wang YanQing <udknight@gmail.com>
Date: Fri, 11 May 2018 10:52:17 +0800
Subject: bpf, arm32: fix inconsistent naming about emit_a32_lsr_{r64,i64}
The names for BPF_ALU64 | BPF_ARSH are emit_a32_arsh_*,
the names for BPF_ALU64 | BPF_LSH are emit_a32_lsh_*, but
the names for BPF_ALU64 | BPF_RSH are emit_a32_lsr_*.
For consistence reason, let's rename emit_a32_lsr_* to
emit_a32_rsh_*.
This patch also corrects a wrong comment.
Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Wang YanQing <udknight@gmail.com>
Cc: Shubham Bansal <illusionist.neo@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux@armlinux.org.uk
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
arch/arm/net/bpf_jit_32.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
(limited to 'arch/arm')
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 0d542007b49d..6e8b71613039 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -701,7 +701,7 @@ static inline void emit_a32_arsh_r64(const u8 dst[], const u8 src[], bool dstk,
}
/* dst = dst >> src */
-static inline void emit_a32_lsr_r64(const u8 dst[], const u8 src[], bool dstk,
+static inline void emit_a32_rsh_r64(const u8 dst[], const u8 src[], bool dstk,
bool sstk, struct jit_ctx *ctx) {
const u8 *tmp = bpf2a32[TMP_REG_1];
const u8 *tmp2 = bpf2a32[TMP_REG_2];
@@ -717,7 +717,7 @@ static inline void emit_a32_lsr_r64(const u8 dst[], const u8 src[], bool dstk,
emit(ARM_LDR_I(rm, ARM_SP, STACK_VAR(dst_hi)), ctx);
}
- /* Do LSH operation */
+ /* Do RSH operation */
emit(ARM_RSB_I(ARM_IP, rt, 32), ctx);
emit(ARM_SUBS_I(tmp2[0], rt, 32), ctx);
emit(ARM_MOV_SR(ARM_LR, rd, SRTYPE_LSR, rt), ctx);
@@ -767,7 +767,7 @@ static inline void emit_a32_lsh_i64(const u8 dst[], bool dstk,
}
/* dst = dst >> val */
-static inline void emit_a32_lsr_i64(const u8 dst[], bool dstk,
+static inline void emit_a32_rsh_i64(const u8 dst[], bool dstk,
const u32 val, struct jit_ctx *ctx) {
const u8 *tmp = bpf2a32[TMP_REG_1];
const u8 *tmp2 = bpf2a32[TMP_REG_2];
@@ -1323,7 +1323,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
case BPF_ALU64 | BPF_RSH | BPF_K:
if (unlikely(imm > 63))
return -EINVAL;
- emit_a32_lsr_i64(dst, dstk, imm, ctx);
+ emit_a32_rsh_i64(dst, dstk, imm, ctx);
break;
/* dst = dst << src */
case BPF_ALU64 | BPF_LSH | BPF_X:
@@ -1331,7 +1331,7 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
break;
/* dst = dst >> src */
case BPF_ALU64 | BPF_RSH | BPF_X:
- emit_a32_lsr_r64(dst, src, dstk, sstk, ctx);
+ emit_a32_rsh_r64(dst, src, dstk, sstk, ctx);
break;
/* dst = dst >> src (signed) */
case BPF_ALU64 | BPF_ARSH | BPF_X:
--
cgit v1.2.3