From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Thu, 7 Nov 2019 12:40:33 +0100
Subject: s390/bpf: Remove unused SEEN_RET0, SEEN_REG_AX and ret0_ip
Patch-mainline: v5.5-rc1
Git-commit: dab2e9eb187cb53c951c0c556172a73ac7f0e834
References: bsc#1177028
We don't need them since commit e1cf4befa297 ("bpf, s390x: remove
ld_abs/ld_ind") and commit a3212b8f15d8 ("bpf, s390x: remove obsolete
exception handling from div/mod").
Also, use BIT(n) instead of 1 << n, because checkpatch says so.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107114033.90505-1-iii@linux.ibm.com
Acked-by: Gary Lin <glin@suse.com>
---
arch/s390/net/bpf_jit_comp.c | 21 +++++----------------
1 file changed, 5 insertions(+), 16 deletions(-)
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -42,7 +42,6 @@ struct bpf_jit {
int lit_start; /* Start of literal pool */
int lit; /* Current position in literal pool */
int base_ip; /* Base address for literal pool */
- int ret0_ip; /* Address of return 0 */
int exit_ip; /* Address of exit */
int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */
int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
@@ -52,12 +51,10 @@ struct bpf_jit {
#define BPF_SIZE_MAX 0xffff /* Max size for program (16 bit branches) */
-#define SEEN_MEM (1 << 0) /* use mem[] for temporary storage */
-#define SEEN_RET0 (1 << 1) /* ret0_ip points to a valid return 0 */
-#define SEEN_LITERAL (1 << 2) /* code uses literals */
-#define SEEN_FUNC (1 << 3) /* calls C functions */
-#define SEEN_TAIL_CALL (1 << 4) /* code uses tail calls */
-#define SEEN_REG_AX (1 << 5) /* code uses constant blinding */
+#define SEEN_MEM BIT(0) /* use mem[] for temporary storage */
+#define SEEN_LITERAL BIT(1) /* code uses literals */
+#define SEEN_FUNC BIT(2) /* calls C functions */
+#define SEEN_TAIL_CALL BIT(3) /* code uses tail calls */
#define SEEN_STACK (SEEN_FUNC | SEEN_MEM)
/*
@@ -447,12 +444,6 @@ static void bpf_jit_prologue(struct bpf_
*/
static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
{
- /* Return 0 */
- if (jit->seen & SEEN_RET0) {
- jit->ret0_ip = jit->prg;
- /* lghi %b0,0 */
- EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
- }
jit->exit_ip = jit->prg;
/* Load exit code: lgr %r2,%b0 */
EMIT4(0xb9040000, REG_2, BPF_REG_0);
@@ -515,8 +506,6 @@ static noinline int bpf_jit_insn(struct
s16 off = insn->off;
unsigned int mask;
- if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
- jit->seen |= SEEN_REG_AX;
switch (insn->code) {
/*
* BPF_MOV
@@ -1111,7 +1100,7 @@ static noinline int bpf_jit_insn(struct
break;
case BPF_JMP | BPF_EXIT: /* return b0 */
last = (i == fp->len - 1) ? 1 : 0;
- if (last && !(jit->seen & SEEN_RET0))
+ if (last)
break;
/* j <exit> */
EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);