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path: root/arch/x86/net/bpf_jit_comp.c
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Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
-rw-r--r--arch/x86/net/bpf_jit_comp.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index d24a512fd6f3..9ea57389c554 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1341,9 +1341,10 @@ st: if (is_imm8(insn->off))
if (insn->imm == (BPF_AND | BPF_FETCH) ||
insn->imm == (BPF_OR | BPF_FETCH) ||
insn->imm == (BPF_XOR | BPF_FETCH)) {
- u8 *branch_target;
bool is64 = BPF_SIZE(insn->code) == BPF_DW;
u32 real_src_reg = src_reg;
+ u32 real_dst_reg = dst_reg;
+ u8 *branch_target;
/*
* Can't be implemented with a single x86 insn.
@@ -1354,11 +1355,13 @@ st: if (is_imm8(insn->off))
emit_mov_reg(&prog, true, BPF_REG_AX, BPF_REG_0);
if (src_reg == BPF_REG_0)
real_src_reg = BPF_REG_AX;
+ if (dst_reg == BPF_REG_0)
+ real_dst_reg = BPF_REG_AX;
branch_target = prog;
/* Load old value */
emit_ldx(&prog, BPF_SIZE(insn->code),
- BPF_REG_0, dst_reg, insn->off);
+ BPF_REG_0, real_dst_reg, insn->off);
/*
* Perform the (commutative) operation locally,
* put the result in the AUX_REG.
@@ -1369,7 +1372,8 @@ st: if (is_imm8(insn->off))
add_2reg(0xC0, AUX_REG, real_src_reg));
/* Attempt to swap in new value */
err = emit_atomic(&prog, BPF_CMPXCHG,
- dst_reg, AUX_REG, insn->off,
+ real_dst_reg, AUX_REG,
+ insn->off,
BPF_SIZE(insn->code));
if (WARN_ON(err))
return err;
@@ -1383,11 +1387,10 @@ st: if (is_imm8(insn->off))
/* Restore R0 after clobbering RAX */
emit_mov_reg(&prog, true, BPF_REG_0, BPF_REG_AX);
break;
-
}
err = emit_atomic(&prog, insn->imm, dst_reg, src_reg,
- insn->off, BPF_SIZE(insn->code));
+ insn->off, BPF_SIZE(insn->code));
if (err)
return err;
break;