Improve code readability by moving the BPF JIT function epilogue
generation code to a dedicated emit_epilogue() function, analagous to
the existing emit_prologue() function.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/net/bpf_jit_comp.c | 37 ++++++++++++++++++++++++-------------
1 file changed, 24 insertions(+), 13 deletions(-)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 32bfab4e21eb..da8c988b0f0f 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -240,6 +240,28 @@ static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf)
*pprog = prog;
}
+static void emit_epilogue(u8 **pprog)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+ /* mov rbx, qword ptr [rbp+0] */
+ EMIT4(0x48, 0x8B, 0x5D, 0);
+ /* mov r13, qword ptr [rbp+8] */
+ EMIT4(0x4C, 0x8B, 0x6D, 8);
+ /* mov r14, qword ptr [rbp+16] */
+ EMIT4(0x4C, 0x8B, 0x75, 16);
+ /* mov r15, qword ptr [rbp+24] */
+ EMIT4(0x4C, 0x8B, 0x7D, 24);
+
+ /* add rbp, AUX_STACK_SPACE */
+ EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE);
+ EMIT1(0xC9); /* leave */
+ EMIT1(0xC3); /* ret */
+
+ *pprog = prog;
+}
+
/*
* Generate the following code:
*
@@ -1036,19 +1058,8 @@ xadd: if (is_imm8(insn->off))
seen_exit = true;
/* Update cleanup_addr */
ctx->cleanup_addr = proglen;
- /* mov rbx, qword ptr [rbp+0] */
- EMIT4(0x48, 0x8B, 0x5D, 0);
- /* mov r13, qword ptr [rbp+8] */
- EMIT4(0x4C, 0x8B, 0x6D, 8);
- /* mov r14, qword ptr [rbp+16] */
- EMIT4(0x4C, 0x8B, 0x75, 16);
- /* mov r15, qword ptr [rbp+24] */
- EMIT4(0x4C, 0x8B, 0x7D, 24);
-
- /* add rbp, AUX_STACK_SPACE */
- EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE);
- EMIT1(0xC9); /* leave */
- EMIT1(0xC3); /* ret */
+
+ emit_epilogue(&prog);
break;
default:
--
2.20.1
