[PATCH bpf-next v4 03/10] bpf, x86: Refactor func emit_prologue

[Yonghong Song <yonghong.song@xxxxxxxxx>]

Refactor function emit_prologue() such that it has bpf_prog as one of
arguments. This can reduce the number of total arguments since later
on there will be more arguments being added to this function.

Also add a variable 'stack_depth' to hold the value for
  bpf_prog->aux->stack_depth
to simplify the code.

Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
 arch/x86/net/bpf_jit_comp.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 06b080b61aa5..6d24389e58a1 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -489,10 +489,12 @@ static void emit_prologue_tail_call(u8 **pprog, bool is_subprog)
  * bpf_tail_call helper will skip the first X86_TAIL_CALL_OFFSET bytes
  * while jumping to another program
  */
-static void emit_prologue(u8 **pprog, u32 stack_depth, bool ebpf_from_cbpf,
-			  bool tail_call_reachable, bool is_subprog,
-			  bool is_exception_cb)
+static void emit_prologue(u8 **pprog, u32 stack_depth, struct bpf_prog *bpf_prog,
+			  bool tail_call_reachable)
 {
+	bool ebpf_from_cbpf = bpf_prog_was_classic(bpf_prog);
+	bool is_exception_cb = bpf_prog->aux->exception_cb;
+	bool is_subprog = bpf_is_subprog(bpf_prog);
 	u8 *prog = *pprog;
 
 	emit_cfi(&prog, is_subprog ? cfi_bpf_subprog_hash : cfi_bpf_hash);
@@ -1424,17 +1426,18 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
 	u64 arena_vm_start, user_vm_start;
 	int i, excnt = 0;
 	int ilen, proglen = 0;
+	u32 stack_depth;
 	u8 *prog = temp;
 	int err;
 
+	stack_depth = bpf_prog->aux->stack_depth;
+
 	arena_vm_start = bpf_arena_get_kern_vm_start(bpf_prog->aux->arena);
 	user_vm_start = bpf_arena_get_user_vm_start(bpf_prog->aux->arena);
 
 	detect_reg_usage(insn, insn_cnt, callee_regs_used);
 
-	emit_prologue(&prog, bpf_prog->aux->stack_depth,
-		      bpf_prog_was_classic(bpf_prog), tail_call_reachable,
-		      bpf_is_subprog(bpf_prog), bpf_prog->aux->exception_cb);
+	emit_prologue(&prog, stack_depth, bpf_prog, tail_call_reachable);
 	/* Exception callback will clobber callee regs for its own use, and
 	 * restore the original callee regs from main prog's stack frame.
 	 */
@@ -2128,7 +2131,7 @@ st:			if (is_imm8(insn->off))
 
 			func = (u8 *) __bpf_call_base + imm32;
 			if (tail_call_reachable) {
-				LOAD_TAIL_CALL_CNT_PTR(bpf_prog->aux->stack_depth);
+				LOAD_TAIL_CALL_CNT_PTR(stack_depth);
 				ip += 7;
 			}
 			if (!imm32)
@@ -2145,13 +2148,13 @@ st:			if (is_imm8(insn->off))
 							  &bpf_prog->aux->poke_tab[imm32 - 1],
 							  &prog, image + addrs[i - 1],
 							  callee_regs_used,
-							  bpf_prog->aux->stack_depth,
+							  stack_depth,
 							  ctx);
 			else
 				emit_bpf_tail_call_indirect(bpf_prog,
 							    &prog,
 							    callee_regs_used,
-							    bpf_prog->aux->stack_depth,
+							    stack_depth,
 							    image + addrs[i - 1],
 							    ctx);
 			break;
-- 
2.43.5