Commit f4b21ed0 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
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bpf, x86: Avoid repeated usage of bpf_prog->aux->stack_depth 



Refactor the code to avoid repeated usage of bpf_prog->aux->stack_depth
in do_jit() func. If the private stack is used, the stack_depth will be
0 for that prog. Refactoring make it easy to adjust stack_depth.

Signed-off-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241112163917.2224189-1-yonghong.song@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent e00931c0

arch/x86/net/bpf_jit_comp.c

+7 −4
Original line number Diff line number Diff line
@@ -1425,14 +1425,17 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image 
	int i, excnt = 0;

	int ilen, proglen = 0;

	u8 *prog = temp;

	u32 stack_depth;

	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,

	emit_prologue(&prog, stack_depth,

		      bpf_prog_was_classic(bpf_prog), tail_call_reachable,

		      bpf_is_subprog(bpf_prog), bpf_prog->aux->exception_cb);

	/* Exception callback will clobber callee regs for its own use, and
@@ -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;