Commit 93fd420d authored by Menglong Dong's avatar Menglong Dong Committed by Alexei Starovoitov
Browse files

bpf, riscv: introduce emit_store_stack_imm64() for trampoline 



Introduce a helper to store 64-bit immediate on the trampoline stack with
a help of a register.

Signed-off-by: default avatarMenglong Dong <dongml2@chinatelecom.cn>
Tested-by: default avatarBjörn Töpel <bjorn@kernel.org>
Acked-by: default avatarBjörn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20260208053311.698352-2-dongml2@chinatelecom.cn


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Reviewed-by: default avatarPu Lehui <pulehui@huawei.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 2669dde7

arch/riscv/net/bpf_jit_comp64.c

+14 −11
Original line number Diff line number Diff line
@@ -926,6 +926,14 @@ static void restore_stack_args(int nr_stack_args, int args_off, int stk_arg_off, 
	}

}



static void emit_store_stack_imm64(u8 reg, int stack_off, u64 imm64,

				   struct rv_jit_context *ctx)

{

	/* Load imm64 into reg and store it at [FP + stack_off]. */

	emit_imm(reg, (s64)imm64, ctx);

	emit_sd(RV_REG_FP, stack_off, reg, ctx);

}



static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_off,

			   int run_ctx_off, bool save_ret, struct rv_jit_context *ctx)

{
@@ -933,12 +941,10 @@ static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_of 
	struct bpf_prog *p = l->link.prog;

	int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie);



	if (l->cookie) {

		emit_imm(RV_REG_T1, l->cookie, ctx);

		emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_T1, ctx);

	} else {

	if (l->cookie)

		emit_store_stack_imm64(RV_REG_T1, -run_ctx_off + cookie_off, l->cookie, ctx);

	else

		emit_sd(RV_REG_FP, -run_ctx_off + cookie_off, RV_REG_ZERO, ctx);

	}



	/* arg1: prog */

	emit_imm(RV_REG_A0, (const s64)p, ctx);
@@ -1123,13 +1129,10 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, 
	emit_sd(RV_REG_FP, -sreg_off, RV_REG_S1, ctx);



	/* store ip address of the traced function */

	if (flags & BPF_TRAMP_F_IP_ARG) {

		emit_imm(RV_REG_T1, (const s64)func_addr, ctx);

		emit_sd(RV_REG_FP, -ip_off, RV_REG_T1, ctx);

	}

	if (flags & BPF_TRAMP_F_IP_ARG)

		emit_store_stack_imm64(RV_REG_T1, -ip_off, (u64)func_addr, ctx);



	emit_li(RV_REG_T1, nr_arg_slots, ctx);

	emit_sd(RV_REG_FP, -nregs_off, RV_REG_T1, ctx);

	emit_store_stack_imm64(RV_REG_T1, -nregs_off, nr_arg_slots, ctx);



	store_args(nr_arg_slots, args_off, ctx);