Commit 10541b37 authored by Xu Kuohai's avatar Xu Kuohai Committed by Daniel Borkmann
Browse files

riscv, bpf: Fix incorrect runtime stats 



When __bpf_prog_enter() returns zero, the s1 register is not set to zero,
resulting in incorrect runtime stats. Fix it by setting s1 immediately upon
the return of __bpf_prog_enter().

Fixes: 49b5e77a ("riscv, bpf: Add bpf trampoline support for RV64")
Signed-off-by: default avatarXu Kuohai <xukuohai@huawei.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarPu Lehui <pulehui@huawei.com>
Acked-by: default avatarBjörn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/bpf/20240416064208.2919073-3-xukuohai@huaweicloud.com
parent dc7d7447

arch/riscv/net/bpf_jit_comp64.c

+3 −3
Original line number Diff line number Diff line
@@ -722,6 +722,9 @@ static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_of 
	if (ret)

		return ret;



	/* store prog start time */

	emit_mv(RV_REG_S1, RV_REG_A0, ctx);



	/* if (__bpf_prog_enter(prog) == 0)

	 *	goto skip_exec_of_prog;

	 */
@@ -729,9 +732,6 @@ static int invoke_bpf_prog(struct bpf_tramp_link *l, int args_off, int retval_of 
	/* nop reserved for conditional jump */

	emit(rv_nop(), ctx);



	/* store prog start time */

	emit_mv(RV_REG_S1, RV_REG_A0, ctx);



	/* arg1: &args_off */

	emit_addi(RV_REG_A0, RV_REG_FP, -args_off, ctx);

	if (!p->jited)