6.6-stable review patch. If anyone has any objections, please let me know.
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From: Xu Kuohai xukuohai@huawei.com
[ Upstream commit 10541b374aa05c8118cc6a529a615882e53f261b ]
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: 49b5e77ae3e2 ("riscv, bpf: Add bpf trampoline support for RV64") Signed-off-by: Xu Kuohai xukuohai@huawei.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Pu Lehui pulehui@huawei.com Acked-by: Björn Töpel bjorn@kernel.org Link: https://lore.kernel.org/bpf/20240416064208.2919073-3-xukuohai@huaweicloud.co... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/net/bpf_jit_comp64.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c index 8581693e62d39..b3990874e4818 100644 --- a/arch/riscv/net/bpf_jit_comp64.c +++ b/arch/riscv/net/bpf_jit_comp64.c @@ -740,6 +740,9 @@ 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; */ @@ -747,9 +750,6 @@ 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)