This is a note to let you know that I've just added the patch titled
riscv, bpf: Fix incorrect runtime stats
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-bpf-fix-incorrect-runtime-stats.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4e6e34245fc1d54da5415a7c6e0c2dd78f881b9f
Author: Xu Kuohai <xukuohai@xxxxxxxxxx>
Date: Tue Apr 16 14:42:08 2024 +0800
riscv, bpf: Fix incorrect runtime stats
[ 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@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Reviewed-by: Pu Lehui <pulehui@xxxxxxxxxx>
Acked-by: Björn Töpel <bjorn@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20240416064208.2919073-3-xukuohai@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 719a97e7edb2c..0bd747d1d00fc 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)
