[PATCH bpf-next v1 3/7] bpf, arm64: Use resolved pointer for timed may_goto
From: Siddharth Chintamaneni <hidden>
Date: 2026-09-04 19:51:59
Also in:
bpf, linux-riscv, linux-s390
Subsystem:
arm64 port (aarch64 architecture), bpf jit for arm64, bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Catalin Marinas, Will Deacon, Daniel Borkmann, Alexei Starovoitov, Puranjay Mohan, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
The timed may_goto fixup now passes the resolved counter pointer through
BPF_REG_AX instead of a stack offset.
Copy the pointer directly into the first argument register rather than
adding it to the BPF frame pointer again.
Fixes: 16175375da36 ("bpf, arm64: Add JIT support for timed may_goto")
Reported-by: Jeremy Jean <redacted>
Link: https://lore.kernel.org/all/20260824213158.3755932-2-Jeremy.Jean@oss.cyber.gouv.fr/ (local)
Assisted-by: Copilot:gpt-5.6-sol
Signed-off-by: Siddharth Chintamaneni <redacted>
---
arch/arm64/net/bpf_timed_may_goto.S | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/net/bpf_timed_may_goto.S b/arch/arm64/net/bpf_timed_may_goto.S
index a9a802711a7f..53148c9a1c58 100644
--- a/arch/arm64/net/bpf_timed_may_goto.S
+++ b/arch/arm64/net/bpf_timed_may_goto.S@@ -14,16 +14,10 @@ SYM_FUNC_START(arch_bpf_timed_may_goto) stp x3, x4, [sp, #48] /* - * Stack depth was passed in BPF_REG_AX (x9), add it to the BPF_FP - * (x25) to get the pointer to count and timestamp and pass it as the - * first argument in x0. - * - * Before generating the call to arch_bpf_timed_may_goto, the verifier - * generates a load instruction using FP, i.e. REG_AX = *(u64 *)(FP - - * stack_off_cnt), so BPF_REG_FP (x25) is always set up by the arm64 - * jit in this case. + * BPF_REG_AX (x9) contains the count and timestamp pointer; pass it as + * the first argument in x0. */ - add x0, x9, x25 + mov x0, x9 bl bpf_check_timed_may_goto /* BPF_REG_AX(x9) will be stored into count, so move return value to it. */ mov x9, x0
--
2.43.0