[PATCH bpf-next v2 03/21] bpf, x86: Factor out bpf_arch_text_poke_prepare_insns() helper on x86_64
flat view
COOLING4d
From: Leon Hwang <hidden>
Date: 2026-10-12 15:41:48
Also in:
bpf, linux-kselftest, lkml
Subsystem:
bpf jit for x86 64-bit, bpf [general] (safe dynamic programs and tools), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Revision v2 of 2 in this series.
Revisions (2)
- v1 [diff vs current]
- v2 current
In the following commit, it also needs to prepare both old_insn and new_insn when add text-poke batch support. So, factor out bpf_arch_text_poke_prepare_insns() helper for text-poke batch support. No functional changes intended. Signed-off-by: Leon Hwang <redacted> --- arch/x86/net/bpf_jit_comp.c | 38 ++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 083fcd6cf15b..74033373dc06 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c@@ -646,13 +646,12 @@ static int emit_jump(u8 **pprog, void *func, void *ip) return emit_patch(pprog, func, ip, 0xE9); } -static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t, - enum bpf_text_poke_type new_t, - void *old_addr, void *new_addr) +static int bpf_arch_text_poke_prepare_insns(void *ip, enum bpf_text_poke_type old_t, + enum bpf_text_poke_type new_t, + void *old_addr, void *new_addr, + u8 *old_insn, u8 *new_insn) { const u8 *nop_insn = x86_nops[5]; - u8 old_insn[X86_PATCH_SIZE]; - u8 new_insn[X86_PATCH_SIZE]; u8 *prog; int ret;
@@ -676,18 +675,31 @@ static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t, return ret; } - ret = -EBUSY; - mutex_lock(&text_mutex); + return 0; +} + +static int __bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t, + enum bpf_text_poke_type new_t, + void *old_addr, void *new_addr) +{ + u8 old_insn[X86_PATCH_SIZE]; + u8 new_insn[X86_PATCH_SIZE]; + int ret; + + ret = bpf_arch_text_poke_prepare_insns(ip, old_t, new_t, old_addr, new_addr, old_insn, + new_insn); + if (ret) + return ret; + + guard(mutex)(&text_mutex); + if (memcmp(ip, old_insn, X86_PATCH_SIZE)) - goto out; - ret = 1; + return -EBUSY; if (memcmp(ip, new_insn, X86_PATCH_SIZE)) { smp_text_poke_single(ip, new_insn, X86_PATCH_SIZE, NULL); - ret = 0; + return 0; } -out: - mutex_unlock(&text_mutex); - return ret; + return 1; } int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
--
2.55.0