From: Puranjay Mohan Date: Mon, 13 Apr 2026 19:11:08 +0000 (-0700) Subject: bpf, arm64: Remove redundant bpf_flush_icache() after pack allocator finalize X-Git-Url: http://git.ipfire.org/index.cgi?a=commitdiff_plain;h=42f18ae53011826cfd3c84d041817e7f07bc645b;p=thirdparty%2Fkernel%2Flinux.git bpf, arm64: Remove redundant bpf_flush_icache() after pack allocator finalize bpf_flush_icache() calls flush_icache_range() to clean the data cache and invalidate the instruction cache for the JITed code region. However, since commit 1dad391daef1 ("bpf, arm64: use bpf_prog_pack for memory management"), this flush is redundant. bpf_jit_binary_pack_finalize() copies the JITed instructions to the ROX region via bpf_arch_text_copy() -> aarch64_insn_copy() -> __text_poke(), and __text_poke() already calls flush_icache_range() on the written range. The subsequent bpf_flush_icache() repeats the same cache maintenance on an overlapping range, including an unnecessary second synchronous IPI to all CPUs via kick_all_cpus_sync(). Remove the redundant bpf_flush_icache() call and its now-unused definition. Fixes: 1dad391daef1 ("bpf, arm64: use bpf_prog_pack for memory management") Acked-by: Song Liu Signed-off-by: Puranjay Mohan Acked-by: Breno Leitao Link: https://lore.kernel.org/r/20260413191111.3426023-2-puranjay@kernel.org Signed-off-by: Alexei Starovoitov --- diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 4aad9483f8a50..524b67c0867e7 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -18,7 +18,6 @@ #include #include -#include #include #include #include @@ -1961,11 +1960,6 @@ static int validate_ctx(struct jit_ctx *ctx) return 0; } -static inline void bpf_flush_icache(void *start, void *end) -{ - flush_icache_range((unsigned long)start, (unsigned long)end); -} - static void priv_stack_init_guard(void __percpu *priv_stack_ptr, int alloc_size) { int cpu, underflow_idx = (alloc_size - PRIV_STACK_GUARD_SZ) >> 3; @@ -2204,12 +2198,6 @@ skip_init_ctx: prog = orig_prog; goto out_off; } - /* - * The instructions have now been copied to the ROX region from - * where they will execute. Now the data cache has to be cleaned to - * the PoU and the I-cache has to be invalidated for the VAs. - */ - bpf_flush_icache(ro_header, ctx.ro_image + ctx.idx); } else { jit_data->ctx = ctx; jit_data->ro_image = ro_image_ptr;