github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-30 18:13:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

bpf, arm64: Remove redundant bpf_flush_icache() after pack allocator finalize

Browse Source 
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 1dad391dae ("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: 1dad391dae ("bpf, arm64: use bpf_prog_pack for memory management")
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20260413191111.3426023-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Puranjay Mohan 2026-04-13 12:11:08 -07:00 committed by Alexei Starovoitov
parent 4fddde2a73
commit 42f18ae530
1 changed files with 0 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/arm64/net/bpf_jit_comp.c
View File

@ -18,7 +18,6 @@
#include <asm/asm-extable.h>
#include <asm/byteorder.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/debug-monitors.h>
#include <asm/insn.h>
@ -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 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
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;