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

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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 48a8f78c50 ("bpf, riscv: use prog pack allocator in the
BPF JIT"), this flush is redundant.

bpf_jit_binary_pack_finalize() copies the JITed instructions to the ROX
region via bpf_arch_text_copy() -> patch_text_nosync(), and
patch_text_nosync() already calls flush_icache_range() on the written
range. The subsequent bpf_flush_icache() repeats the same cache
maintenance on an overlapping range.

Remove the redundant bpf_flush_icache() call and its now-unused
definition.

Fixes: 48a8f78c50 ("bpf, riscv: use prog pack allocator in the BPF JIT")
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Reviewed-by: Pu Lehui <pulehui@huawei.com>
Tested-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260413191111.3426023-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Puranjay Mohan
2026-04-13 12:11:09 -07:00
committed by Alexei Starovoitov
parent 42f18ae530
commit 46ee1342b8
2 changed files with 0 additions and 13 deletions
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6
arch/riscv/net/bpf_jit.h
View File

@@ -11,7 +11,6 @@
#include <linux/bpf.h>
#include <linux/filter.h>
#include <asm/cacheflush.h>
/* verify runtime detection extension status */
#define rv_ext_enabled(ext) \
@@ -105,11 +104,6 @@ static inline void bpf_fill_ill_insns(void *area, unsigned int size)
memset(area, 0, size);
}
static inline void bpf_flush_icache(void *start, void *end)
{
flush_icache_range((unsigned long)start, (unsigned long)end);
}
/* Emit a 4-byte riscv instruction. */
static inline void emit(const u32 insn, struct rv_jit_context *ctx)
{

7
arch/riscv/net/bpf_jit_core.c
View File

@@ -183,13 +183,6 @@ skip_init_ctx:
prog = orig_prog;
goto out_offset;
}
/*
* The instructions have now been copied to the ROX region from
* where they will execute.
* Write any modified data cache blocks out to memory and
* invalidate the corresponding blocks in the instruction cache.
*/
bpf_flush_icache(jit_data->ro_header, ctx->ro_insns + ctx->ninsns);
for (i = 0; i < prog->len; i++)
ctx->offset[i] = ninsns_rvoff(ctx->offset[i]);
bpf_prog_fill_jited_linfo(prog, ctx->offset);