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arm64, bpf: Use bpf_prog_pack for arm64 bpf trampoline 

We used bpf_prog_pack to aggregate bpf programs into huge page to
relieve the iTLB pressure on the system. This was merged for ARM64[1]
We can apply it to bpf trampoline as well. This would increase the
preformance of fentry and struct_ops programs.

[1] https://lore.kernel.org/bpf/20240228141824.119877-1-puranjay12@gmail.com/

Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Reviewed-by: Pu Lehui <pulehui@huawei.com>
Message-ID: <20240304202803.31400-1-puranjay12@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Puranjay Mohan 2024-03-04 20:28:03 +00:00 committed by Alexei Starovoitov
parent a27e89673a
commit 96b0f5addc
1 changed files with 46 additions and 9 deletions
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55
arch/arm64/net/bpf_jit_comp.c
View File

@ -2076,7 +2076,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
/* store return value */
emit(A64_STR64I(A64_R(0), A64_SP, retval_off), ctx);
/* reserve a nop for bpf_tramp_image_put */
im->ip_after_call = ctx->image + ctx->idx;
im->ip_after_call = ctx->ro_image + ctx->idx;
emit(A64_NOP, ctx);
}
@ -2091,7 +2091,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
run_ctx_off, false);
if (flags & BPF_TRAMP_F_CALL_ORIG) {
im->ip_epilogue = ctx->image + ctx->idx;
im->ip_epilogue = ctx->ro_image + ctx->idx;
emit_addr_mov_i64(A64_R(0), (const u64)im, ctx);
emit_call((const u64)__bpf_tramp_exit, ctx);
}
@ -2124,9 +2124,6 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
emit(A64_RET(A64_R(10)), ctx);
}
if (ctx->image)
bpf_flush_icache(ctx->image, ctx->image + ctx->idx);
kfree(branches);
return ctx->idx;
@ -2169,14 +2166,43 @@ int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
return ret < 0 ? ret : ret * AARCH64_INSN_SIZE;
}
int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image,
void *image_end, const struct btf_func_model *m,
void *arch_alloc_bpf_trampoline(unsigned int size)
{
return bpf_prog_pack_alloc(size, jit_fill_hole);
}
void arch_free_bpf_trampoline(void *image, unsigned int size)
{
bpf_prog_pack_free(image, size);
}
void arch_protect_bpf_trampoline(void *image, unsigned int size)
{
}
void arch_unprotect_bpf_trampoline(void *image, unsigned int size)
{
}
int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *ro_image,
void *ro_image_end, const struct btf_func_model *m,
u32 flags, struct bpf_tramp_links *tlinks,
void *func_addr)
{
int ret, nregs;
void *image, *tmp;
u32 size = ro_image_end - ro_image;
/* image doesn't need to be in module memory range, so we can
* use kvmalloc.
*/
image = kvmalloc(size, GFP_KERNEL);
if (!image)
return -ENOMEM;
struct jit_ctx ctx = {
.image = image,
.ro_image = ro_image,
.idx = 0,
};
@ -2185,15 +2211,26 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image,
if (nregs > 8)
return -ENOTSUPP;
jit_fill_hole(image, (unsigned int)(image_end - image));
jit_fill_hole(image, (unsigned int)(ro_image_end - ro_image));
ret = prepare_trampoline(&ctx, im, tlinks, func_addr, nregs, flags);
if (ret > 0 && validate_code(&ctx) < 0)
if (ret > 0 && validate_code(&ctx) < 0) {
ret = -EINVAL;
goto out;
}
if (ret > 0)
ret *= AARCH64_INSN_SIZE;
tmp = bpf_arch_text_copy(ro_image, image, size);
if (IS_ERR(tmp)) {
ret = PTR_ERR(tmp);
goto out;
}
bpf_flush_icache(ro_image, ro_image + size);
out:
kvfree(image);
return ret;
}