[PATCH v2 2/4] powerpc/bpf: implement bpf_arch_text_copy
From: Hari Bathini <hbathini@linux.ibm.com>
Date: 2023-03-09 18:02:51
Also in:
bpf
Subsystem:
bpf jit for powerpc (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Hari Bathini, Christophe Leroy, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
bpf_arch_text_copy is used to dump JITed binary to RX page, allowing multiple BPF programs to share the same page. Use the newly introduced patch_instructions() to implement it. Around 5X improvement in speed of execution observed, using the new patch_instructions() function over patch_instruction(), while running the tests from test_bpf.ko. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> --- arch/powerpc/net/bpf_jit_comp.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index e93aefcfb83f..0a70319116d1 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c@@ -13,9 +13,12 @@ #include <linux/netdevice.h> #include <linux/filter.h> #include <linux/if_vlan.h> -#include <asm/kprobes.h> +#include <linux/memory.h> #include <linux/bpf.h> +#include <asm/kprobes.h> +#include <asm/code-patching.h> + #include "bpf_jit.h" static void bpf_jit_fill_ill_insns(void *area, unsigned int size)
@@ -272,3 +275,21 @@ int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct code ctx->exentry_idx++; return 0; } + +void *bpf_arch_text_copy(void *dst, void *src, size_t len) +{ + void *ret = ERR_PTR(-EINVAL); + int err; + + if (WARN_ON_ONCE(core_kernel_text((unsigned long)dst))) + return ret; + + ret = dst; + mutex_lock(&text_mutex); + err = patch_instructions(dst, src, false, len); + if (err) + ret = ERR_PTR(err); + mutex_unlock(&text_mutex); + + return ret; +}
--
2.39.2