From: Song Liu <song@kernel.org> mainline inclusion from mainline-v6.8-rc1 commit 3ba026fca8786161b0c4d75be396e61d6816e0a1 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8335 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ---------------------------------------------------------------------- There are three major changes here: 1. Add arch_[alloc|free]_bpf_trampoline based on bpf_prog_pack; 2. Let arch_prepare_bpf_trampoline handle ROX input image, this requires arch_prepare_bpf_trampoline allocating a temporary RW buffer; 3. Update __arch_prepare_bpf_trampoline() to handle a RW buffer (rw_image) and a ROX buffer (image). This part is similar to the image/rw_image logic in bpf_int_jit_compile(). Signed-off-by: Song Liu <song@kernel.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20231206224054.492250-8-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- arch/x86/net/bpf_jit_comp.c | 98 +++++++++++++++++++++++++++---------- 1 file changed, 72 insertions(+), 26 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 34d722dc8e1b..724636778ea5 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -2171,7 +2171,8 @@ static void restore_regs(const struct btf_func_model *m, u8 **prog, static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, struct bpf_tramp_link *l, int stack_size, - int run_ctx_off, bool save_ret) + int run_ctx_off, bool save_ret, + void *image, void *rw_image) { u8 *prog = *pprog; u8 *jmp_insn; @@ -2199,7 +2200,7 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, else EMIT4(0x48, 0x8D, 0x75, -run_ctx_off); - if (emit_rsb_call(&prog, bpf_trampoline_enter(p), prog)) + if (emit_rsb_call(&prog, bpf_trampoline_enter(p), image + (prog - (u8 *)rw_image))) return -EINVAL; /* remember prog start time returned by __bpf_prog_enter */ emit_mov_reg(&prog, true, BPF_REG_6, BPF_REG_0); @@ -2223,7 +2224,7 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, (long) p->insnsi >> 32, (u32) (long) p->insnsi); /* call JITed bpf program or interpreter */ - if (emit_rsb_call(&prog, p->bpf_func, prog)) + if (emit_rsb_call(&prog, p->bpf_func, image + (prog - (u8 *)rw_image))) return -EINVAL; /* @@ -2250,7 +2251,7 @@ static int invoke_bpf_prog(const struct btf_func_model *m, u8 **pprog, EMIT3_off32(0x48, 0x8D, 0x95, -run_ctx_off); else EMIT4(0x48, 0x8D, 0x55, -run_ctx_off); - if (emit_rsb_call(&prog, bpf_trampoline_exit(p), prog)) + if (emit_rsb_call(&prog, bpf_trampoline_exit(p), image + (prog - (u8 *)rw_image))) return -EINVAL; *pprog = prog; @@ -2285,14 +2286,15 @@ static int emit_cond_near_jump(u8 **pprog, void *func, void *ip, u8 jmp_cond) static int invoke_bpf(const struct btf_func_model *m, u8 **pprog, struct bpf_tramp_links *tl, int stack_size, - int run_ctx_off, bool save_ret) + int run_ctx_off, bool save_ret, + void *image, void *rw_image) { int i; u8 *prog = *pprog; for (i = 0; i < tl->nr_links; i++) { if (invoke_bpf_prog(m, &prog, tl->links[i], stack_size, - run_ctx_off, save_ret)) + run_ctx_off, save_ret, image, rw_image)) return -EINVAL; } *pprog = prog; @@ -2301,7 +2303,8 @@ static int invoke_bpf(const struct btf_func_model *m, u8 **pprog, static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, struct bpf_tramp_links *tl, int stack_size, - int run_ctx_off, u8 **branches) + int run_ctx_off, u8 **branches, + void *image, void *rw_image) { u8 *prog = *pprog; int i; @@ -2312,7 +2315,8 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, emit_mov_imm32(&prog, false, BPF_REG_0, 0); emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); for (i = 0; i < tl->nr_links; i++) { - if (invoke_bpf_prog(m, &prog, tl->links[i], stack_size, run_ctx_off, true)) + if (invoke_bpf_prog(m, &prog, tl->links[i], stack_size, run_ctx_off, true, + image, rw_image)) return -EINVAL; /* mod_ret prog stored return value into [rbp - 8]. Emit: @@ -2395,7 +2399,8 @@ static int invoke_bpf_mod_ret(const struct btf_func_model *m, u8 **pprog, * add rsp, 8 // skip eth_type_trans's frame * ret // return to its caller */ -static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *image_end, +static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_image, + void *rw_image_end, void *image, const struct btf_func_model *m, u32 flags, struct bpf_tramp_links *tlinks, void *func_addr) @@ -2494,7 +2499,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image orig_call += X86_PATCH_SIZE; } - prog = image; + prog = rw_image; EMIT_ENDBR(); /* @@ -2536,7 +2541,8 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image if (flags & BPF_TRAMP_F_CALL_ORIG) { /* arg1: mov rdi, im */ emit_mov_imm64(&prog, BPF_REG_1, (long) im >> 32, (u32) (long) im); - if (emit_rsb_call(&prog, __bpf_tramp_enter, prog)) { + if (emit_rsb_call(&prog, __bpf_tramp_enter, + image + (prog - (u8 *)rw_image))) { ret = -EINVAL; goto cleanup; } @@ -2544,7 +2550,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image if (fentry->nr_links) if (invoke_bpf(m, &prog, fentry, regs_off, run_ctx_off, - flags & BPF_TRAMP_F_RET_FENTRY_RET)) + flags & BPF_TRAMP_F_RET_FENTRY_RET, image, rw_image)) return -EINVAL; if (fmod_ret->nr_links) { @@ -2554,7 +2560,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image return -ENOMEM; if (invoke_bpf_mod_ret(m, &prog, fmod_ret, regs_off, - run_ctx_off, branches)) { + run_ctx_off, branches, image, rw_image)) { ret = -EINVAL; goto cleanup; } @@ -2575,14 +2581,14 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image EMIT2(0xff, 0xd3); /* call *rbx */ } else { /* call original function */ - if (emit_rsb_call(&prog, orig_call, prog)) { + if (emit_rsb_call(&prog, orig_call, image + (prog - (u8 *)rw_image))) { ret = -EINVAL; goto cleanup; } } /* remember return value in a stack for bpf prog to access */ emit_stx(&prog, BPF_DW, BPF_REG_FP, BPF_REG_0, -8); - im->ip_after_call = prog; + im->ip_after_call = image + (prog - (u8 *)rw_image); memcpy(prog, x86_nops[5], X86_PATCH_SIZE); prog += X86_PATCH_SIZE; } @@ -2598,12 +2604,13 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image * aligned address of do_fexit. */ for (i = 0; i < fmod_ret->nr_links; i++) - emit_cond_near_jump(&branches[i], prog, branches[i], - X86_JNE); + emit_cond_near_jump(&branches[i], image + (prog - (u8 *)rw_image), + image + (branches[i] - (u8 *)rw_image), X86_JNE); } if (fexit->nr_links) - if (invoke_bpf(m, &prog, fexit, regs_off, run_ctx_off, false)) { + if (invoke_bpf(m, &prog, fexit, regs_off, run_ctx_off, + false, image, rw_image)) { ret = -EINVAL; goto cleanup; } @@ -2616,10 +2623,10 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image * restored to R0. */ if (flags & BPF_TRAMP_F_CALL_ORIG) { - im->ip_epilogue = prog; + im->ip_epilogue = image + (prog - (u8 *)rw_image); /* arg1: mov rdi, im */ emit_mov_imm64(&prog, BPF_REG_1, (long) im >> 32, (u32) (long) im); - if (emit_rsb_call(&prog, __bpf_tramp_exit, prog)) { + if (emit_rsb_call(&prog, __bpf_tramp_exit, image + (prog - (u8 *)rw_image))) { ret = -EINVAL; goto cleanup; } @@ -2638,25 +2645,64 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image if (flags & BPF_TRAMP_F_SKIP_FRAME) /* skip our return address and return to parent */ EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */ - emit_return(&prog, prog); + emit_return(&prog, image + (prog - (u8 *)rw_image)); /* Make sure the trampoline generation logic doesn't overflow */ - if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) { + if (WARN_ON_ONCE(prog > (u8 *)rw_image_end - BPF_INSN_SAFETY)) { ret = -EFAULT; goto cleanup; } - ret = prog - (u8 *)image + BPF_INSN_SAFETY; + ret = prog - (u8 *)rw_image + BPF_INSN_SAFETY; cleanup: kfree(branches); return ret; } +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 *image, void *image_end, const struct btf_func_model *m, u32 flags, struct bpf_tramp_links *tlinks, void *func_addr) { - return __arch_prepare_bpf_trampoline(im, image, image_end, m, flags, tlinks, func_addr); + void *rw_image, *tmp; + int ret; + u32 size = image_end - image; + + /* rw_image doesn't need to be in module memory range, so we can + * use kvmalloc. + */ + rw_image = kvmalloc(size, GFP_KERNEL); + if (!rw_image) + return -ENOMEM; + + ret = __arch_prepare_bpf_trampoline(im, rw_image, rw_image + size, image, m, + flags, tlinks, func_addr); + if (ret < 0) + goto out; + + tmp = bpf_arch_text_copy(image, rw_image, size); + if (IS_ERR(tmp)) + ret = PTR_ERR(tmp); +out: + kvfree(rw_image); + return ret; } int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags, @@ -2677,8 +2723,8 @@ int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags, if (!image) return -ENOMEM; - ret = __arch_prepare_bpf_trampoline(&im, image, image + PAGE_SIZE, m, flags, - tlinks, func_addr); + ret = __arch_prepare_bpf_trampoline(&im, image, image + PAGE_SIZE, image, + m, flags, tlinks, func_addr); bpf_jit_free_exec(image); return ret; } -- 2.34.1