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[34.242.96.229]) by smtp.gmail.com with ESMTPSA id h10-20020a5d504a000000b00313e8dc7facsm4883533wrt.116.2023.06.26.01.58.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 01:58:13 -0700 (PDT) From: Puranjay Mohan To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, bpf@vger.kernel.org, kpsingh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v4 1/3] bpf: make bpf_prog_pack allocator portable Date: Mon, 26 Jun 2023 08:58:09 +0000 Message-Id: <20230626085811.3192402-2-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230626085811.3192402-1-puranjay12@gmail.com> References: <20230626085811.3192402-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net The bpf_prog_pack allocator currently uses module_alloc() and module_memfree() to allocate and free memory. This is not portable because different architectures use different methods for allocating memory for BPF programs. Like ARM64 uses vmalloc()/vfree(). Use bpf_jit_alloc_exec() and bpf_jit_free_exec() for memory management in bpf_prog_pack allocator. Other architectures can override these with their implementation and will be able to use bpf_prog_pack directly. Signed-off-by: Puranjay Mohan Acked-by: Song Liu --- Changes in V3 => v4 - No changes Changes in V2 => V3: - No changes Changes in v1 => v2: - No code changes. - Added Acked-by: Song Liu kernel/bpf/core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index dc85240a0134..599136cb5096 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -860,7 +860,7 @@ static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_ins GFP_KERNEL); if (!pack) return NULL; - pack->ptr = module_alloc(BPF_PROG_PACK_SIZE); + pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE); if (!pack->ptr) { kfree(pack); return NULL; @@ -884,7 +884,7 @@ void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns) mutex_lock(&pack_mutex); if (size > BPF_PROG_PACK_SIZE) { size = round_up(size, PAGE_SIZE); - ptr = module_alloc(size); + ptr = bpf_jit_alloc_exec(size); if (ptr) { bpf_fill_ill_insns(ptr, size); set_vm_flush_reset_perms(ptr); @@ -922,7 +922,7 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr) mutex_lock(&pack_mutex); if (hdr->size > BPF_PROG_PACK_SIZE) { - module_memfree(hdr); + bpf_jit_free_exec(hdr); goto out; } @@ -946,7 +946,7 @@ void bpf_prog_pack_free(struct bpf_binary_header *hdr) if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0, BPF_PROG_CHUNK_COUNT, 0) == 0) { list_del(&pack->list); - module_memfree(pack->ptr); + bpf_jit_free_exec(pack->ptr); kfree(pack); } out: From patchwork Mon Jun 26 08:58:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13292523 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C7256AB1 for ; Mon, 26 Jun 2023 08:58:17 +0000 (UTC) Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BA1310C2; Mon, 26 Jun 2023 01:58:16 -0700 (PDT) Received: by mail-wr1-x42c.google.com with SMTP id ffacd0b85a97d-3113dabc549so4588605f8f.1; Mon, 26 Jun 2023 01:58:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687769894; x=1690361894; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=g89tOe+fXjd3eCewwiEMcP/rgT7hBlO+AcyleoZQ3c4=; b=KY0lFmAyiGPNFi5tejVkCcdML67r0m78mXYhfhaNGCExzjzcs4nhYQIlel/8BYJRpz lfJONMAVjcHCJoBzkI699nWEtuBaxhq4kUnUzVfCp05RtNkxj/MNfRMmkwqF2dGcptlp K7WCs3Dpzq03D6B5J1Y+pYbq7jphYR0ctaBFILc+EgjFpGk/2jYY0JVpw6Mojp+pnkHF oXn0DUAwYrCVOM+Sv4+yZGrcQ6/BdpbMGLHoG/hTWFRe9VdFj+XLKbB9kG5C0ozms0N4 L68Qd5rzZyyhPK6dC5WoUSjRvBj0BM37fSNgn8FGG5KJ0b6VIQDBl++oMAAX7fhemqfZ 7+mQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687769894; x=1690361894; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=g89tOe+fXjd3eCewwiEMcP/rgT7hBlO+AcyleoZQ3c4=; b=XDoxSozuqgkdTcfrj7Ka/9+BcAvwdJ3d5/1jJaKbni0JDFfH+HXRo2KCoYbqaRyPQh KXwK3LeswYnNcAk+VxtEgxk1ppC4YMJp0qkgrUfuG88TyVTFUIXUp5f5/6r/6x4jYHZV 2j6CWIxddU8LmzVMJpvqdJf95XAxTqQtKgVLix0i5es0FLRpgP3ef/hm4Li3etOmlpaO jgkzXylx4tCHu0bpEinpl2vPAOdrQ1wCuP4AygnvFtWjqUXnY4GiinsvoFUMNRyHlNdW sHQEc7RzNBwy8eH4AZ9uSEuSDgw+9YP6OIof+WZGxd/rYFnQYPRbArW+F5KctZ/keQhu 3Qug== X-Gm-Message-State: AC+VfDyIB4U66qL/3M/etS114rXIhgLMsQ65ZPo4gcvL/kFIF0Uv3/yv 2h+MIUZiXnp7n3OkAQpw92E= X-Google-Smtp-Source: ACHHUZ4m62deog5lFK8+0lA0KYE/r/VTwsXj5L2YGdFLyxwDG7jb6AmJwJCCJu5KOCig62//DhK1dw== X-Received: by 2002:a05:6000:1004:b0:30a:dd26:63cd with SMTP id a4-20020a056000100400b0030add2663cdmr33892488wrx.5.1687769894028; Mon, 26 Jun 2023 01:58:14 -0700 (PDT) Received: from ip-172-31-22-112.eu-west-1.compute.internal (ec2-34-242-96-229.eu-west-1.compute.amazonaws.com. [34.242.96.229]) by smtp.gmail.com with ESMTPSA id h10-20020a5d504a000000b00313e8dc7facsm4883533wrt.116.2023.06.26.01.58.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 01:58:13 -0700 (PDT) From: Puranjay Mohan To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, bpf@vger.kernel.org, kpsingh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v4 2/3] arm64: patching: Add aarch64_insn_copy() Date: Mon, 26 Jun 2023 08:58:10 +0000 Message-Id: <20230626085811.3192402-3-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230626085811.3192402-1-puranjay12@gmail.com> References: <20230626085811.3192402-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net This will be used by BPF JIT compiler to dump JITed binary to a RX huge page, and thus allow multiple BPF programs sharing the a huge (2MB) page. The bpf_prog_pack allocator that implements the above feature allocates a RX/RW buffer pair. The JITed code is written to the RW buffer and then this function will be used to copy the code from RW to RX buffer. Signed-off-by: Puranjay Mohan Acked-by: Song Liu --- Changes in v3 => v4 - No changes Changes in v2 => v3 - No changes Changes in v1 => v2: - Renamed addr/opcode to dst/src. - Added Acked-by: Song Liu arch/arm64/include/asm/patching.h | 1 + arch/arm64/kernel/patching.c | 39 +++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/arch/arm64/include/asm/patching.h b/arch/arm64/include/asm/patching.h index 68908b82b168..f78a0409cbdb 100644 --- a/arch/arm64/include/asm/patching.h +++ b/arch/arm64/include/asm/patching.h @@ -8,6 +8,7 @@ int aarch64_insn_read(void *addr, u32 *insnp); int aarch64_insn_write(void *addr, u32 insn); int aarch64_insn_write_literal_u64(void *addr, u64 val); +void *aarch64_insn_copy(void *dst, const void *src, size_t len); int aarch64_insn_patch_text_nosync(void *addr, u32 insn); int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c index b4835f6d594b..419a9428402e 100644 --- a/arch/arm64/kernel/patching.c +++ b/arch/arm64/kernel/patching.c @@ -105,6 +105,45 @@ noinstr int aarch64_insn_write_literal_u64(void *addr, u64 val) return ret; } +/** + * aarch64_insn_copy - Copy instructions into (an unused part of) RX memory + * @dst: address to modify + * @src: source of the copy + * @len: length to copy + * + * Useful for JITs to dump new code blocks into unused regions of RX memory. + */ +noinstr void *aarch64_insn_copy(void *dst, const void *src, size_t len) +{ + unsigned long flags; + size_t patched = 0; + size_t size; + void *waddr; + void *ptr; + int ret; + + raw_spin_lock_irqsave(&patch_lock, flags); + + while (patched < len) { + ptr = dst + patched; + size = min_t(size_t, PAGE_SIZE - offset_in_page(ptr), + len - patched); + + waddr = patch_map(ptr, FIX_TEXT_POKE0); + ret = copy_to_kernel_nofault(waddr, src + patched, size); + patch_unmap(FIX_TEXT_POKE0); + + if (ret < 0) { + raw_spin_unlock_irqrestore(&patch_lock, flags); + return NULL; + } + patched += size; + } + raw_spin_unlock_irqrestore(&patch_lock, flags); + + return dst; +} + int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) { u32 *tp = addr; From patchwork Mon Jun 26 08:58:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13292525 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D4626FA1 for ; Mon, 26 Jun 2023 08:58:19 +0000 (UTC) Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88C762723; Mon, 26 Jun 2023 01:58:16 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id 5b1f17b1804b1-3fa70ec8d17so35199065e9.1; Mon, 26 Jun 2023 01:58:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687769895; x=1690361895; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=5i6ERh1cNmAmSBJdCUvzjUDJeDW4Go6V1bRVLdgUVO4=; b=nnh3t8J8zcxxotxX5qEsNJFdmTJgqCGMTS5BreYm4H7cjTfQ/n90LFyuJ+JmQ9IRuH 32+Yb6c1NR9Wm5hYZM6TDzMjieMYAGcHLXaqaGnGB8zBvyBoAUp45xwcfyXGu3cQVqKf Hnk3d3sFPL8wrGQzHBJIRkhV5XGK5uDnNLqRlM2GLjp3yeRuA+XAOiMwb8xxMh/XP+2G aF9E2knkZdRSqQCC/RO2zTRaZWiW7+TWxffiBvKAaTwAAVed1xriwssaVT4+MUmPjVjI twe2IcEOQi2k1L7q3wWriLQw1KNZO3XX6f1Ui+o0msbFL1jgaEKeSYjPOEL7LndOKBDa 5F1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687769895; x=1690361895; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=5i6ERh1cNmAmSBJdCUvzjUDJeDW4Go6V1bRVLdgUVO4=; b=IpBa9Un6Sb5g//OZrFXfILgs+8d2mA2AbKcqcU3zpU9306uMzmKDS2zDoNhWkeb8mH BhvR8SxC/i5DAn2JC5BqemsNS07aYLHFET2wABUKu4BcbgpgcvGLsKAJCc0QxDzZFT+T l8ISkSSti6/zX1cGyr7cmWLDZjJN00sevWvczxu68fRGF1k/agE1Hn5R4dVs28NUmRJk g8qF4PdXiNos4fRpKlX3gkhdP2o0k02pYHbFr3knw/CkoQC2FMDAb7fn0C44+xQSYBFf 8PviRet4dWesViqyZ87QfHY3tMmV/m/9kC0XYNd8x6x2+Me/4NTTdsoHZ+UpKaliA4cB L3rQ== X-Gm-Message-State: AC+VfDxUhTgOzOw1F172voW+yTvhapjwQtcqU2Ub7Yx6598RNIo5Gc/c 6stjA9MF1yi31kQR56RRUH1JMvFv0eSk1bs308i5wQ== X-Google-Smtp-Source: ACHHUZ47FEyGqK6Tao3ltj9Lfc0JvJOGVs0Mwuhq9/hOWhPsnr2zPacJ538nQYASV7PmQ3UsdeK0Jg== X-Received: by 2002:a05:600c:d8:b0:3f9:c9f4:acf1 with SMTP id u24-20020a05600c00d800b003f9c9f4acf1mr12509701wmm.7.1687769894589; Mon, 26 Jun 2023 01:58:14 -0700 (PDT) Received: from ip-172-31-22-112.eu-west-1.compute.internal (ec2-34-242-96-229.eu-west-1.compute.amazonaws.com. [34.242.96.229]) by smtp.gmail.com with ESMTPSA id h10-20020a5d504a000000b00313e8dc7facsm4883533wrt.116.2023.06.26.01.58.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 01:58:14 -0700 (PDT) From: Puranjay Mohan To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, bpf@vger.kernel.org, kpsingh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: puranjay12@gmail.com Subject: [PATCH bpf-next v4 3/3] bpf, arm64: use bpf_jit_binary_pack_alloc Date: Mon, 26 Jun 2023 08:58:11 +0000 Message-Id: <20230626085811.3192402-4-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230626085811.3192402-1-puranjay12@gmail.com> References: <20230626085811.3192402-1-puranjay12@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net Use bpf_jit_binary_pack_alloc for memory management of JIT binaries in ARM64 BPF JIT. The bpf_jit_binary_pack_alloc creates a pair of RW and RX buffers. The JIT writes the program into the RW buffer. When the JIT is done, the program is copied to the final RX buffer with bpf_jit_binary_pack_finalize. Implement bpf_arch_text_copy() and bpf_arch_text_invalidate() for ARM64 JIT as these functions are required by bpf_jit_binary_pack allocator. Signed-off-by: Puranjay Mohan Acked-by: Song Liu --- Changes in v3 => v4: - Fix the cache maintenance by cleaning the data cache and invalidating the i-Cache only *after* copying the instructions to the ROX region. Changes in v2 => v3: - Set prog = orig_prog; in the failure path of bpf_jit_binary_pack_finalize() call. - Add comments explaining the usage of the offsets in the exception table. Changes in v1 => v2: - Made the naming of ro_ prefix consistent. Now image/header/image_ptr are read/write and ro_image/ro_header/ro_image_ptr are read-only. arch/arm64/net/bpf_jit_comp.c | 145 ++++++++++++++++++++++++++++------ 1 file changed, 121 insertions(+), 24 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 145b540ec34f..cd05f0c513f4 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -76,6 +76,7 @@ struct jit_ctx { int *offset; int exentry_idx; __le32 *image; + __le32 *ro_image; u32 stack_size; int fpb_offset; }; @@ -205,6 +206,20 @@ static void jit_fill_hole(void *area, unsigned int size) *ptr++ = cpu_to_le32(AARCH64_BREAK_FAULT); } +int bpf_arch_text_invalidate(void *dst, size_t len) +{ + __le32 *ptr; + int ret; + + for (ptr = dst; len >= sizeof(u32); len -= sizeof(u32)) { + ret = aarch64_insn_patch_text_nosync(ptr++, AARCH64_BREAK_FAULT); + if (ret) + return ret; + } + + return 0; +} + static inline int epilogue_offset(const struct jit_ctx *ctx) { int to = ctx->epilogue_offset; @@ -701,7 +716,8 @@ static int add_exception_handler(const struct bpf_insn *insn, struct jit_ctx *ctx, int dst_reg) { - off_t offset; + off_t ins_offset; + off_t fixup_offset; unsigned long pc; struct exception_table_entry *ex; @@ -717,12 +733,17 @@ static int add_exception_handler(const struct bpf_insn *insn, return -EINVAL; ex = &ctx->prog->aux->extable[ctx->exentry_idx]; - pc = (unsigned long)&ctx->image[ctx->idx - 1]; + pc = (unsigned long)&ctx->ro_image[ctx->idx - 1]; - offset = pc - (long)&ex->insn; - if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN)) + /* + * This is the relative offset of the instruction that may fault from + * the exception table itself. This will be written to the exception + * table and if this instruction faults, the destination register will + * be set to '0' and the execution will jump to the next instruction. + */ + ins_offset = pc - (long)&ex->insn; + if (WARN_ON_ONCE(ins_offset >= 0 || ins_offset < INT_MIN)) return -ERANGE; - ex->insn = offset; /* * Since the extable follows the program, the fixup offset is always @@ -731,12 +752,25 @@ static int add_exception_handler(const struct bpf_insn *insn, * bits. We don't need to worry about buildtime or runtime sort * modifying the upper bits because the table is already sorted, and * isn't part of the main exception table. + * + * The fixup_offset is set to the next instruction from the instruction + * that may fault. The execution will jump to this after handling the + * fault. */ - offset = (long)&ex->fixup - (pc + AARCH64_INSN_SIZE); - if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, offset)) + fixup_offset = (long)&ex->fixup - (pc + AARCH64_INSN_SIZE); + if (!FIELD_FIT(BPF_FIXUP_OFFSET_MASK, fixup_offset)) return -ERANGE; - ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) | + /* + * The offsets above have been calculated using the RO buffer but we + * need to use the R/W buffer for writes. + * switch ex to rw buffer for writing. + */ + ex = (void *)ctx->image + ((void *)ex - (void *)ctx->ro_image); + + ex->insn = ins_offset; + + ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, fixup_offset) | FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg); ex->type = EX_TYPE_BPF; @@ -1446,7 +1480,8 @@ static inline void bpf_flush_icache(void *start, void *end) struct arm64_jit_data { struct bpf_binary_header *header; - u8 *image; + u8 *ro_image; + struct bpf_binary_header *ro_header; struct jit_ctx ctx; }; @@ -1455,12 +1490,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) int image_size, prog_size, extable_size, extable_align, extable_offset; struct bpf_prog *tmp, *orig_prog = prog; struct bpf_binary_header *header; + struct bpf_binary_header *ro_header; struct arm64_jit_data *jit_data; bool was_classic = bpf_prog_was_classic(prog); bool tmp_blinded = false; bool extra_pass = false; struct jit_ctx ctx; u8 *image_ptr; + u8 *ro_image_ptr; if (!prog->jit_requested) return orig_prog; @@ -1487,8 +1524,11 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) } if (jit_data->ctx.offset) { ctx = jit_data->ctx; - image_ptr = jit_data->image; + ro_image_ptr = jit_data->ro_image; + ro_header = jit_data->ro_header; header = jit_data->header; + image_ptr = (void *)header + ((void *)ro_image_ptr + - (void *)ro_header); extra_pass = true; prog_size = sizeof(u32) * ctx.idx; goto skip_init_ctx; @@ -1533,18 +1573,27 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) /* also allocate space for plt target */ extable_offset = round_up(prog_size + PLT_TARGET_SIZE, extable_align); image_size = extable_offset + extable_size; - header = bpf_jit_binary_alloc(image_size, &image_ptr, - sizeof(u32), jit_fill_hole); - if (header == NULL) { + ro_header = bpf_jit_binary_pack_alloc(image_size, &ro_image_ptr, + sizeof(u32), &header, &image_ptr, + jit_fill_hole); + if (!ro_header) { prog = orig_prog; goto out_off; } /* 2. Now, the actual pass. */ + /* + * Use the image(RW) for writing the JITed instructions. But also save + * the ro_image(RX) for calculating the offsets in the image. The RW + * image will be later copied to the RX image from where the program + * will run. The bpf_jit_binary_pack_finalize() will do this copy in the + * final step. + */ ctx.image = (__le32 *)image_ptr; + ctx.ro_image = (__le32 *)ro_image_ptr; if (extable_size) - prog->aux->extable = (void *)image_ptr + extable_offset; + prog->aux->extable = (void *)ro_image_ptr + extable_offset; skip_init_ctx: ctx.idx = 0; ctx.exentry_idx = 0; @@ -1552,9 +1601,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) build_prologue(&ctx, was_classic); if (build_body(&ctx, extra_pass)) { - bpf_jit_binary_free(header); prog = orig_prog; - goto out_off; + goto out_free_hdr; } build_epilogue(&ctx); @@ -1562,34 +1610,44 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) /* 3. Extra pass to validate JITed code. */ if (validate_ctx(&ctx)) { - bpf_jit_binary_free(header); prog = orig_prog; - goto out_off; + goto out_free_hdr; } /* And we're done. */ if (bpf_jit_enable > 1) bpf_jit_dump(prog->len, prog_size, 2, ctx.image); - bpf_flush_icache(header, ctx.image + ctx.idx); - if (!prog->is_func || extra_pass) { if (extra_pass && ctx.idx != jit_data->ctx.idx) { pr_err_once("multi-func JIT bug %d != %d\n", ctx.idx, jit_data->ctx.idx); - bpf_jit_binary_free(header); prog->bpf_func = NULL; prog->jited = 0; prog->jited_len = 0; + goto out_free_hdr; + } + if (WARN_ON(bpf_jit_binary_pack_finalize(prog, ro_header, + header))) { + /* ro_header has been freed */ + ro_header = NULL; + prog = orig_prog; goto out_off; } - bpf_jit_binary_lock_ro(header); + /* + * 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->image = image_ptr; + jit_data->ro_image = ro_image_ptr; jit_data->header = header; + jit_data->ro_header = ro_header; } - prog->bpf_func = (void *)ctx.image; + + prog->bpf_func = (void *)ctx.ro_image; prog->jited = 1; prog->jited_len = prog_size; @@ -1610,6 +1668,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) bpf_jit_prog_release_other(prog, prog == orig_prog ? tmp : orig_prog); return prog; + +out_free_hdr: + if (header) { + bpf_arch_text_copy(&ro_header->size, &header->size, + sizeof(header->size)); + bpf_jit_binary_pack_free(ro_header, header); + } + goto out_off; } bool bpf_jit_supports_kfunc_call(void) @@ -1617,6 +1683,13 @@ bool bpf_jit_supports_kfunc_call(void) return true; } +void *bpf_arch_text_copy(void *dst, void *src, size_t len) +{ + if (!aarch64_insn_copy(dst, src, len)) + return ERR_PTR(-EINVAL); + return dst; +} + u64 bpf_jit_alloc_exec_limit(void) { return VMALLOC_END - VMALLOC_START; @@ -2221,3 +2294,27 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type poke_type, return ret; } + +void bpf_jit_free(struct bpf_prog *prog) +{ + if (prog->jited) { + struct arm64_jit_data *jit_data = prog->aux->jit_data; + struct bpf_binary_header *hdr; + + /* + * If we fail the final pass of JIT (from jit_subprogs), + * the program may not be finalized yet. Call finalize here + * before freeing it. + */ + if (jit_data) { + bpf_jit_binary_pack_finalize(prog, jit_data->ro_header, + jit_data->header); + kfree(jit_data); + } + hdr = bpf_jit_binary_pack_hdr(prog); + bpf_jit_binary_pack_free(hdr, NULL); + WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(prog)); + } + + bpf_prog_unlock_free(prog); +}