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[54.154.23.32]) by smtp.gmail.com with ESMTPSA id a4-20020a056000050400b0030ae3a6be4asm31352451wrf.72.2023.06.19.03.01.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Jun 2023 03:01:22 -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 v3 1/3] bpf: make bpf_prog_pack allocator portable Date: Mon, 19 Jun 2023 10:01:19 +0000 Message-Id: <20230619100121.27534-2-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230619100121.27534-1-puranjay12@gmail.com> References: <20230619100121.27534-1-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 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 19 10:01:20 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13284294 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 A42A3C8C8 for ; Mon, 19 Jun 2023 10:01:51 +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 DE2FEE4D; Mon, 19 Jun 2023 03:01:25 -0700 (PDT) Received: by mail-wr1-x42c.google.com with SMTP id ffacd0b85a97d-31110aea814so3314286f8f.2; Mon, 19 Jun 2023 03:01:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687168884; x=1689760884; 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=pfL8kOHIfnY7PiBiCXPYIlsy0Fts7anKA/DneQ6qt2M=; b=FctDpddQkBXnzOoMsS1SofViEs4R2DxUET5Tefl8hEjNIY/Ao4Alj88BKwOeirwwAU hFf3x+XTPakAn+B5zlBv+57ObBx/Cbu0T+2qQ2Y07ojIatgvxHkpwklkIJkMz/I3CoKU J22O4pzjidWxgmYTa2P2ZgmBJs7ziIMiMKH8GCrmsySFgeWIu8u5T0yrqQ5Rv6MwpPpH nXoEfN5ipABKmZIdHYlaOS3Ru1c2OcZbEsGlotU8hKhgEU03r93xZumCopfcOSn1zkXD /i8xxcuIn5nA5ZtzkdbyQi0f4ebsUbw5+JQMLu93RvzBUo3bg1UJLL0ZaHPoC/nS+Btt wdvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687168884; x=1689760884; 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=pfL8kOHIfnY7PiBiCXPYIlsy0Fts7anKA/DneQ6qt2M=; b=ZDrkuOfKvfbUkquhNEKWmI/DAMtOY1dxs2ITa5NjxNfoYgeP8CawsWmHNWu4CLKMdO MdJeqySi/e3Em9r9DgL7QfZDFlucBzYOV+cKwL5tCIfZ2DX7qZ9VgZYjyYuRxEa6fr3a 5caMfVTfJ6FRTJU/sDQCQMrW1vmZvyNavGBDUlWrVQDBHtbV9bVP9AV8cETCbTvdJ/RO zC9OuaAdRIZk3uDA3Plzc01g0jgz21xsdaJUFbxNgMizB2siUrN/RXwPvr7nNv41qYYW /xNnCcApBPg0CfQ2i9jrelXZFg3c+b9V7E0MNo/G6n39qpzEmwpC8PTjjzuGMvZi5IZj rRGg== X-Gm-Message-State: AC+VfDyfTArq/8aE3JYyTvuptfc9k75i+tEMn8Mkw0YhsHlXmB71VsDT oLAdWEUPdVVJI2ayo2g8sf0= X-Google-Smtp-Source: ACHHUZ5GtcUkypYA3SHjL16gLS67dE/eMRqVmiWQ8WMBU18yMUOPhUtB3mKROVBzH9x9PT8vqX1uMQ== X-Received: by 2002:a5d:6605:0:b0:311:e03:f644 with SMTP id n5-20020a5d6605000000b003110e03f644mr8435206wru.18.1687168883759; Mon, 19 Jun 2023 03:01:23 -0700 (PDT) Received: from ip-172-31-22-112.eu-west-1.compute.internal (ec2-54-154-23-32.eu-west-1.compute.amazonaws.com. [54.154.23.32]) by smtp.gmail.com with ESMTPSA id a4-20020a056000050400b0030ae3a6be4asm31352451wrf.72.2023.06.19.03.01.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Jun 2023 03:01:23 -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 v3 2/3] arm64: patching: Add aarch64_insn_copy() Date: Mon, 19 Jun 2023 10:01:20 +0000 Message-Id: <20230619100121.27534-3-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230619100121.27534-1-puranjay12@gmail.com> References: <20230619100121.27534-1-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 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 19 10:01:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13284295 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 43DA1C8C8 for ; Mon, 19 Jun 2023 10:01:52 +0000 (UTC) Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 904E5E51; Mon, 19 Jun 2023 03:01:26 -0700 (PDT) Received: by mail-wr1-x436.google.com with SMTP id ffacd0b85a97d-3112902f785so1568296f8f.0; Mon, 19 Jun 2023 03:01:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687168885; x=1689760885; 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=oNzh9W1RqJi05ddV+vbT5hHJexaATtR85nsZBfiq1mk=; b=Zu3ItRVlyn7DLb5mJivfTg6uPE/h9VNlvVEpJmMgSj/YEvmC+LO4Dk3CjP0w9lBJeL vjs6J3Q9UuVbnsvHMH0JeOTj5/cTutX5Pvv/p5Dvk+155qUtA0+xC/qiyfIJuIdn2aWN P+YQsSLEc/aWauwh0ICedp2TZN5Gpdci1Gt6idrLmg/+6bbR74iaqZFPqtd3mrETRznu qhg7Vqb1LUjbdXjB1ulgT7oKWLeQWZ5LDlX/+wXM3pHfbz6tX1hfNsvPvKyIarpXGDZQ xnJsi1z6NNJW8vmzzdVwIypUiA3Q6fgP3o1+H2NHT6/u5n1qsnvsHoWSn2TDrE1fOVxv P/7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687168885; x=1689760885; 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=oNzh9W1RqJi05ddV+vbT5hHJexaATtR85nsZBfiq1mk=; b=eNBg2RAE8FRAxbhSWo1bXjMjfcqFU3PbqWmvFEa+xi8ApPu6Bvzx0sHgcNfet58yoM dPB0ybLw79fzecUAe/RGOAaPjt/RIZnZUNB/UG5TnNpIODnah4DB888ClSwi3G3YZ3fi T3SABKpVWdHMsTGfHSFN1ujHdj6Y3tS80bJoaK5VOfdnhhcjNQdlg70FslkGVDPerliX M/39b4a0jRSaLP0QAERGC0rD5LLzWqM0TelUhncoL6jttqyp7m3iI7dWZdX+3U4Ks9vC ILVQ2smApHvpQkc0eLowZlxAupyvwj/RzM1d3U5IuN9cjmlMb+NBL8tYJbIThuR2whXD JKAw== X-Gm-Message-State: AC+VfDxJ1a6+ZjZD6tcY3eLPpAKHdf0oTMDcPXmB8pwffRN2AL5TF0vb jtgU5kXjFhkyOESZMH4QncF7q8l4uf3nV+O0AmWuWg== X-Google-Smtp-Source: ACHHUZ7moC3rNSNISVzPKW95heyaS6IjoZhQZ9+VrBe7QMY0L1GwId48LF7J/MbxuRa1cdt2UHIGJA== X-Received: by 2002:adf:edc8:0:b0:30f:ba87:4290 with SMTP id v8-20020adfedc8000000b0030fba874290mr7971266wro.17.1687168884502; Mon, 19 Jun 2023 03:01:24 -0700 (PDT) Received: from ip-172-31-22-112.eu-west-1.compute.internal (ec2-54-154-23-32.eu-west-1.compute.amazonaws.com. [54.154.23.32]) by smtp.gmail.com with ESMTPSA id a4-20020a056000050400b0030ae3a6be4asm31352451wrf.72.2023.06.19.03.01.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Jun 2023 03:01:24 -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 v3 3/3] bpf, arm64: use bpf_jit_binary_pack_alloc Date: Mon, 19 Jun 2023 10:01:21 +0000 Message-Id: <20230619100121.27534-4-puranjay12@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230619100121.27534-1-puranjay12@gmail.com> References: <20230619100121.27534-1-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 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 | 138 ++++++++++++++++++++++++++++------ 1 file changed, 115 insertions(+), 23 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 145b540ec34f..b781e42878c8 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 +1610,39 @@ 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); + bpf_flush_icache(ro_header, ctx.ro_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); } 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 +1663,14 @@ 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 +1678,13 @@ 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 +2289,27 @@ 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); +}