From patchwork Tue Nov 3 09:19:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddharth Gupta X-Patchwork-Id: 11877429 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0573A6A2 for ; Tue, 3 Nov 2020 12:58:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA38F207BB for ; Tue, 3 Nov 2020 12:58:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="MOfaBTqF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729093AbgKCM6d (ORCPT ); Tue, 3 Nov 2020 07:58:33 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:52765 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729099AbgKCM6c (ORCPT ); Tue, 3 Nov 2020 07:58:32 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1604408310; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=EKZ+yFNfbwC66+rp+MUF5603nUwBjux7TbBt+fLB8hM=; b=MOfaBTqFna7T8Am+bGtOEEdRIRN5C0UyoeY0mI5eIyYu9v4h+UyV6Cs+p0vHljTArd7sWUMw hZ6AoC9Od6ivDsHjkXa1eRYlTaFxRZDsbkx7pSfnw+A/+AdEez0rAhOOtXgb/aJkoMH5insL 7SrbDENrcvcBNCkgMuzyNEgdTWU= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI4ZWZiZiIsICJsaW51eC1yZW1vdGVwcm9jQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-east-1.postgun.com with SMTP id 5fa153ec75bebe827ae93afd (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 03 Nov 2020 12:58:19 GMT Sender: sidgup=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 0D75DC38537; Tue, 3 Nov 2020 09:19:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from sidgup-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sidgup) by smtp.codeaurora.org (Postfix) with ESMTPSA id D2D8DC38537; Tue, 3 Nov 2020 09:19:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D2D8DC38537 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=sidgup@codeaurora.org From: Siddharth Gupta To: agross@kernel.org, bjorn.andersson@linaro.org, ohad@wizery.com, linux-remoteproc@vger.kernel.org Cc: Siddharth Gupta , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, tsoni@codeaurora.org, psodagud@codeaurora.org, rishabhb@codeaurora.org, linux-doc@vger.kernel.org Subject: [PATCH v7 2/4] remoteproc: coredump: Add minidump functionality Date: Tue, 3 Nov 2020 01:19:18 -0800 Message-Id: <1604395160-12443-3-git-send-email-sidgup@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1604395160-12443-1-git-send-email-sidgup@codeaurora.org> References: <1604395160-12443-1-git-send-email-sidgup@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-remoteproc@vger.kernel.org This change adds a new kind of core dump mechanism which instead of dumping entire program segments of the firmware, dumps sections of the remoteproc memory which are sufficient to allow debugging the firmware. This function thus uses section headers instead of program headers during creation of the core dump elf. Signed-off-by: Rishabh Bhatnagar Signed-off-by: Siddharth Gupta --- drivers/remoteproc/remoteproc_coredump.c | 140 ++++++++++++++++++++++++++++ drivers/remoteproc/remoteproc_elf_helpers.h | 26 ++++++ include/linux/remoteproc.h | 1 + 3 files changed, 167 insertions(+) diff --git a/drivers/remoteproc/remoteproc_coredump.c b/drivers/remoteproc/remoteproc_coredump.c index 34530dc..a6c0099 100644 --- a/drivers/remoteproc/remoteproc_coredump.c +++ b/drivers/remoteproc/remoteproc_coredump.c @@ -323,3 +323,143 @@ void rproc_coredump(struct rproc *rproc) */ wait_for_completion(&dump_state.dump_done); } + +/** + * rproc_minidump() - perform minidump + * @rproc: rproc handle + * + * This function will generate an ELF header for the registered sections of + * segments and create a devcoredump device associated with rproc. Based on + * the coredump configuration this function will directly copy the segments + * from device memory to userspace or copy segments from device memory to + * a separate buffer, which can then be read by userspace. + * The first approach avoids using extra vmalloc memory. But it will stall + * recovery flow until dump is read by userspace. + */ +void rproc_minidump(struct rproc *rproc) +{ + struct rproc_dump_segment *segment; + void *shdr; + void *ehdr; + size_t data_size; + size_t strtbl_size = 0; + size_t strtbl_index = 1; + size_t offset; + void *data; + u8 class = rproc->elf_class; + int shnum; + struct rproc_coredump_state dump_state; + unsigned int dump_conf = rproc->dump_conf; + char *str_tbl = "STR_TBL"; + + if (list_empty(&rproc->dump_segments) || + dump_conf == RPROC_COREDUMP_DISABLED) + return; + + if (class == ELFCLASSNONE) { + dev_err(&rproc->dev, "Elf class is not set\n"); + return; + } + + /* + * We allocate two extra section headers. The first one is null. + * Second section header is for the string table. Also space is + * allocated for string table. + */ + data_size = elf_size_of_hdr(class) + 2 * elf_size_of_shdr(class); + shnum = 2; + + /* the extra byte is for the null character at index 0 */ + strtbl_size += strlen(str_tbl) + 2; + + list_for_each_entry(segment, &rproc->dump_segments, node) { + data_size += elf_size_of_shdr(class); + strtbl_size += strlen(segment->priv) + 1; + if (dump_conf == RPROC_COREDUMP_ENABLED) + data_size += segment->size; + shnum++; + } + + data_size += strtbl_size; + + data = vmalloc(data_size); + if (!data) + return; + + ehdr = data; + memset(ehdr, 0, elf_size_of_hdr(class)); + /* e_ident field is common for both elf32 and elf64 */ + elf_hdr_init_ident(ehdr, class); + + elf_hdr_set_e_type(class, ehdr, ET_CORE); + elf_hdr_set_e_machine(class, ehdr, rproc->elf_machine); + elf_hdr_set_e_version(class, ehdr, EV_CURRENT); + elf_hdr_set_e_entry(class, ehdr, rproc->bootaddr); + elf_hdr_set_e_shoff(class, ehdr, elf_size_of_hdr(class)); + elf_hdr_set_e_ehsize(class, ehdr, elf_size_of_hdr(class)); + elf_hdr_set_e_shentsize(class, ehdr, elf_size_of_shdr(class)); + elf_hdr_set_e_shnum(class, ehdr, shnum); + elf_hdr_set_e_shstrndx(class, ehdr, 1); + + /* + * The zeroth index of the section header is reserved and is rarely used. + * Set the section header as null (SHN_UNDEF) and move to the next one. + */ + shdr = data + elf_hdr_get_e_shoff(class, ehdr); + memset(shdr, 0, elf_size_of_shdr(class)); + shdr += elf_size_of_shdr(class); + + /* Initialize the string table. */ + offset = elf_hdr_get_e_shoff(class, ehdr) + + elf_size_of_shdr(class) * elf_hdr_get_e_shnum(class, ehdr); + memset(data + offset, 0, strtbl_size); + + /* Fill in the string table section header. */ + memset(shdr, 0, elf_size_of_shdr(class)); + elf_shdr_set_sh_type(class, shdr, SHT_STRTAB); + elf_shdr_set_sh_offset(class, shdr, offset); + elf_shdr_set_sh_size(class, shdr, strtbl_size); + elf_shdr_set_sh_entsize(class, shdr, 0); + elf_shdr_set_sh_flags(class, shdr, 0); + elf_shdr_set_sh_name(class, shdr, set_section_name(str_tbl, ehdr, class, &strtbl_index)); + offset += elf_shdr_get_sh_size(class, shdr); + shdr += elf_size_of_shdr(class); + + list_for_each_entry(segment, &rproc->dump_segments, node) { + memset(shdr, 0, elf_size_of_shdr(class)); + elf_shdr_set_sh_type(class, shdr, SHT_PROGBITS); + elf_shdr_set_sh_offset(class, shdr, offset); + elf_shdr_set_sh_addr(class, shdr, segment->da); + elf_shdr_set_sh_size(class, shdr, segment->size); + elf_shdr_set_sh_entsize(class, shdr, 0); + elf_shdr_set_sh_flags(class, shdr, SHF_WRITE); + elf_shdr_set_sh_name(class, shdr, + set_section_name(segment->priv, ehdr, class, &strtbl_index)); + + /* No need to copy segments for inline dumps */ + if (dump_conf == RPROC_COREDUMP_ENABLED) + rproc_copy_segment(rproc, data + offset, segment, 0, + segment->size); + offset += elf_shdr_get_sh_size(class, shdr); + shdr += elf_size_of_shdr(class); + } + + if (dump_conf == RPROC_COREDUMP_ENABLED) { + dev_coredumpv(&rproc->dev, data, data_size, GFP_KERNEL); + return; + } + + /* Initialize the dump state struct to be used by rproc_coredump_read */ + dump_state.rproc = rproc; + dump_state.header = data; + init_completion(&dump_state.dump_done); + + dev_coredumpm(&rproc->dev, NULL, &dump_state, data_size, GFP_KERNEL, + rproc_coredump_read, rproc_coredump_free); + + /* Wait until the dump is read and free is called. Data is freed + * by devcoredump framework automatically after 5 minutes. + */ + wait_for_completion(&dump_state.dump_done); +} +EXPORT_SYMBOL(rproc_minidump); diff --git a/drivers/remoteproc/remoteproc_elf_helpers.h b/drivers/remoteproc/remoteproc_elf_helpers.h index 4b6be7b..fa669ad 100644 --- a/drivers/remoteproc/remoteproc_elf_helpers.h +++ b/drivers/remoteproc/remoteproc_elf_helpers.h @@ -65,6 +65,7 @@ ELF_GEN_FIELD_GET_SET(hdr, e_type, u16) ELF_GEN_FIELD_GET_SET(hdr, e_version, u32) ELF_GEN_FIELD_GET_SET(hdr, e_ehsize, u32) ELF_GEN_FIELD_GET_SET(hdr, e_phentsize, u16) +ELF_GEN_FIELD_GET_SET(hdr, e_shentsize, u16) ELF_GEN_FIELD_GET_SET(phdr, p_paddr, u64) ELF_GEN_FIELD_GET_SET(phdr, p_vaddr, u64) @@ -75,6 +76,9 @@ ELF_GEN_FIELD_GET_SET(phdr, p_offset, u64) ELF_GEN_FIELD_GET_SET(phdr, p_flags, u32) ELF_GEN_FIELD_GET_SET(phdr, p_align, u64) +ELF_GEN_FIELD_GET_SET(shdr, sh_type, u32) +ELF_GEN_FIELD_GET_SET(shdr, sh_flags, u32) +ELF_GEN_FIELD_GET_SET(shdr, sh_entsize, u16) ELF_GEN_FIELD_GET_SET(shdr, sh_size, u64) ELF_GEN_FIELD_GET_SET(shdr, sh_offset, u64) ELF_GEN_FIELD_GET_SET(shdr, sh_name, u32) @@ -93,4 +97,26 @@ ELF_STRUCT_SIZE(shdr) ELF_STRUCT_SIZE(phdr) ELF_STRUCT_SIZE(hdr) +static inline unsigned int set_section_name(const char *name, void *ehdr, u8 class, size_t *index) +{ + u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr); + void *shdr; + char *strtab; + size_t idx, ret; + + shdr = ehdr + elf_size_of_hdr(class) + shstrndx * elf_size_of_shdr(class); + strtab = ehdr + elf_shdr_get_sh_offset(class, shdr); + idx = index ? *index : 0; + if (!strtab || !name) + return 0; + + ret = idx; + strcpy((strtab + idx), name); + idx += strlen(name) + 1; + if (index) + *index = idx; + + return ret; +} + #endif /* REMOTEPROC_ELF_LOADER_H */ diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index a419878..844021e 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -656,6 +656,7 @@ rproc_of_resm_mem_entry_init(struct device *dev, u32 of_resm_idx, size_t len, int rproc_boot(struct rproc *rproc); void rproc_shutdown(struct rproc *rproc); void rproc_report_crash(struct rproc *rproc, enum rproc_crash_type type); +void rproc_minidump(struct rproc *rproc); int rproc_coredump_add_segment(struct rproc *rproc, dma_addr_t da, size_t size); int rproc_coredump_add_custom_segment(struct rproc *rproc, dma_addr_t da, size_t size,