From patchwork Thu Nov 19 21:05:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddharth Gupta X-Patchwork-Id: 11918975 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEFC1C71156 for ; Thu, 19 Nov 2020 21:06:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D02924686 for ; Thu, 19 Nov 2020 21:06:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="SP9pJclS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725907AbgKSVF7 (ORCPT ); Thu, 19 Nov 2020 16:05:59 -0500 Received: from m42-4.mailgun.net ([69.72.42.4]:51536 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726460AbgKSVF5 (ORCPT ); Thu, 19 Nov 2020 16:05:57 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1605819956; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=UQQRLEuHUEInm4aNU7lJ8YMbwm1KSTUWSy6Q+hsMiwQ=; b=SP9pJclSIFY63WCHRNYrhTKyhL6LHJH3H+4k/JeLrTdx1ME7kIc5Of54c2d5GXh3CGT0bvSF kn9p/BQBjFBCaQs2y9ZZVNDlKXKcsoO0Zr6eZ6ATVqkfo7sc4B/IBRPJCoD+wTpfQi9WrL+Z R7NX8FrmMd/iM7FydYXwdirhsMs= 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-n10.prod.us-east-1.postgun.com with SMTP id 5fb6de337f0cfa6a167a4d23 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 19 Nov 2020 21:05:55 GMT Sender: sidgup=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 72D90C43464; Thu, 19 Nov 2020 21:05:54 +0000 (UTC) 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 A8016C43465; Thu, 19 Nov 2020 21:05:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org A8016C43465 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 v8 2/4] remoteproc: coredump: Add minidump functionality Date: Thu, 19 Nov 2020 13:05:33 -0800 Message-Id: <1605819935-10726-3-git-send-email-sidgup@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1605819935-10726-1-git-send-email-sidgup@codeaurora.org> References: <1605819935-10726-1-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. Co-developed-by: Rishabh Bhatnagar Signed-off-by: Rishabh Bhatnagar Signed-off-by: Siddharth Gupta Reviewed-by: Bjorn Andersson --- 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..81ec154 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_coredump_using_sections() - perform coredump using section headers + * @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_coredump_using_sections(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, elf_strtbl_add(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, + elf_strtbl_add(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_coredump_using_sections); diff --git a/drivers/remoteproc/remoteproc_elf_helpers.h b/drivers/remoteproc/remoteproc_elf_helpers.h index 4b6be7b..26404e6 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 elf_strtbl_add(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..cdf2722 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_coredump_using_sections(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,