From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932206AbeBVLTq (ORCPT ); Thu, 22 Feb 2018 06:19:46 -0500 Received: from mail-io0-f194.google.com ([209.85.223.194]:42035 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932080AbeBVLTm (ORCPT ); Thu, 22 Feb 2018 06:19:42 -0500 X-Google-Smtp-Source: AG47ELvcnoD7SYc473DoFSz6PQn8wHvwpCD1FHDvuPHvy16MPV9l6Cq3pBtfnRHhh/STK521GTxvDg== From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com, bauerman@linux.vnet.ibm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, mpe@ellerman.id.au, dyoung@redhat.com, bhe@redhat.com, arnd@arndb.de, ard.biesheuvel@linaro.org, julien.thierry@arm.com Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, AKASHI Takahiro Subject: [PATCH v8 09/13] arm64: kexec_file: add crash dump support Date: Thu, 22 Feb 2018 20:17:28 +0900 Message-Id: <20180222111732.23051-10-takahiro.akashi@linaro.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180222111732.23051-1-takahiro.akashi@linaro.org> References: <20180222111732.23051-1-takahiro.akashi@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To enable crash dump (kdump), we need to * prepare the contents of ELF header of /proc/vmcore through load_crashdump_segments(), and * set up two device tree properties, "linux,usable-memory-range" and "linux,elfcorehdr", which repsectively represent a memory range to be used on crash dump kernel and a region of ELF core header (The logic of this cod is also from kexec-tools.) Signed-off-by: AKASHI Takahiro Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/include/asm/kexec.h | 5 + arch/arm64/kernel/machine_kexec_file.c | 211 +++++++++++++++++++++++++++++++++ 2 files changed, 216 insertions(+) diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index fc562db22d46..d7427d510e1b 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -99,6 +99,10 @@ static inline void crash_post_resume(void) {} struct kimage_arch { phys_addr_t dtb_mem; void *dtb_buf; + /* Core ELF header buffer */ + void *elf_headers; + unsigned long elf_headers_sz; + unsigned long elf_load_addr; }; struct kimage; @@ -110,6 +114,7 @@ extern int load_other_segments(struct kimage *image, unsigned long kernel_load_addr, char *initrd, unsigned long initrd_len, char *cmdline, unsigned long cmdline_len); +extern int load_crashdump_segments(struct kimage *image); #endif #endif /* __ASSEMBLY__ */ diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c index 12012f247501..fc132047c8cd 100644 --- a/arch/arm64/kernel/machine_kexec_file.c +++ b/arch/arm64/kernel/machine_kexec_file.c @@ -19,6 +19,7 @@ #include #include #include +#include static int __dt_root_addr_cells; static int __dt_root_size_cells; @@ -32,6 +33,10 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image) vfree(image->arch.dtb_buf); image->arch.dtb_buf = NULL; + vfree(image->arch.elf_headers); + image->arch.elf_headers = NULL; + image->arch.elf_headers_sz = 0; + return _kimage_file_post_load_cleanup(image); } @@ -49,6 +54,78 @@ int arch_kexec_walk_mem(struct kexec_buf *kbuf, return walk_system_ram_res(0, ULONG_MAX, kbuf, func); } +static int __init arch_kexec_file_init(void) +{ + /* Those values are used later on loading the kernel */ + __dt_root_addr_cells = dt_root_addr_cells; + __dt_root_size_cells = dt_root_size_cells; + + return 0; +} +late_initcall(arch_kexec_file_init); + +#define FDT_ALIGN(x, a) (((x) + (a) - 1) & ~((a) - 1)) +#define FDT_TAGALIGN(x) (FDT_ALIGN((x), FDT_TAGSIZE)) + +static int fdt_prop_len(const char *prop_name, int len) +{ + return (strlen(prop_name) + 1) + + sizeof(struct fdt_property) + + FDT_TAGALIGN(len); +} + +static bool cells_size_fitted(unsigned long base, unsigned long size) +{ + /* if *_cells >= 2, cells can hold 64-bit values anyway */ + if ((__dt_root_addr_cells == 1) && (base >= (1ULL << 32))) + return false; + + if ((__dt_root_size_cells == 1) && (size >= (1ULL << 32))) + return false; + + return true; +} + +static void fill_property(void *buf, u64 val64, int cells) +{ + u32 val32; + + if (cells == 1) { + val32 = cpu_to_fdt32((u32)val64); + memcpy(buf, &val32, sizeof(val32)); + } else { + memset(buf, 0, cells * sizeof(u32) - sizeof(u64)); + buf += cells * sizeof(u32) - sizeof(u64); + + val64 = cpu_to_fdt64(val64); + memcpy(buf, &val64, sizeof(val64)); + } +} + +static int fdt_setprop_range(void *fdt, int nodeoffset, const char *name, + unsigned long addr, unsigned long size) +{ + void *buf, *prop; + size_t buf_size; + int result; + + buf_size = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32); + prop = buf = vmalloc(buf_size); + if (!buf) + return -ENOMEM; + + fill_property(prop, addr, __dt_root_addr_cells); + prop += __dt_root_addr_cells * sizeof(u32); + + fill_property(prop, size, __dt_root_size_cells); + + result = fdt_setprop(fdt, nodeoffset, name, buf, buf_size); + + vfree(buf); + + return result; +} + static int setup_dtb(struct kimage *image, unsigned long initrd_load_addr, unsigned long initrd_len, char *cmdline, unsigned long cmdline_len, @@ -61,10 +138,26 @@ static int setup_dtb(struct kimage *image, int range_len; int ret; + /* check ranges against root's #address-cells and #size-cells */ + if (image->type == KEXEC_TYPE_CRASH && + (!cells_size_fitted(image->arch.elf_load_addr, + image->arch.elf_headers_sz) || + !cells_size_fitted(crashk_res.start, + crashk_res.end - crashk_res.start + 1))) { + pr_err("Crash memory region doesn't fit into DT's root cell sizes.\n"); + ret = -EINVAL; + goto out_err; + } + /* duplicate dt blob */ buf_size = fdt_totalsize(initial_boot_params); range_len = (__dt_root_addr_cells + __dt_root_size_cells) * sizeof(u32); + if (image->type == KEXEC_TYPE_CRASH) + buf_size += fdt_prop_len("linux,elfcorehdr", range_len) + + fdt_prop_len("linux,usable-memory-range", + range_len); + if (initrd_load_addr) buf_size += fdt_prop_len("initrd-start", sizeof(u64)) + fdt_prop_len("initrd-end", sizeof(u64)); @@ -86,6 +179,23 @@ static int setup_dtb(struct kimage *image, if (nodeoffset < 0) goto out_err; + if (image->type == KEXEC_TYPE_CRASH) { + /* add linux,elfcorehdr */ + ret = fdt_setprop_range(buf, nodeoffset, "linux,elfcorehdr", + image->arch.elf_load_addr, + image->arch.elf_headers_sz); + if (ret) + goto out_err; + + /* add linux,usable-memory-range */ + ret = fdt_setprop_range(buf, nodeoffset, + "linux,usable-memory-range", + crashk_res.start, + crashk_res.end - crashk_res.start + 1); + if (ret) + goto out_err; + } + /* add bootargs */ if (cmdline) { ret = fdt_setprop(buf, nodeoffset, "bootargs", @@ -187,3 +297,104 @@ int load_other_segments(struct kimage *image, unsigned long kernel_load_addr, image->arch.dtb_buf = NULL; return ret; } + +static int get_nr_ranges_callback(struct resource *res, void *arg) +{ + unsigned int *nr_ranges = arg; + + (*nr_ranges)++; + return 0; +} + +static int add_mem_range_callback(struct resource *res, void *arg) +{ + struct crash_mem *cmem = arg; + + cmem->ranges[cmem->nr_ranges].start = res->start; + cmem->ranges[cmem->nr_ranges].end = res->end; + cmem->nr_ranges++; + + return 0; +} + +static struct crash_mem *get_crash_memory_ranges(void) +{ + unsigned int nr_ranges; + struct crash_mem *cmem; + + nr_ranges = 1; /* for exclusion of crashkernel region */ + walk_system_ram_res(0, -1, &nr_ranges, get_nr_ranges_callback); + + cmem = vmalloc(sizeof(struct crash_mem) + + sizeof(struct crash_mem_range) * nr_ranges); + if (!cmem) + return NULL; + + cmem->max_nr_ranges = nr_ranges; + cmem->nr_ranges = 0; + walk_system_ram_res(0, -1, cmem, add_mem_range_callback); + + /* Exclude crashkernel region */ + if (crash_exclude_mem_range(cmem, crashk_res.start, crashk_res.end)) { + vfree(cmem); + return NULL; + } + + return cmem; +} + +static int prepare_elf_core_header(void **addr, unsigned long *sz) +{ + struct crash_mem *cmem; + int ret = 0; + + cmem = get_crash_memory_ranges(); + if (!cmem) + return -ENOMEM; + + /* 1: add segment for kernel map */ + ret = crash_prepare_elf64_headers(cmem, 1, addr, sz); + + vfree(cmem); + return ret; +} + +int load_crashdump_segments(struct kimage *image) +{ + void *elf_addr; + unsigned long elf_sz; + struct kexec_buf kbuf; + int ret; + + if (image->type != KEXEC_TYPE_CRASH) + return 0; + + ret = prepare_elf_core_header(&elf_addr, &elf_sz); + if (ret) { + pr_err("Preparing elf core header failed\n"); + return ret; + } + + kbuf.image = image; + kbuf.buffer = elf_addr; + kbuf.bufsz = elf_sz; + kbuf.memsz = elf_sz; + kbuf.buf_align = PAGE_SIZE; + kbuf.buf_min = crashk_res.start; + kbuf.buf_max = crashk_res.end + 1; + kbuf.top_down = 1; + + ret = kexec_add_buffer(&kbuf); + if (ret) { + vfree(elf_addr); + return ret; + } + image->arch.elf_headers = elf_addr; + image->arch.elf_headers_sz = elf_sz; + image->arch.elf_load_addr = kbuf.mem; + + pr_debug("Loaded elf core header at 0x%lx bufsz=0x%lx memsz=0x%lx\n", + image->arch.elf_load_addr, elf_sz, elf_sz); + + return ret; +} -- 2.16.2