From d67297ad343ec02a88f947b45526c92d2870aed3 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 12 Jun 2019 14:52:49 -0300 Subject: [PATCH] docs: kdump: convert docs to ReST and rename to *.rst Convert kdump documentation to ReST and add it to the user faced manual, as the documents are mainly focused on sysadmins that would be enabling kdump. Note: the vmcoreinfo.rst has one very long title on one of its sub-sections: PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|PG_hwpoision|PG_head_mask|PAGE_BUDDY_MAPCOUNT_VALUE(~PG_buddy)|PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline) I opted to break this one, into two entries with the same content, in order to make it easier to display after being parsed in html and PDF. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/bug-hunting.rst | 2 +- .../admin-guide/kernel-parameters.txt | 6 +- Documentation/kdump/index.rst | 21 +++ Documentation/kdump/{kdump.txt => kdump.rst} | 131 +++++++++++------- .../kdump/{vmcoreinfo.txt => vmcoreinfo.rst} | 59 ++++---- .../powerpc/firmware-assisted-dump.txt | 2 +- .../translations/zh_CN/oops-tracing.txt | 2 +- Documentation/watchdog/hpwdt.txt | 2 +- arch/arm/Kconfig | 2 +- arch/arm64/Kconfig | 2 +- arch/sh/Kconfig | 2 +- arch/x86/Kconfig | 4 +- 12 files changed, 137 insertions(+), 98 deletions(-) create mode 100644 Documentation/kdump/index.rst rename Documentation/kdump/{kdump.txt => kdump.rst} (91%) rename Documentation/kdump/{vmcoreinfo.txt => vmcoreinfo.rst} (95%) diff --git a/Documentation/admin-guide/bug-hunting.rst b/Documentation/admin-guide/bug-hunting.rst index f278b289e260..b761aa2a51d2 100644 --- a/Documentation/admin-guide/bug-hunting.rst +++ b/Documentation/admin-guide/bug-hunting.rst @@ -90,7 +90,7 @@ the disk is not available then you have three options: run a null modem to a second machine and capture the output there using your favourite communication program. Minicom works well. -(3) Use Kdump (see Documentation/kdump/kdump.txt), +(3) Use Kdump (see Documentation/kdump/kdump.rst), extract the kernel ring buffer from old memory with using dmesg gdbmacro in Documentation/kdump/gdbmacros.txt. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 81c168b25b20..2148fd289851 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -708,14 +708,14 @@ [KNL, x86_64] select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. - See Documentation/kdump/kdump.txt for further details. + See Documentation/kdump/kdump.rst for further details. crashkernel=range1:size1[,range2:size2,...][@offset] [KNL] Same as above, but depends on the memory in the running system. The syntax of range is start-[end] where start and end are both a memory unit (amount[KMG]). See also - Documentation/kdump/kdump.txt for an example. + Documentation/kdump/kdump.rst for an example. crashkernel=size[KMG],high [KNL, x86_64] range could be above 4G. Allow kernel @@ -1209,7 +1209,7 @@ Specifies physical address of start of kernel core image elf header and optionally the size. Generally kexec loader will pass this option to capture kernel. - See Documentation/kdump/kdump.txt for details. + See Documentation/kdump/kdump.rst for details. enable_mtrr_cleanup [X86] The kernel tries to adjust MTRR layout from continuous diff --git a/Documentation/kdump/index.rst b/Documentation/kdump/index.rst new file mode 100644 index 000000000000..2b17fcf6867a --- /dev/null +++ b/Documentation/kdump/index.rst @@ -0,0 +1,21 @@ +:orphan: + +================================================================ +Documentation for Kdump - The kexec-based Crash Dumping Solution +================================================================ + +This document includes overview, setup and installation, and analysis +information. + +.. toctree:: + :maxdepth: 1 + + kdump + vmcoreinfo + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.rst similarity index 91% rename from Documentation/kdump/kdump.txt rename to Documentation/kdump/kdump.rst index 3162eeb8c262..ac7e131d2935 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.rst @@ -71,9 +71,8 @@ This is a symlink to the latest version. The latest kexec-tools git tree is available at: -git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git -and -http://www.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git +- git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git +- http://www.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git There is also a gitweb interface available at http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git @@ -81,25 +80,25 @@ http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git More information about kexec-tools can be found at http://horms.net/projects/kexec/ -3) Unpack the tarball with the tar command, as follows: +3) Unpack the tarball with the tar command, as follows:: - tar xvpzf kexec-tools.tar.gz + tar xvpzf kexec-tools.tar.gz -4) Change to the kexec-tools directory, as follows: +4) Change to the kexec-tools directory, as follows:: - cd kexec-tools-VERSION + cd kexec-tools-VERSION -5) Configure the package, as follows: +5) Configure the package, as follows:: - ./configure + ./configure -6) Compile the package, as follows: +6) Compile the package, as follows:: - make + make -7) Install the package, as follows: +7) Install the package, as follows:: - make install + make install Build the system and dump-capture kernels @@ -126,25 +125,25 @@ dump-capture kernels for enabling kdump support. System kernel config options ---------------------------- -1) Enable "kexec system call" in "Processor type and features." +1) Enable "kexec system call" in "Processor type and features.":: - CONFIG_KEXEC=y + CONFIG_KEXEC=y 2) Enable "sysfs file system support" in "Filesystem" -> "Pseudo - filesystems." This is usually enabled by default. + filesystems." This is usually enabled by default:: - CONFIG_SYSFS=y + CONFIG_SYSFS=y Note that "sysfs file system support" might not appear in the "Pseudo filesystems" menu if "Configure standard kernel features (for small systems)" is not enabled in "General Setup." In this case, check the - .config file itself to ensure that sysfs is turned on, as follows: + .config file itself to ensure that sysfs is turned on, as follows:: - grep 'CONFIG_SYSFS' .config + grep 'CONFIG_SYSFS' .config -3) Enable "Compile the kernel with debug info" in "Kernel hacking." +3) Enable "Compile the kernel with debug info" in "Kernel hacking.":: - CONFIG_DEBUG_INFO=Y + CONFIG_DEBUG_INFO=Y This causes the kernel to be built with debug symbols. The dump analysis tools require a vmlinux with debug symbols in order to read @@ -154,29 +153,32 @@ Dump-capture kernel config options (Arch Independent) ----------------------------------------------------- 1) Enable "kernel crash dumps" support under "Processor type and - features": + features":: - CONFIG_CRASH_DUMP=y + CONFIG_CRASH_DUMP=y -2) Enable "/proc/vmcore support" under "Filesystems" -> "Pseudo filesystems". +2) Enable "/proc/vmcore support" under "Filesystems" -> "Pseudo filesystems":: + + CONFIG_PROC_VMCORE=y - CONFIG_PROC_VMCORE=y (CONFIG_PROC_VMCORE is set by default when CONFIG_CRASH_DUMP is selected.) Dump-capture kernel config options (Arch Dependent, i386 and x86_64) -------------------------------------------------------------------- 1) On i386, enable high memory support under "Processor type and - features": + features":: + + CONFIG_HIGHMEM64G=y + + or:: - CONFIG_HIGHMEM64G=y - or - CONFIG_HIGHMEM4G + CONFIG_HIGHMEM4G 2) On i386 and x86_64, disable symmetric multi-processing support - under "Processor type and features": + under "Processor type and features":: - CONFIG_SMP=n + CONFIG_SMP=n (If CONFIG_SMP=y, then specify maxcpus=1 on the kernel command line when loading the dump-capture kernel, see section "Load the Dump-capture @@ -184,9 +186,9 @@ Dump-capture kernel config options (Arch Dependent, i386 and x86_64) 3) If one wants to build and use a relocatable kernel, Enable "Build a relocatable kernel" support under "Processor type and - features" + features":: - CONFIG_RELOCATABLE=y + CONFIG_RELOCATABLE=y 4) Use a suitable value for "Physical address where the kernel is loaded" (under "Processor type and features"). This only appears when @@ -211,13 +213,13 @@ Dump-capture kernel config options (Arch Dependent, i386 and x86_64) Dump-capture kernel config options (Arch Dependent, ppc64) ---------------------------------------------------------- -1) Enable "Build a kdump crash kernel" support under "Kernel" options: +1) Enable "Build a kdump crash kernel" support under "Kernel" options:: - CONFIG_CRASH_DUMP=y + CONFIG_CRASH_DUMP=y -2) Enable "Build a relocatable kernel" support +2) Enable "Build a relocatable kernel" support:: - CONFIG_RELOCATABLE=y + CONFIG_RELOCATABLE=y Make and install the kernel and its modules. @@ -231,11 +233,13 @@ Dump-capture kernel config options (Arch Dependent, ia64) The crashkernel region can be automatically placed by the system kernel at run time. This is done by specifying the base address as 0, - or omitting it all together. + or omitting it all together:: - crashkernel=256M@0 - or - crashkernel=256M + crashkernel=256M@0 + + or:: + + crashkernel=256M If the start address is specified, note that the start address of the kernel will be aligned to 64Mb, so if the start address is not then @@ -245,9 +249,9 @@ Dump-capture kernel config options (Arch Dependent, arm) ---------------------------------------------------------- - To use a relocatable kernel, - Enable "AUTO_ZRELADDR" support under "Boot" options: + Enable "AUTO_ZRELADDR" support under "Boot" options:: - AUTO_ZRELADDR=y + AUTO_ZRELADDR=y Dump-capture kernel config options (Arch Dependent, arm64) ---------------------------------------------------------- @@ -265,12 +269,12 @@ on the value of System RAM -- that's mostly for distributors that pre-setup the kernel command line to avoid a unbootable system after some memory has been removed from the machine. -The syntax is: +The syntax is:: crashkernel=:[,:,...][@offset] range=start-[end] -For example: +For example:: crashkernel=512M-2G:64M,2G-:128M @@ -326,35 +330,46 @@ can choose to load the uncompressed vmlinux or compressed bzImage/vmlinuz of dump-capture kernel. Following is the summary. For i386 and x86_64: + - Use vmlinux if kernel is not relocatable. - Use bzImage/vmlinuz if kernel is relocatable. + For ppc64: + - Use vmlinux + For ia64: + - Use vmlinux or vmlinuz.gz + For s390x: + - Use image or bzImage + For arm: + - Use zImage + For arm64: + - Use vmlinux or Image If you are using an uncompressed vmlinux image then use following command -to load dump-capture kernel. +to load dump-capture kernel:: kexec -p \ --initrd= --args-linux \ --append="root= " If you are using a compressed bzImage/vmlinuz, then use following command -to load dump-capture kernel. +to load dump-capture kernel:: kexec -p \ --initrd= \ --append="root= " If you are using a compressed zImage, then use following command -to load dump-capture kernel. +to load dump-capture kernel:: kexec --type zImage -p \ --initrd= \ @@ -362,7 +377,7 @@ to load dump-capture kernel. --append="root= " If you are using an uncompressed Image, then use following command -to load dump-capture kernel. +to load dump-capture kernel:: kexec -p \ --initrd= \ @@ -376,18 +391,23 @@ Following are the arch specific command line options to be used while loading dump-capture kernel. For i386, x86_64 and ia64: + "1 irqpoll maxcpus=1 reset_devices" For ppc64: + "1 maxcpus=1 noirqdistrib reset_devices" For s390x: + "1 maxcpus=1 cgroup_disable=memory" For arm: + "1 maxcpus=1 reset_devices" For arm64: + "1 maxcpus=1 reset_devices" Notes on loading the dump-capture kernel: @@ -464,7 +484,7 @@ Write Out the Dump File ======================= After the dump-capture kernel is booted, write out the dump file with -the following command: +the following command:: cp /proc/vmcore @@ -476,7 +496,7 @@ Before analyzing the dump image, you should reboot into a stable kernel. You can do limited analysis using GDB on the dump file copied out of /proc/vmcore. Use the debug vmlinux built with -g and run the following -command: +command:: gdb vmlinux @@ -504,6 +524,11 @@ to achieve the same behaviour. Contact ======= -Vivek Goyal (vgoyal@redhat.com) -Maneesh Soni (maneesh@in.ibm.com) +- Vivek Goyal (vgoyal@redhat.com) +- Maneesh Soni (maneesh@in.ibm.com) + +GDB macros +========== +.. include:: gdbmacros.txt + :literal: diff --git a/Documentation/kdump/vmcoreinfo.txt b/Documentation/kdump/vmcoreinfo.rst similarity index 95% rename from Documentation/kdump/vmcoreinfo.txt rename to Documentation/kdump/vmcoreinfo.rst index bb94a4bd597a..007a6b86e0ee 100644 --- a/Documentation/kdump/vmcoreinfo.txt +++ b/Documentation/kdump/vmcoreinfo.rst @@ -1,8 +1,7 @@ -================================================================ - VMCOREINFO -================================================================ +========== +VMCOREINFO +========== -=========== What is it? =========== @@ -12,7 +11,6 @@ values, field offsets, etc. These data are packed into an ELF note section and used by user-space tools like crash and makedumpfile to analyze a kernel's memory layout. -================ Common variables ================ @@ -49,7 +47,7 @@ in a system, one bit position per node number. Used to keep track of which nodes are in the system and online. swapper_pg_dir -------------- +-------------- The global page directory pointer of the kernel. Used to translate virtual to physical addresses. @@ -132,16 +130,14 @@ nodemask_t The size of a nodemask_t type. Used to compute the number of online nodes. -(page, flags|_refcount|mapping|lru|_mapcount|private|compound_dtor| - compound_order|compound_head) -------------------------------------------------------------------- +(page, flags|_refcount|mapping|lru|_mapcount|private|compound_dtor|compound_order|compound_head) +------------------------------------------------------------------------------------------------- User-space tools compute their values based on the offset of these variables. The variables are used when excluding unnecessary pages. -(pglist_data, node_zones|nr_zones|node_mem_map|node_start_pfn|node_ - spanned_pages|node_id) -------------------------------------------------------------------- +(pglist_data, node_zones|nr_zones|node_mem_map|node_start_pfn|node_spanned_pages|node_id) +----------------------------------------------------------------------------------------- On NUMA machines, each NUMA node has a pg_data_t to describe its memory layout. On UMA machines there is a single pglist_data which describes the @@ -245,21 +241,25 @@ NR_FREE_PAGES On linux-2.6.21 or later, the number of free pages is in vm_stat[NR_FREE_PAGES]. Used to get the number of free pages. -PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|PG_hwpoision -|PG_head_mask|PAGE_BUDDY_MAPCOUNT_VALUE(~PG_buddy) -|PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline) ------------------------------------------------------------------ +PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_slab|PG_hwpoision|PG_head_mask +------------------------------------------------------------------------------ Page attributes. These flags are used to filter various unnecessary for dumping pages. +PAGE_BUDDY_MAPCOUNT_VALUE(~PG_buddy)|PAGE_OFFLINE_MAPCOUNT_VALUE(~PG_offline) +----------------------------------------------------------------------------- + +More page attributes. These flags are used to filter various unnecessary for +dumping pages. + + HUGETLB_PAGE_DTOR ----------------- The HUGETLB_PAGE_DTOR flag denotes hugetlbfs pages. Makedumpfile excludes these pages. -====== x86_64 ====== @@ -318,12 +318,12 @@ address. Currently, sme_mask stores the value of the C-bit position. If needed, additional SME-relevant info can be placed in that variable. -For example: -[ misc ][ enc bit ][ other misc SME info ] -0000_0000_0000_0000_1000_0000_0000_0000_0000_0000_..._0000 -63 59 55 51 47 43 39 35 31 27 ... 3 +For example:: + + [ misc ][ enc bit ][ other misc SME info ] + 0000_0000_0000_0000_1000_0000_0000_0000_0000_0000_..._0000 + 63 59 55 51 47 43 39 35 31 27 ... 3 -====== x86_32 ====== @@ -335,7 +335,6 @@ of a higher page table lookup overhead, and also consumes more page table space per process. Used to check whether PAE was enabled in the crash kernel when converting virtual addresses to physical addresses. -==== ia64 ==== @@ -366,7 +365,6 @@ PGTABLE_3|PGTABLE_4 User-space tools need to know whether the crash kernel was in 3-level or 4-level paging mode. Used to distinguish the page table. -===== ARM64 ===== @@ -395,9 +393,8 @@ KERNELOFFSET The kernel randomization offset. Used to compute the page offset. If KASLR is disabled, this value is zero. -==== arm -==== +=== ARM_LPAE -------- @@ -405,12 +402,11 @@ ARM_LPAE It indicates whether the crash kernel supports large physical address extensions. Used to translate virtual to physical addresses. -==== s390 ==== lowcore_ptr ----------- +----------- An array with a pointer to the lowcore of every CPU. Used to print the psw and all registers information. @@ -425,7 +421,6 @@ Used to get the vmalloc_start address from the high_memory symbol. The maximum number of CPUs. -======= powerpc ======= @@ -460,9 +455,8 @@ Page size definitions, i.e. 4k, 64k, or 16M. Used to make vtop translations. -vmemmap_backing|(vmemmap_backing, list)|(vmemmap_backing, phys)| -(vmemmap_backing, virt_addr) ----------------------------------------------------------------- +vmemmap_backing|(vmemmap_backing, list)|(vmemmap_backing, phys)|(vmemmap_backing, virt_addr) +-------------------------------------------------------------------------------------------- The vmemmap virtual address space management does not have a traditional page table to track which virtual struct pages are backed by a physical @@ -480,7 +474,6 @@ member. Used in vtop translations. -== sh == diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt index 18c5feef2577..0c41d6d463f3 100644 --- a/Documentation/powerpc/firmware-assisted-dump.txt +++ b/Documentation/powerpc/firmware-assisted-dump.txt @@ -59,7 +59,7 @@ as follows: the default calculated size. Use this option if default boot memory size is not sufficient for second kernel to boot successfully. For syntax of crashkernel= parameter, - refer to Documentation/kdump/kdump.txt. If any offset is + refer to Documentation/kdump/kdump.rst. If any offset is provided in crashkernel= parameter, it will be ignored as fadump uses a predefined offset to reserve memory for boot memory dump preservation in case of a crash. diff --git a/Documentation/translations/zh_CN/oops-tracing.txt b/Documentation/translations/zh_CN/oops-tracing.txt index 93fa061cf9e4..368ddd05b304 100644 --- a/Documentation/translations/zh_CN/oops-tracing.txt +++ b/Documentation/translations/zh_CN/oops-tracing.txt @@ -53,7 +53,7 @@ cat /proc/kmsg > file， 然而你必须介入中止传输， kmsg是一个“ （2）用串口终端启动（请参看Documentation/admin-guide/serial-console.rst），运行一个null modem到另一台机器并用你喜欢的通讯工具获取输出。Minicom工作地很好。 -（3）使用Kdump（请参看Documentation/kdump/kdump.txt）， +（3）使用Kdump（请参看Documentation/kdump/kdump.rst）， 使用在Documentation/kdump/gdbmacros.txt中定义的dmesg gdb宏，从旧的内存中提取内核 环形缓冲区。 diff --git a/Documentation/watchdog/hpwdt.txt b/Documentation/watchdog/hpwdt.txt index 55df692c5595..aaa9e4b4bdcd 100644 --- a/Documentation/watchdog/hpwdt.txt +++ b/Documentation/watchdog/hpwdt.txt @@ -51,7 +51,7 @@ Last reviewed: 08/20/2018 and loop forever. This is generally not what a watchdog user wants. For those wishing to learn more please see: - Documentation/kdump/kdump.txt + Documentation/kdump/kdump.rst Documentation/admin-guide/kernel-parameters.txt (panic=) Your Linux Distribution specific documentation. diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 0f220264cc23..249d788f3124 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2010,7 +2010,7 @@ config CRASH_DUMP kdump/kexec. The crash dump kernel must be compiled to a memory address not used by the main kernel - For more details see Documentation/kdump/kdump.txt + For more details see Documentation/kdump/kdump.rst config AUTO_ZRELADDR bool "Auto calculation of the decompressed kernel image address" diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 697ea0510729..27568506e1eb 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -994,7 +994,7 @@ config CRASH_DUMP reserved region and then later executed after a crash by kdump/kexec. - For more details see Documentation/kdump/kdump.txt + For more details see Documentation/kdump/kdump.rst config XEN_DOM0 def_bool y diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig index b77f512bb176..ce1a28654507 100644 --- a/arch/sh/Kconfig +++ b/arch/sh/Kconfig @@ -623,7 +623,7 @@ config CRASH_DUMP to a memory address not used by the main kernel using PHYSICAL_START. - For more details see Documentation/kdump/kdump.txt + For more details see Documentation/kdump/kdump.rst config KEXEC_JUMP bool "kexec jump (EXPERIMENTAL)" diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9f1f7b47621c..8fbd685dd984 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2037,7 +2037,7 @@ config CRASH_DUMP to a memory address not used by the main kernel or BIOS using PHYSICAL_START, or it must be built as a relocatable image (CONFIG_RELOCATABLE=y). - For more details see Documentation/kdump/kdump.txt + For more details see Documentation/kdump/kdump.rst config KEXEC_JUMP bool "kexec jump" @@ -2074,7 +2074,7 @@ config PHYSICAL_START the reserved region. In other words, it can be set based on the "X" value as specified in the "crashkernel=YM@XM" command line boot parameter passed to the panic-ed - kernel. Please take a look at Documentation/kdump/kdump.txt + kernel. Please take a look at Documentation/kdump/kdump.rst for more details about crash dumps. Usage of bzImage for capturing the crash dump is recommended as -- GitLab