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 for sub-sections. I opted to break this one, in order to make it easier to display in html. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx> --- Documentation/kdump/kdump.txt | 131 +++++++++++++++++------------ Documentation/kdump/vmcoreinfo.txt | 59 ++++++------- 2 files changed, 104 insertions(+), 86 deletions(-) diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index 51814450a7f8..1da2d7b765f6 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt @@ -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_HIGHMEM4G + CONFIG_HIGHMEM64G=y + + or:: + + 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=<range1>:<size1>[,<range2>:<size2>,...][@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 <dump-capture-kernel-vmlinux-image> \ --initrd=<initrd-for-dump-capture-kernel> --args-linux \ --append="root=<root-dev> <arch-specific-options>" If you are using a compressed bzImage/vmlinuz, then use following command -to load dump-capture kernel. +to load dump-capture kernel:: kexec -p <dump-capture-kernel-bzImage> \ --initrd=<initrd-for-dump-capture-kernel> \ --append="root=<root-dev> <arch-specific-options>" 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 <dump-capture-kernel-bzImage> \ --initrd=<initrd-for-dump-capture-kernel> \ @@ -362,7 +377,7 @@ to load dump-capture kernel. --append="root=<root-dev> <arch-specific-options>" If you are using an uncompressed Image, then use following command -to load dump-capture kernel. +to load dump-capture kernel:: kexec -p <dump-capture-kernel-Image> \ --initrd=<initrd-for-dump-capture-kernel> \ @@ -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 <dump-file> @@ -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 <dump-file> @@ -504,6 +524,11 @@ to achieve the same behaviour. Contact ======= -Vivek Goyal (vgoyal@xxxxxxxxxx) -Maneesh Soni (maneesh@xxxxxxxxxx) +- Vivek Goyal (vgoyal@xxxxxxxxxx) +- Maneesh Soni (maneesh@xxxxxxxxxx) +GDB macros +========== + +.. include:: gdbmacros.txt + :literal: diff --git a/Documentation/kdump/vmcoreinfo.txt b/Documentation/kdump/vmcoreinfo.txt index bb94a4bd597a..007a6b86e0ee 100644 --- a/Documentation/kdump/vmcoreinfo.txt +++ b/Documentation/kdump/vmcoreinfo.txt @@ -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 == -- 2.20.1
