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Diffstat (limited to 'Documentation/admin-guide/kdump/vmcoreinfo.rst')
| -rw-r--r-- | Documentation/admin-guide/kdump/vmcoreinfo.rst | 167 |
1 files changed, 138 insertions, 29 deletions
diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 007a6b86e0ee..6726f439958c 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -39,6 +39,12 @@ call. User-space tools can get the kernel name, host name, kernel release number, kernel version, architecture name and OS type from it. +(uts_namespace, name) +--------------------- + +Offset of the name's member. Crash Utility and Makedumpfile get +the start address of the init_uts_ns.name from this. + node_online_map --------------- @@ -93,6 +99,11 @@ It exists in the sparse memory mapping model, and it is also somewhat similar to the mem_map variable, both of them are used to translate an address. +MAX_PHYSMEM_BITS +---------------- + +Defines the maximum supported physical address space memory. + page ---- @@ -184,50 +195,123 @@ from this. Free areas descriptor. User-space tools use this value to iterate the free_area ranges. MAX_ORDER is used by the zone buddy allocator. -log_first_idx +prb +--- + +A pointer to the printk ringbuffer (struct printk_ringbuffer). This +may be pointing to the static boot ringbuffer or the dynamically +allocated ringbuffer, depending on when the core dump occurred. +Used by user-space tools to read the active kernel log buffer. + +printk_rb_static +---------------- + +A pointer to the static boot printk ringbuffer. If @prb has a +different value, this is useful for viewing the initial boot messages, +which may have been overwritten in the dynamically allocated +ringbuffer. + +clear_seq +--------- + +The sequence number of the printk() record after the last clear +command. It indicates the first record after the last +SYSLOG_ACTION_CLEAR, like issued by 'dmesg -c'. Used by user-space +tools to dump a subset of the dmesg log. + +printk_ringbuffer +----------------- + +The size of a printk_ringbuffer structure. This structure contains all +information required for accessing the various components of the +kernel log buffer. + +(printk_ringbuffer, desc_ring|text_data_ring|dict_data_ring|fail) +----------------------------------------------------------------- + +Offsets for the various components of the printk ringbuffer. Used by +user-space tools to view the kernel log buffer without requiring the +declaration of the structure. + +prb_desc_ring ------------- -Index of the first record stored in the buffer log_buf. Used by -user-space tools to read the strings in the log_buf. +The size of the prb_desc_ring structure. This structure contains +information about the set of record descriptors. -log_buf -------- +(prb_desc_ring, count_bits|descs|head_id|tail_id) +------------------------------------------------- + +Offsets for the fields describing the set of record descriptors. Used +by user-space tools to be able to traverse the descriptors without +requiring the declaration of the structure. + +prb_desc +-------- + +The size of the prb_desc structure. This structure contains +information about a single record descriptor. + +(prb_desc, info|state_var|text_blk_lpos|dict_blk_lpos) +------------------------------------------------------ -Console output is written to the ring buffer log_buf at index -log_first_idx. Used to get the kernel log. +Offsets for the fields describing a record descriptors. Used by +user-space tools to be able to read descriptors without requiring +the declaration of the structure. -log_buf_len +prb_data_blk_lpos +----------------- + +The size of the prb_data_blk_lpos structure. This structure contains +information about where the text or dictionary data (data block) is +located within the respective data ring. + +(prb_data_blk_lpos, begin|next) +------------------------------- + +Offsets for the fields describing the location of a data block. Used +by user-space tools to be able to locate data blocks without +requiring the declaration of the structure. + +printk_info ----------- -log_buf's length. +The size of the printk_info structure. This structure contains all +the meta-data for a record. -clear_idx ---------- +(printk_info, seq|ts_nsec|text_len|dict_len|caller_id) +------------------------------------------------------ -The index that the next printk() record to read after the last clear -command. It indicates the first record after the last SYSLOG_ACTION -_CLEAR, like issued by 'dmesg -c'. Used by user-space tools to dump -the dmesg log. +Offsets for the fields providing the meta-data for a record. Used by +user-space tools to be able to read the information without requiring +the declaration of the structure. -log_next_idx ------------- +prb_data_ring +------------- -The index of the next record to store in the buffer log_buf. Used to -compute the index of the current buffer position. +The size of the prb_data_ring structure. This structure contains +information about a set of data blocks. -printk_log ----------- +(prb_data_ring, size_bits|data|head_lpos|tail_lpos) +--------------------------------------------------- + +Offsets for the fields describing a set of data blocks. Used by +user-space tools to be able to access the data blocks without +requiring the declaration of the structure. + +atomic_long_t +------------- -The size of a structure printk_log. Used to compute the size of -messages, and extract dmesg log. It encapsulates header information for -log_buf, such as timestamp, syslog level, etc. +The size of the atomic_long_t structure. Used by user-space tools to +be able to copy the full structure, regardless of its +architecture-specific implementation. -(printk_log, ts_nsec|len|text_len|dict_len) -------------------------------------------- +(atomic_long_t, counter) +------------------------ -It represents field offsets in struct printk_log. User space tools -parse it and check whether the values of printk_log's members have been -changed. +Offset for the long value of an atomic_long_t variable. Used by +user-space tools to access the long value without requiring the +architecture-specific declaration. (free_area.free_list, MIGRATE_TYPES) ------------------------------------ @@ -393,6 +477,31 @@ KERNELOFFSET The kernel randomization offset. Used to compute the page offset. If KASLR is disabled, this value is zero. +KERNELPACMASK +------------- + +The mask to extract the Pointer Authentication Code from a kernel virtual +address. + +TCR_EL1.T1SZ +------------ + +Indicates the size offset of the memory region addressed by TTBR1_EL1. +The region size is 2^(64-T1SZ) bytes. + +TTBR1_EL1 is the table base address register specified by ARMv8-A +architecture which is used to lookup the page-tables for the Virtual +addresses in the higher VA range (refer to ARMv8 ARM document for +more details). + +MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END +----------------------------------------------------------------------------- + +Used to get the correct ranges: + MODULES_VADDR ~ MODULES_END-1 : Kernel module space. + VMALLOC_START ~ VMALLOC_END-1 : vmalloc() / ioremap() space. + VMEMMAP_START ~ VMEMMAP_END-1 : vmemmap region, used for struct page array. + arm === |