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The sequence of actions done by device drivers to append their device specific hardware/firmware logs to /proc/vmcore are as follows: 1. During probe (before hardware is initialized), device drivers register to the vmcore module (via vmcore_add_device_dump()), with callback function, along with buffer size and log name needed for firmware/hardware log collection. 2. vmcore module allocates the buffer with requested size. It adds an Elf note and invokes the device driver's registered callback function. 3. Device driver collects all hardware/firmware logs into the buffer and returns control back to vmcore module. Ensure that the device dump buffer size is always aligned to page size so that it can be mmaped. Also, rename alloc_elfnotes_buf() to vmcore_alloc_buf() to make it more generic and reserve NT_VMCOREDD note type to indicate vmcore device dump. Suggested-by: Eric Biederman <ebiederm@xmission.com>. Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com> Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
99 lines
3.9 KiB
Plaintext
99 lines
3.9 KiB
Plaintext
config PROC_FS
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bool "/proc file system support" if EXPERT
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default y
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help
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This is a virtual file system providing information about the status
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of the system. "Virtual" means that it doesn't take up any space on
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your hard disk: the files are created on the fly by the kernel when
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you try to access them. Also, you cannot read the files with older
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version of the program less: you need to use more or cat.
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It's totally cool; for example, "cat /proc/interrupts" gives
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information about what the different IRQs are used for at the moment
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(there is a small number of Interrupt ReQuest lines in your computer
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that are used by the attached devices to gain the CPU's attention --
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often a source of trouble if two devices are mistakenly configured
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to use the same IRQ). The program procinfo to display some
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information about your system gathered from the /proc file system.
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Before you can use the /proc file system, it has to be mounted,
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meaning it has to be given a location in the directory hierarchy.
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That location should be /proc. A command such as "mount -t proc proc
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/proc" or the equivalent line in /etc/fstab does the job.
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The /proc file system is explained in the file
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<file:Documentation/filesystems/proc.txt> and on the proc(5) manpage
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("man 5 proc").
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This option will enlarge your kernel by about 67 KB. Several
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programs depend on this, so everyone should say Y here.
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config PROC_KCORE
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bool "/proc/kcore support" if !ARM
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depends on PROC_FS && MMU
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help
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Provides a virtual ELF core file of the live kernel. This can
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be read with gdb and other ELF tools. No modifications can be
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made using this mechanism.
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config PROC_VMCORE
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bool "/proc/vmcore support"
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depends on PROC_FS && CRASH_DUMP
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default y
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help
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Exports the dump image of crashed kernel in ELF format.
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config PROC_VMCORE_DEVICE_DUMP
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bool "Device Hardware/Firmware Log Collection"
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depends on PROC_VMCORE
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default n
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help
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After kernel panic, device drivers can collect the device
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specific snapshot of their hardware or firmware before the
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underlying devices are initialized in crash recovery kernel.
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Note that the device driver must be present in the crash
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recovery kernel's initramfs to collect its underlying device
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snapshot.
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If you say Y here, the collected device dumps will be added
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as ELF notes to /proc/vmcore.
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config PROC_SYSCTL
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bool "Sysctl support (/proc/sys)" if EXPERT
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depends on PROC_FS
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select SYSCTL
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default y
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---help---
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The sysctl interface provides a means of dynamically changing
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certain kernel parameters and variables on the fly without requiring
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a recompile of the kernel or reboot of the system. The primary
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interface is through /proc/sys. If you say Y here a tree of
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modifiable sysctl entries will be generated beneath the
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/proc/sys directory. They are explained in the files
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in <file:Documentation/sysctl/>. Note that enabling this
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option will enlarge the kernel by at least 8 KB.
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As it is generally a good thing, you should say Y here unless
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building a kernel for install/rescue disks or your system is very
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limited in memory.
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config PROC_PAGE_MONITOR
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default y
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depends on PROC_FS && MMU
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bool "Enable /proc page monitoring" if EXPERT
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help
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Various /proc files exist to monitor process memory utilization:
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/proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
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/proc/kpagecount, and /proc/kpageflags. Disabling these
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interfaces will reduce the size of the kernel by approximately 4kb.
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config PROC_CHILDREN
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bool "Include /proc/<pid>/task/<tid>/children file"
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default n
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help
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Provides a fast way to retrieve first level children pids of a task. See
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<file:Documentation/filesystems/proc.txt> for more information.
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Say Y if you are running any user-space software which takes benefit from
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this interface. For example, rkt is such a piece of software.
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