• Rahul Lakkireddy's avatar
    vmcore: add API to collect hardware dump in second kernel · 2724273e
    Rahul Lakkireddy authored
    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: default avatarRahul Lakkireddy <rahul.lakkireddy@chelsio.com>
    Signed-off-by: default avatarGanesh Goudar <ganeshgr@chelsio.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    2724273e
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