moonjuice/kernel_arpi
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

vmcore: add API to collect hardware dump in second kernel

Browse Source 
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>
This commit is contained in:
Rahul Lakkireddy
2018-05-02 15:17:17 +05:30
committed by David S. Miller
parent 289e1f4e9e
commit 2724273e8f
6 changed files with 184 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
include/linux/crash_dump.h
View File

@@ -5,6 +5,7 @@
#include <linux/kexec.h>
#include <linux/proc_fs.h>
#include <linux/elf.h>
#include <uapi/linux/vmcore.h>
#include <asm/pgtable.h> /* for pgprot_t */
@@ -93,4 +94,21 @@ static inline bool is_kdump_kernel(void) { return 0; }
#endif /* CONFIG_CRASH_DUMP */
extern unsigned long saved_max_pfn;
/* Device Dump information to be filled by drivers */
struct vmcoredd_data {
char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
unsigned int size; /* Size of the dump */
/* Driver's registered callback to be invoked to collect dump */
int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
};
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
int vmcore_add_device_dump(struct vmcoredd_data *data);
#else
static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
{
return -EOPNOTSUPP;
}
#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
#endif /* LINUX_CRASHDUMP_H */