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author | Johannes Berg <johannes.berg@intel.com> | 2014-09-12 09:01:56 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-09-23 22:53:15 -0700 |
commit | 833c95456a70826d1384883b73fd23aff24d366f (patch) | |
tree | be9235e0df06fdc85deb13d1193b6120ed7196bd /include/linux/devcoredump.h | |
parent | 00e262fd8744678262a0f662f1b5d45fc1f52e10 (diff) | |
download | lwn-833c95456a70826d1384883b73fd23aff24d366f.tar.gz lwn-833c95456a70826d1384883b73fd23aff24d366f.zip |
device coredump: add new device coredump class
Many devices run firmware and/or complex hardware, and most of that
can have bugs. When it misbehaves, however, it is often much harder
to debug than software running on the host.
Introduce a "device coredump" mechanism to allow dumping internal
device/firmware state through a generalized mechanism. As devices
are different and information needed can vary accordingly, this
doesn't prescribe a file format - it just provides mechanism to
get data to be able to capture it in a generalized way (e.g. in
distributions.)
The dumped data will be readable in sysfs in the virtual device's
data file under /sys/class/devcoredump/devcd*/. Writing to it will
free the data and remove the device, as does a 5-minute timeout.
Note that generalized capturing of such data may result in privacy
issues, so users generally need to be involved. In order to allow
certain users/system integrators/... to disable the feature at all,
introduce a Kconfig option to override the drivers that would like
to have the feature.
For now, this provides two ways of dumping data:
1) with a vmalloc'ed area, that is then given to the subsystem
and freed after retrieval or timeout
2) with a generalized reader/free function method
We could/should add more options, e.g. a list of pages, since the
vmalloc area is very limited on some architectures.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/devcoredump.h')
-rw-r--r-- | include/linux/devcoredump.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h new file mode 100644 index 000000000000..c0a360e99f64 --- /dev/null +++ b/include/linux/devcoredump.h @@ -0,0 +1,35 @@ +#ifndef __DEVCOREDUMP_H +#define __DEVCOREDUMP_H + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/vmalloc.h> + +#ifdef CONFIG_DEV_COREDUMP +void dev_coredumpv(struct device *dev, const void *data, size_t datalen, + gfp_t gfp); + +void dev_coredumpm(struct device *dev, struct module *owner, + const void *data, size_t datalen, gfp_t gfp, + ssize_t (*read)(char *buffer, loff_t offset, size_t count, + const void *data, size_t datalen), + void (*free)(const void *data)); +#else +static inline void dev_coredumpv(struct device *dev, const void *data, + size_t datalen, gfp_t gfp) +{ + vfree(data); +} + +static inline void +dev_coredumpm(struct device *dev, struct module *owner, + const void *data, size_t datalen, gfp_t gfp, + ssize_t (*read)(char *buffer, loff_t offset, size_t count, + const void *data, size_t datalen), + void (*free)(const void *data)) +{ + free(data); +} +#endif /* CONFIG_DEV_COREDUMP */ + +#endif /* __DEVCOREDUMP_H */ |