From 833c95456a70826d1384883b73fd23aff24d366f Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 12 Sep 2014 09:01:56 +0200 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- include/linux/devcoredump.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/linux/devcoredump.h (limited to 'include/linux/devcoredump.h') 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 +#include +#include + +#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 */ -- cgit