From 522566376a3f8373fbd5ff75bb8a7a2da701c1a7 Mon Sep 17 00:00:00 2001 From: Aviya Erenfeld Date: Thu, 14 Apr 2016 11:59:31 +0200 Subject: devcoredump: add scatterlist support Add scatterlist support (dev_coredumpsg) to allow drivers to avoid vmalloc() like dev_coredumpm(), while also avoiding the module reference that the latter function requires. This internally uses dev_coredumpm() with function inside the devcoredump module, requiring removing the const (which touches the driver using it.) Signed-off-by: Aviya Erenfeld Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- drivers/base/devcoredump.c | 83 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 74 insertions(+), 9 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 1bd120a..240374f 100644 --- a/drivers/base/devcoredump.c +++ b/drivers/base/devcoredump.c @@ -4,6 +4,7 @@ * GPL LICENSE SUMMARY * * Copyright(c) 2014 Intel Mobile Communications GmbH + * Copyright(c) 2015 Intel Deutschland GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of version 2 of the GNU General Public License as @@ -41,12 +42,12 @@ static bool devcd_disabled; struct devcd_entry { struct device devcd_dev; - const void *data; + void *data; size_t datalen; struct module *owner; ssize_t (*read)(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen); - void (*free)(const void *data); + void *data, size_t datalen); + void (*free)(void *data); struct delayed_work del_wk; struct device *failing_dev; }; @@ -174,7 +175,7 @@ static struct class devcd_class = { }; static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen) + void *data, size_t datalen) { if (offset > datalen) return -EINVAL; @@ -188,6 +189,11 @@ static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, return count; } +static void devcd_freev(void *data) +{ + vfree(data); +} + /** * dev_coredumpv - create device coredump with vmalloc data * @dev: the struct device for the crashed device @@ -198,10 +204,10 @@ static ssize_t devcd_readv(char *buffer, loff_t offset, size_t count, * This function takes ownership of the vmalloc'ed data and will free * it when it is no longer used. See dev_coredumpm() for more information. */ -void dev_coredumpv(struct device *dev, const void *data, size_t datalen, +void dev_coredumpv(struct device *dev, void *data, size_t datalen, gfp_t gfp) { - dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, vfree); + dev_coredumpm(dev, NULL, data, datalen, gfp, devcd_readv, devcd_freev); } EXPORT_SYMBOL_GPL(dev_coredumpv); @@ -213,6 +219,44 @@ static int devcd_match_failing(struct device *dev, const void *failing) } /** + * devcd_free_sgtable - free all the memory of the given scatterlist table + * (i.e. both pages and scatterlist instances) + * NOTE: if two tables allocated with devcd_alloc_sgtable and then chained + * using the sg_chain function then that function should be called only once + * on the chained table + * @table: pointer to sg_table to free + */ +static void devcd_free_sgtable(void *data) +{ + _devcd_free_sgtable(data); +} + +/** + * devcd_read_from_table - copy data from sg_table to a given buffer + * and return the number of bytes read + * @buffer: the buffer to copy the data to it + * @buf_len: the length of the buffer + * @data: the scatterlist table to copy from + * @offset: start copy from @offset@ bytes from the head of the data + * in the given scatterlist + * @data_len: the length of the data in the sg_table + */ +static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset, + size_t buf_len, void *data, + size_t data_len) +{ + struct scatterlist *table = data; + + if (offset > data_len) + return -EINVAL; + + if (offset + buf_len > data_len) + buf_len = data_len - offset; + return sg_pcopy_to_buffer(table, sg_nents(table), buffer, buf_len, + offset); +} + +/** * dev_coredumpm - create device coredump with read/free methods * @dev: the struct device for the crashed device * @owner: the module that contains the read/free functions, use %THIS_MODULE @@ -228,10 +272,10 @@ static int devcd_match_failing(struct device *dev, const void *failing) * function will be called to free the data. */ void dev_coredumpm(struct device *dev, struct module *owner, - const void *data, size_t datalen, gfp_t gfp, + 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)) + void *data, size_t datalen), + void (*free)(void *data)) { static atomic_t devcd_count = ATOMIC_INIT(0); struct devcd_entry *devcd; @@ -291,6 +335,27 @@ void dev_coredumpm(struct device *dev, struct module *owner, } EXPORT_SYMBOL_GPL(dev_coredumpm); +/** + * dev_coredumpmsg - create device coredump that uses scatterlist as data + * parameter + * @dev: the struct device for the crashed device + * @table: the dump data + * @datalen: length of the data + * @gfp: allocation flags + * + * Creates a new device coredump for the given device. If a previous one hasn't + * been read yet, the new coredump is discarded. The data lifetime is determined + * by the device coredump framework and when it is no longer needed + * it will free the data. + */ +void dev_coredumpsg(struct device *dev, struct scatterlist *table, + size_t datalen, gfp_t gfp) +{ + dev_coredumpm(dev, NULL, table, datalen, gfp, devcd_read_from_sgtable, + devcd_free_sgtable); +} +EXPORT_SYMBOL_GPL(dev_coredumpsg); + static int __init devcoredump_init(void) { return class_register(&devcd_class); -- cgit v1.1