From 522566376a3f8373fbd5ff75bb8a7a2da701c1a7 Mon Sep 17 00:00:00 2001 From: Aviya Erenfeld Date: Thu, 14 Apr 2016 11:59:31 +0200 Subject: [PATCH] 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 ++++++++++++++++-- .../net/wireless/intel/iwlwifi/mvm/fw-dbg.c | 4 +- include/linux/devcoredump.h | 86 +++++++++++++++++-- 3 files changed, 154 insertions(+), 19 deletions(-) diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c index 1bd120a0b084..240374fd1838 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); @@ -212,6 +218,44 @@ static int devcd_match_failing(struct device *dev, const void *failing) return devcd->failing_dev == 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 @@ -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); diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c index 4856eac120f6..a4b0581d2275 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c @@ -71,7 +71,7 @@ #include "iwl-csr.h" static ssize_t iwl_mvm_read_coredump(char *buffer, loff_t offset, size_t count, - const void *data, size_t datalen) + void *data, size_t datalen) { const struct iwl_mvm_dump_ptrs *dump_ptrs = data; ssize_t bytes_read; @@ -104,7 +104,7 @@ static ssize_t iwl_mvm_read_coredump(char *buffer, loff_t offset, size_t count, return bytes_read + bytes_read_trans; } -static void iwl_mvm_free_coredump(const void *data) +static void iwl_mvm_free_coredump(void *data) { const struct iwl_mvm_dump_ptrs *fw_error_dump = data; diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h index c0a360e99f64..269521f143ac 100644 --- a/include/linux/devcoredump.h +++ b/include/linux/devcoredump.h @@ -1,3 +1,22 @@ +/* + * This file is provided under the GPLv2 license. + * + * GPL LICENSE SUMMARY + * + * 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 + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * The full GNU General Public License is included in this distribution + * in the file called COPYING. + */ #ifndef __DEVCOREDUMP_H #define __DEVCOREDUMP_H @@ -5,17 +24,62 @@ #include #include +#include +#include + +/* + * _devcd_free_sgtable - free all the memory of the given scatterlist table + * (i.e. both pages and scatterlist instances) + * NOTE: if two tables allocated and chained using the sg_chain function then + * this function should be called only once on the first table + * @table: pointer to sg_table to free + */ +static inline void _devcd_free_sgtable(struct scatterlist *table) +{ + int i; + struct page *page; + struct scatterlist *iter; + struct scatterlist *delete_iter; + + /* free pages */ + iter = table; + for_each_sg(table, iter, sg_nents(table), i) { + page = sg_page(iter); + if (page) + __free_page(page); + } + + /* then free all chained tables */ + iter = table; + delete_iter = table; /* always points on a head of a table */ + while (!sg_is_last(iter)) { + iter++; + if (sg_is_chain(iter)) { + iter = sg_chain_ptr(iter); + kfree(delete_iter); + delete_iter = iter; + } + } + + /* free the last table */ + kfree(delete_iter); +} + + #ifdef CONFIG_DEV_COREDUMP -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); 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)); + +void dev_coredumpsg(struct device *dev, struct scatterlist *table, + size_t datalen, gfp_t gfp); #else -static inline void dev_coredumpv(struct device *dev, const void *data, +static inline void dev_coredumpv(struct device *dev, void *data, size_t datalen, gfp_t gfp) { vfree(data); @@ -23,13 +87,19 @@ static inline void dev_coredumpv(struct device *dev, const void *data, static inline 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)) { free(data); } + +static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table, + size_t datalen, gfp_t gfp) +{ + _devcd_free_sgtable(table); +} #endif /* CONFIG_DEV_COREDUMP */ #endif /* __DEVCOREDUMP_H */ -- 2.39.5