From 64a07bd82ed526d813b64b0957543eef55bdf9c0 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sun, 26 Mar 2006 01:36:55 -0800 Subject: [PATCH] protect remove_proc_entry It has been discovered that the remove_proc_entry has a race in the removing of entries in the proc file system that are siblings. There's no protection around the traversing and removing of elements that belong in the same subdirectory. This subdirectory list is protected in other areas by the BKL. So the BKL was at first used to protect this area too, but unfortunately, remove_proc_entry may be called with spinlocks held. The BKL may schedule, so this was not a solution. The final solution was to add a new global spin lock to protect this list, called proc_subdir_lock. This lock now protects the list in remove_proc_entry, and I also went around looking for other areas that this list is modified and added this protection there too. Care must be taken since these locations call several functions that may also schedule. Since I don't see any location that these functions that modify the subdirectory list are called by interrupts, the irqsave/restore versions of the spin lock was _not_ used. Signed-off-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/proc_fs.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/proc_fs.h') diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index aa6322d45198..6b12b0f661b4 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -4,6 +4,7 @@ #include #include #include +#include #include /* @@ -92,6 +93,8 @@ extern struct proc_dir_entry *proc_bus; extern struct proc_dir_entry *proc_root_driver; extern struct proc_dir_entry *proc_root_kcore; +extern spinlock_t proc_subdir_lock; + extern void proc_root_init(void); extern void proc_misc_init(void); -- cgit v1.2.2 From 22e6c1b39c648850438decd491f62d311800c7db Mon Sep 17 00:00:00 2001 From: Maneesh Soni Date: Sun, 26 Mar 2006 01:37:29 -0800 Subject: [PATCH] Use loff_t for size in struct proc_dir_entry Change proc_dir_entry->size to be loff_t to represent files like /proc/vmcore for 32bit systems with more than 4G memory. Needed for seeing correct size for /proc/vmcore for 32-bit systems with > 4G RAM. Signed-off-by: Maneesh Soni Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/proc_fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/proc_fs.h') diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 6b12b0f661b4..cb224cf653b1 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -56,7 +56,7 @@ struct proc_dir_entry { nlink_t nlink; uid_t uid; gid_t gid; - unsigned long size; + loff_t size; struct inode_operations * proc_iops; struct file_operations * proc_fops; get_info_t *get_info; -- cgit v1.2.2 From 99ac48f54a91d02140c497edc31dc57d4bc5c85d Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Tue, 28 Mar 2006 01:56:41 -0800 Subject: [PATCH] mark f_ops const in the inode Mark the f_ops members of inodes as const, as well as fix the ripple-through this causes by places that copy this f_ops and then "do stuff" with it. Signed-off-by: Arjan van de Ven Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/proc_fs.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/proc_fs.h') diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index cb224cf653b1..6d03d025fcd5 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -58,7 +58,7 @@ struct proc_dir_entry { gid_t gid; loff_t size; struct inode_operations * proc_iops; - struct file_operations * proc_fops; + const struct file_operations * proc_fops; get_info_t *get_info; struct module *owner; struct proc_dir_entry *next, *parent, *subdir; @@ -189,7 +189,7 @@ static inline struct proc_dir_entry *proc_net_create(const char *name, } static inline struct proc_dir_entry *proc_net_fops_create(const char *name, - mode_t mode, struct file_operations *fops) + mode_t mode, const struct file_operations *fops) { struct proc_dir_entry *res = create_proc_entry(name, mode, proc_net); if (res) -- cgit v1.2.2 From 4b6f5d20b04dcbc3d888555522b90ba6d36c4106 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Tue, 28 Mar 2006 01:56:42 -0800 Subject: [PATCH] Make most file operations structs in fs/ const This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/proc_fs.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include/linux/proc_fs.h') diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 6d03d025fcd5..135871df9911 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -128,9 +128,9 @@ extern int proc_match(int, const char *,struct proc_dir_entry *); extern int proc_readdir(struct file *, void *, filldir_t); extern struct dentry *proc_lookup(struct inode *, struct dentry *, struct nameidata *); -extern struct file_operations proc_kcore_operations; -extern struct file_operations proc_kmsg_operations; -extern struct file_operations ppc_htab_operations; +extern const struct file_operations proc_kcore_operations; +extern const struct file_operations proc_kmsg_operations; +extern const struct file_operations ppc_htab_operations; /* * proc_tty.c -- cgit v1.2.2