The patch titled
proc: introduce proc_create_data to setup de->data
has been removed from the -mm tree. Its filename was
proc-introduce-proc_create_data-to-setup-de-data.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: proc: introduce proc_create_data to setup de->data
From: "Denis V. Lunev" <den@xxxxxxxxxx>
This set of patches fixes an proc ->open'less usage due to ->proc_fops flip in
the most part of the kernel code. The original OOPS is described in the
commit 2d3a4e3666325a9709cc8ea2e88151394e8f20fc:
Typical PDE creation code looks like:
pde = create_proc_entry("foo", 0, NULL);
if (pde)
pde->proc_fops = &foo_proc_fops;
Notice that PDE is first created, only then ->proc_fops is set up to
final value. This is a problem because right after creation
a) PDE is fully visible in /proc , and
b) ->proc_fops are proc_file_operations which do not have ->open callback. So, it's
possible to ->read without ->open (see one class of oopses below).
The fix is new API called proc_create() which makes sure ->proc_fops are
set up before gluing PDE to main tree. Typical new code looks like:
pde = proc_create("foo", 0, NULL, &foo_proc_fops);
if (!pde)
return -ENOMEM;
Fix most networking users for a start.
In the long run, create_proc_entry() for regular files will go.
In addition to this, proc_create_data is introduced to fix reading from
proc without PDE->data. The race is basically the same as above.
create_proc_entries is replaced in the entire kernel code as new method
is also simply better.
This patch:
The problem is the same as for de->proc_fops. Right now PDE becomes visible
without data set. So, the entry could be looked up without data. This, in
most cases, will simply OOPS.
proc_create_data call is created to address this issue. proc_create now
becomes a wrapper around it.
Signed-off-by: Denis V. Lunev <den@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
Cc: Chris Mason <chris.mason@xxxxxxxxxx>
Acked-by: David Howells <dhowells@xxxxxxxxxx>
Cc: Dmitry Torokhov <dtor@xxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Grant Grundler <grundler@xxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
Cc: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jaroslav Kysela <perex@xxxxxxx>
Cc: Jeff Garzik <jgarzik@xxxxxxxxx>
Cc: Jeff Mahoney <jeffm@xxxxxxxx>
Cc: Jesper Nilsson <jesper.nilsson@xxxxxxxx>
Cc: Karsten Keil <kkeil@xxxxxxx>
Cc: Kyle McMartin <kyle@xxxxxxxxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
Cc: Matthew Wilcox <matthew@xxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>
Cc: Mikael Starvik <starvik@xxxxxxxx>
Cc: Nadia Derbey <Nadia.Derbey@xxxxxxxx>
Cc: Neil Brown <neilb@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Osterlund <petero2@xxxxxxxxx>
Cc: Pierre Peiffer <peifferp@xxxxxxxxx>
Cc: Russell King <rmk@xxxxxxxxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/generic.c | 8 +++++---
fs/proc/root.c | 2 +-
include/linux/proc_fs.h | 17 +++++++++++++++--
3 files changed, 21 insertions(+), 6 deletions(-)
diff -puN fs/proc/generic.c~proc-introduce-proc_create_data-to-setup-de-data fs/proc/generic.c
--- a/fs/proc/generic.c~proc-introduce-proc_create_data-to-setup-de-data
+++ a/fs/proc/generic.c
@@ -675,9 +675,10 @@ struct proc_dir_entry *create_proc_entry
return ent;
}
-struct proc_dir_entry *proc_create(const char *name, mode_t mode,
- struct proc_dir_entry *parent,
- const struct file_operations *proc_fops)
+struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
+ struct proc_dir_entry *parent,
+ const struct file_operations *proc_fops,
+ void *data)
{
struct proc_dir_entry *pde;
nlink_t nlink;
@@ -698,6 +699,7 @@ struct proc_dir_entry *proc_create(const
if (!pde)
goto out;
pde->proc_fops = proc_fops;
+ pde->data = data;
if (proc_register(parent, pde) < 0)
goto out_free;
return pde;
diff -puN fs/proc/root.c~proc-introduce-proc_create_data-to-setup-de-data fs/proc/root.c
--- a/fs/proc/root.c~proc-introduce-proc_create_data-to-setup-de-data
+++ a/fs/proc/root.c
@@ -230,5 +230,5 @@ void pid_ns_release_proc(struct pid_name
EXPORT_SYMBOL(proc_symlink);
EXPORT_SYMBOL(proc_mkdir);
EXPORT_SYMBOL(create_proc_entry);
-EXPORT_SYMBOL(proc_create);
+EXPORT_SYMBOL(proc_create_data);
EXPORT_SYMBOL(remove_proc_entry);
diff -puN include/linux/proc_fs.h~proc-introduce-proc_create_data-to-setup-de-data include/linux/proc_fs.h
--- a/include/linux/proc_fs.h~proc-introduce-proc_create_data-to-setup-de-data
+++ a/include/linux/proc_fs.h
@@ -116,9 +116,10 @@ void de_put(struct proc_dir_entry *de);
extern struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
struct proc_dir_entry *parent);
-struct proc_dir_entry *proc_create(const char *name, mode_t mode,
+struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
struct proc_dir_entry *parent,
- const struct file_operations *proc_fops);
+ const struct file_operations *proc_fops,
+ void *data);
extern void remove_proc_entry(const char *name, struct proc_dir_entry *parent);
extern struct vfsmount *proc_mnt;
@@ -173,6 +174,12 @@ extern struct proc_dir_entry *proc_mkdir
extern struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode,
struct proc_dir_entry *parent);
+static inline struct proc_dir_entry *proc_create(const char *name, mode_t mode,
+ struct proc_dir_entry *parent, const struct file_operations *proc_fops)
+{
+ return proc_create_data(name, mode, parent, proc_fops, NULL);
+}
+
static inline struct proc_dir_entry *create_proc_read_entry(const char *name,
mode_t mode, struct proc_dir_entry *base,
read_proc_t *read_proc, void * data)
@@ -214,6 +221,12 @@ static inline struct proc_dir_entry *pro
{
return NULL;
}
+static inline struct proc_dir_entry *proc_create_data(const char *name,
+ mode_t mode, struct proc_dir_entry *parent,
+ const struct file_operations *proc_fops, void *data)
+{
+ return NULL;
+}
#define remove_proc_entry(name, parent) do {} while (0)
static inline struct proc_dir_entry *proc_symlink(const char *name,
_
Patches currently in -mm which might be from den@xxxxxxxxxx are
origin.patch
drivers-use-non-racy-method-for-proc-entries-creation-2-rio.patch
sunrpc-assign-pde-data-before-gluing-pde-into-proc-tree.patch
netfilter-assign-pde-data-before-gluing-pde-into-proc-tree.patch
net-assign-pde-data-before-gluing-pde-into-proc-tree.patch
ipv6-assign-pde-data-before-gluing-pde-into-proc-tree.patch
atm-assign-pde-data-before-gluing-pde-into-proc-tree.patch
vlan-assign-pde-data-before-gluing-pde-into-proc-tree.patch
cciss-assign-pde-data-before-gluing-pde-into-proc-tree.patch
powerpc-assign-pde-data-before-gluing-pde-into-proc-tree.patch
ipv4-assign-pde-data-before-gluing-pde-into-proc-tree.patch
netfilter-assign-pde-fops-before-gluing-pde-into-proc-tree.patch
netfilter-assign-pde-data-before-gluing-pde-into-proc-tree-2.patch
netns-assign-pde-data-before-gluing-entry-into-proc-tree.patch
proc-use-non-racy-method-for-proc-page_owner-creation-page_owner.patch
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