The patch titled
uml: locking documentation
has been added to the -mm tree. Its filename is
uml-locking-documentation.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: uml: locking documentation
From: Jeff Dike <jdike@xxxxxxxxxxx>
Some locking documentation and a cleanup. uml_exitcode is copied into a local
before sprintf sees it, in case sprintf does anything non-atomic with it.
The rest are comments about why certain globals don't need any kind of
locking.
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/um/drivers/null.c | 1 +
arch/um/drivers/random.c | 4 ++++
arch/um/drivers/stderr_console.c | 2 ++
arch/um/drivers/stdio_console.c | 1 +
arch/um/kernel/exitcode.c | 8 ++++++--
5 files changed, 14 insertions(+), 2 deletions(-)
diff -puN arch/um/drivers/null.c~uml-locking-documentation arch/um/drivers/null.c
--- a/arch/um/drivers/null.c~uml-locking-documentation
+++ a/arch/um/drivers/null.c
@@ -8,6 +8,7 @@
#include "chan_user.h"
#include "os.h"
+/* This address is used only as a unique identifer */
static int null_chan;
static void *null_init(char *str, int device, const struct chan_opts *opts)
diff -puN arch/um/drivers/random.c~uml-locking-documentation arch/um/drivers/random.c
--- a/arch/um/drivers/random.c~uml-locking-documentation
+++ a/arch/um/drivers/random.c
@@ -20,6 +20,10 @@
#define RNG_MISCDEV_MINOR 183 /* official */
+/* Changed at init time, in the non-modular case, and at module load
+ * time, in the module case. Presumably, the module subsystem
+ * protects against a module being loaded twice at the same time.
+ */
static int random_fd = -1;
static int rng_dev_open (struct inode *inode, struct file *filp)
diff -puN arch/um/drivers/stderr_console.c~uml-locking-documentation arch/um/drivers/stderr_console.c
--- a/arch/um/drivers/stderr_console.c~uml-locking-documentation
+++ a/arch/um/drivers/stderr_console.c
@@ -9,6 +9,8 @@
/*
* Don't register by default -- as this registeres very early in the
* boot process it becomes the default console.
+ *
+ * Initialized at init time.
*/
static int use_stderr_console = 0;
diff -puN arch/um/drivers/stdio_console.c~uml-locking-documentation arch/um/drivers/stdio_console.c
--- a/arch/um/drivers/stdio_console.c~uml-locking-documentation
+++ a/arch/um/drivers/stdio_console.c
@@ -108,6 +108,7 @@ static int con_open(struct tty_struct *t
return line_open(vts, tty);
}
+/* Set in an initcall, checked in an exitcall */
static int con_init_done = 0;
static const struct tty_operations console_ops = {
diff -puN arch/um/kernel/exitcode.c~uml-locking-documentation arch/um/kernel/exitcode.c
--- a/arch/um/kernel/exitcode.c~uml-locking-documentation
+++ a/arch/um/kernel/exitcode.c
@@ -16,9 +16,13 @@ int uml_exitcode = 0;
static int read_proc_exitcode(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
- int len;
+ int len, val;
- len = sprintf(page, "%d\n", uml_exitcode);
+ /* Save uml_exitcode in a local so that we don't need to guarantee
+ * that sprintf accesses it atomically.
+ */
+ val = uml_exitcode;
+ len = sprintf(page, "%d\n", val);
len -= off;
if(len <= off+count) *eof = 1;
*start = page + off;
_
Patches currently in -mm which might be from jdike@xxxxxxxxxxx are
origin.patch
uml-assign-random-macs-to-interfaces-if-necessary.patch
uml-mechanical-tidying-after-random-macs-change.patch
uml-locking-documentation.patch
uml-close-file-descriptor-leaks.patch
uml-stack-consumption-reduction.patch
uml-remove-pte_mkexec.patch
simplify-update_times-avoid-jiffies-jiffies_64-aliasing-problem-2.patch
kill-wall_jiffies.patch
const-struct-tty_operations.patch
namespaces-utsname-switch-to-using-uts-namespaces.patch
introduce-kernel_execve.patch
rename-the-provided-execve-functions-to-kernel_execve.patch
provide-kernel_execve-on-all-architectures.patch
provide-kernel_execve-on-all-architectures-fix.patch
remove-the-use-of-_syscallx-macros-in-uml.patch
sh64-remove-the-use-of-kernel-syscalls.patch
remove-remaining-errno-and-__kernel_syscalls__-references.patch
-
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