Patchset related to hibernation resume:
- enhancement to make the use of an existing resume file more general
- add kstrimdup function which trims and duplicates a string
Both patches are based on the 3.13 tag. This was tested on a
Beaglebone black with partial hibernation support, and compiled for
x86_64.
[PATCH v6 1/2] mm: add kstrimdup function
include/linux/string.h | 1 +
mm/util.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 31 insertions(+)
Adds the kstrimdup function to duplicate and trim whitespace
from a string. This is useful for working with user input to
sysfs.
[PATCH v6 2/2] PM / Hibernate: use name_to_dev_t to parse resume
kernel/power/hibernate.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
Use name_to_dev_t to parse the /sys/power/resume file making the
syntax more flexible. It supports the previous use syntax
and additionally can support other formats such as
/dev/devicenode and UUID= formats.
By changing /sys/debug/resume to accept the same syntax as
the resume=device parameter, we can parse the resume=device
in the initrd init script and use the resume device directly
from the kernel command line.
Changes in v6:
--------------
* Revert tricky / confusing while loop indexing
Changes in v5:
--------------
* Change kstrimdup to minimize allocated memory. Now allocates only
the memory needed for the string instead of using strim.
Changes in v4:
--------------
* Dropped name_to_dev_t rework in favor of adding kstrimdup
* adjusted resume_store
Changes in v3:
--------------
* Dropped documentation patch as it went in through trivial
* Added patch for name_to_dev_t to support directly parsing userspace
buffer
Changes in v2:
--------------
* Added check for null return of kstrndup in hibernate.c
Thanks,
Sebastian
kstrimdup creates a whitespace-trimmed duplicate of the passed
in null-terminated string. This is useful for strings coming
from sysfs that often include trailing whitespace due to user
input.
Thanks to Joe Perches for this implementation.
Signed-off-by: Sebastian Capella <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Mikulas Patocka <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Rik van Riel <[email protected]> (commit_signer:5/10=50%)
Cc: Michel Lespinasse <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Jerome Marchand <[email protected]>
Cc: Mikulas Patocka <[email protected]>
Cc: Joonsoo Kim <[email protected]>
---
include/linux/string.h | 1 +
mm/util.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h
index ac889c5..f29f9a0 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -114,6 +114,7 @@ void *memchr_inv(const void *s, int c, size_t n);
extern char *kstrdup(const char *s, gfp_t gfp);
extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
+extern char *kstrimdup(const char *s, gfp_t gfp);
extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
diff --git a/mm/util.c b/mm/util.c
index 808f375..a8b731c 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -1,6 +1,7 @@
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
+#include <linux/ctype.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/sched.h>
@@ -63,6 +64,35 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp)
EXPORT_SYMBOL(kstrndup);
/**
+ * kstrimdup - Trim and copy a %NUL terminated string.
+ * @s: the string to trim and duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Returns an address, which the caller must kfree, containing
+ * a duplicate of the passed string with leading and/or trailing
+ * whitespace (as defined by isspace) removed.
+ */
+char *kstrimdup(const char *s, gfp_t gfp)
+{
+ char *buf;
+ char *begin = skip_spaces(s);
+ size_t len = strlen(begin);
+
+ while (len && isspace(begin[len - 1]))
+ len--;
+
+ buf = kmalloc_track_caller(len + 1, gfp);
+ if (!buf)
+ return NULL;
+
+ memcpy(buf, begin, len);
+ buf[len] = '\0';
+
+ return buf;
+}
+EXPORT_SYMBOL(kstrimdup);
+
+/**
* kmemdup - duplicate region of memory
*
* @src: memory region to duplicate
--
1.7.9.5
Use the name_to_dev_t call to parse the device name echo'd to
to /sys/power/resume. This imitates the method used in hibernate.c
in software_resume, and allows the resume partition to be specified
using other equivalent device formats as well. By allowing
/sys/debug/resume to accept the same syntax as the resume=device
parameter, we can parse the resume=device in the init script and
use the resume device directly from the kernel command line.
Signed-off-by: Sebastian Capella <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Cc: Len Brown <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
---
kernel/power/hibernate.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 0121dab..49d7a37 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -972,26 +972,27 @@ static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
- unsigned int maj, min;
dev_t res;
- int ret = -EINVAL;
+ char *name = kstrimdup(buf, GFP_KERNEL);
- if (sscanf(buf, "%u:%u", &maj, &min) != 2)
- goto out;
+ if (name == NULL)
+ return -ENOMEM;
- res = MKDEV(maj,min);
- if (maj != MAJOR(res) || min != MINOR(res))
- goto out;
+ res = name_to_dev_t(name);
- lock_system_sleep();
- swsusp_resume_device = res;
- unlock_system_sleep();
- printk(KERN_INFO "PM: Starting manual resume from disk\n");
- noresume = 0;
- software_resume();
- ret = n;
- out:
- return ret;
+ if (res != 0) {
+ lock_system_sleep();
+ swsusp_resume_device = res;
+ unlock_system_sleep();
+ printk(KERN_INFO "PM: Starting manual resume from disk\n");
+ noresume = 0;
+ software_resume();
+ } else {
+ n = -EINVAL;
+ }
+
+ kfree(name);
+ return n;
}
power_attr(resume);
--
1.7.9.5
On Thu, 30 Jan 2014, Sebastian Capella wrote:
> kstrimdup creates a whitespace-trimmed duplicate of the passed
> in null-terminated string. This is useful for strings coming
> from sysfs that often include trailing whitespace due to user
> input.
>
> Thanks to Joe Perches for this implementation.
>
> Signed-off-by: Sebastian Capella <[email protected]>
Acked-by: David Rientjes <[email protected]>
> ---
> include/linux/string.h | 1 +
> mm/util.c | 30 ++++++++++++++++++++++++++++++
> 2 files changed, 31 insertions(+)
>
> diff --git a/include/linux/string.h b/include/linux/string.h
> index ac889c5..f29f9a0 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -114,6 +114,7 @@ void *memchr_inv(const void *s, int c, size_t n);
>
> extern char *kstrdup(const char *s, gfp_t gfp);
> extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
> +extern char *kstrimdup(const char *s, gfp_t gfp);
> extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
>
> extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
> diff --git a/mm/util.c b/mm/util.c
> index 808f375..a8b731c 100644
> --- a/mm/util.c
> +++ b/mm/util.c
> @@ -1,6 +1,7 @@
> #include <linux/mm.h>
> #include <linux/slab.h>
> #include <linux/string.h>
> +#include <linux/ctype.h>
> #include <linux/export.h>
> #include <linux/err.h>
> #include <linux/sched.h>
> @@ -63,6 +64,35 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp)
> EXPORT_SYMBOL(kstrndup);
>
> /**
> + * kstrimdup - Trim and copy a %NUL terminated string.
> + * @s: the string to trim and duplicate
> + * @gfp: the GFP mask used in the kmalloc() call when allocating memory
> + *
> + * Returns an address, which the caller must kfree, containing
> + * a duplicate of the passed string with leading and/or trailing
> + * whitespace (as defined by isspace) removed.
> + */
> +char *kstrimdup(const char *s, gfp_t gfp)
> +{
> + char *buf;
> + char *begin = skip_spaces(s);
This could be const.
> + size_t len = strlen(begin);
> +
> + while (len && isspace(begin[len - 1]))
> + len--;
> +
> + buf = kmalloc_track_caller(len + 1, gfp);
> + if (!buf)
> + return NULL;
> +
> + memcpy(buf, begin, len);
> + buf[len] = '\0';
> +
> + return buf;
> +}
> +EXPORT_SYMBOL(kstrimdup);
> +
> +/**
> * kmemdup - duplicate region of memory
> *
> * @src: memory region to duplicate