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 sebastian.capella@linaro.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Joe Perches joe@perches.com Cc: Mikulas Patocka mpatocka@redhat.com Cc: David Rientjes rientjes@google.com Cc: Rik van Riel riel@redhat.com (commit_signer:5/10=50%) Cc: Michel Lespinasse walken@google.com Cc: Shaohua Li shli@kernel.org Cc: Jerome Marchand jmarchan@redhat.com Cc: Mikulas Patocka mpatocka@redhat.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com --- 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
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 sebastian.capella@linaro.org
Acked-by: David Rientjes rientjes@google.com
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
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 sebastian.capella@linaro.org Acked-by: Pavel Machek pavel@ucw.cz Cc: Len Brown len.brown@intel.com Cc: "Rafael J. Wysocki" rjw@rjwysocki.net --- 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);
linaro-kernel@lists.linaro.org
-
David Rientjes -
Sebastian Capella