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authorArnd Bergmann <arnd@arndb.de>2012-01-09 16:16:29 +0000
committerArnd Bergmann <arnd@arndb.de>2012-01-09 16:16:29 +0000
commitdcf7ec5ee62a78123057a1e286c88ca739717409 (patch)
treefa3f19434638a942ba66d236dde4d9aaadf8b370 /drivers/oprofile/oprofilefs.c
parentMerge branch 'drivers/rtc-sa1100' into next/drivers (diff)
parentMerge branch 'samsung/cleanup' into samsung/driver (diff)
downloadlinux-dev-dcf7ec5ee62a78123057a1e286c88ca739717409.tar.xz
linux-dev-dcf7ec5ee62a78123057a1e286c88ca739717409.zip
Merge branch 'samsung/driver' into next/drivers
Conflicts: arch/arm/mach-mxs/include/mach/common.h Pull in previous samsung conflict merges and do a trivial merge of an mxs double-add conflict. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/oprofile/oprofilefs.c')
-rw-r--r--drivers/oprofile/oprofilefs.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c
index d0de6cc2d7a5..2f0aa0f700e6 100644
--- a/drivers/oprofile/oprofilefs.c
+++ b/drivers/oprofile/oprofilefs.c
@@ -60,6 +60,13 @@ ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t cou
}
+/*
+ * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains
+ * unchanged and might be uninitialized. This follows write syscall
+ * implementation when count is zero: "If count is zero ... [and if]
+ * no errors are detected, 0 will be returned without causing any
+ * other effect." (man 2 write)
+ */
int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
{
char tmpbuf[TMPBUFSIZE];
@@ -79,7 +86,7 @@ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_
raw_spin_lock_irqsave(&oprofilefs_lock, flags);
*val = simple_strtoul(tmpbuf, NULL, 0);
raw_spin_unlock_irqrestore(&oprofilefs_lock, flags);
- return 0;
+ return count;
}
@@ -99,7 +106,7 @@ static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_
return -EINVAL;
retval = oprofilefs_ulong_from_user(&value, buf, count);
- if (retval)
+ if (retval <= 0)
return retval;
retval = oprofile_set_ulong(file->private_data, value);