[PATCH v3 0/4] lib: add "on" and "off" to strtobool

[PATCH v3 0/4] lib: add "on" and "off" to strtobool

[Kees Cook]

This consolidates logic for handling "on"/"off" parsing for bools into the
strtobool function, by way of moving it into kstrtobool (with helpers),
and updating various callers.

v3:
- removed unused "base" argument
- fixed missing description change
- retained inverted __setup return values
- removed needless extra buffer in cifs

v2:
- moved to kstroto* style

 arch/powerpc/kernel/rtasd.c                    |    7 --
 arch/powerpc/platforms/pseries/hotplug-cpu.c   |   10 ---
 arch/s390/kernel/time.c                        |    8 ---
 arch/s390/kernel/topology.c                    |    7 --
 arch/x86/kernel/aperture_64.c                  |   12 ----
 drivers/net/wireless/marvell/mwifiex/debugfs.c |   10 +--
 fs/cifs/cifs_debug.c                           |   56 +++++----------------
 fs/cifs/cifs_debug.h                           |    2 
 fs/cifs/cifsfs.c                               |    6 +-
 fs/cifs/cifsglob.h                             |    4 -
 include/linux/kernel.h                         |    2 
 include/linux/string.h                         |    6 +-
 include/linux/tick.h                           |    2 
 kernel/time/hrtimer.c                          |   10 ---
 kernel/time/tick-sched.c                       |   10 ---
 lib/kstrtox.c                                  |   64 +++++++++++++++++++++++++
 lib/string.c                                   |   29 -----------
 17 files changed, 110 insertions(+), 135 deletions(-)

-Kees

[PATCH v3 1/4] lib: move strtobool to kstrtobool

[Kees Cook]

Create the kstrtobool_from_user helper and moves strtobool logic into
the new kstrtobool (matching all the other kstrto* functions). Provides
an inline wrapper for existing strtobool callers.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
v3:
- drop needless "base" argument, rasmus
---
 include/linux/kernel.h |  2 ++
 include/linux/string.h |  6 +++++-
 lib/kstrtox.c          | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/string.c           | 29 -----------------------------
 4 files changed, 57 insertions(+), 30 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index f31638c6e873..f4fa2b29c38c 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -357,6 +357,7 @@ int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
+int __must_check kstrtobool(const char *s, bool *res);
 
 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
@@ -368,6 +369,7 @@ int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigne
 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
+int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
 
 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
 {
diff --git a/include/linux/string.h b/include/linux/string.h
index 9eebc66d957a..2217224684c9 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -128,7 +128,11 @@ extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 extern void argv_free(char **argv);
 
 extern bool sysfs_streq(const char *s1, const char *s2);
-extern int strtobool(const char *s, bool *res);
+extern int kstrtobool(const char *s, bool *res);
+static inline int strtobool(const char *s, bool *res)
+{
+	return kstrtobool(s, res);
+}
 
 #ifdef CONFIG_BINARY_PRINTF
 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index 94be244e8441..e8ba4a013e82 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -321,6 +321,56 @@ int kstrtos8(const char *s, unsigned int base, s8 *res)
 }
 EXPORT_SYMBOL(kstrtos8);
 
+/**
+ * kstrtobool - convert common user inputs into boolean values
+ * @s: input string
+ * @res: result
+ *
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
+ * Otherwise it will return -EINVAL.  Value pointed to by res is
+ * updated upon finding a match.
+ */
+int kstrtobool(const char *s, bool *res)
+{
+	if (!s)
+		return -EINVAL;
+
+	switch (s[0]) {
+	case 'y':
+	case 'Y':
+	case '1':
+		*res = true;
+		return 0;
+	case 'n':
+	case 'N':
+	case '0':
+		*res = false;
+		return 0;
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL(kstrtobool);
+
+/*
+ * Since "base" would be a nonsense argument, this open-codes the
+ * _from_user helper instead of using the helper macro below.
+ */
+int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
+{
+	/* Longest string needed to differentiate, newline, terminator */
+	char buf[4];
+
+	count = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, s, count))
+		return -EFAULT;
+	buf[count] = '\0';
+	return kstrtobool(buf, res);
+}
+EXPORT_SYMBOL(kstrtobool_from_user);
+
 #define kstrto_from_user(f, g, type)					\
 int f(const char __user *s, size_t count, unsigned int base, type *res)	\
 {									\
diff --git a/lib/string.c b/lib/string.c
index 0323c0d5629a..1a90db9bc6e1 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -630,35 +630,6 @@ bool sysfs_streq(const char *s1, const char *s2)
 }
 EXPORT_SYMBOL(sysfs_streq);
 
-/**
- * strtobool - convert common user inputs into boolean values
- * @s: input string
- * @res: result
- *
- * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
- * Otherwise it will return -EINVAL.  Value pointed to by res is
- * updated upon finding a match.
- */
-int strtobool(const char *s, bool *res)
-{
-	switch (s[0]) {
-	case 'y':
-	case 'Y':
-	case '1':
-		*res = true;
-		break;
-	case 'n':
-	case 'N':
-	case '0':
-		*res = false;
-		break;
-	default:
-		return -EINVAL;
-	}
-	return 0;
-}
-EXPORT_SYMBOL(strtobool);
-
 #ifndef __HAVE_ARCH_MEMSET
 /**
  * memset - Fill a region of memory with the given value
-- 
2.6.3

[PATCH v3 2/4] lib: update single-char callers of strtobool

[Kees Cook]

Some callers of strtobool were passing a pointer to unterminated strings.
In preparation of adding multi-character processing to kstrtobool, update
the callers to not pass single-character pointers, and switch to using the
new kstrtobool_from_user helper where possible.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Amitkumar Karwar <akarwar@marvell.com>
Cc: Nishant Sarmukadam <nishants@marvell.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
---
v3:
- drop needless buffer, andy.shevchenko
- drop unused "base" argument
---
 drivers/net/wireless/marvell/mwifiex/debugfs.c | 10 ++---
 fs/cifs/cifs_debug.c                           | 56 +++++++-------------------
 fs/cifs/cifs_debug.h                           |  2 +-
 fs/cifs/cifsfs.c                               |  6 +--
 fs/cifs/cifsglob.h                             |  4 +-
 5 files changed, 24 insertions(+), 54 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/debugfs.c b/drivers/net/wireless/marvell/mwifiex/debugfs.c
index 0b9c580af988..2eff989c6d9f 100644
--- a/drivers/net/wireless/marvell/mwifiex/debugfs.c
+++ b/drivers/net/wireless/marvell/mwifiex/debugfs.c
@@ -880,14 +880,12 @@ mwifiex_reset_write(struct file *file,
 {
 	struct mwifiex_private *priv = file->private_data;
 	struct mwifiex_adapter *adapter = priv->adapter;
-	char cmd;
 	bool result;
+	int rc;
 
-	if (copy_from_user(&cmd, ubuf, sizeof(cmd)))
-		return -EFAULT;
-
-	if (strtobool(&cmd, &result))
-		return -EINVAL;
+	rc = kstrtobool_from_user(ubuf, count, &result);
+	if (rc)
+		return rc;
 
 	if (!result)
 		return -EINVAL;
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 50b268483302..788e19195991 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -255,7 +255,6 @@ static const struct file_operations cifs_debug_data_proc_fops = {
 static ssize_t cifs_stats_proc_write(struct file *file,
 		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	char c;
 	bool bv;
 	int rc;
 	struct list_head *tmp1, *tmp2, *tmp3;
@@ -263,11 +262,8 @@ static ssize_t cifs_stats_proc_write(struct file *file,
 	struct cifs_ses *ses;
 	struct cifs_tcon *tcon;
 
-	rc = get_user(c, buffer);
-	if (rc)
-		return rc;
-
-	if (strtobool(&c, &bv) == 0) {
+	rc = kstrtobool_from_user(buffer, count, &bv);
+	if (rc == 0) {
 #ifdef CONFIG_CIFS_STATS2
 		atomic_set(&totBufAllocCount, 0);
 		atomic_set(&totSmBufAllocCount, 0);
@@ -290,6 +286,8 @@ static ssize_t cifs_stats_proc_write(struct file *file,
 			}
 		}
 		spin_unlock(&cifs_tcp_ses_lock);
+	} else {
+		return rc;
 	}
 
 	return count;
@@ -433,17 +431,17 @@ static int cifsFYI_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifsFYI_proc_write(struct file *file, const char __user *buffer,
 		size_t count, loff_t *ppos)
 {
-	char c;
+	char c[2] = { '\0' };
 	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = get_user(c[0], buffer);
 	if (rc)
 		return rc;
-	if (strtobool(&c, &bv) == 0)
+	if (strtobool(c, &bv) == 0)
 		cifsFYI = bv;
-	else if ((c > '1') && (c <= '9'))
-		cifsFYI = (int) (c - '0'); /* see cifs_debug.h for meanings */
+	else if ((c[0] > '1') && (c[0] <= '9'))
+		cifsFYI = (int) (c[0] - '0'); /* see cifs_debug.h for meanings */
 
 	return count;
 }
@@ -471,20 +469,12 @@ static int cifs_linux_ext_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifs_linux_ext_proc_write(struct file *file,
 		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	char c;
-	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = kstrtobool_from_user(buffer, count, &linuxExtEnabled);
 	if (rc)
 		return rc;
 
-	rc = strtobool(&c, &bv);
-	if (rc)
-		return rc;
-
-	linuxExtEnabled = bv;
-
 	return count;
 }
 
@@ -511,20 +501,12 @@ static int cifs_lookup_cache_proc_open(struct inode *inode, struct file *file)
 static ssize_t cifs_lookup_cache_proc_write(struct file *file,
 		const char __user *buffer, size_t count, loff_t *ppos)
 {
-	char c;
-	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = kstrtobool_from_user(buffer, count, &lookupCacheEnabled);
 	if (rc)
 		return rc;
 
-	rc = strtobool(&c, &bv);
-	if (rc)
-		return rc;
-
-	lookupCacheEnabled = bv;
-
 	return count;
 }
 
@@ -551,20 +533,12 @@ static int traceSMB_proc_open(struct inode *inode, struct file *file)
 static ssize_t traceSMB_proc_write(struct file *file, const char __user *buffer,
 		size_t count, loff_t *ppos)
 {
-	char c;
-	bool bv;
 	int rc;
 
-	rc = get_user(c, buffer);
+	rc = kstrtobool_from_user(buffer, count, &traceSMB);
 	if (rc)
 		return rc;
 
-	rc = strtobool(&c, &bv);
-	if (rc)
-		return rc;
-
-	traceSMB = bv;
-
 	return count;
 }
 
@@ -622,7 +596,6 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
 	int rc;
 	unsigned int flags;
 	char flags_string[12];
-	char c;
 	bool bv;
 
 	if ((count < 1) || (count > 11))
@@ -635,11 +608,10 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
 
 	if (count < 3) {
 		/* single char or single char followed by null */
-		c = flags_string[0];
-		if (strtobool(&c, &bv) == 0) {
+		if (strtobool(flags_string, &bv) == 0) {
 			global_secflags = bv ? CIFSSEC_MAX : CIFSSEC_DEF;
 			return count;
-		} else if (!isdigit(c)) {
+		} else if (!isdigit(flags_string[0])) {
 			cifs_dbg(VFS, "Invalid SecurityFlags: %s\n",
 					flags_string);
 			return -EINVAL;
diff --git a/fs/cifs/cifs_debug.h b/fs/cifs/cifs_debug.h
index 66cf0f9fff89..c611ca2339d7 100644
--- a/fs/cifs/cifs_debug.h
+++ b/fs/cifs/cifs_debug.h
@@ -25,7 +25,7 @@
 void cifs_dump_mem(char *label, void *data, int length);
 void cifs_dump_detail(void *);
 void cifs_dump_mids(struct TCP_Server_Info *);
-extern int traceSMB;		/* flag which enables the function below */
+extern bool traceSMB;		/* flag which enables the function below */
 void dump_smb(void *, int);
 #define CIFS_INFO	0x01
 #define CIFS_RC		0x02
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index c48ca13673e3..931b446f2a44 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -54,10 +54,10 @@
 #endif
 
 int cifsFYI = 0;
-int traceSMB = 0;
+bool traceSMB;
 bool enable_oplocks = true;
-unsigned int linuxExtEnabled = 1;
-unsigned int lookupCacheEnabled = 1;
+bool linuxExtEnabled = true;
+bool lookupCacheEnabled = true;
 unsigned int global_secflags = CIFSSEC_DEF;
 /* unsigned int ntlmv2_support = 0; */
 unsigned int sign_CIFS_PDUs = 1;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a25b2513f146..d21da9f05bae 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1596,11 +1596,11 @@ GLOBAL_EXTERN atomic_t midCount;
 
 /* Misc globals */
 GLOBAL_EXTERN bool enable_oplocks; /* enable or disable oplocks */
-GLOBAL_EXTERN unsigned int lookupCacheEnabled;
+GLOBAL_EXTERN bool lookupCacheEnabled;
 GLOBAL_EXTERN unsigned int global_secflags;	/* if on, session setup sent
 				with more secure ntlmssp2 challenge/resp */
 GLOBAL_EXTERN unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
-GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
+GLOBAL_EXTERN bool linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
 GLOBAL_EXTERN unsigned int CIFSMaxBufSize;  /* max size not including hdr */
 GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
 GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */
-- 
2.6.3

[PATCH v3 3/4] lib: add "on"/"off" support to kstrtobool

[Kees Cook]

Add support for "on" and "off" when converting to boolean.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
v3:
- add dropped descripion change, andy.shevchenko
---
 lib/kstrtox.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index e8ba4a013e82..d8a5cf66c316 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -326,9 +326,9 @@ EXPORT_SYMBOL(kstrtos8);
  * @s: input string
  * @res: result
  *
- * This routine returns 0 iff the first character is one of 'Yy1Nn0'.
- * Otherwise it will return -EINVAL.  Value pointed to by res is
- * updated upon finding a match.
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
+ * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
+ * pointed to by res is updated upon finding a match.
  */
 int kstrtobool(const char *s, bool *res)
 {
@@ -346,6 +346,20 @@ int kstrtobool(const char *s, bool *res)
 	case '0':
 		*res = false;
 		return 0;
+	case 'o':
+	case 'O':
+		switch (s[1]) {
+		case 'n':
+		case 'N':
+			*res = true;
+			return 0;
+		case 'f':
+		case 'F':
+			*res = false;
+			return 0;
+		default:
+			break;
+		}
 	default:
 		break;
 	}
-- 
2.6.3

[PATCH v3 4/4] param: convert some "on"/"off" users to strtobool

[Kees Cook]

This changes several users of manual "on"/"off" parsing to use strtobool.

Some side-effects:
- these uses will now parse y/n/1/0 meaningfully too
- the early_param uses will now bubble up parse errors

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: x86@kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
---
v3:
- retain __setup return values, andy.shevchenko
- remove unused "base" argument
---
 arch/powerpc/kernel/rtasd.c                  |  7 ++-----
 arch/powerpc/platforms/pseries/hotplug-cpu.c | 10 ++--------
 arch/s390/kernel/time.c                      |  8 ++------
 arch/s390/kernel/topology.c                  |  7 ++-----
 arch/x86/kernel/aperture_64.c                | 12 ++----------
 include/linux/tick.h                         |  2 +-
 kernel/time/hrtimer.c                        | 10 ++--------
 kernel/time/tick-sched.c                     | 10 ++--------
 8 files changed, 15 insertions(+), 51 deletions(-)

diff --git a/arch/powerpc/kernel/rtasd.c b/arch/powerpc/kernel/rtasd.c
index 5a2c049c1c61..0ae5cb84d4e2 100644
--- a/arch/powerpc/kernel/rtasd.c
+++ b/arch/powerpc/kernel/rtasd.c
@@ -49,7 +49,7 @@ static unsigned int rtas_error_log_buffer_max;
 static unsigned int event_scan;
 static unsigned int rtas_event_scan_rate;
 
-static int full_rtas_msgs = 0;
+static bool full_rtas_msgs;
 
 /* Stop logging to nvram after first fatal error */
 static int logging_enabled; /* Until we initialize everything,
@@ -592,10 +592,7 @@ __setup("surveillance=", surveillance_setup);
 
 static int __init rtasmsgs_setup(char *str)
 {
-	if (strcmp(str, "on") == 0)
-		full_rtas_msgs = 1;
-	else if (strcmp(str, "off") == 0)
-		full_rtas_msgs = 0;
+	kstrtobool(str, &full_rtas_msgs);
 
 	return 1;
 }
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 32274f72fe3f..282837a1d74b 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -47,20 +47,14 @@ static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE;
 
 static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE;
 
-static int cede_offline_enabled __read_mostly = 1;
+static bool cede_offline_enabled __read_mostly = true;
 
 /*
  * Enable/disable cede_offline when available.
  */
 static int __init setup_cede_offline(char *str)
 {
-	if (!strcmp(str, "off"))
-		cede_offline_enabled = 0;
-	else if (!strcmp(str, "on"))
-		cede_offline_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return (kstrtobool(str, &cede_offline_enabled) == 0);
 }
 
 __setup("cede_offline=", setup_cede_offline);
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 99f84ac31307..580bc7299ec3 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -1433,7 +1433,7 @@ device_initcall(etr_init_sysfs);
 /*
  * Server Time Protocol (STP) code.
  */
-static int stp_online;
+static bool stp_online;
 static struct stp_sstpi stp_info;
 static void *stp_page;
 
@@ -1444,11 +1444,7 @@ static struct timer_list stp_timer;
 
 static int __init early_parse_stp(char *p)
 {
-	if (strncmp(p, "off", 3) == 0)
-		stp_online = 0;
-	else if (strncmp(p, "on", 2) == 0)
-		stp_online = 1;
-	return 0;
+	return kstrtobool(p, &stp_online);
 }
 early_param("stp", early_parse_stp);
 
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 40b8102fdadb..64298a867589 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -37,7 +37,7 @@ static void set_topology_timer(void);
 static void topology_work_fn(struct work_struct *work);
 static struct sysinfo_15_1_x *tl_info;
 
-static int topology_enabled = 1;
+static bool topology_enabled = true;
 static DECLARE_WORK(topology_work, topology_work_fn);
 
 /*
@@ -444,10 +444,7 @@ static const struct cpumask *cpu_book_mask(int cpu)
 
 static int __init early_parse_topology(char *p)
 {
-	if (strncmp(p, "off", 3))
-		return 0;
-	topology_enabled = 0;
-	return 0;
+	return kstrtobool(p, &topology_enabled);
 }
 early_param("topology", early_parse_topology);
 
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 6e85f713641d..0a2bb1f62e72 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -227,19 +227,11 @@ static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
 	return 0;
 }
 
-static int gart_fix_e820 __initdata = 1;
+static bool gart_fix_e820 __initdata = true;
 
 static int __init parse_gart_mem(char *p)
 {
-	if (!p)
-		return -EINVAL;
-
-	if (!strncmp(p, "off", 3))
-		gart_fix_e820 = 0;
-	else if (!strncmp(p, "on", 2))
-		gart_fix_e820 = 1;
-
-	return 0;
+	return kstrtobool(p, &gart_fix_e820);
 }
 early_param("gart_fix_e820", parse_gart_mem);
 
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 97fd4e543846..0ecdf0e248f4 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -98,7 +98,7 @@ static inline void tick_broadcast_exit(void)
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
-extern int tick_nohz_enabled;
+extern bool tick_nohz_enabled;
 extern int tick_nohz_tick_stopped(void);
 extern void tick_nohz_idle_enter(void);
 extern void tick_nohz_idle_exit(void);
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 435b8850dd80..8b82caa8a407 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -515,7 +515,7 @@ static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
 /*
  * High resolution timer enabled ?
  */
-static int hrtimer_hres_enabled __read_mostly  = 1;
+static bool hrtimer_hres_enabled __read_mostly  = true;
 unsigned int hrtimer_resolution __read_mostly = LOW_RES_NSEC;
 EXPORT_SYMBOL_GPL(hrtimer_resolution);
 
@@ -524,13 +524,7 @@ EXPORT_SYMBOL_GPL(hrtimer_resolution);
  */
 static int __init setup_hrtimer_hres(char *str)
 {
-	if (!strcmp(str, "off"))
-		hrtimer_hres_enabled = 0;
-	else if (!strcmp(str, "on"))
-		hrtimer_hres_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return (kstrtobool(str, &hrtimer_hres_enabled) == 0);
 }
 
 __setup("highres=", setup_hrtimer_hres);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9d7a053545f5..7ff0dccdcd81 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -387,20 +387,14 @@ void __init tick_nohz_init(void)
 /*
  * NO HZ enabled ?
  */
-int tick_nohz_enabled __read_mostly = 1;
+bool tick_nohz_enabled __read_mostly  = true;
 unsigned long tick_nohz_active  __read_mostly;
 /*
  * Enable / Disable tickless mode
  */
 static int __init setup_tick_nohz(char *str)
 {
-	if (!strcmp(str, "off"))
-		tick_nohz_enabled = 0;
-	else if (!strcmp(str, "on"))
-		tick_nohz_enabled = 1;
-	else
-		return 0;
-	return 1;
+	return (kstrtobool(str, &tick_nohz_enabled) == 0);
 }
 
 __setup("nohz=", setup_tick_nohz);
-- 
2.6.3