* [PATCH 0/2] sparc: Fine-tuning for three function implementations
@ 2016-08-25 8:20 SF Markus Elfring
2016-08-25 8:22 ` [PATCH 1/2] sparc: Use kmalloc_array() in three functions SF Markus Elfring
2016-08-25 8:24 ` [PATCH 2/2] sparc: Delete an unnecessary initialisation in led_proc_write() SF Markus Elfring
0 siblings, 2 replies; 7+ messages in thread
From: SF Markus Elfring @ 2016-08-25 8:20 UTC (permalink / raw)
To: sparclinux, David S. Miller
Cc: LKML, kernel-janitors, Julia Lawall, Paolo Bonzini
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 25 Aug 2016 10:05:45 +0200
A few update suggestions were taken into account
from static source code analysis.
Markus Elfring (2):
Use kmalloc_array()
Delete an unnecessary initialisation in led_proc_write()
arch/sparc/kernel/led.c | 4 ++--
arch/sparc/kernel/nmi.c | 4 +++-
arch/sparc/kernel/sys_sparc_64.c | 6 ++++--
3 files changed, 9 insertions(+), 5 deletions(-)
--
2.9.3
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/2] sparc: Use kmalloc_array() in three functions
2016-08-25 8:20 [PATCH 0/2] sparc: Fine-tuning for three function implementations SF Markus Elfring
@ 2016-08-25 8:22 ` SF Markus Elfring
2016-08-29 9:47 ` Paolo Bonzini
2016-08-25 8:24 ` [PATCH 2/2] sparc: Delete an unnecessary initialisation in led_proc_write() SF Markus Elfring
1 sibling, 1 reply; 7+ messages in thread
From: SF Markus Elfring @ 2016-08-25 8:22 UTC (permalink / raw)
To: sparclinux, David S. Miller
Cc: LKML, kernel-janitors, Julia Lawall, Paolo Bonzini
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 25 Aug 2016 09:52:44 +0200
* Multiplications for the size determination of memory allocations
indicated that array data structures should be processed.
Thus reuse the corresponding function "kmalloc_array".
This issue was detected by using the Coccinelle software.
* Replace the specifications of data types by pointer dereferences
to make the corresponding size determination a bit safer according to
the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
arch/sparc/kernel/led.c | 2 +-
arch/sparc/kernel/nmi.c | 4 +++-
arch/sparc/kernel/sys_sparc_64.c | 6 ++++--
3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/sparc/kernel/led.c b/arch/sparc/kernel/led.c
index 3ae36f3..7444e4a 100644
--- a/arch/sparc/kernel/led.c
+++ b/arch/sparc/kernel/led.c
@@ -69,7 +69,7 @@ static ssize_t led_proc_write(struct file *file, const char __user *buffer,
if (count > LED_MAX_LENGTH)
count = LED_MAX_LENGTH;
- buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
+ buf = kmalloc_array(count + 1, sizeof(*buf), GFP_KERNEL);
if (!buf)
return -ENOMEM;
diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c
index a9973bb..b88e97b 100644
--- a/arch/sparc/kernel/nmi.c
+++ b/arch/sparc/kernel/nmi.c
@@ -166,7 +166,9 @@ static int __init check_nmi_watchdog(void)
if (!atomic_read(&nmi_active))
return 0;
- prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(unsigned int), GFP_KERNEL);
+ prev_nmi_count = kmalloc_array(nr_cpu_ids,
+ sizeof(*prev_nmi_count),
+ GFP_KERNEL);
if (!prev_nmi_count) {
err = -ENOMEM;
goto error;
diff --git a/arch/sparc/kernel/sys_sparc_64.c b/arch/sparc/kernel/sys_sparc_64.c
index fe8b8ee..25b7a14 100644
--- a/arch/sparc/kernel/sys_sparc_64.c
+++ b/arch/sparc/kernel/sys_sparc_64.c
@@ -580,8 +580,10 @@ SYSCALL_DEFINE5(utrap_install, utrap_entry_t, type,
unsigned long *p = current_thread_info()->utraps;
current_thread_info()->utraps =
- kmalloc((UT_TRAP_INSTRUCTION_31+1)*sizeof(long),
- GFP_KERNEL);
+ kmalloc_array(UT_TRAP_INSTRUCTION_31 + 1,
+ sizeof(*current_thread_info()
+ ->utraps),
+ GFP_KERNEL);
if (!current_thread_info()->utraps) {
current_thread_info()->utraps = p;
return -ENOMEM;
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH 2/2] sparc: Delete an unnecessary initialisation in led_proc_write()
2016-08-25 8:20 [PATCH 0/2] sparc: Fine-tuning for three function implementations SF Markus Elfring
2016-08-25 8:22 ` [PATCH 1/2] sparc: Use kmalloc_array() in three functions SF Markus Elfring
@ 2016-08-25 8:24 ` SF Markus Elfring
1 sibling, 0 replies; 7+ messages in thread
From: SF Markus Elfring @ 2016-08-25 8:24 UTC (permalink / raw)
To: sparclinux, David S. Miller
Cc: LKML, kernel-janitors, Julia Lawall, Paolo Bonzini
From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 25 Aug 2016 09:55:22 +0200
The local variable "buf" will be set to an appropriate value a bit later.
Thus omit the explicit initialisation at the beginning.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
arch/sparc/kernel/led.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/sparc/kernel/led.c b/arch/sparc/kernel/led.c
index 7444e4a..d6671af 100644
--- a/arch/sparc/kernel/led.c
+++ b/arch/sparc/kernel/led.c
@@ -64,7 +64,7 @@ static int led_proc_open(struct inode *inode, struct file *file)
static ssize_t led_proc_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
- char *buf = NULL;
+ char *buf;
if (count > LED_MAX_LENGTH)
count = LED_MAX_LENGTH;
--
2.9.3
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] sparc: Use kmalloc_array() in three functions
2016-08-25 8:22 ` [PATCH 1/2] sparc: Use kmalloc_array() in three functions SF Markus Elfring
@ 2016-08-29 9:47 ` Paolo Bonzini
2016-08-29 10:36 ` SF Markus Elfring
2016-08-29 11:57 ` walter harms
0 siblings, 2 replies; 7+ messages in thread
From: Paolo Bonzini @ 2016-08-29 9:47 UTC (permalink / raw)
To: SF Markus Elfring, sparclinux, David S. Miller
Cc: LKML, kernel-janitors, Julia Lawall
On 25/08/2016 10:22, SF Markus Elfring wrote:
> --- a/arch/sparc/kernel/led.c
> +++ b/arch/sparc/kernel/led.c
> @@ -69,7 +69,7 @@ static ssize_t led_proc_write(struct file *file, const char __user *buffer,
> if (count > LED_MAX_LENGTH)
> count = LED_MAX_LENGTH;
>
> - buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
> + buf = kmalloc_array(count + 1, sizeof(*buf), GFP_KERNEL);
> if (!buf)
> return -ENOMEM;
>
Here it's probably best to just remove sizeof(char) completely, as it's
1 by definition.
Paolo
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] sparc: Use kmalloc_array() in three functions
2016-08-29 9:47 ` Paolo Bonzini
@ 2016-08-29 10:36 ` SF Markus Elfring
2016-08-29 11:57 ` walter harms
1 sibling, 0 replies; 7+ messages in thread
From: SF Markus Elfring @ 2016-08-29 10:36 UTC (permalink / raw)
To: Paolo Bonzini
Cc: sparclinux, David S. Miller, LKML, kernel-janitors, Julia Lawall
>> @@ -69,7 +69,7 @@ static ssize_t led_proc_write(struct file *file, const char __user *buffer,
>> if (count > LED_MAX_LENGTH)
>> count = LED_MAX_LENGTH;
>>
>> - buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
>> + buf = kmalloc_array(count + 1, sizeof(*buf), GFP_KERNEL);
>> if (!buf)
>> return -ENOMEM;
>>
>
> Here it's probably best to just remove sizeof(char) completely,
> as it's 1 by definition.
Would you like to be prepared anyhow that the shown buffer variable
could eventually store other data than ordinary single byte characters?
Regards,
Markus
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] sparc: Use kmalloc_array() in three functions
2016-08-29 9:47 ` Paolo Bonzini
2016-08-29 10:36 ` SF Markus Elfring
@ 2016-08-29 11:57 ` walter harms
2016-08-29 16:38 ` Paolo Bonzini
1 sibling, 1 reply; 7+ messages in thread
From: walter harms @ 2016-08-29 11:57 UTC (permalink / raw)
To: Paolo Bonzini
Cc: SF Markus Elfring, sparclinux, David S. Miller, LKML,
kernel-janitors, Julia Lawall
Am 29.08.2016 11:47, schrieb Paolo Bonzini:
>
>
> On 25/08/2016 10:22, SF Markus Elfring wrote:
>> --- a/arch/sparc/kernel/led.c
>> +++ b/arch/sparc/kernel/led.c
>> @@ -69,7 +69,7 @@ static ssize_t led_proc_write(struct file *file, const char __user *buffer,
>> if (count > LED_MAX_LENGTH)
>> count = LED_MAX_LENGTH;
>>
>> - buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
>> + buf = kmalloc_array(count + 1, sizeof(*buf), GFP_KERNEL);
>> if (!buf)
>> return -ENOMEM;
>>
>
> Here it's probably best to just remove sizeof(char) completely, as it's
> 1 by definition.
>
> Paolo
I would not do so, if you ever change buf to something else it would break,
having a sizeof(*buf) here is harmless and a known pattern.
re,
wh
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] sparc: Use kmalloc_array() in three functions
2016-08-29 11:57 ` walter harms
@ 2016-08-29 16:38 ` Paolo Bonzini
0 siblings, 0 replies; 7+ messages in thread
From: Paolo Bonzini @ 2016-08-29 16:38 UTC (permalink / raw)
To: wharms
Cc: SF Markus Elfring, sparclinux, David S. Miller, LKML,
kernel-janitors, Julia Lawall
On 29/08/2016 13:57, walter harms wrote:
> > > - buf = kmalloc(sizeof(char) * (count + 1), GFP_KERNEL);
> > > + buf = kmalloc_array(count + 1, sizeof(*buf), GFP_KERNEL);
> > > if (!buf)
> > > return -ENOMEM;
> > >
> >
> > Here it's probably best to just remove sizeof(char) completely, as it's
> > 1 by definition.
>
> I would not do so, if you ever change buf to something else it would break,
> having a sizeof(*buf) here is harmless and a known pattern.
Fair enough, it's not code I maintain.
Paolo
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2016-08-29 16:47 UTC | newest]
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2016-08-25 8:20 [PATCH 0/2] sparc: Fine-tuning for three function implementations SF Markus Elfring
2016-08-25 8:22 ` [PATCH 1/2] sparc: Use kmalloc_array() in three functions SF Markus Elfring
2016-08-29 9:47 ` Paolo Bonzini
2016-08-29 10:36 ` SF Markus Elfring
2016-08-29 11:57 ` walter harms
2016-08-29 16:38 ` Paolo Bonzini
2016-08-25 8:24 ` [PATCH 2/2] sparc: Delete an unnecessary initialisation in led_proc_write() SF Markus Elfring
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