Re: [PATCH 1/3] debugfs: pass NULL as the last parameter of debugfs_print_regs32()
2012/10/27 Greg KH : > On Sat, Oct 27, 2012 at 01:55:42AM +0800, Yan Hong wrote: >> Pass NULL instead of empty string to debugfs_print_regs32() when >> prefix is not used, according to the intention of the code. > > Is this solving a problem? Is it wrong as-is? Is it causing an issue > today? > > thanks, > > greg k-h Hmmm ... this function is rarely used, and maybe over-designed. The 'prefix' feature can be actually removed -- nobody uses it. As to the empty string, it looks like a typo to me. Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/3] debugfs: pass NULL as the last parameter of debugfs_print_regs32()
2012/10/27 Greg KH gre...@linuxfoundation.org: On Sat, Oct 27, 2012 at 01:55:42AM +0800, Yan Hong wrote: Pass NULL instead of empty string to debugfs_print_regs32() when prefix is not used, according to the intention of the code. Is this solving a problem? Is it wrong as-is? Is it causing an issue today? thanks, greg k-h Hmmm ... this function is rarely used, and maybe over-designed. The 'prefix' feature can be actually removed -- nobody uses it. As to the empty string, it looks like a typo to me. Thanks -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/3] proc: return -ENOMEM when inode allocation failed
2012/9/5 Cong Wang :
>>> Why the !memcmp() case is related with ENOMEM ??
>>
>>
>> We are presetting 'error' here. The following proc_get_inode() will try
>> to get an inode, either from inode cache or allocate a new one (and fill
>> it).
>>
>> If we get a NULL inode, that means allocation failed. That's how
>> ENOMEM involved.
>
>
> Then the following patch is probably better than yours:
>
>
> diff --git a/fs/proc/generic.c b/fs/proc/generic.c
> index b3647fe..6b22913 100644
> --- a/fs/proc/generic.c
> +++ b/fs/proc/generic.c
> @@ -427,12 +427,16 @@ struct dentry *proc_lookup_de(struct proc_dir_entry
> *de, struct inode *dir,
>
> if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
> pde_get(de);
> spin_unlock(_subdir_lock);
> - error = -EINVAL;
> inode = proc_get_inode(dir->i_sb, de);
> + if (!inode) {
> + error = -ENOMEM;
> + goto out_put;
> + }
> goto out_unlock;
> }
> }
> spin_unlock(_subdir_lock);
> +
> out_unlock:
>
> if (inode) {
> @@ -440,6 +444,8 @@ out_unlock:
> d_add(dentry, inode);
> return NULL;
> }
> +out_put:
> +
> if (de)
> pde_put(de);
> return ERR_PTR(error);
>
>
Change so many lines to save a assignment to 'error' ...
That's a stye issue. I prefer a simple change, though your
change seems OK to me.
Thanks
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Re: [PATCH 1/3] proc: return -ENOMEM when inode allocation failed
2012/9/5 Cong Wang xiyou.wangc...@gmail.com:
Why the !memcmp() case is related with ENOMEM ??
We are presetting 'error' here. The following proc_get_inode() will try
to get an inode, either from inode cache or allocate a new one (and fill
it).
If we get a NULL inode, that means allocation failed. That's how
ENOMEM involved.
Then the following patch is probably better than yours:
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index b3647fe..6b22913 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -427,12 +427,16 @@ struct dentry *proc_lookup_de(struct proc_dir_entry
*de, struct inode *dir,
if (!memcmp(dentry-d_name.name, de-name, de-namelen)) {
pde_get(de);
spin_unlock(proc_subdir_lock);
- error = -EINVAL;
inode = proc_get_inode(dir-i_sb, de);
+ if (!inode) {
+ error = -ENOMEM;
+ goto out_put;
+ }
goto out_unlock;
}
}
spin_unlock(proc_subdir_lock);
+
out_unlock:
if (inode) {
@@ -440,6 +444,8 @@ out_unlock:
d_add(dentry, inode);
return NULL;
}
+out_put:
+
if (de)
pde_put(de);
return ERR_PTR(error);
Change so many lines to save a assignment to 'error' ...
That's a stye issue. I prefer a simple change, though your
change seems OK to me.
Thanks
--
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the body of a message to majord...@vger.kernel.org
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Re: [PATCH 1/3] proc: return -ENOMEM when inode allocation failed
2012/9/4 Cong Wang :
> On 09/03/2012 10:14 PM, yan wrote:
>>
>> Signed-off-by: yan
>
>
> Please provide a changelog to explain why we need this patch.
I think the title is self explained.
>> ---
>> fs/proc/generic.c |2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/proc/generic.c b/fs/proc/generic.c
>> index b3647fe..9e8f631 100644
>> --- a/fs/proc/generic.c
>> +++ b/fs/proc/generic.c
>> @@ -427,7 +427,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry
>> *de, struct inode *dir,
>> if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
>> pde_get(de);
>> spin_unlock(_subdir_lock);
>> - error = -EINVAL;
>> + error = -ENOMEM;
>
>
> Why the !memcmp() case is related with ENOMEM ??
We are presetting 'error' here. The following proc_get_inode() will try
to get an inode, either from inode cache or allocate a new one (and fill it).
If we get a NULL inode, that means allocation failed. That's how
ENOMEM involved.
Thank you for your reply.
--
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the body of a message to majord...@vger.kernel.org
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Re: [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
2012/9/4 Ryan Mallon > > On 04/09/12 00:14, yan wrote: > > Signed-off-by: yan > > --- > > fs/proc/generic.c |3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/fs/proc/generic.c b/fs/proc/generic.c > > index 9e8f631..38de015 100644 > > --- a/fs/proc/generic.c > > +++ b/fs/proc/generic.c > > @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct > > proc_dir_entry **parent, > > > > len = strlen(fn); > > > > - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, > > GFP_KERNEL); > > + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, > > GFP_KERNEL); > > if (!ent) goto out; > > > > - memset(ent, 0, sizeof(struct proc_dir_entry)); > > memcpy(ent->name, fn, len + 1); > > ent->namelen = len; > > ent->mode = mode; > > Note that this change results in slightly different behaviour. Before > your change only sizeof(struct proc_dir_entry) is zero'ed by memset, and > then the name is filled in (the len + 1 part). After your change the > structure and the name field are both zeroed, so the name field is being > written to twice. The cost is probably negligible though. Oh, I didn't notice that actually. Thank you. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/3] proc: use kzalloc instead of kmalloc and memset
2012/9/4 Ryan Mallon rmal...@gmail.com On 04/09/12 00:14, yan wrote: Signed-off-by: yan clouds@gmail.com --- fs/proc/generic.c |3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 9e8f631..38de015 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -616,10 +616,9 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, len = strlen(fn); - ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); + ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); if (!ent) goto out; - memset(ent, 0, sizeof(struct proc_dir_entry)); memcpy(ent-name, fn, len + 1); ent-namelen = len; ent-mode = mode; Note that this change results in slightly different behaviour. Before your change only sizeof(struct proc_dir_entry) is zero'ed by memset, and then the name is filled in (the len + 1 part). After your change the structure and the name field are both zeroed, so the name field is being written to twice. The cost is probably negligible though. Oh, I didn't notice that actually. Thank you. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 1/3] proc: return -ENOMEM when inode allocation failed
2012/9/4 Cong Wang xiyou.wangc...@gmail.com:
On 09/03/2012 10:14 PM, yan wrote:
Signed-off-by: yan clouds@gmail.com
Please provide a changelog to explain why we need this patch.
I think the title is self explained.
---
fs/proc/generic.c |2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index b3647fe..9e8f631 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -427,7 +427,7 @@ struct dentry *proc_lookup_de(struct proc_dir_entry
*de, struct inode *dir,
if (!memcmp(dentry-d_name.name, de-name, de-namelen)) {
pde_get(de);
spin_unlock(proc_subdir_lock);
- error = -EINVAL;
+ error = -ENOMEM;
Why the !memcmp() case is related with ENOMEM ??
We are presetting 'error' here. The following proc_get_inode() will try
to get an inode, either from inode cache or allocate a new one (and fill it).
If we get a NULL inode, that means allocation failed. That's how
ENOMEM involved.
Thank you for your reply.
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
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