RE: [PATCH] mm: mmap: Simplify the failure return working flow
> From: xili_gchen_5...@hotmail.com > To: mho...@kernel.org > CC: a...@linux-foundation.org; linux-kernel@vger.kernel.org; > kirill.shute...@linux.intel.com; r...@redhat.com; sasha.le...@oracle.com; > linux...@kvack.org > Subject: Re: [PATCH] mm: mmap: Simplify the failure return working flow > Date: Thu, 20 Aug 2015 16:48:21 +0800 > > On 2015年08月20日 15:45, Michal Hocko wrote: >> On Thu 20-08-15 09:27:42, gchen gchen wrote: >> [...] >>> Yes, it is really peculiar, the reason is gmail is not stable in China. >>> I have to send mail in my hotmail address. >>> >>> But I still want to use my gmail as Signed-off-by, since I have already >>> used it, and also its name is a little formal than my hotmail. >>> >>> Welcome any ideas, suggestions and completions for it (e.g. if it is >>> necessary to let send mail and Signed-off-by mail be the same, I shall >>> try). >> >> You can do the following in your .git/config >> >> [user] >> name = YOUR_NAME_FOR_S-O-B >> email = YOUR_GMAIL_ADDRESS >> [sendemail] >> from = YOUR_STABLE_SENDER_ADDRESS >> envelopesender = YOUR_STABLE_SENDER_ADDRESS >> smtpserver = YOUR_STABLE_SMTP >> >> [user] part will be used for s-o-b and Author email while the sendemail >> will be used for git send-email to route the patch properly. If the two >> differ it will add From: user.name as suggested by Andrew. >> > Oh, sorry, it seems, I have to send mail in hotmail website (I can send gmail neither under client nor under website). linux kernel mailing list does not accept QQ mail. Either at present, I can not send hotmail from client (thunderbird client, git client), I guess the reason is the hotmail is blocked in China (but QQ is of cause OK in China). So ... it is a bad news to us all. :-( Welcome any related ideas, suggestions an completions. Thanks. > OK, thank your very much for your details information. :-) > > I shall try to use git to send/recv mails instead of current thunderbird > client (hope I can do it next time, although I am not quite sure). > > > Thanks. > -- > Chen Gang > > Open, share, and attitude like air, water, and life which God blessed >
RE: [PATCH] mm: mmap: Simplify the failure return working flow
From: xili_gchen_5...@hotmail.com To: mho...@kernel.org CC: a...@linux-foundation.org; linux-kernel@vger.kernel.org; kirill.shute...@linux.intel.com; r...@redhat.com; sasha.le...@oracle.com; linux...@kvack.org Subject: Re: [PATCH] mm: mmap: Simplify the failure return working flow Date: Thu, 20 Aug 2015 16:48:21 +0800 On 2015年08月20日 15:45, Michal Hocko wrote: On Thu 20-08-15 09:27:42, gchen gchen wrote: [...] Yes, it is really peculiar, the reason is gmail is not stable in China. I have to send mail in my hotmail address. But I still want to use my gmail as Signed-off-by, since I have already used it, and also its name is a little formal than my hotmail. Welcome any ideas, suggestions and completions for it (e.g. if it is necessary to let send mail and Signed-off-by mail be the same, I shall try). You can do the following in your .git/config [user] name = YOUR_NAME_FOR_S-O-B email = YOUR_GMAIL_ADDRESS [sendemail] from = YOUR_STABLE_SENDER_ADDRESS envelopesender = YOUR_STABLE_SENDER_ADDRESS smtpserver = YOUR_STABLE_SMTP [user] part will be used for s-o-b and Author email while the sendemail will be used for git send-email to route the patch properly. If the two differ it will add From: user.name user.email as suggested by Andrew. Oh, sorry, it seems, I have to send mail in hotmail website (I can send gmail neither under client nor under website). linux kernel mailing list does not accept QQ mail. Either at present, I can not send hotmail from client (thunderbird client, git client), I guess the reason is the hotmail is blocked in China (but QQ is of cause OK in China). So ... it is a bad news to us all. :-( Welcome any related ideas, suggestions an completions. Thanks. OK, thank your very much for your details information. :-) I shall try to use git to send/recv mails instead of current thunderbird client (hope I can do it next time, although I am not quite sure). Thanks. -- Chen Gang Open, share, and attitude like air, water, and life which God blessed
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On 2015年08月20日 15:45, Michal Hocko wrote:
> On Thu 20-08-15 09:27:42, gchen gchen wrote:
> [...]
>> Yes, it is really peculiar, the reason is gmail is not stable in China.
>> I have to send mail in my hotmail address.
>>
>> But I still want to use my gmail as Signed-off-by, since I have already
>> used it, and also its name is a little formal than my hotmail.
>>
>> Welcome any ideas, suggestions and completions for it (e.g. if it is
>> necessary to let send mail and Signed-off-by mail be the same, I shall
>> try).
>
> You can do the following in your .git/config
>
> [user]
> name = YOUR_NAME_FOR_S-O-B
> email = YOUR_GMAIL_ADDRESS
> [sendemail]
> from = YOUR_STABLE_SENDER_ADDRESS
> envelopesender = YOUR_STABLE_SENDER_ADDRESS
> smtpserver = YOUR_STABLE_SMTP
>
> [user] part will be used for s-o-b and Author email while the sendemail
> will be used for git send-email to route the patch properly. If the two
> differ it will add From: user.name as suggested by Andrew.
>
OK, thank your very much for your details information. :-)
I shall try to use git to send/recv mails instead of current thunderbird
client (hope I can do it next time, although I am not quite sure).
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
N�Р骒r��yb�X�肚�v�^�)藓{.n�+�伐�{��赙zXФ�≤�}��财�z�:+v�����赙zZ+��+zf＂�h���~i���z� �wア�?�ㄨ��&�)撷f��^j谦y�m��@A�a囤�
0鹅h���i
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On Thu 20-08-15 09:27:42, gchen gchen wrote: [...] > Yes, it is really peculiar, the reason is gmail is not stable in China. > I have to send mail in my hotmail address. > > But I still want to use my gmail as Signed-off-by, since I have already > used it, and also its name is a little formal than my hotmail. > > Welcome any ideas, suggestions and completions for it (e.g. if it is > necessary to let send mail and Signed-off-by mail be the same, I shall > try). You can do the following in your .git/config [user] name = YOUR_NAME_FOR_S-O-B email = YOUR_GMAIL_ADDRESS [sendemail] from = YOUR_STABLE_SENDER_ADDRESS envelopesender = YOUR_STABLE_SENDER_ADDRESS smtpserver = YOUR_STABLE_SMTP [user] part will be used for s-o-b and Author email while the sendemail will be used for git send-email to route the patch properly. If the two differ it will add From: user.name as suggested by Andrew. -- Michal Hocko SUSE Labs -- 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] mm: mmap: Simplify the failure return working flow
On 2015年08月20日 15:45, Michal Hocko wrote:
On Thu 20-08-15 09:27:42, gchen gchen wrote:
[...]
Yes, it is really peculiar, the reason is gmail is not stable in China.
I have to send mail in my hotmail address.
But I still want to use my gmail as Signed-off-by, since I have already
used it, and also its name is a little formal than my hotmail.
Welcome any ideas, suggestions and completions for it (e.g. if it is
necessary to let send mail and Signed-off-by mail be the same, I shall
try).
You can do the following in your .git/config
[user]
name = YOUR_NAME_FOR_S-O-B
email = YOUR_GMAIL_ADDRESS
[sendemail]
from = YOUR_STABLE_SENDER_ADDRESS
envelopesender = YOUR_STABLE_SENDER_ADDRESS
smtpserver = YOUR_STABLE_SMTP
[user] part will be used for s-o-b and Author email while the sendemail
will be used for git send-email to route the patch properly. If the two
differ it will add From: user.name user.email as suggested by Andrew.
OK, thank your very much for your details information. :-)
I shall try to use git to send/recv mails instead of current thunderbird
client (hope I can do it next time, although I am not quite sure).
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
N�Р骒r��yb�X�肚�v�^�)藓{.n�+�伐�{��赙zXФ�≤�}��财�z�j:+v�����赙zZ+��+zf＂�h���~i���z� �wア�?�ㄨ���)撷f��^j谦y�m��@A�a囤�
0鹅h���i
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On Thu 20-08-15 09:27:42, gchen gchen wrote: [...] Yes, it is really peculiar, the reason is gmail is not stable in China. I have to send mail in my hotmail address. But I still want to use my gmail as Signed-off-by, since I have already used it, and also its name is a little formal than my hotmail. Welcome any ideas, suggestions and completions for it (e.g. if it is necessary to let send mail and Signed-off-by mail be the same, I shall try). You can do the following in your .git/config [user] name = YOUR_NAME_FOR_S-O-B email = YOUR_GMAIL_ADDRESS [sendemail] from = YOUR_STABLE_SENDER_ADDRESS envelopesender = YOUR_STABLE_SENDER_ADDRESS smtpserver = YOUR_STABLE_SMTP [user] part will be used for s-o-b and Author email while the sendemail will be used for git send-email to route the patch properly. If the two differ it will add From: user.name user.email as suggested by Andrew. -- Michal Hocko SUSE Labs -- 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] mm: mmap: Simplify the failure return working flow
On Tue, 18 Aug 2015 15:57:08 -0700 a...@linux-foundation.org
wrote: On Wed, 19 Aug 2015 06:27:58 +0800 Chen Gang
xili_gchen_5...@hotmail.com wrote: From: Chen Gang
xili_gchen_5...@hotmail.com As sent, this patch is
From:you@hotmail and Signed-off-by:you@gmail. This is peculiar.
I'm assuming that it should have been From:you@gmail and I have made
that change to my copy of the patch. You can do this yourself
by putting an explicit From: line at the start of the
changelog.Yes, it is really peculiar, the reason is gmail is
not stable in China.I have to send mail in my hotmail address.But I
still want to use my gmail as Signed-off-by, since I have alreadyused it,
and also its name is a little formal than my hotmail.Welcome any ideas,
suggestions and completions for it (e.g. if it isnecessary to let send mail
and Signed-off-by mail be the same, I shalltry).[...]
So, ---
a/mm/mmap.c~mm-mmap-simplify-the-failure-return-working-flow-fix +++
a/mm/mmap.c @@ -2952,7 +2952,7 @@ struct vm_area_struct
*copy_vma(struct v } else { new_vma =
kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); if
(!new_vma) - return NULL; +
goto out; *new_vma = *vma;
new_vma-vm_start = addr; new_vma-vm_end =
addr + len; @@ -2971,10 +2971,11 @@ struct vm_area_struct
*copy_vma(struct v } return
new_vma; - out_free_mempol: +out_free_mempol:
mpol_put(vma_policy(new_vma)); - out_free_vma:
+out_free_vma: kmem_cache_free(vm_area_cachep,
new_vma); +out: return NULL;
}It is OK to me, thanks.During these days (2-4 months),
I shall try to make some patches forLinux mm: - I am learning Linux
kernel mmu, so I can re-use part of code to user mode (add softmmu to
qemu linux user in my working time). Then I can try some mm patches when
I am reading related code. - At present, cross-building various archs
with allmodconfig looks OK (have no many issues), so for me, I can stop
and start another parts (e.g. mmu, loongson machine of mips arch,
...).Welcome any ideas, suggestions and completions for it: -
Assume I am not quite familiar with mmu -- in honest, I feel I am really
not. - Is it possible to build the related 'softmmu' as a module which
can be used by both kernel mode and user mode (if really it is, I
shall try to perform it -- I can do it in my working time). -
...Thanks.--Chen GangOpen, share, and attitude like
air, water, and life which God blessed
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On Tue, 18 Aug 2015 15:57:08 -0700 a...@linux-foundation.org wrote:
>
> On Wed, 19 Aug 2015 06:27:58 +0800 Chen Gang
> wrote:
>
>> From: Chen Gang
>
> As sent, this patch is From:you@hotmail and Signed-off-by:you@gmail.
>
> This is peculiar. I'm assuming that it should have been From:you@gmail and
> I have made that change to my copy of the patch.
>
> You can do this yourself by putting an explicit From: line at the start
> of the changelog.
>
Yes, it is really peculiar, the reason is gmail is not stable in China.
I have to send mail in my hotmail address.
But I still want to use my gmail as Signed-off-by, since I have already
used it, and also its name is a little formal than my hotmail.
Welcome any ideas, suggestions and completions for it (e.g. if it is
necessary to let send mail and Signed-off-by mail be the same, I shall
try).
[...]
> So,
>
> --- a/mm/mmap.c~mm-mmap-simplify-the-failure-return-working-flow-fix
> +++ a/mm/mmap.c
> @@ -2952,7 +2952,7 @@ struct vm_area_struct *copy_vma(struct v
> } else {
> new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
> if (!new_vma)
> - return NULL;
> + goto out;
> *new_vma = *vma;
> new_vma->vm_start = addr;
> new_vma->vm_end = addr + len;
> @@ -2971,10 +2971,11 @@ struct vm_area_struct *copy_vma(struct v
> }
> return new_vma;
>
> - out_free_mempol:
> +out_free_mempol:
> mpol_put(vma_policy(new_vma));
> - out_free_vma:
> +out_free_vma:
> kmem_cache_free(vm_area_cachep, new_vma);
> +out:
> return NULL;
> }
>
It is OK to me, thanks.
During these days (2-4 months), I shall try to make some patches for
Linux mm:
- I am learning Linux kernel mmu, so I can re-use part of code to user
mode (add softmmu to qemu linux user in my working time). Then I can
try some mm patches when I am reading related code.
- At present, cross-building various archs with allmodconfig looks OK
(have no many issues), so for me, I can stop and start another parts
(e.g. mmu, loongson machine of mips arch, ...).
Welcome any ideas, suggestions and completions for it:
- Assume I am not quite familiar with mmu -- in honest, I feel I am
really not.
- Is it possible to build the related 'softmmu' as a module which can
be used by both kernel mode and user mode (if really it is, I shall
try to perform it -- I can do it in my working time).
- ...
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
Re: [PATCH] mm: mmap: Simplify the failure return working flow
brOn Tue, 18 Aug 2015 15:57:08 -0700 a...@linux-foundation.org
wrote:brgt;brgt; On Wed, 19 Aug 2015 06:27:58 +0800 Chen Gangbrgt;
lt;xili_gchen_5...@hotmail.comgt; wrote:brgt;brgt;gt; From: Chen Gang
lt;xili_gchen_5...@hotmail.comgt;brgt;brgt; As sent, this patch is
From:you@hotmail and Signed-off-by:you@gmail.brgt;brgt; This is peculiar.
I'm assuming that it should have been From:you@gmail andbrgt; I have made
that change to my copy of the patch.brgt;brgt; You can do this yourself
by putting an explicit From: line at the startbrgt; of the
changelog.brgt;brbrYes, it is really peculiar, the reason is gmail is
not stable in China.brI have to send mail in my hotmail address.brbrBut I
still want to use my gmail as Signed-off-by, since I have alreadybrused it,
and also its name is a little formal than my hotmail.brbrWelcome any ideas,
suggestions and completions for it (e.g. if it isbrnecessary to let send mail
and Signed-off-by mail be the same, I shallbrtry).brbr[...]brbrgt;
So,brgt;brgt; ---
a/mm/mmap.c~mm-mmap-simplify-the-failure-return-working-flow-fixbrgt; +++
a/mm/mmap.cbrgt; @@ -2952,7 +2952,7 @@ struct vm_area_struct
*copy_vma(struct vbrgt; } else {brgt; new_vma =
kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);brgt; if
(!new_vma)brgt; - return NULL;brgt; +
goto out;brgt; *new_vma = *vma;brgt;
new_vma-gt;vm_start = addr;brgt; new_vma-gt;vm_end =
addr + len;brgt; @@ -2971,10 +2971,11 @@ struct vm_area_struct
*copy_vma(struct vbrgt; }brgt; return
new_vma;brgt;brgt; - out_free_mempol:brgt; +out_free_mempol:brgt;
mpol_put(vma_policy(new_vma));brgt; - out_free_vma:brgt;
+out_free_vma:brgt; kmem_cache_free(vm_area_cachep,
new_vma);brgt; +out:brgt; return NULL;brgt;
}brgt;brbrIt is OK to me, thanks.brbrDuring these days (2-4 months),
I shall try to make some patches forbrLinux mm:brbr - I am learning Linux
kernel mmu, so I can re-use part of code to userbr mode (add softmmu to
qemu linux user in my working time). Then I canbr try some mm patches when
I am reading related code.brbr - At present, cross-building various archs
with allmodconfig looks OKbr (have no many issues), so for me, I can stop
and start another partsbr (e.g. mmu, loongson machine of mips arch,
...).brbrWelcome any ideas, suggestions and completions for it:brbr -
Assume I am not quite familiar with mmu -- in honest, I feel I ambr really
not.brbr - Is it possible to build the related 'softmmu' as a module which
canbr be used by both kernel mode and user mode (if really it is, I
shallbr try to perform it -- I can do it in my working time).brbr -
...brbrThanks.br--brChen GangbrbrOpen, share, and attitude like
air, water, and life which God blessedbr
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On Tue, 18 Aug 2015 15:57:08 -0700 a...@linux-foundation.org wrote:
On Wed, 19 Aug 2015 06:27:58 +0800 Chen Gang
xili_gchen_5...@hotmail.com wrote:
From: Chen Gang xili_gchen_5...@hotmail.com
As sent, this patch is From:you@hotmail and Signed-off-by:you@gmail.
This is peculiar. I'm assuming that it should have been From:you@gmail and
I have made that change to my copy of the patch.
You can do this yourself by putting an explicit From: line at the start
of the changelog.
Yes, it is really peculiar, the reason is gmail is not stable in China.
I have to send mail in my hotmail address.
But I still want to use my gmail as Signed-off-by, since I have already
used it, and also its name is a little formal than my hotmail.
Welcome any ideas, suggestions and completions for it (e.g. if it is
necessary to let send mail and Signed-off-by mail be the same, I shall
try).
[...]
So,
--- a/mm/mmap.c~mm-mmap-simplify-the-failure-return-working-flow-fix
+++ a/mm/mmap.c
@@ -2952,7 +2952,7 @@ struct vm_area_struct *copy_vma(struct v
} else {
new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!new_vma)
- return NULL;
+ goto out;
*new_vma = *vma;
new_vma-vm_start = addr;
new_vma-vm_end = addr + len;
@@ -2971,10 +2971,11 @@ struct vm_area_struct *copy_vma(struct v
}
return new_vma;
- out_free_mempol:
+out_free_mempol:
mpol_put(vma_policy(new_vma));
- out_free_vma:
+out_free_vma:
kmem_cache_free(vm_area_cachep, new_vma);
+out:
return NULL;
}
It is OK to me, thanks.
During these days (2-4 months), I shall try to make some patches for
Linux mm:
- I am learning Linux kernel mmu, so I can re-use part of code to user
mode (add softmmu to qemu linux user in my working time). Then I can
try some mm patches when I am reading related code.
- At present, cross-building various archs with allmodconfig looks OK
(have no many issues), so for me, I can stop and start another parts
(e.g. mmu, loongson machine of mips arch, ...).
Welcome any ideas, suggestions and completions for it:
- Assume I am not quite familiar with mmu -- in honest, I feel I am
really not.
- Is it possible to build the related 'softmmu' as a module which can
be used by both kernel mode and user mode (if really it is, I shall
try to perform it -- I can do it in my working time).
- ...
Thanks.
--
Chen Gang
Open, share, and attitude like air, water, and life which God blessed
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On Wed, 19 Aug 2015 06:27:58 +0800 Chen Gang
wrote:
> From: Chen Gang
As sent, this patch is From:you@hotmail and Signed-off-by:you@gmail.
This is peculiar. I'm assuming that it should have been From:you@gmail and
I have made that change to my copy of the patch.
You can do this yourself by putting an explicit From: line at the start
of the changelog.
> @@ -2958,23 +2957,23 @@ struct vm_area_struct *copy_vma(struct vm_area_struct
> **vmap,
> *need_rmap_locks = (new_vma->vm_pgoff <= vma->vm_pgoff);
> } else {
> new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
> - if (new_vma) {
> - *new_vma = *vma;
> - new_vma->vm_start = addr;
> - new_vma->vm_end = addr + len;
> - new_vma->vm_pgoff = pgoff;
> - if (vma_dup_policy(vma, new_vma))
> - goto out_free_vma;
> - INIT_LIST_HEAD(_vma->anon_vma_chain);
> - if (anon_vma_clone(new_vma, vma))
> - goto out_free_mempol;
> - if (new_vma->vm_file)
> - get_file(new_vma->vm_file);
> - if (new_vma->vm_ops && new_vma->vm_ops->open)
> - new_vma->vm_ops->open(new_vma);
> - vma_link(mm, new_vma, prev, rb_link, rb_parent);
> - *need_rmap_locks = false;
> - }
> + if (!new_vma)
> + return NULL;
> + *new_vma = *vma;
> + new_vma->vm_start = addr;
> + new_vma->vm_end = addr + len;
> + new_vma->vm_pgoff = pgoff;
> + if (vma_dup_policy(vma, new_vma))
> + goto out_free_vma;
> + INIT_LIST_HEAD(_vma->anon_vma_chain);
> + if (anon_vma_clone(new_vma, vma))
> + goto out_free_mempol;
> + if (new_vma->vm_file)
> + get_file(new_vma->vm_file);
> + if (new_vma->vm_ops && new_vma->vm_ops->open)
> + new_vma->vm_ops->open(new_vma);
> + vma_link(mm, new_vma, prev, rb_link, rb_parent);
> + *need_rmap_locks = false;
> }
> return new_vma;
Embedding a return deep inside the function isn't good. It can lead to
resource leaks, locking leaks etc as the code evolves. This is the
main reason why the kernel uses goto, IMO: single-entry, single-exit.
So,
--- a/mm/mmap.c~mm-mmap-simplify-the-failure-return-working-flow-fix
+++ a/mm/mmap.c
@@ -2952,7 +2952,7 @@ struct vm_area_struct *copy_vma(struct v
} else {
new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!new_vma)
- return NULL;
+ goto out;
*new_vma = *vma;
new_vma->vm_start = addr;
new_vma->vm_end = addr + len;
@@ -2971,10 +2971,11 @@ struct vm_area_struct *copy_vma(struct v
}
return new_vma;
- out_free_mempol:
+out_free_mempol:
mpol_put(vma_policy(new_vma));
- out_free_vma:
+out_free_vma:
kmem_cache_free(vm_area_cachep, new_vma);
+out:
return NULL;
}
_
--
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Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] mm: mmap: Simplify the failure return working flow
On Wed, 19 Aug 2015 06:27:58 +0800 Chen Gang xili_gchen_5...@hotmail.com
wrote:
From: Chen Gang xili_gchen_5...@hotmail.com
As sent, this patch is From:you@hotmail and Signed-off-by:you@gmail.
This is peculiar. I'm assuming that it should have been From:you@gmail and
I have made that change to my copy of the patch.
You can do this yourself by putting an explicit From: line at the start
of the changelog.
@@ -2958,23 +2957,23 @@ struct vm_area_struct *copy_vma(struct vm_area_struct
**vmap,
*need_rmap_locks = (new_vma-vm_pgoff = vma-vm_pgoff);
} else {
new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
- if (new_vma) {
- *new_vma = *vma;
- new_vma-vm_start = addr;
- new_vma-vm_end = addr + len;
- new_vma-vm_pgoff = pgoff;
- if (vma_dup_policy(vma, new_vma))
- goto out_free_vma;
- INIT_LIST_HEAD(new_vma-anon_vma_chain);
- if (anon_vma_clone(new_vma, vma))
- goto out_free_mempol;
- if (new_vma-vm_file)
- get_file(new_vma-vm_file);
- if (new_vma-vm_ops new_vma-vm_ops-open)
- new_vma-vm_ops-open(new_vma);
- vma_link(mm, new_vma, prev, rb_link, rb_parent);
- *need_rmap_locks = false;
- }
+ if (!new_vma)
+ return NULL;
+ *new_vma = *vma;
+ new_vma-vm_start = addr;
+ new_vma-vm_end = addr + len;
+ new_vma-vm_pgoff = pgoff;
+ if (vma_dup_policy(vma, new_vma))
+ goto out_free_vma;
+ INIT_LIST_HEAD(new_vma-anon_vma_chain);
+ if (anon_vma_clone(new_vma, vma))
+ goto out_free_mempol;
+ if (new_vma-vm_file)
+ get_file(new_vma-vm_file);
+ if (new_vma-vm_ops new_vma-vm_ops-open)
+ new_vma-vm_ops-open(new_vma);
+ vma_link(mm, new_vma, prev, rb_link, rb_parent);
+ *need_rmap_locks = false;
}
return new_vma;
Embedding a return deep inside the function isn't good. It can lead to
resource leaks, locking leaks etc as the code evolves. This is the
main reason why the kernel uses goto, IMO: single-entry, single-exit.
So,
--- a/mm/mmap.c~mm-mmap-simplify-the-failure-return-working-flow-fix
+++ a/mm/mmap.c
@@ -2952,7 +2952,7 @@ struct vm_area_struct *copy_vma(struct v
} else {
new_vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!new_vma)
- return NULL;
+ goto out;
*new_vma = *vma;
new_vma-vm_start = addr;
new_vma-vm_end = addr + len;
@@ -2971,10 +2971,11 @@ struct vm_area_struct *copy_vma(struct v
}
return new_vma;
- out_free_mempol:
+out_free_mempol:
mpol_put(vma_policy(new_vma));
- out_free_vma:
+out_free_vma:
kmem_cache_free(vm_area_cachep, new_vma);
+out:
return NULL;
}
_
--
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