Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-10 Thread Wei Yang
On Thu, Oct 10, 2019 at 11:29:44AM +0300, Konstantin Khlebnikov wrote: >On 10/10/2019 06.15, Wei Yang wrote: >> On Thu, Oct 10, 2019 at 10:36:01AM +0800, Wei Yang wrote: >> > Hi, Qian, Shakeel >> > >> > Thanks for testing. >> > >> > Sounds I missed some case to handle. anon_vma_clone() now would

Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-10 Thread Wei Yang
On Thu, Oct 10, 2019 at 11:29:44AM +0300, Konstantin Khlebnikov wrote: >On 10/10/2019 06.15, Wei Yang wrote: >> On Thu, Oct 10, 2019 at 10:36:01AM +0800, Wei Yang wrote: >> > Hi, Qian, Shakeel >> > >> > Thanks for testing. >> > >> > Sounds I missed some case to handle. anon_vma_clone() now would

Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-10 Thread Konstantin Khlebnikov
On 10/10/2019 06.15, Wei Yang wrote: On Thu, Oct 10, 2019 at 10:36:01AM +0800, Wei Yang wrote: Hi, Qian, Shakeel Thanks for testing. Sounds I missed some case to handle. anon_vma_clone() now would be called in vma_adjust, which is a different case when it is introduced. Well, I have to corr

Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-09 Thread Wei Yang
On Thu, Oct 10, 2019 at 10:36:01AM +0800, Wei Yang wrote: >Hi, Qian, Shakeel > >Thanks for testing. > >Sounds I missed some case to handle. anon_vma_clone() now would be called in >vma_adjust, which is a different case when it is introduced. > Well, I have to correct my statement. The reason is we

Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-09 Thread Wei Yang
Hi, Qian, Shakeel Thanks for testing. Sounds I missed some case to handle. anon_vma_clone() now would be called in vma_adjust, which is a different case when it is introduced. BTW, do you have the specific test case? So that I could verify my change. The kernel build test doesn't trigger this.

Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-09 Thread Andrew Morton
On Wed, 9 Oct 2019 15:21:11 -0700 Shakeel Butt wrote: > On Wed, Oct 9, 2019 at 2:30 PM Qian Cai wrote: > > > > The linux-next commit "mm/rmap.c: reuse mergeable anon_vma as parent when > > fork" > > [1] causes a crash on s390 while compiling some C code. Reverted it fixes > > the > > issue. >

Re: "reuse mergeable anon_vma as parent when fork" causes a crash on s390

2019-10-09 Thread Shakeel Butt
On Wed, Oct 9, 2019 at 2:30 PM Qian Cai wrote: > > The linux-next commit "mm/rmap.c: reuse mergeable anon_vma as parent when > fork" > [1] causes a crash on s390 while compiling some C code. Reverted it fixes the > issue. > > [1] > https://lore.kernel.org/lkml/20191004160632.30251-1-richardw.y..