Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Toshi Kani
On Tue, 2016-02-09 at 13:08 +0100, Ingo Molnar wrote: > * Borislav Petkov wrote: > > > On Tue, Feb 09, 2016 at 12:27:32PM +0100, Ingo Molnar wrote: > > > Btw., IIRC GAS is being silly about .L, i.e. there's a difference > > > between these  > > > two variants: > > > > > >  

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Ingo Molnar
* Borislav Petkov wrote: > On Tue, Feb 09, 2016 at 12:27:32PM +0100, Ingo Molnar wrote: > > Btw., IIRC GAS is being silly about .L, i.e. there's a difference between > > these > > two variants: > > > > .Lerror_entry_from_usermode_swapgs: > > .L_error_entry_from_usermode_swapgs: > > > >

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Borislav Petkov
On Tue, Feb 09, 2016 at 12:27:32PM +0100, Ingo Molnar wrote: > Btw., IIRC GAS is being silly about .L, i.e. there's a difference between > these > two variants: > > .Lerror_entry_from_usermode_swapgs: > .L_error_entry_from_usermode_swapgs: > > the latter would be easier to read, but does not

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Ingo Molnar
* Borislav Petkov wrote: > On Tue, Feb 09, 2016 at 11:27:41AM +0100, Ingo Molnar wrote: > > So another pet peeve of mine is to not use numeric labels, please use > > descriptively named labels instead. > > ... and prepend them with ".L" so that they become local labels. Yes. A good example to

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Borislav Petkov
On Tue, Feb 09, 2016 at 11:27:41AM +0100, Ingo Molnar wrote: > So another pet peeve of mine is to not use numeric labels, please use > descriptively named labels instead. ... and prepend them with ".L" so that they become local labels. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Ingo Molnar
* Toshi Kani wrote: > Data corruption issues were observed in tests which initiated > a system crash/reset while accessing BTT devices. This problem > is reproducible. > > The BTT driver calls pmem_rw_bytes() to update data in pmem > devices. This interface calls __copy_user_nocache(), which

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Borislav Petkov
On Tue, Feb 09, 2016 at 11:27:41AM +0100, Ingo Molnar wrote: > So another pet peeve of mine is to not use numeric labels, please use > descriptively named labels instead. ... and prepend them with ".L" so that they become local labels. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Ingo Molnar
* Borislav Petkov wrote: > On Tue, Feb 09, 2016 at 11:27:41AM +0100, Ingo Molnar wrote: > > So another pet peeve of mine is to not use numeric labels, please use > > descriptively named labels instead. > > ... and prepend them with ".L" so that they become local labels. Yes. A

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Ingo Molnar
* Toshi Kani wrote: > Data corruption issues were observed in tests which initiated > a system crash/reset while accessing BTT devices. This problem > is reproducible. > > The BTT driver calls pmem_rw_bytes() to update data in pmem > devices. This interface calls

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Borislav Petkov
On Tue, Feb 09, 2016 at 12:27:32PM +0100, Ingo Molnar wrote: > Btw., IIRC GAS is being silly about .L, i.e. there's a difference between > these > two variants: > > .Lerror_entry_from_usermode_swapgs: > .L_error_entry_from_usermode_swapgs: > > the latter would be easier to read, but does not

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Ingo Molnar
* Borislav Petkov wrote: > On Tue, Feb 09, 2016 at 12:27:32PM +0100, Ingo Molnar wrote: > > Btw., IIRC GAS is being silly about .L, i.e. there's a difference between > > these > > two variants: > > > > .Lerror_entry_from_usermode_swapgs: > >

Re: [PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-09 Thread Toshi Kani
On Tue, 2016-02-09 at 13:08 +0100, Ingo Molnar wrote: > * Borislav Petkov wrote: > > > On Tue, Feb 09, 2016 at 12:27:32PM +0100, Ingo Molnar wrote: > > > Btw., IIRC GAS is being silly about .L, i.e. there's a difference > > > between these  > > > two variants: > > > > > >  

[PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-03 Thread Toshi Kani
Data corruption issues were observed in tests which initiated a system crash/reset while accessing BTT devices. This problem is reproducible. The BTT driver calls pmem_rw_bytes() to update data in pmem devices. This interface calls __copy_user_nocache(), which uses non-temporal stores so that

[PATCH v2] x86/lib/copy_user_64.S: Handle 4-byte nocache copy

2016-02-03 Thread Toshi Kani
Data corruption issues were observed in tests which initiated a system crash/reset while accessing BTT devices. This problem is reproducible. The BTT driver calls pmem_rw_bytes() to update data in pmem devices. This interface calls __copy_user_nocache(), which uses non-temporal stores so that