Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

Larry Finger writes: > On 06/23/2017 03:29 PM, Al Viro wrote: >> On Fri, Jun 23, 2017 at 01:49:16PM -0500, Larry Finger wrote: >> BTW, could you try to check what happens if you kill the if (__builtin_constant_p(n) && (n <= 8)) bits in

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

Larry Finger writes: > On 06/23/2017 03:29 PM, Al Viro wrote: >> On Fri, Jun 23, 2017 at 01:49:16PM -0500, Larry Finger wrote: >> BTW, could you try to check what happens if you kill the if (__builtin_constant_p(n) && (n <= 8)) bits in raw_copy_{to,from}_user()? The

Re: gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

Al Viro writes: > On Sun, Jun 25, 2017 at 04:44:09PM -0500, Segher Boessenkool wrote: > >> Do you have a short stand-alone testcase? 4.6 is ancient, of course, but >> the actual problem may still exist in more recent compilers (if it _is_ >> a compiler problem; if it's

Re: gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

Al Viro writes: > On Sun, Jun 25, 2017 at 04:44:09PM -0500, Segher Boessenkool wrote: > >> Do you have a short stand-alone testcase? 4.6 is ancient, of course, but >> the actual problem may still exist in more recent compilers (if it _is_ >> a compiler problem; if it's not, you *really* want to

Re: gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

On Sun, Jun 25, 2017 at 04:44:09PM -0500, Segher Boessenkool wrote: > Do you have a short stand-alone testcase? 4.6 is ancient, of course, but > the actual problem may still exist in more recent compilers (if it _is_ > a compiler problem; if it's not, you *really* want to know :-) ) Enjoy. At

Re: gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

On Sun, Jun 25, 2017 at 04:44:09PM -0500, Segher Boessenkool wrote: > Do you have a short stand-alone testcase? 4.6 is ancient, of course, but > the actual problem may still exist in more recent compilers (if it _is_ > a compiler problem; if it's not, you *really* want to know :-) ) Enjoy. At

Re: gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

On Sun, Jun 25, 2017 at 09:53:24PM +0100, Al Viro wrote: > Confirmed. It manages to bugger the loop immediately after the (successful) > copying of iovec array in rw_copy_check_uvector(); both with and without > INLINE_COPY_FROM_USER it has (just before the call of copy_from_user()) r27 > set to

Re: gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

On Sun, Jun 25, 2017 at 09:53:24PM +0100, Al Viro wrote: > Confirmed. It manages to bugger the loop immediately after the (successful) > copying of iovec array in rw_copy_check_uvector(); both with and without > INLINE_COPY_FROM_USER it has (just before the call of copy_from_user()) r27 > set to

gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

On Sun, Jun 25, 2017 at 12:14:04PM +0100, Al Viro wrote: > On Sun, Jun 25, 2017 at 10:53:58AM +0100, Al Viro wrote: > > On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > > > > > I made a break through. If I turn off inline copy to/from users for 32-bit > > > ppc with the following

gcc 4.6.3 miscompile on ppc32 (was Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3)

On Sun, Jun 25, 2017 at 12:14:04PM +0100, Al Viro wrote: > On Sun, Jun 25, 2017 at 10:53:58AM +0100, Al Viro wrote: > > On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > > > > > I made a break through. If I turn off inline copy to/from users for 32-bit > > > ppc with the following

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Sun, Jun 25, 2017 at 10:53:58AM +0100, Al Viro wrote: > On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > > > I made a break through. If I turn off inline copy to/from users for 32-bit > > ppc with the following patch, then the system boots: > > OK... So it's 4.6.3 miscompiling

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Sun, Jun 25, 2017 at 10:53:58AM +0100, Al Viro wrote: > On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > > > I made a break through. If I turn off inline copy to/from users for 32-bit > > ppc with the following patch, then the system boots: > > OK... So it's 4.6.3 miscompiling

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > I made a break through. If I turn off inline copy to/from users for 32-bit > ppc with the following patch, then the system boots: OK... So it's 4.6.3 miscompiling something - it is hardware-independent, reproduced in qemu. I'd

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Sat, Jun 24, 2017 at 12:29:23PM -0500, Larry Finger wrote: > I made a break through. If I turn off inline copy to/from users for 32-bit > ppc with the following patch, then the system boots: OK... So it's 4.6.3 miscompiling something - it is hardware-independent, reproduced in qemu. I'd

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/23/2017 03:29 PM, Al Viro wrote: On Fri, Jun 23, 2017 at 01:49:16PM -0500, Larry Finger wrote: BTW, could you try to check what happens if you kill the if (__builtin_constant_p(n) && (n <= 8)) bits in raw_copy_{to,from}_user()? The usefulness of those (in __copy_from_user()

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/23/2017 03:29 PM, Al Viro wrote: On Fri, Jun 23, 2017 at 01:49:16PM -0500, Larry Finger wrote: BTW, could you try to check what happens if you kill the if (__builtin_constant_p(n) && (n <= 8)) bits in raw_copy_{to,from}_user()? The usefulness of those (in __copy_from_user()

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Fri, Jun 23, 2017 at 01:49:16PM -0500, Larry Finger wrote: > > BTW, could you try to check what happens if you kill the > > if (__builtin_constant_p(n) && (n <= 8)) > > bits in raw_copy_{to,from}_user()? The usefulness of those (in > > __copy_from_user() > > originally) had always been

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Fri, Jun 23, 2017 at 01:49:16PM -0500, Larry Finger wrote: > > BTW, could you try to check what happens if you kill the > > if (__builtin_constant_p(n) && (n <= 8)) > > bits in raw_copy_{to,from}_user()? The usefulness of those (in > > __copy_from_user() > > originally) had always been

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/22/2017 02:25 PM, Al Viro wrote: On Thu, Jun 22, 2017 at 09:19:58AM -0500, Larry Finger wrote: Ugh... MintPPC appears to be dead. On KVM with Debian userland (either jessie or wheezy - no difference in result) booting the commit in question with your .config oopses as soon as

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/22/2017 02:25 PM, Al Viro wrote: On Thu, Jun 22, 2017 at 09:19:58AM -0500, Larry Finger wrote: Ugh... MintPPC appears to be dead. On KVM with Debian userland (either jessie or wheezy - no difference in result) booting the commit in question with your .config oopses as soon as

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Thu, Jun 22, 2017 at 08:25:16PM +0100, Al Viro wrote: > > All I know at this > > point is that commit f2ed8beb with 46f401c4 backported boots OK and commit > > 3448890c with the same backport fails. > > > > I will try loading jessie and see what happens. > > I would recheck which kernels are

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Thu, Jun 22, 2017 at 08:25:16PM +0100, Al Viro wrote: > > All I know at this > > point is that commit f2ed8beb with 46f401c4 backported boots OK and commit > > 3448890c with the same backport fails. > > > > I will try loading jessie and see what happens. > > I would recheck which kernels are

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Thu, Jun 22, 2017 at 09:19:58AM -0500, Larry Finger wrote: > > Ugh... MintPPC appears to be dead. On KVM with Debian userland (either > > jessie or wheezy - no difference in result) booting the commit in > > question with your .config oopses as soon as pata_macio is initialized, > > due to

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Thu, Jun 22, 2017 at 09:19:58AM -0500, Larry Finger wrote: > > Ugh... MintPPC appears to be dead. On KVM with Debian userland (either > > jessie or wheezy - no difference in result) booting the commit in > > question with your .config oopses as soon as pata_macio is initialized, > > due to

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/22/2017 09:12 AM, Al Viro wrote: On Wed, Jun 21, 2017 at 04:49:46PM -0500, Larry Finger wrote: On 06/21/2017 04:34 PM, Al Viro wrote: On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: On 06/21/2017 04:22 PM, Al Viro wrote: How about the .config that works on parent of that

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/22/2017 09:12 AM, Al Viro wrote: On Wed, Jun 21, 2017 at 04:49:46PM -0500, Larry Finger wrote: On 06/21/2017 04:34 PM, Al Viro wrote: On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: On 06/21/2017 04:22 PM, Al Viro wrote: How about the .config that works on parent of that

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Wed, Jun 21, 2017 at 04:49:46PM -0500, Larry Finger wrote: > On 06/21/2017 04:34 PM, Al Viro wrote: > > On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: > > > On 06/21/2017 04:22 PM, Al Viro wrote: > > > > How about the .config that works on parent of that commit? > > > > > >

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Wed, Jun 21, 2017 at 04:49:46PM -0500, Larry Finger wrote: > On 06/21/2017 04:34 PM, Al Viro wrote: > > On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: > > > On 06/21/2017 04:22 PM, Al Viro wrote: > > > > How about the .config that works on parent of that commit? > > > > > >

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/21/2017 04:34 PM, Al Viro wrote: On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: On 06/21/2017 04:22 PM, Al Viro wrote: How about the .config that works on parent of that commit? Attached. OK... am I right assuming straight jessie/powerpc userland? Actually Mint 12

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/21/2017 04:34 PM, Al Viro wrote: On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: On 06/21/2017 04:22 PM, Al Viro wrote: How about the .config that works on parent of that commit? Attached. OK... am I right assuming straight jessie/powerpc userland? Actually Mint 12

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: > On 06/21/2017 04:22 PM, Al Viro wrote: > > On Wed, Jun 21, 2017 at 10:10:57AM -0500, Larry Finger wrote: > > > > > I finally finished the bisection by patching each commit that was affected > > > by the bootstrap crash. The faulty

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Wed, Jun 21, 2017 at 04:31:40PM -0500, Larry Finger wrote: > On 06/21/2017 04:22 PM, Al Viro wrote: > > On Wed, Jun 21, 2017 at 10:10:57AM -0500, Larry Finger wrote: > > > > > I finally finished the bisection by patching each commit that was affected > > > by the bootstrap crash. The faulty

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/21/2017 04:22 PM, Al Viro wrote: On Wed, Jun 21, 2017 at 10:10:57AM -0500, Larry Finger wrote: I finally finished the bisection by patching each commit that was affected by the bootstrap crash. The faulty change is commit 3448890c32c32c482c3ec20baa8fdd2ab4f94cc0 ("powerpc: get rid of

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/21/2017 04:22 PM, Al Viro wrote: On Wed, Jun 21, 2017 at 10:10:57AM -0500, Larry Finger wrote: I finally finished the bisection by patching each commit that was affected by the bootstrap crash. The faulty change is commit 3448890c32c32c482c3ec20baa8fdd2ab4f94cc0 ("powerpc: get rid of

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Wed, Jun 21, 2017 at 10:10:57AM -0500, Larry Finger wrote: > I finally finished the bisection by patching each commit that was affected > by the bootstrap crash. The faulty change is commit > 3448890c32c32c482c3ec20baa8fdd2ab4f94cc0 ("powerpc: get rid of zeroing, > switch to RAW_COPY_USER"). I

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On Wed, Jun 21, 2017 at 10:10:57AM -0500, Larry Finger wrote: > I finally finished the bisection by patching each commit that was affected > by the bootstrap crash. The faulty change is commit > 3448890c32c32c482c3ec20baa8fdd2ab4f94cc0 ("powerpc: get rid of zeroing, > switch to RAW_COPY_USER"). I

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/01/2017 11:39 AM, Larry Finger wrote: On my Powerbook G4 aluminum, kernel 4.12-rc1 fails to boot. I cannot save a copy of the early printk messages and I will need to summarize. The kernel finds the hard driver and recognizes the various partitions. All seems normal until after the

Re: Regression in kernel 4.12-rc1 for Powerpc 32 - bisected to commit 3448890c32c3

On 06/01/2017 11:39 AM, Larry Finger wrote: On my Powerbook G4 aluminum, kernel 4.12-rc1 fails to boot. I cannot save a copy of the early printk messages and I will need to summarize. The kernel finds the hard driver and recognizes the various partitions. All seems normal until after the