Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Song Liu
On Fri, Oct 23, 2020 at 10:51 AM Linus Torvalds wrote: > > On Fri, Oct 23, 2020 at 10:00 AM Naresh Kamboju > wrote: > > > > [Old patch from yesterday] > > > > After applying your patch on top on linux next tag 20201015 > > there are two observations, > > 1) i386 build failed. please find build

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Linus Torvalds
On Fri, Oct 23, 2020 at 10:00 AM Naresh Kamboju wrote: > > [Old patch from yesterday] > > After applying your patch on top on linux next tag 20201015 > there are two observations, > 1) i386 build failed. please find build error build Yes, this was expected. That patch explicitly only works on x

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Naresh Kamboju
On Fri, 23 Oct 2020 at 22:03, Linus Torvalds wrote: > > On Fri, Oct 23, 2020 at 8:54 AM Linus Torvalds > wrote: > > > > On Fri, Oct 23, 2020 at 12:14 AM Rasmus Villemoes > > wrote: > > > > > > That's certainly garbage. Now, I don't know if it's a sufficient fix (or > > > could break something el

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Naresh Kamboju
On Fri, 23 Oct 2020 at 08:35, Linus Torvalds wrote: > > On Thu, Oct 22, 2020 at 6:36 PM Daniel Díaz wrote: > > > > The kernel Naresh originally referred to is here: > > https://builds.tuxbuild.com/SCI7Xyjb7V2NbfQ2lbKBZw/ > > is unnecessary (because the 8-byte case is still just a single > regis

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Linus Torvalds
On Fri, Oct 23, 2020 at 8:54 AM Linus Torvalds wrote: > > On Fri, Oct 23, 2020 at 12:14 AM Rasmus Villemoes > wrote: > > > > That's certainly garbage. Now, I don't know if it's a sufficient fix (or > > could break something else), but the obvious first step of rearranging > > so that the ptr argu

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Linus Torvalds
On Fri, Oct 23, 2020 at 12:14 AM Rasmus Villemoes wrote: > > That's certainly garbage. Now, I don't know if it's a sufficient fix (or > could break something else), but the obvious first step of rearranging > so that the ptr argument is evaluated before the assignment to __val_pu Ack. We could do

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Linus Torvalds
On Thu, Oct 22, 2020 at 10:02 PM Sean Christopherson wrote: > > I haven't reproduced the crash, but I did find a smoking gun that confirms the > "register shenanigans are evil shenanigans" theory. I ran into a similar > thing > recently where a seemingly innocuous line of code after loading a va

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-23 Thread Rasmus Villemoes
On 23/10/2020 07.02, Sean Christopherson wrote: > On Thu, Oct 22, 2020 at 08:05:05PM -0700, Linus Torvalds wrote: >> On Thu, Oct 22, 2020 at 6:36 PM Daniel Díaz wrote: >>> >>> The kernel Naresh originally referred to is here: >>> https://builds.tuxbuild.com/SCI7Xyjb7V2NbfQ2lbKBZw/ >> >> Thanks.

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-22 Thread Sean Christopherson
On Thu, Oct 22, 2020 at 08:05:05PM -0700, Linus Torvalds wrote: > On Thu, Oct 22, 2020 at 6:36 PM Daniel Díaz wrote: > > > > The kernel Naresh originally referred to is here: > > https://builds.tuxbuild.com/SCI7Xyjb7V2NbfQ2lbKBZw/ > > Thanks. > > And when I started looking at it, I realized th

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-22 Thread Linus Torvalds
On Thu, Oct 22, 2020 at 6:36 PM Daniel Díaz wrote: > > The kernel Naresh originally referred to is here: > https://builds.tuxbuild.com/SCI7Xyjb7V2NbfQ2lbKBZw/ Thanks. And when I started looking at it, I realized that my original idea ("just look for __put_user_nocheck_X calls, there aren't so

Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000]

2020-10-22 Thread Daniel Díaz
Hello! On Thu, 22 Oct 2020 at 19:11, Linus Torvalds wrote: > On Thu, Oct 22, 2020 at 4:43 PM Linus Torvalds > Would you mind sending me the problematic vmlinux file in private (or, > likely better - a pointer to some place I can download it, it's going > to be huge). The kernel Naresh originally