* rt kernel break printf command's parent process @ 2019-05-27 9:47 ddu 2019-05-28 14:33 ` Sebastian Andrzej Siewior 0 siblings, 1 reply; 4+ messages in thread From: ddu @ 2019-05-27 9:47 UTC (permalink / raw) To: linux-rt-users Hi all I use yocto rt-kernel which rebase on rt kernel: http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto/log/?h=v5.0/standard/preempt-rt/intel-x86 yocto branch: master run command: printf "%0.0f\n" 123.4567 error: [ OK ] Stopped Serial Getty on ttyS0. [ OK ] Started Serial Getty on ttyS0. the system loged out, and let login again. I using bisect to find which commit break the it: --------------------------------------------------------------------------- commit 6115b04921fc2b8a6b9f7de6d35a0202204a36ba Author: Rik van Riel <riel@surriel.com> Date: Sun Sep 9 18:30:50 2018 +0200 x86/fpu: Always store the registers in copy_fpstate_to_sigframe() copy_fpstate_to_sigframe() stores the registers directly to user space. This is okay because the FPU register are valid and saving it directly avoids saving it into kernel memory and making a copy. However<E2><80><A6> We can't keep doing this if we are going to restore the FPU registers on the return to userland. It is possible that the FPU registers will be invalidated in the middle of the save operation and this should be done with disabled preemption / BH. Save the FPU registers to task's FPU struct and copy them to the user memory later on. This code is extracted from an earlier version of the patchset while there still was lazy-FPU on x86. Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --------------------------------------------------------------------------- When I want to revert it, I found it's a serial patches, so if I revert it, I need to revert a serial patches. So can anyone help me to trace where break the return from printf and break the parent process? ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: rt kernel break printf command's parent process 2019-05-27 9:47 rt kernel break printf command's parent process ddu @ 2019-05-28 14:33 ` Sebastian Andrzej Siewior 2019-05-28 16:04 ` Sebastian Andrzej Siewior 0 siblings, 1 reply; 4+ messages in thread From: Sebastian Andrzej Siewior @ 2019-05-28 14:33 UTC (permalink / raw) To: ddu; +Cc: linux-rt-users On 2019-05-27 17:47:04 [+0800], ddu wrote: > Hi all Hi, > I use yocto rt-kernel which rebase on rt kernel: > > http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto/log/?h=v5.0/standard/preempt-rt/intel-x86 > > yocto branch: master > > run command: > > printf "%0.0f\n" 123.4567 > > error: > > [ OK ] Stopped Serial Getty on ttyS0. > [ OK ] Started Serial Getty on ttyS0. Doing this on a x86-64 does not lead to this. Is this 32bit oder 64bit? > the system loged out, and let login again. > > I using bisect to find which commit break the it: … > > When I want to revert it, I found it's a serial patches, so if I revert it, > I need to revert a serial patches. > > So can anyone help me to trace where break the return from printf and break > the parent process? You could remove the FPU patches from the series file and check it still happens. Sebastian ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: rt kernel break printf command's parent process 2019-05-28 14:33 ` Sebastian Andrzej Siewior @ 2019-05-28 16:04 ` Sebastian Andrzej Siewior 2019-05-30 2:19 ` ddu 0 siblings, 1 reply; 4+ messages in thread From: Sebastian Andrzej Siewior @ 2019-05-28 16:04 UTC (permalink / raw) To: ddu; +Cc: linux-rt-users On 2019-05-28 16:33:29 [+0200], To ddu wrote: > On 2019-05-27 17:47:04 [+0800], ddu wrote: > > Hi all > Hi, > > > I use yocto rt-kernel which rebase on rt kernel: > > > > http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto/log/?h=v5.0/standard/preempt-rt/intel-x86 That tree has -rt3. Please update to -rt9. Sebastian ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: rt kernel break printf command's parent process 2019-05-28 16:04 ` Sebastian Andrzej Siewior @ 2019-05-30 2:19 ` ddu 0 siblings, 0 replies; 4+ messages in thread From: ddu @ 2019-05-30 2:19 UTC (permalink / raw) To: Sebastian Andrzej Siewior; +Cc: linux-rt-users Thanks, after I update to -rt9, this have been fixed. //dengke 在 2019/5/29 上午12:04, Sebastian Andrzej Siewior 写道: > On 2019-05-28 16:33:29 [+0200], To ddu wrote: >> On 2019-05-27 17:47:04 [+0800], ddu wrote: >>> Hi all >> Hi, >> >>> I use yocto rt-kernel which rebase on rt kernel: >>> >>> http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto/log/?h=v5.0/standard/preempt-rt/intel-x86 > That tree has -rt3. Please update to -rt9. > > Sebastian > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-05-30 2:19 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-05-27 9:47 rt kernel break printf command's parent process ddu 2019-05-28 14:33 ` Sebastian Andrzej Siewior 2019-05-28 16:04 ` Sebastian Andrzej Siewior 2019-05-30 2:19 ` ddu
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