----- On Feb 21, 2019, at 7:10 PM, Russell King, ARM Linux li...@armlinux.org.uk wrote:
> On Thu, Feb 21, 2019 at 03:02:57PM -0500, Mathieu Desnoyers wrote: >> Hi Arnd, Russell, Linus, >> >> Can we ensure the arm32 kprobes fix I submitted gets upstream before 5.0 >> final ? >> It takes care of an illegal instruction issue with optimized kprobes on >> arm32. >> >> Here is the current state of default kprobes configuration on arm32: >> using them will trigger illegal instruction OOPS on v5.0-rc7, 4.19.24, >> v4.14.102. >> >> My fix is in "accepted" state in the arm patch tracking system: >> >> https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8834/1 >> >> Should I send it directly to Linus as well ? > > Accepted means it's in my tree pending to be sent to Linus. It should > now be in mainline. Have you checked? Hrm, why did I not see it earlier today... it's embarrassing. It's there indeed, all is good! Greg, you should be able to pick it into the stable kernels now. Thanks, Mathieu > >> >> Thanks, >> >> Mathieu >> >> ----- On Feb 18, 2019, at 9:55 AM, Mathieu Desnoyers >> mathieu.desnoy...@efficios.com wrote: >> >> > ----- On Feb 18, 2019, at 7:26 AM, Greg Kroah-Hartman >> > gre...@linuxfoundation.org >> > wrote: >> > >> >> On Wed, Feb 06, 2019 at 01:41:15PM +0900, Masami Hiramatsu wrote: >> >>> On Tue, 5 Feb 2019 15:06:10 +0000 >> >>> Kees Cook <keesc...@chromium.org> wrote: >> >>> >> >>> > On Mon, Feb 4, 2019 at 7:15 PM Mathieu Desnoyers >> >>> > <mathieu.desnoy...@efficios.com> wrote: >> >>> > > >> >>> > > Hi, >> >>> > > >> >>> > > I notice this commit as a possible culprit of the illegal >> >>> > > instructions my lttng >> >>> > > users are noticing on arm32 when using kprobes on a v4.19.13 Linux >> >>> > > kernel >> >>> > > in a Yocto environment [1]. They were able to reproduce the issue >> >>> > > with perf >> >>> > > as well. >> >>> > > >> >>> > > commit e46daee53bb50bde38805f1823a182979724c229 >> >>> > > Author: Kees Cook <keesc...@chromium.org> >> >>> > > Date: Tue Oct 30 22:12:56 2018 +0100 >> >>> > > >> >>> > > ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE >> >>> > > >> >>> > > I *think* the intent there was to do >> >>> > > >> >>> > > - memcpy(code, &optprobe_template_entry, >> >>> > > + memcpy(code, (unsigned long *)&optprobe_template_entry, >> >>> > > >> >>> > > But if you look at the commit, the "&" seems to have been stripped >> >>> > > away, >> >>> > > which happens to change the behavior significantly. >> >>> > >> >>> > Yeah, this was a typo on my part. :( >> >>> >> >>> Ah, I thought it had been fixed as same as x86. >> >>> On x86, all optprobe_template_* are defined as kprobe_opcode_t [], >> >>> but on arm, it still be kprobe_opcode_t. >> >>> >> >>> Hmm, but I think we should use kprobe_opcode_t [] or char[] as >> >>> asm/sections.h >> >>> does. >> >>> OK, I'll prepare for the change. >> >> >> >> Did this ever get fixed in Linus's tree? If so, what is the git commit >> >> id, I can't seem to find anything... >> > >> > It seems to still be in the arm patch tracking system: >> > >> > https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8834/1 >> > >> > If I understand its status correctly, it is applied to the arm tree, but >> > perhaps it has not been pulled by Linus yet ? The code is still broken >> > in Linus' master. >> > >> > It would be important to get this arm kprobes fix upstream before 5.0 >> > final. >> > >> > Thanks, >> > >> > Mathieu >> > >> > >> > -- >> > Mathieu Desnoyers >> > EfficiOS Inc. >> > http://www.efficios.com >> >> -- >> Mathieu Desnoyers >> EfficiOS Inc. >> http://www.efficios.com >> > > -- > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up > According to speedtest.net: 11.9Mbps down 500kbps up -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
