similar to: MmioTrace: Using the Instruction Decoder, etc.

On Fri, 18 Oct 2013 00:11:15 +0400 Eugene Shatokhin <euspectre at gmail.com> wrote: > Hi, > > Good to know that! > > Yes, it should be faster than page faulting, although I haven't done the > benchmarking yet. And yes, it is not needed to disable all but one CPU. In > my current implementation, I use an ordered workqueue to send the data to > the mmapped output

On Sat, 19 Oct 2013 17:12:20 +0400 Eugene Shatokhin <euspectre at gmail.com> wrote: > Hi, > > > Ah, you are not using the ftrace framework nor relayfs? Mmiotrace > used to be relayfs at one point and then converted to ftrace. > > Yes, I considered these when I started working on KernelStrider but finally > borrowed ideas from Perf and implemented them. A mmapped

Hi, Good to know that! Yes, it should be faster than page faulting, although I haven't done the benchmarking yet. And yes, it is not needed to disable all but one CPU. In my current implementation, I use an ordered workqueue to send the data to the mmapped output buffer (where they will be read from from the user space) and that ensures the order of events is kept. May be less than ideal but

On Fri, 25 Oct 2013 17:19:56 +0400 Eugene Shatokhin <euspectre at gmail.com> wrote: > Hi, > > 2013/10/25 Pekka Paalanen <pq at iki.fi> > ... > > We could use some comments from the real reverse-engineers. I used > > to be mostly a tool writer. > > > > Yes, if some experts could share their knowledge of this matter, this would > be most

Hi, 2013/10/25 Pekka Paalanen <pq at iki.fi> > > Just curious, how do you detect interesting instructions to > instrument from uninteresting instructions that do not access mmio > areas? > > As I currently use this for data race detection in general, there is no need to separate accesses to mmio areas from the accesses to other memory. The tool just tracks all except the

Hi, > Ah, you are not using the ftrace framework nor relayfs? Mmiotrace used to be relayfs at one point and then converted to ftrace. Yes, I considered these when I started working on KernelStrider but finally borrowed ideas from Perf and implemented them. A mmapped ring buffer does its job well and has a higher throughput than Ftrace in my case. > Are you saying that you intercept

On Wed, 16 Apr 2008 13:46:09 +0200 Ingo Molnar <mingo at elte.hu> wrote: > > * Pekka Paalanen <pq at iki.fi> wrote: > > > > we should fix this restriction ASAP. Forcibly dropping to UP will > > > cause mmiotrace to be much less useful for diagnostic purposes of > > > Linux > > > > Ok, how do you propose we solve this? > >

After every iounmap mmiotrace has to free kmmio_fault_pages, but it can't do it directly, so it defers freeing by RCU. It usually works, but when mmiotraced code calls ioremap-iounmap multiple times without sleeping between (so RCU won't kick in and start freeing) it can be given the same virtual address, so at every iounmap mmiotrace will schedule the same pages for release. Obviously it

After every iounmap mmiotrace has to free kmmio_fault_pages, but it can't do it directly, so it defers freeing by RCU. It usually works, but when mmiotraced code calls ioremap-iounmap multiple times without sleeping between (so RCU won't kick in and start freeing) it can be given the same virtual address, so at every iounmap mmiotrace will schedule the same pages for release. Obviously it

Hello in dmesg I always have these informations (I tested several kernels between 3.7 and 3.16-rc3): [ 13.742006] nouveau E[ DRM] Pointer to TMDS table invalid [ 13.742036] nouveau [ DRM] DCB version 4.0 [ 13.742038] nouveau E[ DRM] Pointer to flat panel table invalid [ 13.742079] nouveau [ DRM] ACPI backlight interface available, not registering our own [ 13.742082]

On Mon, May 18, 2020 at 2:31 AM Nathan Chancellor <natechancellor at gmail.com> wrote: > > On Wed, Apr 08, 2020 at 01:53:23PM -0700, Nathan Chancellor wrote: > > When building with Clang + -Wtautological-compare and > > CONFIG_CPUMASK_OFFSTACK unset: > > > > arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus' > > equal to a

Jialong Yang <jialong.yang at shingroup.cn> writes: > mmiotrace is a useful tool to trace MMIO accesses. Nowadays, it only > supported on x86 and x86_64 platforms. I've never used mmiotrace, and don't know it well. I'm not necessarily opposed to merging it, but AFAIK it was mostly used for reverse engineering proprietary drivers, where the driver itself couldn't be

Od: "Ilia Mirkin" <imirkin at alum.mit.edu> Do: "Lampshade" <lampshade at poczta.fm>; Wys?ane: 19:07 Czwartek 2014-07-10 Temat: Re: [Nouveau] Warnings in dmesg and results of mmiotrace 10de:1140 Geforce620m Optimus Laptop Acer E1-531G > On Thu, Jul 10, 2014 at 11:01 AM, Lampshade wrote: > > Hello > > in dmesg I always have these informations (I

Is this expected result for Chipset: G98 (NV98)? $ modinfo nvidia -F version 304.123 $ stat -c %s mmiotrace.log 134659197 $ file mmiotrace.log mmiotrace.log: ASCII text $ grep -i lost mmiotrace.log ; echo $? 1 $ ./envytools/rnn/demmio -f mmiotrace.log | perl -e 'open($fh409c, ">fuc409c"); open($fh409d, ">fuc409d"); open($fh41ac, ">fuc41ac");

On Mon, 18 May 2020 11:52:47 -0700 Nick Desaulniers <ndesaulniers at google.com> wrote: > On Mon, May 18, 2020 at 2:31 AM Nathan Chancellor > <natechancellor at gmail.com> wrote: > > > > On Wed, Apr 08, 2020 at 01:53:23PM -0700, Nathan Chancellor wrote: > > > When building with Clang + -Wtautological-compare and > > > CONFIG_CPUMASK_OFFSTACK

If something calls ioremap with an address not aligned to PAGE_SIZE, the returned address might be not aligned as well. This led to a probe registered on exactly the returned address, but the entire page was armed for mmiotracing. On calling iounmap the address passed to unregister_kmmio_probe was PAGE_SIZE aligned by the caller leading to a complete freeze of the machine. We should always page

4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Karol Herbst <kherbst at redhat.com> [ Upstream commit 6d60ce384d1d5ca32b595244db4077a419acc687 ] If something calls ioremap() with an address not aligned to PAGE_SIZE, the returned address might be not aligned as well. This led to a probe registered on exactly the returned address, but

3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Karol Herbst <kherbst at redhat.com> [ Upstream commit 6d60ce384d1d5ca32b595244db4077a419acc687 ] If something calls ioremap() with an address not aligned to PAGE_SIZE, the returned address might be not aligned as well. This led to a probe registered on exactly the returned address, but

4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Karol Herbst <kherbst at redhat.com> [ Upstream commit 6d60ce384d1d5ca32b595244db4077a419acc687 ] If something calls ioremap() with an address not aligned to PAGE_SIZE, the returned address might be not aligned as well. This led to a probe registered on exactly the returned address, but

4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Karol Herbst <kherbst at redhat.com> [ Upstream commit 6d60ce384d1d5ca32b595244db4077a419acc687 ] If something calls ioremap() with an address not aligned to PAGE_SIZE, the returned address might be not aligned as well. This led to a probe registered on exactly the returned address, but