breakpoints don't work for kernel debugging with qemu and gdb

Hello all, Thanks for the helps always.. Today I wanted to debug/analyze linux kernel on qemu and ran qemu but the breakpoints don't seem to work. When I type 'cont' it just goes with booting until it errors. (I wanted to see what happens near the error location, not sure I'll be able to figu

Re: breakpoints don't work for kernel debugging with qemu and gdb

c...@etri.re.kr writes: > Hello all, > > > > Thanks for the helps always.. > > Today I wanted to debug/analyze linux kernel on qemu and ran qemu but the > breakpoints don't seem to work. > > When I type 'cont' it just goes with booting until it errors. (I wanted to > see what happens near the

Re: [QEMU TCG] Qeustion about the PCID Feature in TCG

Kaifeng Xu writes: > Hi, > I am running QEMU in TCG mode (my server doesn't have kvm support), and I > am getting the memory traces in a x86 guest machine of all memory accesses, > including the PCID (process-context identifier, and I need that for my > current research), on a linux host. I hav

Re: Guest OS becomes totally unresponsive when running on VMware

Salvatore Mazzarino writes: > I'm running QEMU v4.2.0 inside a Docker container. The Docker container runs > on a VMware VM running Flatcar Linux OS with kernel version 5.4.92. It > happens that the QEMU process starts to show up an high usage of CPU. The > CPUs that the Qemu process uses go

Re: [QEMU TCG] Qeustion about the PCID Feature in TCG

On 18/02/21 12:43, Alex Bennée wrote: Kaifeng Xu writes: Hi, I am running QEMU in TCG mode (my server doesn't have kvm support), and I am getting the memory traces in a x86 guest machine of all memory accesses, including the PCID (process-context identifier, and I need that for my current res

Re: On emulating Raspberry Pi

Дилян Палаузов writes: > Hello, > > I download the Rapsberry OS > image > https://downloads.raspberrypi.org/raspios_armhf/images/raspios_armhf-2021-01-12/2021-01-11-raspios-buster-armhf.zip > > the kernel kernel-qemu-4.19.50-buster and versatile-pb-buster.dtb > from https://github.com/dhruvvya

Re: QEMU Memory access- to get contents of register after each load/store

Naomi Motwani writes: > Hello! > > I am running a simple addition code on Arm A9 with three variables allotted > to the heap. I need to track the memory locations from where > the code is loading and storing to. I have hereby added the c code and the > assembly version of the same. I need to

Re: Guest OS becomes totally unresponsive when running on VMware

I haven't run the perf command yet. Did I get correctly that you are referring to the Linux command tool perf here, didn't I? Also it's not an option here to run QEMU outside of a container. At this point I'm still waiting to be able to run QEMU newer version and see if the issue still persis

RE: breakpoints don't work for kernel debugging with qemu and gdb

Hi, Alex, Thanks for the reply, I've just checked the breakpoint works for a simple bare-metal application. I've tested with a minimal setup.s that just sets up stack pointer and calls c_entry() which prints "hello". I can do stepi and can set breakpoint at c_entry and the breakpoint works. So t

Re: breakpoints don't work for kernel debugging with qemu and gdb

hi, maybe this is helpful to you: https://github.com/cirosantilli/linux-kernel-module-cheat regards On Thu, Feb 18, 2021 at 09:20:39PM +0900, c...@etri.re.kr wrote: > Hi, Alex, > > Thanks for the reply, I've just checked the breakpoint works for a simple > bare-metal application. > I've tested

Re: breakpoints don't work for kernel debugging with qemu and gdb

Hi, I think the problem is KALSR. You have to disable it disabling the kernel option "Randomize the address of the kernel image (KASLR)", inside Processor type and features. In this way, gdb can translate all the symbols correctly. Regards, Saket On Thu, Feb 18, 2021, 13:41 Oguz Bektas wrote:

RE: breakpoints don't work for kernel debugging with qemu and gdb

Hello Saket Sinha, Wow, that was it!! This will be a tremendous help for me. I changed --append "root=/dev/ram init=/init" To --append "root=/dev/ram init=/init nokaslr" And it stopped at the first bp start_kernel. (below) (gdb) b start_kernel Breakpoint 1 at 0x8000112a09ec: f

Re: Guest OS becomes totally unresponsive when running on VMware

Salvatore Mazzarino writes: > I haven't run the perf command yet. Did I get correctly that you are > referring to the Linux command tool perf here, didn't I? Yes. > > Also it's not an option here to run QEMU outside of a container. You mentioned you had run outside the container before witho

Re: breakpoints don't work for kernel debugging with qemu and gdb

Saket Sinha schrieb: I think the problem is KALSR. You have to disable it disabling the kernel option "Randomize the address of the kernel image (KASLR)", inside Processor type and features. In this way, gdb can translate all the symbols correctly. The easiest way to disable KASLR is to star

Re: On emulating Raspberry Pi

On 18/02/2021 11:57, Alex Bennée wrote: The documentation also lists the current status of the emulation: https://qemu.readthedocs.io/en/latest/system/arm/raspi.html Why don't I have this page in my local documentation? $ qemu-system-arm --version QEMU emulator version 5.1.0 Copyright (c)

Re: On emulating Raspberry Pi

On Thu, 18 Feb 2021 at 15:08, Ottavio Caruso via wrote: > > On 18/02/2021 11:57, Alex Bennée wrote: > > The documentation also lists the current status of the emulation: > > > >https://qemu.readthedocs.io/en/latest/system/arm/raspi.html > > Why don't I have this page in my local documentation?