disable KASLR when using GDB#15
Merged
Merged
Conversation
I was pulling my hair out trying to debug ClangBuiltLinux/linux#852 since breakpoints I set were never hit. Sami Tolvanen (@samitolvanen) reminded me I need to disable KASLR via nokaslr kernel command line parameter. Separate out the -append string from QEMU_ARCH_ARGS, since we need to change it both for interactive and debug mode.
samitolvanen
approved these changes
May 7, 2020
|
Perhaps a comment somewhere could be nice as a remainder. |
Member
Author
|
I wonder if I can extend vmlinux-gdb.py to warn if the kernel was booted with KASLR that it's basically not going to work for any debugging. |
|
@nickdesaulniers That would be way better, yeah! |
Contributor
|
There's only so many places the kernel can be in memory. It shouldn't be too hard to search quickly for the correct KASLR base. What is the right way to update gdb's sense of the base address, though, once its has been located? |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
I was pulling my hair out trying to debug
ClangBuiltLinux/linux#852 since breakpoints I
set were never hit.
Sami Tolvanen (@samitolvanen) reminded me I need to disable KASLR via
nokaslr kernel command line parameter.
Separate out the -append string from QEMU_ARCH_ARGS, since we need to
change it both for interactive and debug mode.