contrib: ptdrgn: fix FaultError when displaying objects #439
Conversation
This file contains 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
Some objects (e.g. percpu variables) cannot be displayed because their memory location is wrong, and displaying them would result in a fault error. In the ptdrgn script, any expression resulting in such an object will crash the entire REPL. For example: >>> prog["cpuhp_state"] Traceback (most recent call last): [ ... ] _drgn.FaultError: could not read memory from kdump: Cannot get page I/O address: PDPT table not present: p4d[0] = 0x0: 0x202a0 Handle these by simply displaying the repr() of the object: >>> prog["cpuhp_state"] Object(prog, 'struct cpuhp_cpu_state', address=0x202a0) >>> Signed-off-by: Stephen Brennan <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
See the commit message for the situation and justification. This is just a quick fix for the ptdrgn script (which I use constantly). But I did end up comparing against the built-in drgn CLI and noticed that the behavior on the example quoted in the commit is a bit confusing too, so I'll create a separate issue on that.