8271486: [lworld] Memory corruption due to out of bound access in MacroAssembler::move_helper #507
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Outdated suggestions cannot be applied.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.
While debugging weird crashes that only showed up when merging current mainline with lworld, I've noticed that we are writing outside of the
reg_state
array inMacroAssembler::move_helper
becausefrom->value()
is-1
(OptoReg::BAD_REG
):valhalla/src/hotspot/cpu/x86/macroAssembler_x86.cpp
Lines 5794 to 5797 in 3c399d9
The register is invalid because it belongs to the second half of a
T_LONG
orT_DOUBLE
argument in the calling convention and should simply be ignored. I've also added asserts to catch similar issues in the future.Thanks,
Tobias
Progress
Issue
Reviewing
Using
git
Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/valhalla pull/507/head:pull/507
$ git checkout pull/507
Update a local copy of the PR:
$ git checkout pull/507
$ git pull https://git.openjdk.java.net/valhalla pull/507/head
Using Skara CLI tools
Checkout this PR locally:
$ git pr checkout 507
View PR using the GUI difftool:
$ git pr show -t 507
Using diff file
Download this PR as a diff file:
https://git.openjdk.java.net/valhalla/pull/507.diff