fix shutdown ordering race condition, prevent use-after-free crash#3004
Open
prasanna-amd wants to merge 5 commits intodevelopfrom
Open
fix shutdown ordering race condition, prevent use-after-free crash#3004prasanna-amd wants to merge 5 commits intodevelopfrom
prasanna-amd wants to merge 5 commits intodevelopfrom
Conversation
prasanna-amd
force-pushed
the
users/prasanna-amd/fix-shutdown-ordering-race
branch
from
d55e667 to
2e0b811
Compare
corey-derochie-amd
approved these changes
Feb 3, 2026
Contributor
corey-derochie-amd
left a comment
corey-derochie-amd
left a comment
There was a problem hiding this comment.
LGTM with minor suggestions.
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Motivation
Fix segmentation fault in rccl tests related to use-after-free race condition
Technical Details
During process exit, HIP runtime's static destructor (amd::RuntimeTearDown) begins
destroying GPU device objects while RCCL's proxy threads are still running. When the
proxy threads call hipFree/hipHostFree to clean up connections, they access
already-destroyed device objects (dev->svmFree(ptr)), causing a use-after-free
crash.
Fix: Register an atexit handler that sets a shutdown flag. Since atexit handlers run
before static destructors, RCCL's free functions can check this flag and skip the
free during shutdown—the OS reclaims all memory at process exit anyway.
JIRA ID
ROCM-1896
Test Plan
tested with all_gather_perf on a 4N system where the segmentation fault can be recreated with one of the nodes having insufficient file descriptors, causing an exit, the main thread goes to exit processing, while the proxy threads are still running, causing the initial segmentation fault. After the fix, the test exits with proper error (when NCCL_DEBUG is enabled), instead of segfault.