Fix assertion failure when duplicate client_id encountered#434
Merged
Syllo merged 1 commit intoSyllo:masterfrom Jan 16, 2026
Merged
Fix assertion failure when duplicate client_id encountered#434Syllo merged 1 commit intoSyllo:masterfrom
Syllo merged 1 commit intoSyllo:masterfrom
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The assertion "We should not be processing a client id twice per update" can fail when a process has multiple file descriptors referencing the same DRM client (e.g., via dup(), fork(), or DRM master operations). The kcmp syscall filters duplicate file descriptions but not distinct file descriptions that report the same underlying DRM client_id. This change converts the debug assertion into a runtime check that gracefully skips duplicate entries and frees any newly allocated cache entries to prevent memory leaks. Fixes the crash: nvtop: ./src/extract_gpuinfo_amdgpu.c:964: parse_drm_fdinfo_amd: Assertion `!cache_entry_check && "We should not be processing a client id twice per update"' failed. Applied to all affected drivers: - AMDGPU - Intel i915 - Intel Xe - Qualcomm MSM (also fixed incorrect hash key usage) - ARM Mali
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Author
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Fixes #435 |
Owner
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Thanks a lot for looking into it |
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Summary
Fixes the assertion failure crash:
Root Cause
The assertion fails when a process has multiple file descriptors referencing the same DRM client (e.g., via
dup(),fork(), or DRM master operations). Thekcmpsyscall filters duplicate file descriptions but not distinct file descriptions that report the same underlying DRMclient_id.Fix
Converts the debug assertion into a runtime check that:
client_identries incurrent_update_process_cacheFiles Changed
Applied fix to all affected drivers:
extract_gpuinfo_amdgpu.c- AMD GPUsextract_gpuinfo_intel_i915.c- Intel i915extract_gpuinfo_intel_xe.c- Intel Xeextract_gpuinfo_msm.c- Qualcomm MSM (also fixed incorrect hash key: was using&cidinstead of&cache_entry->client_id)extract_gpuinfo_mali_common.c- ARM MaliTesting
Tested on AMD GPU where the crash was occurring - nvtop now runs without crashing.