[Bug 281402] zfs: kmsan reports Uninitialized UMA memory from zio_data_buf_alloc

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=281402

--- Comment #5 from Alan Somers <asomers@FreeBSD.org> ---
I've determined the cause of the alerts, and it's boring: SIMD code.  When I
change the raidz implementation to the scalar algorithm, all of the KMSAN
alerts go away.  But with any SIMD algorithm, I get the alerts.  Here's a
summary of the various raidz algorithms.  
  - cycle: warnings
  - fastest: warnings
  - original: ok
  - scaler: ok
  - sse2: warnings
  - ssse3: warnings
  - avx2: warnings
  - avx512f: untested
  - avx512bw: untested

I'll open a separate PR to OpenZFS to make the algorithm easier to select. 
Regarding the false alarms, if KMSAN can't be made to understand SIMD
instructions, would it be possible to annotate functions like raidz_gen_pq_add
with extra information for KMSAN?

-- 
You are receiving this mail because:
You are the assignee for the bug.