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| author | Thomas Gleixner <[email protected]> | 2021-06-11 13:03:16 +0000 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2021-06-24 06:49:03 +0000 |
| commit | 7f049fbdd57f6ea71dc741d903c19c73b2f70950 (patch) | |
| tree | 5b11e726fd368def34a736cfa73511ac95ded45e /drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | |
| parent | Linux 5.13-rc7 (diff) | |
| download | kernel-7f049fbdd57f6ea71dc741d903c19c73b2f70950.tar.gz kernel-7f049fbdd57f6ea71dc741d903c19c73b2f70950.zip | |
perf/x86/intel/lbr: Zero the xstate buffer on allocation
XRSTORS requires a valid xstate buffer to work correctly. XSAVES does not
guarantee to write a fully valid buffer according to the SDM:
"XSAVES does not write to any parts of the XSAVE header other than the
XSTATE_BV and XCOMP_BV fields."
XRSTORS triggers a #GP:
"If bytes 63:16 of the XSAVE header are not all zero."
It's dubious at best how this can work at all when the buffer is not zeroed
before use.
Allocate the buffers with __GFP_ZERO to prevent XRSTORS failure.
Fixes: ce711ea3cab9 ("perf/x86/intel/lbr: Support XSAVES/XRSTORS for LBR context switch")
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c')
0 files changed, 0 insertions, 0 deletions