mirror_zfs/include/os/linux/kernel
Fabian-Gruenbichler b119e2c6f1 SIMD: Use alloc_pages_node to force alignment
fxsave and xsave require the target address to be 16-/64-byte aligned.

kmalloc(_node) does not (yet) offer such fine-grained control over
alignment[0,1], even though it does "the right thing" most of the time
for power-of-2 sizes. unfortunately, alignment is completely off when
using certain debugging or hardening features/configs, such as KASAN,
slub_debug=Z or the not-yet-upstream SLAB_CANARY.

Use alloc_pages_node() instead which allows us to allocate page-aligned
memory. Since fpregs_state is padded to a full page anyway, and this
code is only relevant for x86 which has 4k pages, this approach should
not allocate any unnecessary memory but still guarantee the needed
alignment.

0: https://lwn.net/Articles/787740/
1: https://lore.kernel.org/linux-block/20190826111627.7505-1-vbabka@suse.cz/

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9608 
Closes #9674
2019-12-10 12:53:25 -08:00
..
linux SIMD: Use alloc_pages_node to force alignment 2019-12-10 12:53:25 -08:00
Makefile.am OpenZFS restructuring - move platform specific headers 2019-09-05 09:34:54 -07:00