kmsan: do not round up pg_data_t size

x86's alloc_node_data() rounds up node data size to PAGE_SIZE.  It's not
explained why it's needed, but it's most likely for performance reasons,
since the padding bytes are not used anywhere.  Some other architectures
do it as well, e.g., mips rounds it up to the cache line size.

kmsan_init_shadow() initializes metadata for each node data and assumes
the x86 rounding, which does not match other architectures.  This may
cause the range end to overshoot the end of available memory, in turn
causing virt_to_page_or_null() in kmsan_init_alloc_meta_for_range() to
return NULL, which leads to kernel panic shortly after.

Since the padding bytes are not used, drop the rounding.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ilya Leoshkevich <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Masami Hiramatsu (Google) <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Steven Rostedt (Google) <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions