From: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx>
commit 4ef9ad19e17676b9ef071309bc62020e2373705d upstream.
commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP
boundaries") caused two issues [1] [2] reported on 32 bit system or compat
userspace.
It doesn't make too much sense to force huge page alignment on 32 bit
system due to the constrained virtual address space.
[1] https://lore.kernel.org/linux-mm/d0a136a0-4a31-46bc-adf4-2db109a61672@xxxxxxxxxx/
[2] https://lore.kernel.org/linux-mm/CAJuCfpHXLdQy1a2B6xN2d7quTYwg2OoZseYPZTRpU0eHHKD-sQ@xxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20240118180505.2914778-1-shy828301@xxxxxxxxx
Fixes: efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries")
Signed-off-by: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx>
Reported-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
Reported-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Tested-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
Tested-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Christopher Lameter <cl@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -37,6 +37,7 @@
#include <linux/page_owner.h>
#include <linux/sched/sysctl.h>
#include <linux/memory-tiers.h>
+#include <linux/compat.h>
#include <asm/tlb.h>
#include <asm/pgalloc.h>
@@ -601,6 +602,9 @@ static unsigned long __thp_get_unmapped_
loff_t off_align = round_up(off, size);
unsigned long len_pad, ret;
+ if (IS_ENABLED(CONFIG_32BIT) || in_compat_syscall())
+ return 0;
+
if (off_end <= off_align || (off_end - off_align) < size)
return 0;
Patches currently in stable-queue which might be from yang@xxxxxxxxxxxxxxxxxxxxxx are
queue-6.6/mm-huge_memory-don-t-force-huge-page-alignment-on-32-bit.patch
queue-6.6/mm-huge_memory-use-config_64bit-to-relax-huge-page-alignment-on-32-bit-machines.patch
