diff options
| author | Yang Shi <yang@os.amperecomputing.com> | 2024-01-18 19:05:05 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-01-26 08:52:21 +0100 |
| commit | 4ef9ad19e17676b9ef071309bc62020e2373705d (patch) | |
| tree | c5fde4b74225e57287ea66ed25dbc88b6cc33b68 /mm | |
| parent | userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb (diff) | |
| download | linux-4ef9ad19e17676b9ef071309bc62020e2373705d.tar.xz linux-4ef9ad19e17676b9ef071309bc62020e2373705d.zip | |
mm: huge_memory: don't force huge page alignment on 32 bit
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@kernel.org/
[2] https://lore.kernel.org/linux-mm/CAJuCfpHXLdQy1a2B6xN2d7quTYwg2OoZseYPZTRpU0eHHKD-sQ@mail.gmail.com/
Link: https://lkml.kernel.org/r/20240118180505.2914778-1-shy828301@gmail.com
Fixes: efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries")
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Reported-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Jiri Slaby <jirislaby@kernel.org>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Christopher Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 5f31e51f2235..172b85208276 100644 --- 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> @@ -811,6 +812,9 @@ static unsigned long __thp_get_unmapped_area(struct file *filp, 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; |