| Message ID | 20240118180505.2914778-1-shy828301@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: huge_memory: don't force huge page alignment on 32 bit | expand |
On Thu, Jan 18, 2024 at 10:05:05AM -0800, Yang Shi wrote: > From: Yang Shi <yang@os.amperecomputing.com> > > The 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/ > > Fixes: efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") > 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> > Cc: Rik van Riel <riel@surriel.com> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Christopher Lameter <cl@linux.com> > Signed-off-by: Yang Shi <yang@os.amperecomputing.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 94ef5c02b459..66adecdc509b 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;