Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-04 04:06:26 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

s390/mm: Allow large pages for KASAN shadow mapping

Browse Source 
Commit c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address
spaces") introduced a large_allowed() helper that restricts which mapping
modes can use large pages. This change unintentionally prevented KASAN
shadow mappings from using large pages, despite there being no reason
to avoid them. In fact, large pages are preferred for performance.

Add POPULATE_KASAN_MAP_SHADOW to the allowed list in large_allowed()
to restore large page mappings for KASAN shadows.

While large_allowed() isn't strictly necessary with current mapping
modes since disallowed modes either don't map anything or fail alignment
and size checks, keep it for clarity.

Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Vasily Gorbik 2024-11-22 13:41:33 +01:00 committed by Heiko Carstens
parent 9de3e4bf6c
commit ff123eb774
1 changed files with 11 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/s390/boot/vmem.c
View File

@ -264,7 +264,17 @@ static unsigned long _pa(unsigned long addr, unsigned long size, enum populate_m
static bool large_allowed(enum populate_mode mode)
{
return (mode == POPULATE_DIRECT) || (mode == POPULATE_IDENTITY) || (mode == POPULATE_KERNEL);
switch (mode) {
case POPULATE_DIRECT:
case POPULATE_IDENTITY:
case POPULATE_KERNEL:
#ifdef CONFIG_KASAN
case POPULATE_KASAN_MAP_SHADOW:
#endif
return true;
default:
return false;
}
}
static bool can_large_pud(pud_t *pu_dir, unsigned long addr, unsigned long end,