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| author | Vasily Gorbik <gor@linux.ibm.com> | 2024-11-29 03:07:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-08 11:58:18 +0300 |
| commit | 5f72bf80e74bbbe8c7e4732375b070eabf5f275a (patch) | |
| tree | 4609ff022bf195547df9bb024f6a471e6b89c196 | |
| parent | 1cf21779596859e6bbb291a7d97fbb079f2b8ab1 (diff) | |
| download | linux-5f72bf80e74bbbe8c7e4732375b070eabf5f275a.tar.xz | |
Revert "s390/mm: Allow large pages for KASAN shadow mapping"
commit cc00550b2ae7ab1c7c56669fc004a13d880aaf0a upstream.
This reverts commit ff123eb7741638d55abf82fac090bb3a543c1e74.
Allowing large pages for KASAN shadow mappings isn't inherently wrong,
but adding POPULATE_KASAN_MAP_SHADOW to large_allowed() exposes an issue
in can_large_pud() and can_large_pmd().
Since commit d8073dc6bc04 ("s390/mm: Allow large pages only for aligned
physical addresses"), both can_large_pud() and can_large_pmd() call _pa()
to check if large page physical addresses are aligned. However, _pa()
has a side effect: it allocates memory in POPULATE_KASAN_MAP_SHADOW
mode. This results in massive memory leaks.
The proper fix would be to address both large_allowed() and _pa()'s side
effects, but for now, revert this change to avoid the leaks.
Fixes: ff123eb77416 ("s390/mm: Allow large pages for KASAN shadow mapping")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/s390/boot/vmem.c | 12 |
1 files changed, 1 insertions, 11 deletions
diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c index 824690427b61..3fa28db2fe59 100644 --- a/arch/s390/boot/vmem.c +++ b/arch/s390/boot/vmem.c @@ -264,17 +264,7 @@ static unsigned long _pa(unsigned long addr, unsigned long size, enum populate_m static bool large_allowed(enum populate_mode mode) { - 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; - } + return (mode == POPULATE_DIRECT) || (mode == POPULATE_IDENTITY) || (mode == POPULATE_KERNEL); } static bool can_large_pud(pud_t *pu_dir, unsigned long addr, unsigned long end, |