armbian/linux-rockchip
0
0
Fork 0
mirror of https://github.com/armbian/linux-rockchip.git synced 2026-01-06 11:08:10 -08:00
Code Issues Packages Projects Releases Wiki Activity

ANDROID: disable page table moves when speculative page faults are enabled

Browse Source 
move_page_tables() can move entire pmd or pud without locking individual
ptes. This is problematic for speculative page faults which do not take
mmap_lock because they rely on ptl lock when writing new pte value. To
avoid possible race, disable move_page_tables() optimization when
CONFIG_SPECULATIVE_PAGE_FAULT is enabled.

Bug: 257443051
Change-Id: Ib48dda08ecad1abc60d08fc089a6566a63393c13
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
This commit is contained in:
Suren Baghdasaryan
2022-11-18 17:06:03 -08:00
parent d65d4a0538
commit 0f43357d37
1 changed files with 10 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
mm/mremap.c
View File

@@ -210,7 +210,11 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
drop_rmap_locks(vma);
}
#ifdef CONFIG_HAVE_MOVE_PMD
/*
* Speculative page fault handlers will not detect page table changes done
* without ptl locking.
*/
#if defined(CONFIG_HAVE_MOVE_PMD) && !defined(CONFIG_SPECULATIVE_PAGE_FAULT)
static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
{
@@ -277,7 +281,11 @@ static inline bool move_normal_pmd(struct vm_area_struct *vma,
}
#endif
#ifdef CONFIG_HAVE_MOVE_PUD
/*
* Speculative page fault handlers will not detect page table changes done
* without ptl locking.
*/
#if defined(CONFIG_HAVE_MOVE_PUD) && !defined(CONFIG_SPECULATIVE_PAGE_FAULT)
static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, pud_t *old_pud, pud_t *new_pud)
{