From: Linus Torvalds torvalds@linux-foundation.org
commit eda0047296a16d65a7f2bc60a408f70d178b2014 upstream.
This is done as a separate patch from introducing the new lock_mm_and_find_vma() helper, because while it's an obvious change, it's not what x86 used to do in this area.
We already abort the page fault on fatal signals anyway, so why should we wait for the mmap lock only to then abort later? With the new helper function that returns without the lock held on failure anyway, this is particularly easy and straightforward.
Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Samuel Mendoza-Jonas samjonas@amazon.com Signed-off-by: David Woodhouse dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memory.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
--- a/mm/memory.c +++ b/mm/memory.c @@ -5275,8 +5275,7 @@ static inline bool get_mmap_lock_careful return false; }
- mmap_read_lock(mm); - return true; + return !mmap_read_lock_killable(mm); }
static inline bool mmap_upgrade_trylock(struct mm_struct *mm) @@ -5300,8 +5299,7 @@ static inline bool upgrade_mmap_lock_car if (!search_exception_tables(ip)) return false; } - mmap_write_lock(mm); - return true; + return !mmap_write_lock_killable(mm); }
/*