[PATCH v3 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER

Michel Lespinasse
2020-03-27T22:51:31Z

Define a new initializer for the mmap locking api.
Initially this just evaluates to __RWSEM_INITIALIZER as the API
is defined as wrappers around rwsem.

Signed-off-by: Michel Lespinasse <walken@google.com>
---
arch/x86/kernel/tboot.c | 2 +-
drivers/firmware/efi/efi.c | 2 +-
include/linux/mmap_lock.h | 2 ++
mm/init-mm.c | 2 +-
4 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index b89f6ac6a0c0..4b79335624b1 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -90,7 +90,7 @@ static struct mm_struct tboot_mm = {
.pgd = swapper_pg_dir,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
- .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
+ .mmap_sem = MMAP_LOCK_INITIALIZER(init_mm.mmap_sem),
.page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
.mmlist = LIST_HEAD_INIT(init_mm.mmlist),
};
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 21ea99f65113..5bdfe698cd7f 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -60,7 +60,7 @@ struct mm_struct efi_mm = {
.mm_rb = RB_ROOT,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
- .mmap_sem = __RWSEM_INITIALIZER(efi_mm.mmap_sem),
+ .mmap_sem = MMAP_LOCK_INITIALIZER(efi_mm.mmap_sem),
.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
.mmlist = LIST_HEAD_INIT(efi_mm.mmlist),
.cpu_bitmap = { [BITS_TO_LONGS(NR_CPUS)] = 0},
diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
index a80cf9695514..25a8a5458b84 100644
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -1,6 +1,8 @@
#ifndef _LINUX_MMAP_LOCK_H
#define _LINUX_MMAP_LOCK_H

+#define MMAP_LOCK_INITIALIZER(name) __RWSEM_INITIALIZER(name)
+
static inline void mmap_init_lock(struct mm_struct *mm)
{
init_rwsem(&mm->mmap_sem);
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 19603302a77f..3c128bd6a30c 100644
--- a/mm/init-mm.c
+++ b/mm/init-mm.c
@@ -31,7 +31,7 @@ struct mm_struct init_mm = {
.pgd = swapper_pg_dir,
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
- .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem),
+ .mmap_sem = MMAP_LOCK_INITIALIZER(init_mm.mmap_sem),
.page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
.arg_lock = __SPIN_LOCK_UNLOCKED(init_mm.arg_lock),
.mmlist = LIST_HEAD_INIT(init_mm.mmlist),
--
2.26.0.rc2.310.g2932bb562d-goog