Re: [PATCH v5 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER

[Michel Lespinasse]

On Mon, May 18, 2020 at 12:45:06PM +0200, Vlastimil Babka wrote:
> On 4/22/20 2:14 AM, Michel Lespinasse wrote:
> > 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 
> 
> 
> Reviewed-by: Vlastimil Babka 
> 
> 
> Nit below.
> 
> > +#define MMAP_LOCK_INITIALIZER(name) \
> > +   .mmap_sem = __RWSEM_INITIALIZER(name.mmap_sem),
> 
> "(name).mmap_sem" is safer in a macro?

Thanks, applied in next version.

-- 
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.

Re: [PATCH v5 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER

[Laurent Dufour]

Le 22/04/2020 à 02:14, Michel Lespinasse a écrit :

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 


Despite the same remark Vlastimil wrote about the (name).mmap_sem in the 
MMAP_LOCK_INITIALIZER macro,


Reviewed-by: Laurent Dufour 


---
  arch/x86/kernel/tboot.c| 2 +-
  drivers/firmware/efi/efi.c | 2 +-
  include/linux/mmap_lock.h  | 3 +++
  mm/init-mm.c   | 2 +-
  4 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index b89f6ac6a0c0..885058325c20 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_LOCK_INITIALIZER(init_mm)
.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 911a2bd0f6b7..916313ec8acb 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -54,7 +54,7 @@ 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_LOCK_INITIALIZER(efi_mm)
.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 d1826ce42f00..9e104835a0d1 100644
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -1,6 +1,9 @@
  #ifndef _LINUX_MMAP_LOCK_H
  #define _LINUX_MMAP_LOCK_H
  
+#define MMAP_LOCK_INITIALIZER(name) \

+   .mmap_sem = __RWSEM_INITIALIZER(name.mmap_sem),
+
  static inline void mmap_init_lock(struct mm_struct *mm)
  {
init_rwsem(>mmap_sem);
diff --git a/mm/init-mm.c b/mm/init-mm.c
index 19603302a77f..fe9c03d8e07b 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_LOCK_INITIALIZER(init_mm)
.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),

Re: [PATCH v5 08/10] mmap locking API: add MMAP_LOCK_INITIALIZER

[Vlastimil Babka]

On 4/22/20 2:14 AM, Michel Lespinasse wrote:
> 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 


Reviewed-by: Vlastimil Babka 


Nit below.

> ---
>  arch/x86/kernel/tboot.c| 2 +-
>  drivers/firmware/efi/efi.c | 2 +-
>  include/linux/mmap_lock.h  | 3 +++
>  mm/init-mm.c   | 2 +-
>  4 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
> index b89f6ac6a0c0..885058325c20 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_LOCK_INITIALIZER(init_mm)
>   .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 911a2bd0f6b7..916313ec8acb 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -54,7 +54,7 @@ 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_LOCK_INITIALIZER(efi_mm)
>   .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 d1826ce42f00..9e104835a0d1 100644
> --- a/include/linux/mmap_lock.h
> +++ b/include/linux/mmap_lock.h
> @@ -1,6 +1,9 @@
>  #ifndef _LINUX_MMAP_LOCK_H
>  #define _LINUX_MMAP_LOCK_H
>  
> +#define MMAP_LOCK_INITIALIZER(name) \
> + .mmap_sem = __RWSEM_INITIALIZER(name.mmap_sem),

"(name).mmap_sem" is safer in a macro?

> +
>  static inline void mmap_init_lock(struct mm_struct *mm)
>  {
>   init_rwsem(>mmap_sem);
> diff --git a/mm/init-mm.c b/mm/init-mm.c
> index 19603302a77f..fe9c03d8e07b 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_LOCK_INITIALIZER(init_mm)
>   .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),
>