diff options
| author | Rik van Riel <riel@surriel.com> | 2018-07-16 15:03:31 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-07-17 09:35:30 +0200 |
| commit | c1a2f7f0c06454387c2cd7b93ff1491c715a8c69 (patch) | |
| tree | f3b3cce7e45b2bab54681b23a3947a445ae38a37 /drivers/firmware | |
| parent | 37c45b2354cb2270f246679bedd8bf798cca351c (diff) | |
mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.
This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.
The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.
For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.
Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/efi.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 232f4915223b..7f0b19410a95 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -82,6 +82,7 @@ struct mm_struct efi_mm = { .mmap_sem = __RWSEM_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}, }; static bool disable_runtime; |