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| author | Michel Lespinasse <walken@google.com> | 2020-06-09 07:33:33 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 19:39:14 +0300 |
| commit | aaa2cc56c1cd757efec88a4978ffce4cbf884352 (patch) | |
| tree | 1f3d3e52b98c2c8b1d29978ccbeefc9178b47533 | |
| parent | 89154dd5313f774d3a592451360b78442571b1f8 (diff) | |
| download | linux-aaa2cc56c1cd757efec88a4978ffce4cbf884352.tar.xz | |
mmap locking API: convert nested write lock sites
Add API for nested write locks and convert the few call sites doing that.
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-7-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/um/include/asm/mmu_context.h | 3 | ||||
| -rw-r--r-- | include/linux/mmap_lock.h | 5 | ||||
| -rw-r--r-- | kernel/fork.c | 2 |
3 files changed, 8 insertions, 2 deletions
diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 62262c5c7785..17ddd4edf875 100644 --- a/arch/um/include/asm/mmu_context.h +++ b/arch/um/include/asm/mmu_context.h @@ -8,6 +8,7 @@ #include <linux/sched.h> #include <linux/mm_types.h> +#include <linux/mmap_lock.h> #include <asm/mmu.h> @@ -47,7 +48,7 @@ static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) * when the new ->mm is used for the first time. */ __switch_mm(&new->context.id); - down_write_nested(&new->mmap_sem, 1); + mmap_write_lock_nested(new, SINGLE_DEPTH_NESTING); uml_setup_stubs(new); mmap_write_unlock(new); } diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h index 97ac53b66052..a757cb30ae77 100644 --- a/include/linux/mmap_lock.h +++ b/include/linux/mmap_lock.h @@ -11,6 +11,11 @@ static inline void mmap_write_lock(struct mm_struct *mm) down_write(&mm->mmap_sem); } +static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass) +{ + down_write_nested(&mm->mmap_sem, subclass); +} + static inline int mmap_write_lock_killable(struct mm_struct *mm) { return down_write_killable(&mm->mmap_sem); diff --git a/kernel/fork.c b/kernel/fork.c index d61751ba10dc..142b23645d82 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -501,7 +501,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, /* * Not linked in yet - no deadlock potential: */ - down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING); + mmap_write_lock_nested(mm, SINGLE_DEPTH_NESTING); /* No ordering required: file already has been exposed. */ RCU_INIT_POINTER(mm->exe_file, get_mm_exe_file(oldmm)); |