diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-02-23 01:37:19 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-03-20 21:29:50 -0400 |
| commit | ac2aca2817ca10ad30f86d0d3caa41ea8cc4f0f0 (patch) | |
| tree | d48719c7b748d4bd99aa176fda481b25dbecd1c3 | |
| parent | ea6fb41752dda2e450bd8a318c7400f8cfa9111e (diff) | |
um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
... while calling uml_dup_mmap()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | arch/um/include/asm/mmu_context.h | 11 | ||||
| -rw-r--r-- | arch/um/kernel/skas/mmu.c | 2 |
2 files changed, 10 insertions, 3 deletions
diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 591b3d8d7614..aa4a743dc4ab 100644 --- a/arch/um/include/asm/mmu_context.h +++ b/arch/um/include/asm/mmu_context.h @@ -9,7 +9,7 @@ #include <linux/sched.h> #include <asm/mmu.h> -extern void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm); +extern void uml_setup_stubs(struct mm_struct *mm); extern void arch_exit_mmap(struct mm_struct *mm); #define deactivate_mm(tsk,mm) do { } while (0) @@ -23,7 +23,9 @@ 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); - arch_dup_mmap(old, new); + down_write(&new->mmap_sem); + uml_setup_stubs(new); + up_write(&new->mmap_sem); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, @@ -39,6 +41,11 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, } } +static inline void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm) +{ + uml_setup_stubs(mm); +} + static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) { diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c index db2ef422c1b8..4947b319f53a 100644 --- a/arch/um/kernel/skas/mmu.c +++ b/arch/um/kernel/skas/mmu.c @@ -101,7 +101,7 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm) return ret; } -void arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm) +void uml_setup_stubs(struct mm_struct *mm) { struct page **pages; int err, ret; |