Messages in this thread Patch in this message |  | | From | Davidlohr Bueso <> | Subject | [PATCH 48/64] arch/tile: use mm locking wrappers | Date | Mon, 5 Feb 2018 02:27:38 +0100 |
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From: Davidlohr Bueso <dave@stgolabs.net>
* THIS IS A HACK *
Breaks arch/um/. See comment in fix_range_common().
Signed-off-by: Davidlohr Bueso <dbueso@suse.de> --- arch/um/include/asm/mmu_context.h | 5 +++-- arch/um/kernel/tlb.c | 12 +++++++++++- arch/um/kernel/trap.c | 6 +++--- 3 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/arch/um/include/asm/mmu_context.h b/arch/um/include/asm/mmu_context.h index 98cc3e36385a..7dc202c611db 100644 --- a/arch/um/include/asm/mmu_context.h +++ b/arch/um/include/asm/mmu_context.h @@ -49,14 +49,15 @@ extern void force_flush_all(void); static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) { + DEFINE_RANGE_LOCK_FULL(mmrange); /* * This is called by fs/exec.c and sys_unshare() * when the new ->mm is used for the first time. */ __switch_mm(&new->context.id); - down_write(&new->mmap_sem); + mm_write_lock(new, &mmrange); uml_setup_stubs(new); - up_write(&new->mmap_sem); + mm_write_unlock(new, &mmrange); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c index 37508b190106..eeeeb048b6f4 100644 --- a/arch/um/kernel/tlb.c +++ b/arch/um/kernel/tlb.c @@ -297,10 +297,20 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr, /* This is not an else because ret is modified above */ if (ret) { + /* + * FIXME: this is _wrong_ and will break arch/um. + * + * The right thing to do is modify the flush_tlb_range() + * api, but that in turn would require file_operations + * knowing about mmrange... Compiles cleanly, but sucks + * otherwise. + */ + DEFINE_RANGE_LOCK_FULL(mmrange); + printk(KERN_ERR "fix_range_common: failed, killing current " "process: %d\n", task_tgid_vnr(current)); /* We are under mmap_sem, release it such that current can terminate */ - up_write(¤t->mm->mmap_sem); + mm_write_unlock(current->mm, &mmrange); force_sig(SIGKILL, current); do_signal(¤t->thread.regs); } diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c index e632a14e896e..14dcb83d00a9 100644 --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -47,7 +47,7 @@ int handle_page_fault(unsigned long address, unsigned long ip, if (is_user) flags |= FAULT_FLAG_USER; retry: - down_read(&mm->mmap_sem); + mm_read_lock(mm, &mmrange); vma = find_vma(mm, address); if (!vma) goto out; @@ -123,7 +123,7 @@ int handle_page_fault(unsigned long address, unsigned long ip, #endif flush_tlb_page(vma, address); out: - up_read(&mm->mmap_sem); + mm_read_unlock(mm, &mmrange); out_nosemaphore: return err; @@ -132,7 +132,7 @@ int handle_page_fault(unsigned long address, unsigned long ip, * We ran out of memory, call the OOM killer, and return the userspace * (which will retry the fault, or kill us if we got oom-killed). */ - up_read(&mm->mmap_sem); + mm_read_unlock(mm, &mmrange); if (!is_user) goto out_nosemaphore; pagefault_out_of_memory(); -- 2.13.6
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