parisc: disable preemption during local tlb flush

flush_cache_mm() and flush_cache_range() fetch %sr3 via mfsp().
If it matches mm->context, they flush caches and the TLB. However,
the TLB is cpu-local, so if the code gets preempted shortly after
the mfsp(), and later resumed on another CPU, the wrong TLB is flushed.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 39e02227e231007040c37868aa23e4c4517703d9..a1a7e2b0812f70a2afc5a7c573d3e6c167473715 100644 (file)
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -558,6 +558,7 @@ void flush_cache_mm(struct mm_struct *mm)
                return;
        }
 
+       preempt_disable();
        if (mm->context == mfsp(3)) {
                for (vma = mm->mmap; vma; vma = vma->vm_next) {
                        flush_user_dcache_range_asm(vma->vm_start, vma->vm_end);
@@ -565,6 +566,7 @@ void flush_cache_mm(struct mm_struct *mm)
                                flush_user_icache_range_asm(vma->vm_start, vma->vm_end);
                        flush_tlb_range(vma, vma->vm_start, vma->vm_end);
                }
+               preempt_enable();
                return;
        }
 
@@ -589,6 +591,7 @@ void flush_cache_mm(struct mm_struct *mm)
                        }
                }
        }
+       preempt_enable();
 }
 
 void flush_cache_range(struct vm_area_struct *vma,
@@ -605,11 +608,13 @@ void flush_cache_range(struct vm_area_struct *vma,
                return;
        }
 
+       preempt_disable();
        if (vma->vm_mm->context == mfsp(3)) {
                flush_user_dcache_range_asm(start, end);
                if (vma->vm_flags & VM_EXEC)
                        flush_user_icache_range_asm(start, end);
                flush_tlb_range(vma, start, end);
+               preempt_enable();
                return;
        }
 
@@ -629,6 +634,7 @@ void flush_cache_range(struct vm_area_struct *vma,
                        }
                }
        }
+       preempt_enable();
 }
 
 void