Changeset aaa6af2 in mainline for kernel/arch/mips32/src/mm/tlb.c

Timestamp:

2011-12-20T21:50:12Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

0fd9b35

Parents:

398e33be

Message:

Do not take AS→mutex when reading AS→asid in mips32 TLB-miss handler.
The asid is guaranteed to remain constant while somebody is using the
address space. Moreover, taking the mutex at the beginning of the
miss handler, i.e. before the page tables are searched, breaks kernel
non-identity when someone accesses a non-identity page while holding
e.g. a spinlock (the debug kernel will hit an assertion).

File:

• kernel/arch/mips32/src/mm/tlb.c (modified) (1 diff)

kernel/arch/mips32/src/mm/tlb.c

@@ -95 +95 @@
         
         badvaddr = cp0_badvaddr_read();
-        
-        mutex_lock(&AS->lock);
         asid = AS->asid;
-        mutex_unlock(&AS->lock);
         
         pte = find_mapping_and_check(badvaddr, PF_ACCESS_READ, istate, &pfrc);