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author | Mika Westerberg <mika.westerberg@iki.fi> | 2010-10-28 11:45:22 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-10-28 13:53:47 +0100 |
commit | 4e54d93d3c9846ba1c2644ad06463dafa690d1b7 (patch) | |
tree | 7d692f758a87fdc7d97caa3432542d08075eb427 /arch/arm/mm/cache-fa.S | |
parent | 4e929d2bcf13eeaa9636448c55690b383a910391 (diff) | |
download | op-kernel-dev-4e54d93d3c9846ba1c2644ad06463dafa690d1b7.zip op-kernel-dev-4e54d93d3c9846ba1c2644ad06463dafa690d1b7.tar.gz |
ARM: 6464/2: fix spinlock recursion in adjust_pte()
When running following code in a machine which has VIVT caches and
USE_SPLIT_PTLOCKS is not defined:
fd = open("/etc/passwd", O_RDONLY);
addr = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd, 0);
addr2 = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd, 0);
v = *((int *)addr);
we will hang in spinlock recursion in the page fault handler:
BUG: spinlock recursion on CPU#0, mmap_test/717
lock: c5e295d8, .magic: dead4ead, .owner: mmap_test/717,
.owner_cpu: 0
[<c0026604>] (unwind_backtrace+0x0/0xec)
[<c014ee48>] (do_raw_spin_lock+0x40/0x140)
[<c0027f68>] (update_mmu_cache+0x208/0x250)
[<c0079db4>] (__do_fault+0x320/0x3ec)
[<c007af7c>] (handle_mm_fault+0x2f0/0x6d8)
[<c0027834>] (do_page_fault+0xdc/0x1cc)
[<c00202d0>] (do_DataAbort+0x34/0x94)
This comes from the fact that when USE_SPLIT_PTLOCKS is not defined,
the only lock protecting the page tables is mm->page_table_lock
which is already locked before update_mmu_cache() is called.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/cache-fa.S')
0 files changed, 0 insertions, 0 deletions