https://github.com/torvalds/linux
Revision 84bd6d8b9c0f06b3f188efb479c77e20f05e9a8a authored by David S. Miller on 19 October 2014, 03:03:09 UTC, committed by David S. Miller on 19 October 2014, 03:03:09 UTC
Every path that ends up at do_sparc64_fault() must install a valid FAULT_CODE_* bitmask in the per-thread fault code byte. Two paths leading to the label winfix_trampoline (which expects the FAULT_CODE_* mask in register %g4) were not doing so: 1) For pre-hypervisor TLB protection violation traps, if we took the 'winfix_trampoline' path we wouldn't have %g4 initialized with the FAULT_CODE_* value yet. Resulting in using the TLB_TAG_ACCESS register address value instead. 2) In the TSB miss path, when we notice that we are going to use a hugepage mapping, but we haven't allocated the hugepage TSB yet, we still have to take the window fixup case into consideration and in that particular path we leave %g4 not setup properly. Errors on this sort were largely invisible previously, but after commit 4ccb9272892c33ef1c19a783cfa87103b30c2784 ("sparc64: sun4v TLB error power off events") we now have a fault_code mask bit (FAULT_CODE_BAD_RA) that triggers due to this bug. FAULT_CODE_BAD_RA triggers because this bit is set in TLB_TAG_ACCESS (see #1 above) and thus we get seemingly random bus errors triggered for user processes. Fixes: 4ccb9272892c ("sparc64: sun4v TLB error power off events") Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 52d589a
Tip revision: 84bd6d8b9c0f06b3f188efb479c77e20f05e9a8a authored by David S. Miller on 19 October 2014, 03:03:09 UTC
sparc64: Fix corrupted thread fault code.
sparc64: Fix corrupted thread fault code.
Tip revision: 84bd6d8
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include | ||
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COPYING | -rw-r--r-- | 18.3 KB |
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Makefile | -rw-r--r-- | 53.1 KB |
README | -rw-r--r-- | 18.3 KB |
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