@@ -24,11 +24,11 @@
mov TLB_TAG_ACCESS, %g4 ! For reload of vaddr
/* PROT ** ICACHE line 2: More real fault processing */
+ ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5
bgu,pn %xcc, winfix_trampoline ! Yes, perform winfixup
- ldxa [%g4] ASI_DMMU, %g5 ! Put tagaccess in %g5
- ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault
mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4
- nop
+ ba,pt %xcc, sparc64_realfault_common ! Nope, normal fault
+ nop
nop
nop
nop
@@ -162,10 +162,10 @@ tsb_miss_page_table_walk_sun4v_fastpath:
nop
.previous
- rdpr %tl, %g3
- cmp %g3, 1
+ rdpr %tl, %g7
+ cmp %g7, 1
bne,pn %xcc, winfix_trampoline
- nop
+ mov %g3, %g4
ba,pt %xcc, etrap
rd %pc, %g7
call hugetlb_setup
This is a note to let you know that I have just added a patch titled sparc64: Fix corrupted thread fault code. to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11.11. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 6c558d67258b2a825109425a5d8c6f3f94eba4d3 Mon Sep 17 00:00:00 2001 From: "David S. Miller" <davem@davemloft.net> Date: Sat, 18 Oct 2014 23:03:09 -0400 Subject: sparc64: Fix corrupted thread fault code. [ Upstream commit 84bd6d8b9c0f06b3f188efb479c77e20f05e9a8a ] 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> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/sparc/kernel/dtlb_prot.S | 6 +++--- arch/sparc/kernel/tsb.S | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) -- 1.9.1