--- /dev/null
+From 8e138e0d92c6c9d3d481674fb14e3439b495be37 Mon Sep 17 00:00:00 2001
+From: Josef Bacik <jbacik@fb.com>
+Date: Fri, 17 Nov 2017 14:50:46 -0500
+Subject: btrfs: clear space cache inode generation always
+
+From: Josef Bacik <jbacik@fb.com>
+
+commit 8e138e0d92c6c9d3d481674fb14e3439b495be37 upstream.
+
+We discovered a box that had double allocations, and suspected the space
+cache may be to blame. While auditing the write out path I noticed that
+if we've already setup the space cache we will just carry on. This
+means that any error we hit after cache_save_setup before we go to
+actually write the cache out we won't reset the inode generation, so
+whatever was already written will be considered correct, except it'll be
+stale. Fix this by _always_ resetting the generation on the block group
+inode, this way we only ever have valid or invalid cache.
+
+With this patch I was no longer able to reproduce cache corruption with
+dm-log-writes and my bpf error injection tool.
+
+Signed-off-by: Josef Bacik <jbacik@fb.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/btrfs/extent-tree.c | 14 +++++++-------
+ 1 file changed, 7 insertions(+), 7 deletions(-)
+
+--- a/fs/btrfs/extent-tree.c
++++ b/fs/btrfs/extent-tree.c
+@@ -3219,13 +3219,6 @@ again:
+ goto again;
+ }
+
+- /* We've already setup this transaction, go ahead and exit */
+- if (block_group->cache_generation == trans->transid &&
+- i_size_read(inode)) {
+- dcs = BTRFS_DC_SETUP;
+- goto out_put;
+- }
+-
+ /*
+ * We want to set the generation to 0, that way if anything goes wrong
+ * from here on out we know not to trust this cache when we load up next
+@@ -3235,6 +3228,13 @@ again:
+ ret = btrfs_update_inode(trans, root, inode);
+ WARN_ON(ret);
+
++ /* We've already setup this transaction, go ahead and exit */
++ if (block_group->cache_generation == trans->transid &&
++ i_size_read(inode)) {
++ dcs = BTRFS_DC_SETUP;
++ goto out_put;
++ }
++
+ if (i_size_read(inode) > 0) {
+ ret = btrfs_check_trunc_cache_free_space(root,
+ &root->fs_info->global_block_rsv);
--- /dev/null
+From 61cb57c9ed631c95b54f8e9090c89d18b3695b3c Mon Sep 17 00:00:00 2001
+From: Liran Alon <liran.alon@oracle.com>
+Date: Sun, 5 Nov 2017 16:56:32 +0200
+Subject: KVM: x86: Exit to user-mode on #UD intercept when emulator requires
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Liran Alon <liran.alon@oracle.com>
+
+commit 61cb57c9ed631c95b54f8e9090c89d18b3695b3c upstream.
+
+Instruction emulation after trapping a #UD exception can result in an
+MMIO access, for example when emulating a MOVBE on a processor that
+doesn't support the instruction. In this case, the #UD vmexit handler
+must exit to user mode, but there wasn't any code to do so. Add it for
+both VMX and SVM.
+
+Signed-off-by: Liran Alon <liran.alon@oracle.com>
+Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
+Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
+Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/kvm/svm.c | 2 ++
+ arch/x86/kvm/vmx.c | 2 ++
+ 2 files changed, 4 insertions(+)
+
+--- a/arch/x86/kvm/svm.c
++++ b/arch/x86/kvm/svm.c
+@@ -1785,6 +1785,8 @@ static int ud_interception(struct vcpu_s
+ int er;
+
+ er = emulate_instruction(&svm->vcpu, EMULTYPE_TRAP_UD);
++ if (er == EMULATE_USER_EXIT)
++ return 0;
+ if (er != EMULATE_DONE)
+ kvm_queue_exception(&svm->vcpu, UD_VECTOR);
+ return 1;
+--- a/arch/x86/kvm/vmx.c
++++ b/arch/x86/kvm/vmx.c
+@@ -4899,6 +4899,8 @@ static int handle_exception(struct kvm_v
+
+ if (is_invalid_opcode(intr_info)) {
+ er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD);
++ if (er == EMULATE_USER_EXIT)
++ return 0;
+ if (er != EMULATE_DONE)
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
--- /dev/null
+From 6ea6e84309ca7e0e850b3083e6b09344ee15c290 Mon Sep 17 00:00:00 2001
+From: Paolo Bonzini <pbonzini@redhat.com>
+Date: Fri, 10 Nov 2017 10:49:38 +0100
+Subject: KVM: x86: inject exceptions produced by x86_decode_insn
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Paolo Bonzini <pbonzini@redhat.com>
+
+commit 6ea6e84309ca7e0e850b3083e6b09344ee15c290 upstream.
+
+Sometimes, a processor might execute an instruction while another
+processor is updating the page tables for that instruction's code page,
+but before the TLB shootdown completes. The interesting case happens
+if the page is in the TLB.
+
+In general, the processor will succeed in executing the instruction and
+nothing bad happens. However, what if the instruction is an MMIO access?
+If *that* happens, KVM invokes the emulator, and the emulator gets the
+updated page tables. If the update side had marked the code page as non
+present, the page table walk then will fail and so will x86_decode_insn.
+
+Unfortunately, even though kvm_fetch_guest_virt is correctly returning
+X86EMUL_PROPAGATE_FAULT, x86_decode_insn's caller treats the failure as
+a fatal error if the instruction cannot simply be reexecuted (as is the
+case for MMIO). And this in fact happened sometimes when rebooting
+Windows 2012r2 guests. Just checking ctxt->have_exception and injecting
+the exception if true is enough to fix the case.
+
+Thanks to Eduardo Habkost for helping in the debugging of this issue.
+
+Reported-by: Yanan Fu <yfu@redhat.com>
+Cc: Eduardo Habkost <ehabkost@redhat.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/x86/kvm/x86.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/arch/x86/kvm/x86.c
++++ b/arch/x86/kvm/x86.c
+@@ -5372,6 +5372,8 @@ int x86_emulate_instruction(struct kvm_v
+ if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
+ emulation_type))
+ return EMULATE_DONE;
++ if (ctxt->have_exception && inject_emulated_exception(vcpu))
++ return EMULATE_DONE;
+ if (emulation_type & EMULTYPE_SKIP)
+ return EMULATE_FAIL;
+ return handle_emulation_failure(vcpu);
ipsec-fix-aborted-xfrm-policy-dump-crash.patch
mm-thp-do-not-make-page-table-dirty-unconditionally-in-touch_pd.patch
mm-madvise.c-fix-madvise-infinite-loop-under-special-circumstances.patch
+btrfs-clear-space-cache-inode-generation-always.patch
+kvm-x86-exit-to-user-mode-on-ud-intercept-when-emulator-requires.patch
+kvm-x86-inject-exceptions-produced-by-x86_decode_insn.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
