# git rev-parse -q --verify 50087112592016a3fc10b394a55f1f1a1bde6908^{commit}
50087112592016a3fc10b394a55f1f1a1bde6908
already have revision, skipping fetch
# git checkout -q -f -B kisskb 50087112592016a3fc10b394a55f1f1a1bde6908
# git clean -qxdf
# < git log -1
# commit 50087112592016a3fc10b394a55f1f1a1bde6908
# Author: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
# Date:   Thu Jun 20 11:46:49 2019 +1000
# 
#     KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries
#     
#     When a guest vcpu moves from one physical thread to another it is
#     necessary for the host to perform a tlb flush on the previous core if
#     another vcpu from the same guest is going to run there. This is because the
#     guest may use the local form of the tlb invalidation instruction meaning
#     stale tlb entries would persist where it previously ran. This is handled
#     on guest entry in kvmppc_check_need_tlb_flush() which calls
#     flush_guest_tlb() to perform the tlb flush.
#     
#     Previously the generic radix__local_flush_tlb_lpid_guest() function was
#     used, however the functionality was reimplemented in flush_guest_tlb()
#     to avoid the trace_tlbie() call as the flushing may be done in real
#     mode. The reimplementation in flush_guest_tlb() was missing an erat
#     invalidation after flushing the tlb.
#     
#     This lead to observable memory corruption in the guest due to the
#     caching of stale translations. Fix this by adding the erat invalidation.
#     
#     Fixes: 70ea13f6e609 ("KVM: PPC: Book3S HV: Flush TLB on secondary radix threads")
#     Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 50087112592016a3fc10b394a55f1f1a1bde6908
# < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mgcoge_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  mgcoge_defconfig
# make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mgcoge_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/kernel/futex.c: In function 'do_futex':
/kisskb/src/kernel/futex.c:1658:17: warning: 'oldval' may be used uninitialized in this function [-Wmaybe-uninitialized]
   return oldval == cmparg;
                 ^
/kisskb/src/kernel/futex.c:1633:6: note: 'oldval' was declared here
  int oldval, ret;
      ^
/kisskb/src/arch/powerpc/kernel/head_32.S: Assembler messages:
/kisskb/src/arch/powerpc/kernel/head_32.S:932: Warning: invalid register expression
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_mgcoge_defconfig_powerpc-gcc5
# Build took: 0:00:51.986657