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| author |   Alexander Graf <graf@amazon.com> | 2022-05-10 14:37:17 +0200 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-05-11 23:03:16 +1000 |
| commit | ee8348496c77e3737d0a6cda307a521f2cff954f (patch) | |
| tree | 4221c64fa85554adbf94dd10253fd0769a8fb9ee /arch/powerpc/include/asm/kvm_book3s_asm.h | |
| parent | powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE (diff) | |
| download | linux-dev-ee8348496c77e3737d0a6cda307a521f2cff954f.tar.xz linux-dev-ee8348496c77e3737d0a6cda307a521f2cff954f.zip | |
KVM: PPC: Book3S PR: Enable MSR_DR for switch_mmu_context()
Commit 863771a28e27 ("powerpc/32s: Convert switch_mmu_context() to C")
moved the switch_mmu_context() to C. While in principle a good idea, it
meant that the function now uses the stack. The stack is not accessible
from real mode though.
So to keep calling the function, let's turn on MSR_DR while we call it.
That way, all pointer references to the stack are handled virtually.
In addition, make sure to save/restore r12 on the stack, as it may get
clobbered by the C function.
Fixes: 863771a28e27 ("powerpc/32s: Convert switch_mmu_context() to C")
Cc: stable@vger.kernel.org # v5.14+
Reported-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220510123717.24508-1-graf@amazon.com
Diffstat (limited to 'arch/powerpc/include/asm/kvm_book3s_asm.h')
0 files changed, 0 insertions, 0 deletions