diff options
| author | Michael Neuling <mikey@neuling.org> | 2018-05-18 11:37:42 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-06-06 16:46:20 +0200 |
| commit | 783771fdbfd7f58d704c26c360a3130208772f26 (patch) | |
| tree | a796758dac1bd1434f8974d75323bbb81fea02ea | |
| parent | 55a0e02e858b0afcc8213984fa6d7bcd47ad851a (diff) | |
powerpc/64s: Clear PCR on boot
commit faf37c44a105f3608115785f17cbbf3500f8bc71 upstream.
Clear the PCR (Processor Compatibility Register) on boot to ensure we
are not running in a compatibility mode.
We've seen this cause problems when a crash (and kdump) occurs while
running compat mode guests. The kdump kernel then runs with the PCR
set and causes problems. The symptom in the kdump kernel (also seen in
petitboot after fast-reboot) is early userspace programs taking
sigills on newer instructions (seen in libc).
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/kernel/cpu_setup_power.S | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S index 9c9b7411b28b..55eb3b752ca0 100644 --- a/arch/powerpc/kernel/cpu_setup_power.S +++ b/arch/powerpc/kernel/cpu_setup_power.S @@ -27,6 +27,7 @@ _GLOBAL(__setup_cpu_power7) beqlr li r0,0 mtspr SPRN_LPID,r0 + mtspr SPRN_PCR,r0 mfspr r3,SPRN_LPCR bl __init_LPCR bl __init_tlb_power7 @@ -40,6 +41,7 @@ _GLOBAL(__restore_cpu_power7) beqlr li r0,0 mtspr SPRN_LPID,r0 + mtspr SPRN_PCR,r0 mfspr r3,SPRN_LPCR bl __init_LPCR bl __init_tlb_power7 @@ -55,6 +57,7 @@ _GLOBAL(__setup_cpu_power8) beqlr li r0,0 mtspr SPRN_LPID,r0 + mtspr SPRN_PCR,r0 mfspr r3,SPRN_LPCR ori r3, r3, LPCR_PECEDH bl __init_LPCR @@ -74,6 +77,7 @@ _GLOBAL(__restore_cpu_power8) beqlr li r0,0 mtspr SPRN_LPID,r0 + mtspr SPRN_PCR,r0 mfspr r3,SPRN_LPCR ori r3, r3, LPCR_PECEDH bl __init_LPCR |