From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit fd6e440f20b1a4304553775fc55938848ff617c9 ]
The recent commit 87590ce6e373 ("sysfs/cpu: Add vulnerability folder")
added a generic folder and set of files for reporting information on
CPU vulnerabilities. One of those was for meltdown:
/sys/devices/system/cpu/vulnerabilities/meltdown
This commit wires up that file for 64-bit Book3S powerpc.
For now we default to "Vulnerable" unless the RFI flush is enabled.
That may not actually be true on all hardware, further patches will
refine the reporting based on the CPU/platform etc. But for now we
default to being pessimists.
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/setup_64.c | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index cffaeeee0d3e..a55a246fc784 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -133,6 +133,7 @@ config PPC
select GENERIC_SMP_IDLE_THREAD
select GENERIC_CMOS_UPDATE
select GENERIC_TIME_VSYSCALL_OLD
+ select GENERIC_CPU_VULNERABILITIES if PPC_BOOK3S_64
select GENERIC_CLOCKEVENTS
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index a3993ac21b50..1555778adb9c 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -907,5 +907,13 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
if (!no_rfi_flush)
rfi_flush_enable(enable);
}
+
+ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ if (rfi_flush)
+ return sprintf(buf, "Mitigation: RFI Flush\n");
+
+ return sprintf(buf, "Vulnerable\n");
+}
#endif /* CONFIG_PPC_BOOK3S_64 */
#endif
--
2.14.1