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powerpc/64s: Wire up cpu_show_meltdown()

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commit fd6e440f20b1a4304553775fc55938848ff617c9 upstream.

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@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michael Ellerman 2018-01-16 21:20:05 +11:00 committed by Greg Kroah-Hartman
parent 16d3d10d29
commit 517bdccc3a
2 changed files with 9 additions and 0 deletions
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1
arch/powerpc/Kconfig
View File

@ -164,6 +164,7 @@ config PPC
select GENERIC_CLOCKEVENTS_BROADCAST if SMP
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
select GENERIC_CPU_VULNERABILITIES if PPC_BOOK3S_64
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
select GENERIC_SMP_IDLE_THREAD

8
arch/powerpc/kernel/setup_64.c
View File

@ -884,4 +884,12 @@ 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 */