47837a5c74
The nospec implementation is deeply integrated into the alternatives code: only for nospec an alternative facility list is implemented and used by the alternative code, while it is modified by nospec specific needs. Push down the nospec alternative handling into the nospec by introducing a new alternative type and a specific nospec callback to decide if alternatives should be applied. Also introduce a new global nobp variable which together with facility 82 can be used to decide if nobp is enabled or not. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
23 lines
702 B
C
23 lines
702 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/device.h>
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#include <linux/cpu.h>
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#include <asm/facility.h>
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#include <asm/nospec-branch.h>
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ssize_t cpu_show_spectre_v1(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "Mitigation: __user pointer sanitization\n");
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}
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ssize_t cpu_show_spectre_v2(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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if (test_facility(156))
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return sprintf(buf, "Mitigation: etokens\n");
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if (nospec_uses_trampoline())
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return sprintf(buf, "Mitigation: execute trampolines\n");
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if (nobp_enabled())
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return sprintf(buf, "Mitigation: limited branch prediction\n");
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return sprintf(buf, "Vulnerable\n");
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}
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