Andy Lutomirski ff17bbe0bb x86/vdso: Prevent segfaults due to hoisted vclock reads ... GCC 5.5.0 sometimes cleverly hoists reads of the pvclock and/or hvclock pages before the vclock mode checks. This creates a path through vclock_gettime() in which no vclock is enabled at all (due to disabled TSC on old CPUs, for example) but the pvclock or hvclock page nevertheless read. This will segfault on bare metal. This fixes commit 459e3a2153 ("gcc-9: properly declare the {pv,hv}clock_page storage") in the sense that, before that commit, GCC didn't seem to generate the offending code. There was nothing wrong with that commit per se, and -stable maintainers should backport this to all supported kernels regardless of whether the offending commit was present, since the same crash could just as easily be triggered by the phase of the moon. On GCC 9.1.1, this doesn't seem to affect the generated code at all, so I'm not too concerned about performance regressions from this fix. Cc: stable@vger.kernel.org Cc: x86@kernel.org Cc: Borislav Petkov <bp@alien8.de> Reported-by: Duncan Roe <duncan_roe@optusnet.com.au> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2019-06-21 13:31:52 -07:00
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boot	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
configs
crypto	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
entry	x86/vdso: Prevent segfaults due to hoisted vclock reads	2019-06-21 13:31:52 -07:00
events	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
hyperv
ia32
include	SPDX update for 5.2-rc6	2019-06-21 09:58:42 -07:00
kernel	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
kvm	SPDX update for 5.2-rc6	2019-06-21 09:58:42 -07:00
lib	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504	2019-06-19 17:09:56 +02:00
math-emu
mm	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2019-06-17 15:55:34 -07:00
oprofile
pci	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 387	2019-06-05 17:37:11 +02:00
platform	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
power	SPDX update for 5.2-rc4	2019-06-08 12:52:42 -07:00
purgatory	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230	2019-06-19 17:09:06 +02:00
ras
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um	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
video
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