These patches address a number of instrumentation issues that were found after
the x86/entry overhaul. When combined with rcu/urgent and objtool/urgent, these
patches make UBSAN/KASAN/KCSAN happy again.
Part of making this all work is bumping the minimum GCC version for KASAN
builds to gcc-8.3, the reason for this is that the __no_sanitize_address
function attribute is broken in GCC releases before that.
No known GCC version has a working __no_sanitize_undefined, however because the
only noinstr violation that results from this happens when an UB is found, we
treat it like WARN. That is, we allow it to violate the noinstr rules in order
to get the warning out.
-----BEGIN PGP SIGNATURE-----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=fcu1
-----END PGP SIGNATURE-----
Merge tag 'x86_entry_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 entry fixes from Borislav Petkov:
"This is the x86/entry urgent pile which has accumulated since the
merge window.
It is not the smallest but considering the almost complete entry core
rewrite, the amount of fixes to follow is somewhat higher than usual,
which is to be expected.
Peter Zijlstra says:
'These patches address a number of instrumentation issues that were
found after the x86/entry overhaul. When combined with rcu/urgent
and objtool/urgent, these patches make UBSAN/KASAN/KCSAN happy
again.
Part of making this all work is bumping the minimum GCC version for
KASAN builds to gcc-8.3, the reason for this is that the
__no_sanitize_address function attribute is broken in GCC releases
before that.
No known GCC version has a working __no_sanitize_undefined, however
because the only noinstr violation that results from this happens
when an UB is found, we treat it like WARN. That is, we allow it to
violate the noinstr rules in order to get the warning out'"
* tag 'x86_entry_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/entry: Fix #UD vs WARN more
x86/entry: Increase entry_stack size to a full page
x86/entry: Fixup bad_iret vs noinstr
objtool: Don't consider vmlinux a C-file
kasan: Fix required compiler version
compiler_attributes.h: Support no_sanitize_undefined check with GCC 4
x86/entry, bug: Comment the instrumentation_begin() usage for WARN()
x86/entry, ubsan, objtool: Whitelist __ubsan_handle_*()
x86/entry, cpumask: Provide non-instrumented variant of cpu_is_offline()
compiler_types.h: Add __no_sanitize_{address,undefined} to noinstr
kasan: Bump required compiler version
x86, kcsan: Add __no_kcsan to noinstr
kcsan: Remove __no_kcsan_or_inline
x86, kcsan: Remove __no_kcsan_or_inline usage
a358505d8a