diff options
| author | Marc Zyngier <maz@kernel.org> | 2020-07-06 17:37:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-22 09:32:50 +0200 |
| commit | 71d65a3fc62888505bcaff5eaabf8ffc6b6d7be2 (patch) | |
| tree | fe9408757c3e318993f8dbd49e2441b1f3370cce /arch/arm/include | |
| parent | 36d60eba862d6842d6da4d3792b3cf1cde1c22b2 (diff) | |
arm64: Introduce a way to disable the 32bit vdso
commit 97884ca8c2925d14c32188e865069f21378b4b4f upstream.
[this is a redesign rather than a backport]
We have a class of errata (grouped under the ARM64_WORKAROUND_1418040
banner) that force the trapping of counter access from 32bit EL0.
We would normally disable the whole vdso for such defect, except that
it would disable it for 64bit userspace as well, which is a shame.
Instead, add a new vdso_clock_mode, which signals that the vdso
isn't usable for compat tasks. This gets checked in the new
vdso_clocksource_ok() helper, now provided for the 32bit vdso.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200706163802.1836732-2-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/clocksource.h | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/arm/include/asm/clocksource.h b/arch/arm/include/asm/clocksource.h index 0b350a7e26f3..afb7a59828fe 100644 --- a/arch/arm/include/asm/clocksource.h +++ b/arch/arm/include/asm/clocksource.h @@ -1,8 +1,17 @@ #ifndef _ASM_CLOCKSOURCE_H #define _ASM_CLOCKSOURCE_H +enum vdso_arch_clockmode { + /* vdso clocksource not usable */ + VDSO_CLOCKMODE_NONE, + /* vdso clocksource usable */ + VDSO_CLOCKMODE_ARCHTIMER, + VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT = VDSO_CLOCKMODE_ARCHTIMER, +}; + struct arch_clocksource_data { - bool vdso_direct; /* Usable for direct VDSO access? */ + /* Usable for direct VDSO access? */ + enum vdso_arch_clockmode clock_mode; }; #endif |