From: Wei Li <liwei391@huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I53K4K CVE: NA backport: openEuler-22.03-LTS Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Currently, clear_page() uses DC ZVA instruction unconditionally. But it should make sure that DCZID_EL0.DZP, which indicates whether or not use of DC ZVA instruction is prohibited, is zero when using the instruction. Use STNP instead when DCZID_EL0.DZP == 1. Fixes: f27bb139c387 ("arm64: Miscellaneous library functions") Based-on-patch-by: Reiji Watanabe <reijiw@google.com> Signed-off-by: Wei Li <liwei391@huawei.com> Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- arch/arm64/kernel/cpufeature.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 809dcac24e18..7d110ce5d7f4 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1792,6 +1792,9 @@ static bool has_mor_nontemporal(const struct arm64_cpu_capabilities *entry) static bool can_clearpage_use_stnp(const struct arm64_cpu_capabilities *entry, int scope) { + if (read_sysreg(dczid_el0) & BIT(DCZID_DZP_SHIFT)) + return true; + return use_clearpage_stnp && has_mor_nontemporal(entry); } -- 2.20.1