From: Ard Biesheuvel <ardb@kernel.org> mainline inclusion from mainline-v6.7-rc4 commit f5259997f3e8d6edfcc2daf5b2c0b34f074d7bc0 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/9850 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------- Commit 42c5a3b04bf6 refactored the KPTI init code in a way that results in the use of non-global kernel mappings even on systems that have no need for it, and even when KPTI has been disabled explicitly via the command line. Ensure that this only happens when we have decided (based on the detected system-wide CPU features) that KPTI should be enabled. Fixes: 42c5a3b04bf6 ("arm64: Split kpti_install_ng_mappings()") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20231127120049.2258650-6-ardb@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- arch/arm64/kernel/cpufeature.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 2cf8d9fd7504..827150effb2a 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1914,6 +1914,10 @@ static int __init __kpti_install_ng_mappings(void *__unused) static void __init kpti_install_ng_mappings(void) { + /* Check whether KPTI is going to be used */ + if (!cpus_have_cap(ARM64_UNMAP_KERNEL_AT_EL0)) + return; + /* * We don't need to rewrite the page-tables if either we've done * it already or we have KASLR enabled and therefore have not -- 2.43.0