diff options
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/mte.c | 3 |
2 files changed, 9 insertions, 4 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 9ca5ffd8d817..5e68d65e675e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2279,17 +2279,21 @@ static void bti_enable(const struct arm64_cpu_capabilities *__unused) #ifdef CONFIG_ARM64_MTE static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap) { + static bool cleared_zero_page = false; + sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0); mte_cpu_setup(); /* * Clear the tags in the zero page. This needs to be done via the - * linear map which has the Tagged attribute. + * linear map which has the Tagged attribute. Since this page is + * always mapped as pte_special(), set_pte_at() will not attempt to + * clear the tags or set PG_mte_tagged. */ - if (try_page_mte_tagging(ZERO_PAGE(0))) { + if (!cleared_zero_page) { + cleared_zero_page = true; mte_clear_page_tags(lm_alias(empty_zero_page)); - set_page_mte_tagged(ZERO_PAGE(0)); } kasan_init_hw_tags_cpu(); diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 6174671be7c1..5d63ca966737 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -428,7 +428,8 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr, put_page(page); break; } - WARN_ON_ONCE(!page_mte_tagged(page)); + + WARN_ON_ONCE(!page_mte_tagged(page) && !is_zero_page(page)); /* limit access to the end of the page */ offset = offset_in_page(addr); |