diff options
Diffstat (limited to 'arch/arm64/kernel/mte.c')
| -rw-r--r-- | arch/arm64/kernel/mte.c | 48 |
1 files changed, 41 insertions, 7 deletions
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 78b3e0f8e997..57b30bcf9f21 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -15,6 +15,7 @@ #include <linux/swapops.h> #include <linux/thread_info.h> #include <linux/types.h> +#include <linux/uaccess.h> #include <linux/uio.h> #include <asm/barrier.h> @@ -76,6 +77,9 @@ void mte_sync_tags(pte_t old_pte, pte_t pte) mte_sync_page_tags(page, old_pte, check_swap, pte_is_tagged); } + + /* ensure the tags are visible before the PTE is set */ + smp_wmb(); } int memcmp_pages(struct page *page1, struct page *page2) @@ -106,7 +110,8 @@ int memcmp_pages(struct page *page1, struct page *page2) static inline void __mte_enable_kernel(const char *mode, unsigned long tcf) { /* Enable MTE Sync Mode for EL1. */ - sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, tcf); + sysreg_clear_set(sctlr_el1, SCTLR_EL1_TCF_MASK, + SYS_FIELD_PREP(SCTLR_EL1, TCF, tcf)); isb(); pr_info_once("MTE: enabled in %s mode at EL1\n", mode); @@ -122,12 +127,12 @@ void mte_enable_kernel_sync(void) WARN_ONCE(system_uses_mte_async_or_asymm_mode(), "MTE async mode enabled system wide!"); - __mte_enable_kernel("synchronous", SCTLR_ELx_TCF_SYNC); + __mte_enable_kernel("synchronous", SCTLR_EL1_TCF_SYNC); } void mte_enable_kernel_async(void) { - __mte_enable_kernel("asynchronous", SCTLR_ELx_TCF_ASYNC); + __mte_enable_kernel("asynchronous", SCTLR_EL1_TCF_ASYNC); /* * MTE async mode is set system wide by the first PE that @@ -144,7 +149,7 @@ void mte_enable_kernel_async(void) void mte_enable_kernel_asymm(void) { if (cpus_have_cap(ARM64_MTE_ASYMM)) { - __mte_enable_kernel("asymmetric", SCTLR_ELx_TCF_ASYMM); + __mte_enable_kernel("asymmetric", SCTLR_EL1_TCF_ASYMM); /* * MTE asymm mode behaves as async mode for store @@ -216,11 +221,11 @@ static void mte_update_sctlr_user(struct task_struct *task) * default order. */ if (resolved_mte_tcf & MTE_CTRL_TCF_ASYMM) - sctlr |= SCTLR_EL1_TCF0_ASYMM; + sctlr |= SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF0, ASYMM); else if (resolved_mte_tcf & MTE_CTRL_TCF_ASYNC) - sctlr |= SCTLR_EL1_TCF0_ASYNC; + sctlr |= SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF0, ASYNC); else if (resolved_mte_tcf & MTE_CTRL_TCF_SYNC) - sctlr |= SCTLR_EL1_TCF0_SYNC; + sctlr |= SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF0, SYNC); task->thread.sctlr_user = sctlr; } @@ -543,3 +548,32 @@ static int register_mte_tcf_preferred_sysctl(void) return 0; } subsys_initcall(register_mte_tcf_preferred_sysctl); + +/* + * Return 0 on success, the number of bytes not probed otherwise. + */ +size_t mte_probe_user_range(const char __user *uaddr, size_t size) +{ + const char __user *end = uaddr + size; + int err = 0; + char val; + + __raw_get_user(val, uaddr, err); + if (err) + return size; + + uaddr = PTR_ALIGN(uaddr, MTE_GRANULE_SIZE); + while (uaddr < end) { + /* + * A read is sufficient for mte, the caller should have probed + * for the pte write permission if required. + */ + __raw_get_user(val, uaddr, err); + if (err) + return end - uaddr; + uaddr += MTE_GRANULE_SIZE; + } + (void)val; + + return 0; +} |