diff options
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r-- | arch/arm64/kernel/cpufeature.c | 1 | ||||
-rw-r--r-- | arch/arm64/kernel/cpuinfo.c | 1 | ||||
-rw-r--r-- | arch/arm64/kernel/entry-common.c | 3 | ||||
-rw-r--r-- | arch/arm64/kernel/entry.S | 7 | ||||
-rw-r--r-- | arch/arm64/kernel/mte.c | 36 | ||||
-rw-r--r-- | arch/arm64/kernel/process.c | 3 |
6 files changed, 42 insertions, 9 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 6d1da359f804..3f9a1a325fbc 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2479,6 +2479,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { #endif #ifdef CONFIG_ARM64_MTE HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_MTE, CAP_HWCAP, KERNEL_HWCAP_MTE), + HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_MTE_ASYMM, CAP_HWCAP, KERNEL_HWCAP_MTE3), #endif /* CONFIG_ARM64_MTE */ HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_ECV_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV), HWCAP_CAP(SYS_ID_AA64MMFR1_EL1, ID_AA64MMFR1_AFP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AFP), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 591c18a889a5..330b92ea863a 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -97,6 +97,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_ECV] = "ecv", [KERNEL_HWCAP_AFP] = "afp", [KERNEL_HWCAP_RPRES] = "rpres", + [KERNEL_HWCAP_MTE3] = "mte3", }; #ifdef CONFIG_COMPAT diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index ef7fcefb96bd..7093b578e325 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -6,6 +6,7 @@ */ #include <linux/context_tracking.h> +#include <linux/kasan.h> #include <linux/linkage.h> #include <linux/lockdep.h> #include <linux/ptrace.h> @@ -56,6 +57,7 @@ static void noinstr enter_from_kernel_mode(struct pt_regs *regs) { __enter_from_kernel_mode(regs); mte_check_tfsr_entry(); + mte_disable_tco_entry(current); } /* @@ -103,6 +105,7 @@ static __always_inline void __enter_from_user_mode(void) CT_WARN_ON(ct_state() != CONTEXT_USER); user_exit_irqoff(); trace_hardirqs_off_finish(); + mte_disable_tco_entry(current); } static __always_inline void enter_from_user_mode(struct pt_regs *regs) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index eb59621d6c6a..a3ee79bcd5cb 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -310,13 +310,6 @@ alternative_if ARM64_HAS_IRQ_PRIO_MASKING alternative_else_nop_endif #endif - /* Re-enable tag checking (TCO set on exception entry) */ -#ifdef CONFIG_ARM64_MTE -alternative_if ARM64_MTE - SET_PSTATE_TCO(0) -alternative_else_nop_endif -#endif - /* * Registers that may be useful after this macro is invoked: * diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index f418ebc65f95..78b3e0f8e997 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -186,6 +186,11 @@ void mte_check_tfsr_el1(void) } #endif +/* + * This is where we actually resolve the system and process MTE mode + * configuration into an actual value in SCTLR_EL1 that affects + * userspace. + */ static void mte_update_sctlr_user(struct task_struct *task) { /* @@ -199,9 +204,20 @@ static void mte_update_sctlr_user(struct task_struct *task) unsigned long pref, resolved_mte_tcf; pref = __this_cpu_read(mte_tcf_preferred); + /* + * If there is no overlap between the system preferred and + * program requested values go with what was requested. + */ resolved_mte_tcf = (mte_ctrl & pref) ? pref : mte_ctrl; sctlr &= ~SCTLR_EL1_TCF0_MASK; - if (resolved_mte_tcf & MTE_CTRL_TCF_ASYNC) + /* + * Pick an actual setting. The order in which we check for + * set bits and map into register values determines our + * default order. + */ + if (resolved_mte_tcf & MTE_CTRL_TCF_ASYMM) + sctlr |= SCTLR_EL1_TCF0_ASYMM; + else if (resolved_mte_tcf & MTE_CTRL_TCF_ASYNC) sctlr |= SCTLR_EL1_TCF0_ASYNC; else if (resolved_mte_tcf & MTE_CTRL_TCF_SYNC) sctlr |= SCTLR_EL1_TCF0_SYNC; @@ -253,6 +269,9 @@ void mte_thread_switch(struct task_struct *next) mte_update_sctlr_user(next); mte_update_gcr_excl(next); + /* TCO may not have been disabled on exception entry for the current task. */ + mte_disable_tco_entry(next); + /* * Check if an async tag exception occurred at EL1. * @@ -293,6 +312,17 @@ long set_mte_ctrl(struct task_struct *task, unsigned long arg) if (arg & PR_MTE_TCF_SYNC) mte_ctrl |= MTE_CTRL_TCF_SYNC; + /* + * If the system supports it and both sync and async modes are + * specified then implicitly enable asymmetric mode. + * Userspace could see a mix of both sync and async anyway due + * to differing or changing defaults on CPUs. + */ + if (cpus_have_cap(ARM64_MTE_ASYMM) && + (arg & PR_MTE_TCF_ASYNC) && + (arg & PR_MTE_TCF_SYNC)) + mte_ctrl |= MTE_CTRL_TCF_ASYMM; + task->thread.mte_ctrl = mte_ctrl; if (task == current) { preempt_disable(); @@ -467,6 +497,8 @@ static ssize_t mte_tcf_preferred_show(struct device *dev, return sysfs_emit(buf, "async\n"); case MTE_CTRL_TCF_SYNC: return sysfs_emit(buf, "sync\n"); + case MTE_CTRL_TCF_ASYMM: + return sysfs_emit(buf, "asymm\n"); default: return sysfs_emit(buf, "???\n"); } @@ -482,6 +514,8 @@ static ssize_t mte_tcf_preferred_store(struct device *dev, tcf = MTE_CTRL_TCF_ASYNC; else if (sysfs_streq(buf, "sync")) tcf = MTE_CTRL_TCF_SYNC; + else if (cpus_have_cap(ARM64_MTE_ASYMM) && sysfs_streq(buf, "asymm")) + tcf = MTE_CTRL_TCF_ASYMM; else return -EINVAL; diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 5369e649fa79..7fa97df55e3a 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -635,7 +635,8 @@ long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg) return -EINVAL; if (system_supports_mte()) - valid_mask |= PR_MTE_TCF_MASK | PR_MTE_TAG_MASK; + valid_mask |= PR_MTE_TCF_SYNC | PR_MTE_TCF_ASYNC \ + | PR_MTE_TAG_MASK; if (arg & ~valid_mask) return -EINVAL; |