diff options
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/kernel/entry.S | 10 | ||||
-rw-r--r-- | arch/arm64/kernel/mte.c | 26 |
2 files changed, 31 insertions, 5 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index bc6d5a970a13..2f69ae43941d 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -168,9 +168,9 @@ alternative_else_nop_endif .macro mte_set_kernel_gcr, tmp, tmp2 #ifdef CONFIG_KASAN_HW_TAGS -alternative_if_not ARM64_MTE +alternative_cb kasan_hw_tags_enable b 1f -alternative_else_nop_endif +alternative_cb_end mov \tmp, KERNEL_GCR_EL1 msr_s SYS_GCR_EL1, \tmp 1: @@ -178,10 +178,10 @@ alternative_else_nop_endif .endm .macro mte_set_user_gcr, tsk, tmp, tmp2 -#ifdef CONFIG_ARM64_MTE -alternative_if_not ARM64_MTE +#ifdef CONFIG_KASAN_HW_TAGS +alternative_cb kasan_hw_tags_enable b 1f -alternative_else_nop_endif +alternative_cb_end ldr \tmp, [\tsk, #THREAD_MTE_CTRL] mte_set_gcr \tmp, \tmp2 diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index e5e801bc5312..0cdae086966e 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -179,6 +179,30 @@ static void mte_update_sctlr_user(struct task_struct *task) task->thread.sctlr_user = sctlr; } +static void mte_update_gcr_excl(struct task_struct *task) +{ + /* + * SYS_GCR_EL1 will be set to current->thread.mte_ctrl value by + * mte_set_user_gcr() in kernel_exit, but only if KASAN is enabled. + */ + if (kasan_hw_tags_enabled()) + return; + + write_sysreg_s( + ((task->thread.mte_ctrl >> MTE_CTRL_GCR_USER_EXCL_SHIFT) & + SYS_GCR_EL1_EXCL_MASK) | SYS_GCR_EL1_RRND, + SYS_GCR_EL1); +} + +void __init kasan_hw_tags_enable(struct alt_instr *alt, __le32 *origptr, + __le32 *updptr, int nr_inst) +{ + BUG_ON(nr_inst != 1); /* Branch -> NOP */ + + if (kasan_hw_tags_enabled()) + *updptr = cpu_to_le32(aarch64_insn_gen_nop()); +} + void mte_thread_init_user(void) { if (!system_supports_mte()) @@ -198,6 +222,7 @@ void mte_thread_switch(struct task_struct *next) return; mte_update_sctlr_user(next); + mte_update_gcr_excl(next); /* * Check if an async tag exception occurred at EL1. @@ -243,6 +268,7 @@ long set_mte_ctrl(struct task_struct *task, unsigned long arg) if (task == current) { preempt_disable(); mte_update_sctlr_user(task); + mte_update_gcr_excl(task); update_sctlr_el1(task->thread.sctlr_user); preempt_enable(); } |