diff options
Diffstat (limited to 'arch/arm64/include/asm/asm-uaccess.h')
| -rw-r--r-- | arch/arm64/include/asm/asm-uaccess.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h new file mode 100644 index 000000000..5ef624fef --- /dev/null +++ b/arch/arm64/include/asm/asm-uaccess.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_ASM_UACCESS_H +#define __ASM_ASM_UACCESS_H + +#include <asm/alternative.h> +#include <asm/kernel-pgtable.h> +#include <asm/mmu.h> +#include <asm/sysreg.h> +#include <asm/assembler.h> + +/* + * User access enabling/disabling macros. + */ +#ifdef CONFIG_ARM64_SW_TTBR0_PAN + .macro __uaccess_ttbr0_disable, tmp1 + mrs \tmp1, ttbr1_el1 // swapper_pg_dir + bic \tmp1, \tmp1, #TTBR_ASID_MASK + sub \tmp1, \tmp1, #PAGE_SIZE // reserved_pg_dir just before swapper_pg_dir + msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1 + isb + add \tmp1, \tmp1, #PAGE_SIZE + msr ttbr1_el1, \tmp1 // set reserved ASID + isb + .endm + + .macro __uaccess_ttbr0_enable, tmp1, tmp2 + get_current_task \tmp1 + ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1 + mrs \tmp2, ttbr1_el1 + extr \tmp2, \tmp2, \tmp1, #48 + ror \tmp2, \tmp2, #16 + msr ttbr1_el1, \tmp2 // set the active ASID + isb + msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1 + isb + .endm + + .macro uaccess_ttbr0_disable, tmp1, tmp2 +alternative_if_not ARM64_HAS_PAN + save_and_disable_irq \tmp2 // avoid preemption + __uaccess_ttbr0_disable \tmp1 + restore_irq \tmp2 +alternative_else_nop_endif + .endm + + .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 +alternative_if_not ARM64_HAS_PAN + save_and_disable_irq \tmp3 // avoid preemption + __uaccess_ttbr0_enable \tmp1, \tmp2 + restore_irq \tmp3 +alternative_else_nop_endif + .endm +#else + .macro uaccess_ttbr0_disable, tmp1, tmp2 + .endm + + .macro uaccess_ttbr0_enable, tmp1, tmp2, tmp3 + .endm +#endif + +#endif |