1 /* SPDX-License-Identifier: GPL-2.0-only */
3 #ifndef __ASM_UACCESS_ASM_H__
4 #define __ASM_UACCESS_ASM_H__
6 #include <asm/asm-offsets.h>
7 #include <asm/domain.h>
8 #include <asm/memory.h>
9 #include <asm/thread_info.h>
12 #ifdef CONFIG_THUMB2_KERNEL
19 .macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
20 #ifndef CONFIG_CPU_USE_DOMAINS
21 adds \tmp, \addr, #\size - 1
22 sbcscc \tmp, \tmp, \limit
24 #ifdef CONFIG_CPU_SPECTRE
31 .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
32 #ifdef CONFIG_CPU_SPECTRE
34 subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr
35 addhs \tmp, \tmp, #1 @ if (tmp >= 0) {
36 subshs \tmp, \tmp, \size @ tmp = limit - (addr + size) }
37 movlo \addr, #0 @ if (tmp < 0) addr = NULL
42 .macro uaccess_disable, tmp, isb=1
43 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
45 * Whenever we re-enter userspace, the domains should always be
48 mov \tmp, #DACR_UACCESS_DISABLE
49 mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register
56 .macro uaccess_enable, tmp, isb=1
57 #ifdef CONFIG_CPU_SW_DOMAIN_PAN
59 * Whenever we re-enter userspace, the domains should always be
62 mov \tmp, #DACR_UACCESS_ENABLE
63 mcr p15, 0, \tmp, c3, c0, 0
70 #if defined(CONFIG_CPU_SW_DOMAIN_PAN) || defined(CONFIG_CPU_USE_DOMAINS)
77 * Save the address limit on entry to a privileged exception.
79 * If we are using the DACR for kernel access by the user accessors
80 * (CONFIG_CPU_USE_DOMAINS=y), always reset the DACR kernel domain
81 * back to client mode, whether or not \disable is set.
83 * If we are using SW PAN, set the DACR user domain to no access
86 .macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
87 ldr \tmp1, [\tsk, #TI_ADDR_LIMIT]
89 str \tmp2, [\tsk, #TI_ADDR_LIMIT]
90 DACR( mrc p15, 0, \tmp0, c3, c0, 0)
91 DACR( str \tmp0, [sp, #SVC_DACR])
92 str \tmp1, [sp, #SVC_ADDR_LIMIT]
93 .if \disable && IS_ENABLED(CONFIG_CPU_SW_DOMAIN_PAN)
94 /* kernel=client, user=no access */
95 mov \tmp2, #DACR_UACCESS_DISABLE
96 mcr p15, 0, \tmp2, c3, c0, 0
98 .elseif IS_ENABLED(CONFIG_CPU_USE_DOMAINS)
100 bic \tmp2, \tmp0, #domain_mask(DOMAIN_KERNEL)
101 orr \tmp2, \tmp2, #domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT)
102 mcr p15, 0, \tmp2, c3, c0, 0
107 /* Restore the user access state previously saved by uaccess_entry */
108 .macro uaccess_exit, tsk, tmp0, tmp1
109 ldr \tmp1, [sp, #SVC_ADDR_LIMIT]
110 DACR( ldr \tmp0, [sp, #SVC_DACR])
111 str \tmp1, [\tsk, #TI_ADDR_LIMIT]
112 DACR( mcr p15, 0, \tmp0, c3, c0, 0)
117 #endif /* __ASM_UACCESS_ASM_H__ */