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-rw-r--r--arch/arm/include/asm/uaccess-asm.h25
1 files changed, 20 insertions, 5 deletions
diff --git a/arch/arm/include/asm/uaccess-asm.h b/arch/arm/include/asm/uaccess-asm.h
index e46468b91eaa..907571fd05c6 100644
--- a/arch/arm/include/asm/uaccess-asm.h
+++ b/arch/arm/include/asm/uaccess-asm.h
@@ -67,15 +67,21 @@
#endif
.endm
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+#if defined(CONFIG_CPU_SW_DOMAIN_PAN) || defined(CONFIG_CPU_USE_DOMAINS)
#define DACR(x...) x
#else
#define DACR(x...)
#endif
/*
- * Save the address limit on entry to a privileged exception and
- * if using PAN, save and disable usermode access.
+ * Save the address limit on entry to a privileged exception.
+ *
+ * If we are using the DACR for kernel access by the user accessors
+ * (CONFIG_CPU_USE_DOMAINS=y), always reset the DACR kernel domain
+ * back to client mode, whether or not \disable is set.
+ *
+ * If we are using SW PAN, set the DACR user domain to no access
+ * if \disable is set.
*/
.macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
ldr \tmp1, [\tsk, #TI_ADDR_LIMIT]
@@ -84,8 +90,17 @@
DACR( mrc p15, 0, \tmp0, c3, c0, 0)
DACR( str \tmp0, [sp, #SVC_DACR])
str \tmp1, [sp, #SVC_ADDR_LIMIT]
- .if \disable
- uaccess_disable \tmp0
+ .if \disable && IS_ENABLED(CONFIG_CPU_SW_DOMAIN_PAN)
+ /* kernel=client, user=no access */
+ mov \tmp2, #DACR_UACCESS_DISABLE
+ mcr p15, 0, \tmp2, c3, c0, 0
+ instr_sync
+ .elseif IS_ENABLED(CONFIG_CPU_USE_DOMAINS)
+ /* kernel=client */
+ bic \tmp2, \tmp0, #domain_mask(DOMAIN_KERNEL)
+ orr \tmp2, \tmp2, #domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT)
+ mcr p15, 0, \tmp2, c3, c0, 0
+ instr_sync
.endif
.endm