ARM: uaccess: consolidate uaccess asm to asm/uaccess-asm.h

Consolidate the user access assembly code to asm/uaccess-asm.h.  This
moves the csdb, check_uaccess, uaccess_mask_range_ptr, uaccess_enable,
uaccess_disable, uaccess_save, uaccess_restore macros, and creates two
new ones for exception entry and exit - uaccess_entry and uaccess_exit.

This makes the uaccess_save and uaccess_restore macros private to
asm/uaccess-asm.h.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 9992912..3546d29 100644 (file)
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -18,11 +18,11 @@
 #endif
 
 #include <asm/ptrace.h>
-#include <asm/domain.h>
 #include <asm/opcodes-virt.h>
 #include <asm/asm-offsets.h>
 #include <asm/page.h>
 #include <asm/thread_info.h>
+#include <asm/uaccess-asm.h>
 
 #define IOMEM(x)       (x)
 
@@ -446,79 +446,6 @@ THUMB(     orr     \reg , \reg , #PSR_T_BIT        )
        .size \name , . - \name
        .endm
 
-       .macro  csdb
-#ifdef CONFIG_THUMB2_KERNEL
-       .inst.w 0xf3af8014
-#else
-       .inst   0xe320f014
-#endif
-       .endm
-
-       .macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
-#ifndef CONFIG_CPU_USE_DOMAINS
-       adds    \tmp, \addr, #\size - 1
-       sbcscc  \tmp, \tmp, \limit
-       bcs     \bad
-#ifdef CONFIG_CPU_SPECTRE
-       movcs   \addr, #0
-       csdb
-#endif
-#endif
-       .endm
-
-       .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
-#ifdef CONFIG_CPU_SPECTRE
-       sub     \tmp, \limit, #1
-       subs    \tmp, \tmp, \addr       @ tmp = limit - 1 - addr
-       addhs   \tmp, \tmp, #1          @ if (tmp >= 0) {
-       subshs  \tmp, \tmp, \size       @ tmp = limit - (addr + size) }
-       movlo   \addr, #0               @ if (tmp < 0) addr = NULL
-       csdb
-#endif
-       .endm
-
-       .macro  uaccess_disable, tmp, isb=1
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
-       /*
-        * Whenever we re-enter userspace, the domains should always be
-        * set appropriately.
-        */
-       mov     \tmp, #DACR_UACCESS_DISABLE
-       mcr     p15, 0, \tmp, c3, c0, 0         @ Set domain register
-       .if     \isb
-       instr_sync
-       .endif
-#endif
-       .endm
-
-       .macro  uaccess_enable, tmp, isb=1
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
-       /*
-        * Whenever we re-enter userspace, the domains should always be
-        * set appropriately.
-        */
-       mov     \tmp, #DACR_UACCESS_ENABLE
-       mcr     p15, 0, \tmp, c3, c0, 0
-       .if     \isb
-       instr_sync
-       .endif
-#endif
-       .endm
-
-       .macro  uaccess_save, tmp
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
-       mrc     p15, 0, \tmp, c3, c0, 0
-       str     \tmp, [sp, #SVC_DACR]
-#endif
-       .endm
-
-       .macro  uaccess_restore
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
-       ldr     r0, [sp, #SVC_DACR]
-       mcr     p15, 0, r0, c3, c0, 0
-#endif
-       .endm
-
        .irp    c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
        .macro  ret\c, reg
 #if __LINUX_ARM_ARCH__ < 6

diff --git a/arch/arm/include/asm/uaccess-asm.h b/arch/arm/include/asm/uaccess-asm.h
new file mode 100644 (file)
index 0000000..d475e3e
--- /dev/null
+++ b/arch/arm/include/asm/uaccess-asm.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_UACCESS_ASM_H__
+#define __ASM_UACCESS_ASM_H__
+
+#include <asm/asm-offsets.h>
+#include <asm/domain.h>
+#include <asm/memory.h>
+#include <asm/thread_info.h>
+
+       .macro  csdb
+#ifdef CONFIG_THUMB2_KERNEL
+       .inst.w 0xf3af8014
+#else
+       .inst   0xe320f014
+#endif
+       .endm
+
+       .macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
+#ifndef CONFIG_CPU_USE_DOMAINS
+       adds    \tmp, \addr, #\size - 1
+       sbcscc  \tmp, \tmp, \limit
+       bcs     \bad
+#ifdef CONFIG_CPU_SPECTRE
+       movcs   \addr, #0
+       csdb
+#endif
+#endif
+       .endm
+
+       .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
+#ifdef CONFIG_CPU_SPECTRE
+       sub     \tmp, \limit, #1
+       subs    \tmp, \tmp, \addr       @ tmp = limit - 1 - addr
+       addhs   \tmp, \tmp, #1          @ if (tmp >= 0) {
+       subshs  \tmp, \tmp, \size       @ tmp = limit - (addr + size) }
+       movlo   \addr, #0               @ if (tmp < 0) addr = NULL
+       csdb
+#endif
+       .endm
+
+       .macro  uaccess_disable, tmp, isb=1
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+       /*
+        * Whenever we re-enter userspace, the domains should always be
+        * set appropriately.
+        */
+       mov     \tmp, #DACR_UACCESS_DISABLE
+       mcr     p15, 0, \tmp, c3, c0, 0         @ Set domain register
+       .if     \isb
+       instr_sync
+       .endif
+#endif
+       .endm
+
+       .macro  uaccess_enable, tmp, isb=1
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+       /*
+        * Whenever we re-enter userspace, the domains should always be
+        * set appropriately.
+        */
+       mov     \tmp, #DACR_UACCESS_ENABLE
+       mcr     p15, 0, \tmp, c3, c0, 0
+       .if     \isb
+       instr_sync
+       .endif
+#endif
+       .endm
+
+       .macro  uaccess_save, tmp
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+       mrc     p15, 0, \tmp, c3, c0, 0
+       str     \tmp, [sp, #SVC_DACR]
+#endif
+       .endm
+
+       .macro  uaccess_restore
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+       ldr     r0, [sp, #SVC_DACR]
+       mcr     p15, 0, r0, c3, c0, 0
+#endif
+       .endm
+
+       /*
+        * Save the address limit on entry to a privileged exception and
+        * if using PAN, save and disable usermode access.
+        */
+       .macro  uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
+       ldr     \tmp0, [\tsk, #TI_ADDR_LIMIT]
+       mov     \tmp1, #TASK_SIZE
+       str     \tmp1, [\tsk, #TI_ADDR_LIMIT]
+       str     \tmp0, [sp, #SVC_ADDR_LIMIT]
+       uaccess_save \tmp0
+       .if \disable
+       uaccess_disable \tmp0
+       .endif
+       .endm
+
+       /* Restore the user access state previously saved by uaccess_entry */
+       .macro  uaccess_exit, tsk, tmp0, tmp1
+       ldr     \tmp1, [sp, #SVC_ADDR_LIMIT]
+       uaccess_restore
+       str     \tmp1, [\tsk, #TI_ADDR_LIMIT]
+       .endm
+
+#endif /* __ASM_UACCESS_ASM_H__ */

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 77f5483..55a47df 100644 (file)
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -27,6 +27,7 @@
 #include <asm/unistd.h>
 #include <asm/tls.h>
 #include <asm/system_info.h>
+#include <asm/uaccess-asm.h>
 
 #include "entry-header.S"
 #include <asm/entry-macro-multi.S>
@@ -179,15 +180,7 @@ ENDPROC(__und_invalid)
        stmia   r7, {r2 - r6}
 
        get_thread_info tsk
-       ldr     r0, [tsk, #TI_ADDR_LIMIT]
-       mov     r1, #TASK_SIZE
-       str     r1, [tsk, #TI_ADDR_LIMIT]
-       str     r0, [sp, #SVC_ADDR_LIMIT]
-
-       uaccess_save r0
-       .if \uaccess
-       uaccess_disable r0
-       .endif
+       uaccess_entry tsk, r0, r1, r2, \uaccess
 
        .if \trace
 #ifdef CONFIG_TRACE_IRQFLAGS

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 32051ec..40db0f9 100644 (file)
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -6,6 +6,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/errno.h>
 #include <asm/thread_info.h>
+#include <asm/uaccess-asm.h>
 #include <asm/v7m.h>
 
 @ Bad Abort numbers
@@ -217,9 +218,7 @@
        blne    trace_hardirqs_off
 #endif
        .endif
-       ldr     r1, [sp, #SVC_ADDR_LIMIT]
-       uaccess_restore
-       str     r1, [tsk, #TI_ADDR_LIMIT]
+       uaccess_exit tsk, r0, r1
 
 #ifndef CONFIG_THUMB2_KERNEL
        @ ARM mode SVC restore
@@ -263,9 +262,7 @@
        @ on the stack remains correct).
        @
        .macro  svc_exit_via_fiq
-       ldr     r1, [sp, #SVC_ADDR_LIMIT]
-       uaccess_restore
-       str     r1, [tsk, #TI_ADDR_LIMIT]
+       uaccess_exit tsk, r0, r1
 #ifndef CONFIG_THUMB2_KERNEL
        @ ARM mode restore
        mov     r0, sp