summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/kuser32.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/kernel/kuser32.S')
-rw-r--r--arch/arm64/kernel/kuser32.S118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm64/kernel/kuser32.S b/arch/arm64/kernel/kuser32.S
new file mode 100644
index 000000000..997e6b27f
--- /dev/null
+++ b/arch/arm64/kernel/kuser32.S
@@ -0,0 +1,118 @@
+/*
+ * Low-level user helpers placed in the vectors page for AArch32.
+ * Based on the kuser helpers in arch/arm/kernel/entry-armv.S.
+ *
+ * Copyright (C) 2005-2011 Nicolas Pitre <nico@fluxnic.net>
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * AArch32 user helpers.
+ *
+ * Each segment is 32-byte aligned and will be moved to the top of the high
+ * vector page. New segments (if ever needed) must be added in front of
+ * existing ones. This mechanism should be used only for things that are
+ * really small and justified, and not be abused freely.
+ *
+ * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
+ */
+
+#include <asm/unistd.h>
+
+ .align 5
+ .globl __kuser_helper_start
+__kuser_helper_start:
+
+__kuser_cmpxchg64: // 0xffff0f60
+ .inst 0xe92d00f0 // push {r4, r5, r6, r7}
+ .inst 0xe1c040d0 // ldrd r4, r5, [r0]
+ .inst 0xe1c160d0 // ldrd r6, r7, [r1]
+ .inst 0xe1b20f9f // 1: ldrexd r0, r1, [r2]
+ .inst 0xe0303004 // eors r3, r0, r4
+ .inst 0x00313005 // eoreqs r3, r1, r5
+ .inst 0x01a23e96 // stlexdeq r3, r6, [r2]
+ .inst 0x03330001 // teqeq r3, #1
+ .inst 0x0afffff9 // beq 1b
+ .inst 0xf57ff05b // dmb ish
+ .inst 0xe2730000 // rsbs r0, r3, #0
+ .inst 0xe8bd00f0 // pop {r4, r5, r6, r7}
+ .inst 0xe12fff1e // bx lr
+
+ .align 5
+__kuser_memory_barrier: // 0xffff0fa0
+ .inst 0xf57ff05b // dmb ish
+ .inst 0xe12fff1e // bx lr
+
+ .align 5
+__kuser_cmpxchg: // 0xffff0fc0
+ .inst 0xe1923f9f // 1: ldrex r3, [r2]
+ .inst 0xe0533000 // subs r3, r3, r0
+ .inst 0x01823e91 // stlexeq r3, r1, [r2]
+ .inst 0x03330001 // teqeq r3, #1
+ .inst 0x0afffffa // beq 1b
+ .inst 0xf57ff05b // dmb ish
+ .inst 0xe2730000 // rsbs r0, r3, #0
+ .inst 0xe12fff1e // bx lr
+
+ .align 5
+__kuser_get_tls: // 0xffff0fe0
+ .inst 0xee1d0f70 // mrc p15, 0, r0, c13, c0, 3
+ .inst 0xe12fff1e // bx lr
+ .rep 5
+ .word 0
+ .endr
+
+__kuser_helper_version: // 0xffff0ffc
+ .word ((__kuser_helper_end - __kuser_helper_start) >> 5)
+ .globl __kuser_helper_end
+__kuser_helper_end:
+
+/*
+ * AArch32 sigreturn code
+ *
+ * For ARM syscalls, the syscall number has to be loaded into r7.
+ * We do not support an OABI userspace.
+ *
+ * For Thumb syscalls, we also pass the syscall number via r7. We therefore
+ * need two 16-bit instructions.
+ */
+ .globl __aarch32_sigret_code_start
+__aarch32_sigret_code_start:
+
+ /*
+ * ARM Code
+ */
+ .byte __NR_compat_sigreturn, 0x70, 0xa0, 0xe3 // mov r7, #__NR_compat_sigreturn
+ .byte __NR_compat_sigreturn, 0x00, 0x00, 0xef // svc #__NR_compat_sigreturn
+
+ /*
+ * Thumb code
+ */
+ .byte __NR_compat_sigreturn, 0x27 // svc #__NR_compat_sigreturn
+ .byte __NR_compat_sigreturn, 0xdf // mov r7, #__NR_compat_sigreturn
+
+ /*
+ * ARM code
+ */
+ .byte __NR_compat_rt_sigreturn, 0x70, 0xa0, 0xe3 // mov r7, #__NR_compat_rt_sigreturn
+ .byte __NR_compat_rt_sigreturn, 0x00, 0x00, 0xef // svc #__NR_compat_rt_sigreturn
+
+ /*
+ * Thumb code
+ */
+ .byte __NR_compat_rt_sigreturn, 0x27 // svc #__NR_compat_rt_sigreturn
+ .byte __NR_compat_rt_sigreturn, 0xdf // mov r7, #__NR_compat_rt_sigreturn
+
+ .globl __aarch32_sigret_code_end
+__aarch32_sigret_code_end: