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authorCatalin Marinas <catalin.marinas@arm.com>2012-03-05 11:49:32 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2012-09-17 13:42:11 +0100
commit0aea86a2176c22647a5b683768f858d880d5e05b (patch)
tree6ffad0914ef41e69c672a0862f5a10a9e9f3cb43 /arch/arm64/lib
parent2c020ed8d148f7562c01abaf875c9bbfb9a40a83 (diff)
downloadlinux-0aea86a2176c22647a5b683768f858d880d5e05b.tar.gz
arm64: User access library functions
This patch add support for various user access functions. These functions use the standard LDR/STR instructions and not the LDRT/STRT variants in order to allow kernel addresses (after set_fs(KERNEL_DS)). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm64/lib')
-rw-r--r--arch/arm64/lib/clear_user.S58
-rw-r--r--arch/arm64/lib/copy_from_user.S66
-rw-r--r--arch/arm64/lib/copy_in_user.S63
-rw-r--r--arch/arm64/lib/copy_to_user.S61
-rw-r--r--arch/arm64/lib/strncpy_from_user.S50
-rw-r--r--arch/arm64/lib/strnlen_user.S47
6 files changed, 345 insertions, 0 deletions
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
new file mode 100644
index 00000000000..6e0ed93d51f
--- /dev/null
+++ b/arch/arm64/lib/clear_user.S
@@ -0,0 +1,58 @@
+/*
+ * Based on arch/arm/lib/clear_user.S
+ *
+ * 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/>.
+ */
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+ .text
+
+/* Prototype: int __clear_user(void *addr, size_t sz)
+ * Purpose : clear some user memory
+ * Params : addr - user memory address to clear
+ * : sz - number of bytes to clear
+ * Returns : number of bytes NOT cleared
+ *
+ * Alignment fixed up by hardware.
+ */
+ENTRY(__clear_user)
+ mov x2, x1 // save the size for fixup return
+ subs x1, x1, #8
+ b.mi 2f
+1:
+USER(9f, str xzr, [x0], #8 )
+ subs x1, x1, #8
+ b.pl 1b
+2: adds x1, x1, #4
+ b.mi 3f
+USER(9f, str wzr, [x0], #4 )
+ sub x1, x1, #4
+3: adds x1, x1, #2
+ b.mi 4f
+USER(9f, strh wzr, [x0], #2 )
+ sub x1, x1, #2
+4: adds x1, x1, #1
+ b.mi 5f
+ strb wzr, [x0]
+5: mov x0, #0
+ ret
+ENDPROC(__clear_user)
+
+ .section .fixup,"ax"
+ .align 2
+9: mov x0, x2 // return the original size
+ ret
+ .previous
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
new file mode 100644
index 00000000000..5e27add9d36
--- /dev/null
+++ b/arch/arm64/lib/copy_from_user.S
@@ -0,0 +1,66 @@
+/*
+ * 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/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Copy from user space to a kernel buffer (alignment handled by the hardware)
+ *
+ * Parameters:
+ * x0 - to
+ * x1 - from
+ * x2 - n
+ * Returns:
+ * x0 - bytes not copied
+ */
+ENTRY(__copy_from_user)
+ add x4, x1, x2 // upper user buffer boundary
+ subs x2, x2, #8
+ b.mi 2f
+1:
+USER(9f, ldr x3, [x1], #8 )
+ subs x2, x2, #8
+ str x3, [x0], #8
+ b.pl 1b
+2: adds x2, x2, #4
+ b.mi 3f
+USER(9f, ldr w3, [x1], #4 )
+ sub x2, x2, #4
+ str w3, [x0], #4
+3: adds x2, x2, #2
+ b.mi 4f
+USER(9f, ldrh w3, [x1], #2 )
+ sub x2, x2, #2
+ strh w3, [x0], #2
+4: adds x2, x2, #1
+ b.mi 5f
+USER(9f, ldrb w3, [x1] )
+ strb w3, [x0]
+5: mov x0, #0
+ ret
+ENDPROC(__copy_from_user)
+
+ .section .fixup,"ax"
+ .align 2
+9: sub x2, x4, x1
+ mov x3, x2
+10: strb wzr, [x0], #1 // zero remaining buffer space
+ subs x3, x3, #1
+ b.ne 10b
+ mov x0, x2 // bytes not copied
+ ret
+ .previous
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
new file mode 100644
index 00000000000..84b6c9bb9b9
--- /dev/null
+++ b/arch/arm64/lib/copy_in_user.S
@@ -0,0 +1,63 @@
+/*
+ * Copy from user space to user space
+ *
+ * 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/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Copy from user space to user space (alignment handled by the hardware)
+ *
+ * Parameters:
+ * x0 - to
+ * x1 - from
+ * x2 - n
+ * Returns:
+ * x0 - bytes not copied
+ */
+ENTRY(__copy_in_user)
+ add x4, x0, x2 // upper user buffer boundary
+ subs x2, x2, #8
+ b.mi 2f
+1:
+USER(9f, ldr x3, [x1], #8 )
+ subs x2, x2, #8
+USER(9f, str x3, [x0], #8 )
+ b.pl 1b
+2: adds x2, x2, #4
+ b.mi 3f
+USER(9f, ldr w3, [x1], #4 )
+ sub x2, x2, #4
+USER(9f, str w3, [x0], #4 )
+3: adds x2, x2, #2
+ b.mi 4f
+USER(9f, ldrh w3, [x1], #2 )
+ sub x2, x2, #2
+USER(9f, strh w3, [x0], #2 )
+4: adds x2, x2, #1
+ b.mi 5f
+USER(9f, ldrb w3, [x1] )
+USER(9f, strb w3, [x0] )
+5: mov x0, #0
+ ret
+ENDPROC(__copy_in_user)
+
+ .section .fixup,"ax"
+ .align 2
+9: sub x0, x4, x0 // bytes not copied
+ ret
+ .previous
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
new file mode 100644
index 00000000000..a0aeeb9b7a2
--- /dev/null
+++ b/arch/arm64/lib/copy_to_user.S
@@ -0,0 +1,61 @@
+/*
+ * 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/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Copy to user space from a kernel buffer (alignment handled by the hardware)
+ *
+ * Parameters:
+ * x0 - to
+ * x1 - from
+ * x2 - n
+ * Returns:
+ * x0 - bytes not copied
+ */
+ENTRY(__copy_to_user)
+ add x4, x0, x2 // upper user buffer boundary
+ subs x2, x2, #8
+ b.mi 2f
+1:
+ ldr x3, [x1], #8
+ subs x2, x2, #8
+USER(9f, str x3, [x0], #8 )
+ b.pl 1b
+2: adds x2, x2, #4
+ b.mi 3f
+ ldr w3, [x1], #4
+ sub x2, x2, #4
+USER(9f, str w3, [x0], #4 )
+3: adds x2, x2, #2
+ b.mi 4f
+ ldrh w3, [x1], #2
+ sub x2, x2, #2
+USER(9f, strh w3, [x0], #2 )
+4: adds x2, x2, #1
+ b.mi 5f
+ ldrb w3, [x1]
+USER(9f, strb w3, [x0] )
+5: mov x0, #0
+ ret
+ENDPROC(__copy_to_user)
+
+ .section .fixup,"ax"
+ .align 2
+9: sub x0, x4, x0 // bytes not copied
+ ret
+ .previous
diff --git a/arch/arm64/lib/strncpy_from_user.S b/arch/arm64/lib/strncpy_from_user.S
new file mode 100644
index 00000000000..56e448a831a
--- /dev/null
+++ b/arch/arm64/lib/strncpy_from_user.S
@@ -0,0 +1,50 @@
+/*
+ * Based on arch/arm/lib/strncpy_from_user.S
+ *
+ * Copyright (C) 1995-2000 Russell King
+ * 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/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+
+ .text
+ .align 5
+
+/*
+ * Copy a string from user space to kernel space.
+ * x0 = dst, x1 = src, x2 = byte length
+ * returns the number of characters copied (strlen of copied string),
+ * -EFAULT on exception, or "len" if we fill the whole buffer
+ */
+ENTRY(__strncpy_from_user)
+ mov x4, x1
+1: subs x2, x2, #1
+ bmi 2f
+USER(9f, ldrb w3, [x1], #1 )
+ strb w3, [x0], #1
+ cbnz w3, 1b
+ sub x1, x1, #1 // take NUL character out of count
+2: sub x0, x1, x4
+ ret
+ENDPROC(__strncpy_from_user)
+
+ .section .fixup,"ax"
+ .align 0
+9: strb wzr, [x0] // null terminate
+ mov x0, #-EFAULT
+ ret
+ .previous
diff --git a/arch/arm64/lib/strnlen_user.S b/arch/arm64/lib/strnlen_user.S
new file mode 100644
index 00000000000..7f7b176a564
--- /dev/null
+++ b/arch/arm64/lib/strnlen_user.S
@@ -0,0 +1,47 @@
+/*
+ * Based on arch/arm/lib/strnlen_user.S
+ *
+ * Copyright (C) 1995-2000 Russell King
+ * 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/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/errno.h>
+
+ .text
+ .align 5
+
+/* Prototype: unsigned long __strnlen_user(const char *str, long n)
+ * Purpose : get length of a string in user memory
+ * Params : str - address of string in user memory
+ * Returns : length of string *including terminator*
+ * or zero on exception, or n if too long
+ */
+ENTRY(__strnlen_user)
+ mov x2, x0
+1: subs x1, x1, #1
+ b.mi 2f
+USER(9f, ldrb w3, [x0], #1 )
+ cbnz w3, 1b
+2: sub x0, x0, x2
+ ret
+ENDPROC(__strnlen_user)
+
+ .section .fixup,"ax"
+ .align 0
+9: mov x0, #0
+ ret
+ .previous