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-rw-r--r--arch/x86/lib/putuser.S122
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
new file mode 100644
index 000000000..b7dfd6024
--- /dev/null
+++ b/arch/x86/lib/putuser.S
@@ -0,0 +1,122 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * __put_user functions.
+ *
+ * (C) Copyright 2005 Linus Torvalds
+ * (C) Copyright 2005 Andi Kleen
+ * (C) Copyright 2008 Glauber Costa
+ *
+ * These functions have a non-standard call interface
+ * to make them more efficient, especially as they
+ * return an error value in addition to the "real"
+ * return value.
+ */
+#include <linux/linkage.h>
+#include <asm/thread_info.h>
+#include <asm/errno.h>
+#include <asm/asm.h>
+#include <asm/smap.h>
+#include <asm/export.h>
+
+
+/*
+ * __put_user_X
+ *
+ * Inputs: %eax[:%edx] contains the data
+ * %ecx contains the address
+ *
+ * Outputs: %ecx is error code (0 or -EFAULT)
+ *
+ * Clobbers: %ebx needed for task pointer
+ *
+ * These functions should not modify any other registers,
+ * as they get called from within inline assembly.
+ */
+
+#ifdef CONFIG_X86_5LEVEL
+#define LOAD_TASK_SIZE_MINUS_N(n) \
+ ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \
+ __stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57
+#else
+#define LOAD_TASK_SIZE_MINUS_N(n) \
+ mov $(TASK_SIZE_MAX - (n)),%_ASM_BX
+#endif
+
+.text
+SYM_FUNC_START(__put_user_1)
+ LOAD_TASK_SIZE_MINUS_N(0)
+ cmp %_ASM_BX,%_ASM_CX
+ jae .Lbad_put_user
+SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL)
+ ENDBR
+ ASM_STAC
+1: movb %al,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_1)
+EXPORT_SYMBOL(__put_user_1)
+EXPORT_SYMBOL(__put_user_nocheck_1)
+
+SYM_FUNC_START(__put_user_2)
+ LOAD_TASK_SIZE_MINUS_N(1)
+ cmp %_ASM_BX,%_ASM_CX
+ jae .Lbad_put_user
+SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL)
+ ENDBR
+ ASM_STAC
+2: movw %ax,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_2)
+EXPORT_SYMBOL(__put_user_2)
+EXPORT_SYMBOL(__put_user_nocheck_2)
+
+SYM_FUNC_START(__put_user_4)
+ LOAD_TASK_SIZE_MINUS_N(3)
+ cmp %_ASM_BX,%_ASM_CX
+ jae .Lbad_put_user
+SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL)
+ ENDBR
+ ASM_STAC
+3: movl %eax,(%_ASM_CX)
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_4)
+EXPORT_SYMBOL(__put_user_4)
+EXPORT_SYMBOL(__put_user_nocheck_4)
+
+SYM_FUNC_START(__put_user_8)
+ LOAD_TASK_SIZE_MINUS_N(7)
+ cmp %_ASM_BX,%_ASM_CX
+ jae .Lbad_put_user
+SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL)
+ ENDBR
+ ASM_STAC
+4: mov %_ASM_AX,(%_ASM_CX)
+#ifdef CONFIG_X86_32
+5: movl %edx,4(%_ASM_CX)
+#endif
+ xor %ecx,%ecx
+ ASM_CLAC
+ RET
+SYM_FUNC_END(__put_user_8)
+EXPORT_SYMBOL(__put_user_8)
+EXPORT_SYMBOL(__put_user_nocheck_8)
+
+SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
+ ASM_CLAC
+.Lbad_put_user:
+ movl $-EFAULT,%ecx
+ RET
+SYM_CODE_END(.Lbad_put_user_clac)
+
+ _ASM_EXTABLE_UA(1b, .Lbad_put_user_clac)
+ _ASM_EXTABLE_UA(2b, .Lbad_put_user_clac)
+ _ASM_EXTABLE_UA(3b, .Lbad_put_user_clac)
+ _ASM_EXTABLE_UA(4b, .Lbad_put_user_clac)
+#ifdef CONFIG_X86_32
+ _ASM_EXTABLE_UA(5b, .Lbad_put_user_clac)
+#endif