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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/x86/lib/putuser.S
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/lib/putuser.S')
-rw-r--r--arch/x86/lib/putuser.S103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
new file mode 100644
index 000000000..96dce5fe2
--- /dev/null
+++ b/arch/x86/lib/putuser.S
@@ -0,0 +1,103 @@
+/* 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: %eax is error code (0 or -EFAULT)
+ *
+ * These functions should not modify any other registers,
+ * as they get called from within inline assembly.
+ */
+
+#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX
+#define EXIT ASM_CLAC ; \
+ ret
+
+.text
+ENTRY(__put_user_1)
+ ENTER
+ cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+1: movb %al,(%_ASM_CX)
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_1)
+EXPORT_SYMBOL(__put_user_1)
+
+ENTRY(__put_user_2)
+ ENTER
+ mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
+ sub $1,%_ASM_BX
+ cmp %_ASM_BX,%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+2: movw %ax,(%_ASM_CX)
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_2)
+EXPORT_SYMBOL(__put_user_2)
+
+ENTRY(__put_user_4)
+ ENTER
+ mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
+ sub $3,%_ASM_BX
+ cmp %_ASM_BX,%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+3: movl %eax,(%_ASM_CX)
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_4)
+EXPORT_SYMBOL(__put_user_4)
+
+ENTRY(__put_user_8)
+ ENTER
+ mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
+ sub $7,%_ASM_BX
+ cmp %_ASM_BX,%_ASM_CX
+ jae bad_put_user
+ ASM_STAC
+4: mov %_ASM_AX,(%_ASM_CX)
+#ifdef CONFIG_X86_32
+5: movl %edx,4(%_ASM_CX)
+#endif
+ xor %eax,%eax
+ EXIT
+ENDPROC(__put_user_8)
+EXPORT_SYMBOL(__put_user_8)
+
+bad_put_user:
+ movl $-EFAULT,%eax
+ EXIT
+END(bad_put_user)
+
+ _ASM_EXTABLE(1b,bad_put_user)
+ _ASM_EXTABLE(2b,bad_put_user)
+ _ASM_EXTABLE(3b,bad_put_user)
+ _ASM_EXTABLE(4b,bad_put_user)
+#ifdef CONFIG_X86_32
+ _ASM_EXTABLE(5b,bad_put_user)
+#endif