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authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-14 16:43:24 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-14 16:43:24 -0400
commita3da5bf84a97d48cfaf66c6842470fc403da5121 (patch)
treecdf66c0cff8c61eedd60601fc9dffdd1ed39b880 /arch/x86/lib/getuser.S
parent3b23e665b68387f5ee7b21f7b75ceea4d9acae4a (diff)
parentd59fdcf2ac501de99c3dfb452af5e254d4342886 (diff)
Merge branch 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (821 commits) x86: make 64bit hpet_set_mapping to use ioremap too, v2 x86: get x86_phys_bits early x86: max_low_pfn_mapped fix #4 x86: change _node_to_cpumask_ptr to return const ptr x86: I/O APIC: remove an IRQ2-mask hack x86: fix numaq_tsc_disable calling x86, e820: remove end_user_pfn x86: max_low_pfn_mapped fix, #3 x86: max_low_pfn_mapped fix, #2 x86: max_low_pfn_mapped fix, #1 x86_64: fix delayed signals x86: remove conflicting nx6325 and nx6125 quirks x86: Recover timer_ack lost in the merge of the NMI watchdog x86: I/O APIC: Never configure IRQ2 x86: L-APIC: Always fully configure IRQ0 x86: L-APIC: Set IRQ0 as edge-triggered x86: merge dwarf2 headers x86: use AS_CFI instead of UNWIND_INFO x86: use ignore macro instead of hash comment x86: use matching CFI_ENDPROC ...
Diffstat (limited to 'arch/x86/lib/getuser.S')
-rw-r--r--arch/x86/lib/getuser.S104
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
new file mode 100644
index 000000000000..ad374003742f
--- /dev/null
+++ b/arch/x86/lib/getuser.S
@@ -0,0 +1,104 @@
1/*
2 * __get_user functions.
3 *
4 * (C) Copyright 1998 Linus Torvalds
5 * (C) Copyright 2005 Andi Kleen
6 * (C) Copyright 2008 Glauber Costa
7 *
8 * These functions have a non-standard call interface
9 * to make them more efficient, especially as they
10 * return an error value in addition to the "real"
11 * return value.
12 */
13
14/*
15 * __get_user_X
16 *
17 * Inputs: %[r|e]ax contains the address.
18 * The register is modified, but all changes are undone
19 * before returning because the C code doesn't know about it.
20 *
21 * Outputs: %[r|e]ax is error code (0 or -EFAULT)
22 * %[r|e]dx contains zero-extended value
23 *
24 *
25 * These functions should not modify any other registers,
26 * as they get called from within inline assembly.
27 */
28
29#include <linux/linkage.h>
30#include <asm/dwarf2.h>
31#include <asm/page.h>
32#include <asm/errno.h>
33#include <asm/asm-offsets.h>
34#include <asm/thread_info.h>
35#include <asm/asm.h>
36
37 .text
38ENTRY(__get_user_1)
39 CFI_STARTPROC
40 GET_THREAD_INFO(%_ASM_DX)
41 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
42 jae bad_get_user
431: movzb (%_ASM_AX),%edx
44 xor %eax,%eax
45 ret
46 CFI_ENDPROC
47ENDPROC(__get_user_1)
48
49ENTRY(__get_user_2)
50 CFI_STARTPROC
51 add $1,%_ASM_AX
52 jc bad_get_user
53 GET_THREAD_INFO(%_ASM_DX)
54 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
55 jae bad_get_user
562: movzwl -1(%_ASM_AX),%edx
57 xor %eax,%eax
58 ret
59 CFI_ENDPROC
60ENDPROC(__get_user_2)
61
62ENTRY(__get_user_4)
63 CFI_STARTPROC
64 add $3,%_ASM_AX
65 jc bad_get_user
66 GET_THREAD_INFO(%_ASM_DX)
67 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
68 jae bad_get_user
693: mov -3(%_ASM_AX),%edx
70 xor %eax,%eax
71 ret
72 CFI_ENDPROC
73ENDPROC(__get_user_4)
74
75#ifdef CONFIG_X86_64
76ENTRY(__get_user_8)
77 CFI_STARTPROC
78 add $7,%_ASM_AX
79 jc bad_get_user
80 GET_THREAD_INFO(%_ASM_DX)
81 cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
82 jae bad_get_user
834: movq -7(%_ASM_AX),%_ASM_DX
84 xor %eax,%eax
85 ret
86 CFI_ENDPROC
87ENDPROC(__get_user_8)
88#endif
89
90bad_get_user:
91 CFI_STARTPROC
92 xor %edx,%edx
93 mov $(-EFAULT),%_ASM_AX
94 ret
95 CFI_ENDPROC
96END(bad_get_user)
97
98.section __ex_table,"a"
99 _ASM_PTR 1b,bad_get_user
100 _ASM_PTR 2b,bad_get_user
101 _ASM_PTR 3b,bad_get_user
102#ifdef CONFIG_X86_64
103 _ASM_PTR 4b,bad_get_user
104#endif