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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-26 19:57:16 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-26 19:57:16 -0400
commit1e2aec873ad6d16538512dbb96853caa1fa076af (patch)
treed792b19ac47be44debd24610ae27f1330fa490e4 /arch
parentae32adc1e06d096399f195eeda12d443d53539c4 (diff)
parent2c66f623631709aa5f2e4c14c7e089682e7394a3 (diff)
Merge branch 'generic-string-functions'
This makes <asm/word-at-a-time.h> actually live up to its promise of allowing architectures to help tune the string functions that do their work a word at a time. David had already taken the x86 strncpy_from_user() function, modified it to work on sparc, and then done the extra work to make it generically useful. This then expands on that work by making x86 use that generic version, completing the circle. But more importantly, it fixes up the word-at-a-time interfaces so that it's now easy to also support things like strnlen_user(), and pretty much most random string functions. David reports that it all works fine on sparc, and Jonas Bonn reported that an earlier version of this worked on OpenRISC too. It's pretty easy for architectures to add support for this and just replace their private versions with the generic code. * generic-string-functions: sparc: use the new generic strnlen_user() function x86: use the new generic strnlen_user() function lib: add generic strnlen_user() function word-at-a-time: make the interfaces truly generic x86: use generic strncpy_from_user routine
Diffstat (limited to 'arch')
-rw-r--r--arch/openrisc/include/asm/Kbuild1
-rw-r--r--arch/sparc/Kconfig1
-rw-r--r--arch/sparc/include/asm/Kbuild1
-rw-r--r--arch/sparc/include/asm/uaccess_32.h22
-rw-r--r--arch/sparc/include/asm/uaccess_64.h8
-rw-r--r--arch/sparc/lib/Makefile1
-rw-r--r--arch/sparc/lib/ksyms.c2
-rw-r--r--arch/sparc/lib/strlen_user_32.S109
-rw-r--r--arch/sparc/lib/strlen_user_64.S97
-rw-r--r--arch/x86/Kconfig2
-rw-r--r--arch/x86/include/asm/uaccess.h4
-rw-r--r--arch/x86/include/asm/uaccess_32.h17
-rw-r--r--arch/x86/include/asm/uaccess_64.h3
-rw-r--r--arch/x86/include/asm/word-at-a-time.h32
-rw-r--r--arch/x86/lib/usercopy.c97
-rw-r--r--arch/x86/lib/usercopy_32.c41
-rw-r--r--arch/x86/lib/usercopy_64.c48
17 files changed, 46 insertions, 440 deletions
diff --git a/arch/openrisc/include/asm/Kbuild b/arch/openrisc/include/asm/Kbuild
index c936483bc8e2..3f35c38d7b64 100644
--- a/arch/openrisc/include/asm/Kbuild
+++ b/arch/openrisc/include/asm/Kbuild
@@ -66,3 +66,4 @@ generic-y += topology.h
66generic-y += types.h 66generic-y += types.h
67generic-y += ucontext.h 67generic-y += ucontext.h
68generic-y += user.h 68generic-y += user.h
69generic-y += word-at-a-time.h
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 15e9e05740da..83bd051754e1 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -35,6 +35,7 @@ config SPARC
35 select GENERIC_CMOS_UPDATE 35 select GENERIC_CMOS_UPDATE
36 select GENERIC_CLOCKEVENTS 36 select GENERIC_CLOCKEVENTS
37 select GENERIC_STRNCPY_FROM_USER 37 select GENERIC_STRNCPY_FROM_USER
38 select GENERIC_STRNLEN_USER
38 39
39config SPARC32 40config SPARC32
40 def_bool !64BIT 41 def_bool !64BIT
diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild
index 2c2e38821f60..67f83e0a0d68 100644
--- a/arch/sparc/include/asm/Kbuild
+++ b/arch/sparc/include/asm/Kbuild
@@ -21,3 +21,4 @@ generic-y += div64.h
21generic-y += local64.h 21generic-y += local64.h
22generic-y += irq_regs.h 22generic-y += irq_regs.h
23generic-y += local.h 23generic-y += local.h
24generic-y += word-at-a-time.h
diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 59586b57ef1a..53a28dd59f59 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -16,6 +16,8 @@
16 16
17#ifndef __ASSEMBLY__ 17#ifndef __ASSEMBLY__
18 18
19#include <asm/processor.h>
20
19#define ARCH_HAS_SORT_EXTABLE 21#define ARCH_HAS_SORT_EXTABLE
20#define ARCH_HAS_SEARCH_EXTABLE 22#define ARCH_HAS_SEARCH_EXTABLE
21 23
@@ -304,24 +306,8 @@ static inline unsigned long clear_user(void __user *addr, unsigned long n)
304 return n; 306 return n;
305} 307}
306 308
307extern long __strlen_user(const char __user *); 309extern __must_check long strlen_user(const char __user *str);
308extern long __strnlen_user(const char __user *, long len); 310extern __must_check long strnlen_user(const char __user *str, long n);
309
310static inline long strlen_user(const char __user *str)
311{
312 if (!access_ok(VERIFY_READ, str, 0))
313 return 0;
314 else
315 return __strlen_user(str);
316}
317
318static inline long strnlen_user(const char __user *str, long len)
319{
320 if (!access_ok(VERIFY_READ, str, 0))
321 return 0;
322 else
323 return __strnlen_user(str, len);
324}
325 311
326#endif /* __ASSEMBLY__ */ 312#endif /* __ASSEMBLY__ */
327 313
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index dcdfb89cbf3f..7c831d848b4e 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -17,6 +17,8 @@
17 17
18#ifndef __ASSEMBLY__ 18#ifndef __ASSEMBLY__
19 19
20#include <asm/processor.h>
21
20/* 22/*
21 * Sparc64 is segmented, though more like the M68K than the I386. 23 * Sparc64 is segmented, though more like the M68K than the I386.
22 * We use the secondary ASI to address user memory, which references a 24 * We use the secondary ASI to address user memory, which references a
@@ -257,11 +259,9 @@ extern unsigned long __must_check __clear_user(void __user *, unsigned long);
257 259
258#define clear_user __clear_user 260#define clear_user __clear_user
259 261
260extern long __strlen_user(const char __user *); 262extern __must_check long strlen_user(const char __user *str);
261extern long __strnlen_user(const char __user *, long len); 263extern __must_check long strnlen_user(const char __user *str, long n);
262 264
263#define strlen_user __strlen_user
264#define strnlen_user __strnlen_user
265#define __copy_to_user_inatomic ___copy_to_user 265#define __copy_to_user_inatomic ___copy_to_user
266#define __copy_from_user_inatomic ___copy_from_user 266#define __copy_from_user_inatomic ___copy_from_user
267 267
diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 943d98dc4cdb..dff4096f3dec 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -10,7 +10,6 @@ lib-y += strlen.o
10lib-y += checksum_$(BITS).o 10lib-y += checksum_$(BITS).o
11lib-$(CONFIG_SPARC32) += blockops.o 11lib-$(CONFIG_SPARC32) += blockops.o
12lib-y += memscan_$(BITS).o memcmp.o strncmp_$(BITS).o 12lib-y += memscan_$(BITS).o memcmp.o strncmp_$(BITS).o
13lib-y += strlen_user_$(BITS).o
14lib-$(CONFIG_SPARC32) += divdi3.o udivdi3.o 13lib-$(CONFIG_SPARC32) += divdi3.o udivdi3.o
15lib-$(CONFIG_SPARC32) += copy_user.o locks.o 14lib-$(CONFIG_SPARC32) += copy_user.o locks.o
16lib-$(CONFIG_SPARC64) += atomic_64.o 15lib-$(CONFIG_SPARC64) += atomic_64.o
diff --git a/arch/sparc/lib/ksyms.c b/arch/sparc/lib/ksyms.c
index 6b278abdb63d..3b31218cafc6 100644
--- a/arch/sparc/lib/ksyms.c
+++ b/arch/sparc/lib/ksyms.c
@@ -15,8 +15,6 @@
15 15
16/* string functions */ 16/* string functions */
17EXPORT_SYMBOL(strlen); 17EXPORT_SYMBOL(strlen);
18EXPORT_SYMBOL(__strlen_user);
19EXPORT_SYMBOL(__strnlen_user);
20EXPORT_SYMBOL(strncmp); 18EXPORT_SYMBOL(strncmp);
21 19
22/* mem* functions */ 20/* mem* functions */
diff --git a/arch/sparc/lib/strlen_user_32.S b/arch/sparc/lib/strlen_user_32.S
deleted file mode 100644
index 8c8a371df3c9..000000000000
--- a/arch/sparc/lib/strlen_user_32.S
+++ /dev/null
@@ -1,109 +0,0 @@
1/* strlen_user.S: Sparc optimized strlen_user code
2 *
3 * Return length of string in userspace including terminating 0
4 * or 0 for error
5 *
6 * Copyright (C) 1991,1996 Free Software Foundation
7 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
8 * Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9 */
10
11#define LO_MAGIC 0x01010101
12#define HI_MAGIC 0x80808080
13
1410:
15 ldub [%o0], %o5
16 cmp %o5, 0
17 be 1f
18 add %o0, 1, %o0
19 andcc %o0, 3, %g0
20 be 4f
21 or %o4, %lo(HI_MAGIC), %o3
2211:
23 ldub [%o0], %o5
24 cmp %o5, 0
25 be 2f
26 add %o0, 1, %o0
27 andcc %o0, 3, %g0
28 be 5f
29 sethi %hi(LO_MAGIC), %o4
3012:
31 ldub [%o0], %o5
32 cmp %o5, 0
33 be 3f
34 add %o0, 1, %o0
35 b 13f
36 or %o4, %lo(LO_MAGIC), %o2
371:
38 retl
39 mov 1, %o0
402:
41 retl
42 mov 2, %o0
433:
44 retl
45 mov 3, %o0
46
47 .align 4
48 .global __strlen_user, __strnlen_user
49__strlen_user:
50 sethi %hi(32768), %o1
51__strnlen_user:
52 mov %o1, %g1
53 mov %o0, %o1
54 andcc %o0, 3, %g0
55 bne 10b
56 sethi %hi(HI_MAGIC), %o4
57 or %o4, %lo(HI_MAGIC), %o3
584:
59 sethi %hi(LO_MAGIC), %o4
605:
61 or %o4, %lo(LO_MAGIC), %o2
6213:
63 ld [%o0], %o5
642:
65 sub %o5, %o2, %o4
66 andcc %o4, %o3, %g0
67 bne 82f
68 add %o0, 4, %o0
69 sub %o0, %o1, %g2
7081: cmp %g2, %g1
71 blu 13b
72 mov %o0, %o4
73 ba,a 1f
74
75 /* Check every byte. */
7682: srl %o5, 24, %g5
77 andcc %g5, 0xff, %g0
78 be 1f
79 add %o0, -3, %o4
80 srl %o5, 16, %g5
81 andcc %g5, 0xff, %g0
82 be 1f
83 add %o4, 1, %o4
84 srl %o5, 8, %g5
85 andcc %g5, 0xff, %g0
86 be 1f
87 add %o4, 1, %o4
88 andcc %o5, 0xff, %g0
89 bne 81b
90 sub %o0, %o1, %g2
91
92 add %o4, 1, %o4
931:
94 retl
95 sub %o4, %o1, %o0
96
97 .section .fixup,#alloc,#execinstr
98 .align 4
999:
100 retl
101 clr %o0
102
103 .section __ex_table,#alloc
104 .align 4
105
106 .word 10b, 9b
107 .word 11b, 9b
108 .word 12b, 9b
109 .word 13b, 9b
diff --git a/arch/sparc/lib/strlen_user_64.S b/arch/sparc/lib/strlen_user_64.S
deleted file mode 100644
index c3df71fa4928..000000000000
--- a/arch/sparc/lib/strlen_user_64.S
+++ /dev/null
@@ -1,97 +0,0 @@
1/* strlen_user.S: Sparc64 optimized strlen_user code
2 *
3 * Return length of string in userspace including terminating 0
4 * or 0 for error
5 *
6 * Copyright (C) 1991,1996 Free Software Foundation
7 * Copyright (C) 1996,1999 David S. Miller (davem@redhat.com)
8 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
9 */
10
11#include <linux/linkage.h>
12#include <asm/asi.h>
13
14#define LO_MAGIC 0x01010101
15#define HI_MAGIC 0x80808080
16
17 .align 4
18ENTRY(__strlen_user)
19 sethi %hi(32768), %o1
20ENTRY(__strnlen_user)
21 mov %o1, %g1
22 mov %o0, %o1
23 andcc %o0, 3, %g0
24 be,pt %icc, 9f
25 sethi %hi(HI_MAGIC), %o4
2610: lduba [%o0] %asi, %o5
27 brz,pn %o5, 21f
28 add %o0, 1, %o0
29 andcc %o0, 3, %g0
30 be,pn %icc, 4f
31 or %o4, %lo(HI_MAGIC), %o3
3211: lduba [%o0] %asi, %o5
33 brz,pn %o5, 22f
34 add %o0, 1, %o0
35 andcc %o0, 3, %g0
36 be,pt %icc, 13f
37 srl %o3, 7, %o2
3812: lduba [%o0] %asi, %o5
39 brz,pn %o5, 23f
40 add %o0, 1, %o0
41 ba,pt %icc, 2f
4215: lda [%o0] %asi, %o5
439: or %o4, %lo(HI_MAGIC), %o3
444: srl %o3, 7, %o2
4513: lda [%o0] %asi, %o5
462: sub %o5, %o2, %o4
47 andcc %o4, %o3, %g0
48 bne,pn %icc, 82f
49 add %o0, 4, %o0
50 sub %o0, %o1, %g2
5181: cmp %g2, %g1
52 blu,pt %icc, 13b
53 mov %o0, %o4
54 ba,a,pt %xcc, 1f
55
56 /* Check every byte. */
5782: srl %o5, 24, %g7
58 andcc %g7, 0xff, %g0
59 be,pn %icc, 1f
60 add %o0, -3, %o4
61 srl %o5, 16, %g7
62 andcc %g7, 0xff, %g0
63 be,pn %icc, 1f
64 add %o4, 1, %o4
65 srl %o5, 8, %g7
66 andcc %g7, 0xff, %g0
67 be,pn %icc, 1f
68 add %o4, 1, %o4
69 andcc %o5, 0xff, %g0
70 bne,pt %icc, 81b
71 sub %o0, %o1, %g2
72 add %o4, 1, %o4
731: retl
74 sub %o4, %o1, %o0
7521: retl
76 mov 1, %o0
7722: retl
78 mov 2, %o0
7923: retl
80 mov 3, %o0
81ENDPROC(__strlen_user)
82ENDPROC(__strnlen_user)
83
84 .section .fixup,#alloc,#execinstr
85 .align 4
8630:
87 retl
88 clr %o0
89
90 .section __ex_table,"a"
91 .align 4
92
93 .word 10b, 30b
94 .word 11b, 30b
95 .word 12b, 30b
96 .word 15b, 30b
97 .word 13b, 30b
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 81c3e8be789a..d700811785ea 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -93,6 +93,8 @@ config X86
93 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 93 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
94 select GENERIC_TIME_VSYSCALL if X86_64 94 select GENERIC_TIME_VSYSCALL if X86_64
95 select KTIME_SCALAR if X86_32 95 select KTIME_SCALAR if X86_32
96 select GENERIC_STRNCPY_FROM_USER
97 select GENERIC_STRNLEN_USER
96 98
97config INSTRUCTION_DECODER 99config INSTRUCTION_DECODER
98 def_bool (KPROBES || PERF_EVENTS || UPROBES) 100 def_bool (KPROBES || PERF_EVENTS || UPROBES)
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 851fe0dc13bc..04cd6882308e 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -32,6 +32,7 @@
32 32
33#define segment_eq(a, b) ((a).seg == (b).seg) 33#define segment_eq(a, b) ((a).seg == (b).seg)
34 34
35#define user_addr_max() (current_thread_info()->addr_limit.seg)
35#define __addr_ok(addr) \ 36#define __addr_ok(addr) \
36 ((unsigned long __force)(addr) < \ 37 ((unsigned long __force)(addr) < \
37 (current_thread_info()->addr_limit.seg)) 38 (current_thread_info()->addr_limit.seg))
@@ -565,6 +566,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
565extern __must_check long 566extern __must_check long
566strncpy_from_user(char *dst, const char __user *src, long count); 567strncpy_from_user(char *dst, const char __user *src, long count);
567 568
569extern __must_check long strlen_user(const char __user *str);
570extern __must_check long strnlen_user(const char __user *str, long n);
571
568/* 572/*
569 * movsl can be slow when source and dest are not both 8-byte aligned 573 * movsl can be slow when source and dest are not both 8-byte aligned
570 */ 574 */
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 8084bc73b18c..576e39bca6ad 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -213,23 +213,6 @@ static inline unsigned long __must_check copy_from_user(void *to,
213 return n; 213 return n;
214} 214}
215 215
216/**
217 * strlen_user: - Get the size of a string in user space.
218 * @str: The string to measure.
219 *
220 * Context: User context only. This function may sleep.
221 *
222 * Get the size of a NUL-terminated string in user space.
223 *
224 * Returns the size of the string INCLUDING the terminating NUL.
225 * On exception, returns 0.
226 *
227 * If there is a limit on the length of a valid string, you may wish to
228 * consider using strnlen_user() instead.
229 */
230#define strlen_user(str) strnlen_user(str, LONG_MAX)
231
232long strnlen_user(const char __user *str, long n);
233unsigned long __must_check clear_user(void __user *mem, unsigned long len); 216unsigned long __must_check clear_user(void __user *mem, unsigned long len);
234unsigned long __must_check __clear_user(void __user *mem, unsigned long len); 217unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
235 218
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index fcd4b6f3ef02..8e796fbbf9c6 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -208,9 +208,6 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
208 } 208 }
209} 209}
210 210
211__must_check long strnlen_user(const char __user *str, long n);
212__must_check long __strnlen_user(const char __user *str, long n);
213__must_check long strlen_user(const char __user *str);
214__must_check unsigned long clear_user(void __user *mem, unsigned long len); 211__must_check unsigned long clear_user(void __user *mem, unsigned long len);
215__must_check unsigned long __clear_user(void __user *mem, unsigned long len); 212__must_check unsigned long __clear_user(void __user *mem, unsigned long len);
216 213
diff --git a/arch/x86/include/asm/word-at-a-time.h b/arch/x86/include/asm/word-at-a-time.h
index ae03facfadd6..5b238981542a 100644
--- a/arch/x86/include/asm/word-at-a-time.h
+++ b/arch/x86/include/asm/word-at-a-time.h
@@ -10,6 +10,11 @@
10 * bit count instruction, that might be better than the multiply 10 * bit count instruction, that might be better than the multiply
11 * and shift, for example. 11 * and shift, for example.
12 */ 12 */
13struct word_at_a_time {
14 const unsigned long one_bits, high_bits;
15};
16
17#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
13 18
14#ifdef CONFIG_64BIT 19#ifdef CONFIG_64BIT
15 20
@@ -37,10 +42,31 @@ static inline long count_masked_bytes(long mask)
37 42
38#endif 43#endif
39 44
40/* Return the high bit set in the first byte that is a zero */ 45/* Return nonzero if it has a zero */
41static inline unsigned long has_zero(unsigned long a) 46static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
47{
48 unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
49 *bits = mask;
50 return mask;
51}
52
53static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
54{
55 return bits;
56}
57
58static inline unsigned long create_zero_mask(unsigned long bits)
59{
60 bits = (bits - 1) & ~bits;
61 return bits >> 7;
62}
63
64/* The mask we created is directly usable as a bytemask */
65#define zero_bytemask(mask) (mask)
66
67static inline unsigned long find_zero(unsigned long mask)
42{ 68{
43 return ((a - REPEAT_BYTE(0x01)) & ~a) & REPEAT_BYTE(0x80); 69 return count_masked_bytes(mask);
44} 70}
45 71
46/* 72/*
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index 2e4e4b02c37a..f61ee67ec00f 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -43,100 +43,3 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
43 return len; 43 return len;
44} 44}
45EXPORT_SYMBOL_GPL(copy_from_user_nmi); 45EXPORT_SYMBOL_GPL(copy_from_user_nmi);
46
47/*
48 * Do a strncpy, return length of string without final '\0'.
49 * 'count' is the user-supplied count (return 'count' if we
50 * hit it), 'max' is the address space maximum (and we return
51 * -EFAULT if we hit it).
52 */
53static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
54{
55 long res = 0;
56
57 /*
58 * Truncate 'max' to the user-specified limit, so that
59 * we only have one limit we need to check in the loop
60 */
61 if (max > count)
62 max = count;
63
64 while (max >= sizeof(unsigned long)) {
65 unsigned long c, mask;
66
67 /* Fall back to byte-at-a-time if we get a page fault */
68 if (unlikely(__get_user(c,(unsigned long __user *)(src+res))))
69 break;
70 mask = has_zero(c);
71 if (mask) {
72 mask = (mask - 1) & ~mask;
73 mask >>= 7;
74 *(unsigned long *)(dst+res) = c & mask;
75 return res + count_masked_bytes(mask);
76 }
77 *(unsigned long *)(dst+res) = c;
78 res += sizeof(unsigned long);
79 max -= sizeof(unsigned long);
80 }
81
82 while (max) {
83 char c;
84
85 if (unlikely(__get_user(c,src+res)))
86 return -EFAULT;
87 dst[res] = c;
88 if (!c)
89 return res;
90 res++;
91 max--;
92 }
93
94 /*
95 * Uhhuh. We hit 'max'. But was that the user-specified maximum
96 * too? If so, that's ok - we got as much as the user asked for.
97 */
98 if (res >= count)
99 return res;
100
101 /*
102 * Nope: we hit the address space limit, and we still had more
103 * characters the caller would have wanted. That's an EFAULT.
104 */
105 return -EFAULT;
106}
107
108/**
109 * strncpy_from_user: - Copy a NUL terminated string from userspace.
110 * @dst: Destination address, in kernel space. This buffer must be at
111 * least @count bytes long.
112 * @src: Source address, in user space.
113 * @count: Maximum number of bytes to copy, including the trailing NUL.
114 *
115 * Copies a NUL-terminated string from userspace to kernel space.
116 *
117 * On success, returns the length of the string (not including the trailing
118 * NUL).
119 *
120 * If access to userspace fails, returns -EFAULT (some data may have been
121 * copied).
122 *
123 * If @count is smaller than the length of the string, copies @count bytes
124 * and returns @count.
125 */
126long
127strncpy_from_user(char *dst, const char __user *src, long count)
128{
129 unsigned long max_addr, src_addr;
130
131 if (unlikely(count <= 0))
132 return 0;
133
134 max_addr = current_thread_info()->addr_limit.seg;
135 src_addr = (unsigned long)src;
136 if (likely(src_addr < max_addr)) {
137 unsigned long max = max_addr - src_addr;
138 return do_strncpy_from_user(dst, src, count, max);
139 }
140 return -EFAULT;
141}
142EXPORT_SYMBOL(strncpy_from_user);
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 883b216c60b2..1781b2f950e2 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -95,47 +95,6 @@ __clear_user(void __user *to, unsigned long n)
95} 95}
96EXPORT_SYMBOL(__clear_user); 96EXPORT_SYMBOL(__clear_user);
97 97
98/**
99 * strnlen_user: - Get the size of a string in user space.
100 * @s: The string to measure.
101 * @n: The maximum valid length
102 *
103 * Get the size of a NUL-terminated string in user space.
104 *
105 * Returns the size of the string INCLUDING the terminating NUL.
106 * On exception, returns 0.
107 * If the string is too long, returns a value greater than @n.
108 */
109long strnlen_user(const char __user *s, long n)
110{
111 unsigned long mask = -__addr_ok(s);
112 unsigned long res, tmp;
113
114 might_fault();
115
116 __asm__ __volatile__(
117 " testl %0, %0\n"
118 " jz 3f\n"
119 " andl %0,%%ecx\n"
120 "0: repne; scasb\n"
121 " setne %%al\n"
122 " subl %%ecx,%0\n"
123 " addl %0,%%eax\n"
124 "1:\n"
125 ".section .fixup,\"ax\"\n"
126 "2: xorl %%eax,%%eax\n"
127 " jmp 1b\n"
128 "3: movb $1,%%al\n"
129 " jmp 1b\n"
130 ".previous\n"
131 _ASM_EXTABLE(0b,2b)
132 :"=&r" (n), "=&D" (s), "=&a" (res), "=&c" (tmp)
133 :"0" (n), "1" (s), "2" (0), "3" (mask)
134 :"cc");
135 return res & mask;
136}
137EXPORT_SYMBOL(strnlen_user);
138
139#ifdef CONFIG_X86_INTEL_USERCOPY 98#ifdef CONFIG_X86_INTEL_USERCOPY
140static unsigned long 99static unsigned long
141__copy_user_intel(void __user *to, const void *from, unsigned long size) 100__copy_user_intel(void __user *to, const void *from, unsigned long size)
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 0d0326f388c0..e5b130bc2d0e 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -52,54 +52,6 @@ unsigned long clear_user(void __user *to, unsigned long n)
52} 52}
53EXPORT_SYMBOL(clear_user); 53EXPORT_SYMBOL(clear_user);
54 54
55/*
56 * Return the size of a string (including the ending 0)
57 *
58 * Return 0 on exception, a value greater than N if too long
59 */
60
61long __strnlen_user(const char __user *s, long n)
62{
63 long res = 0;
64 char c;
65
66 while (1) {
67 if (res>n)
68 return n+1;
69 if (__get_user(c, s))
70 return 0;
71 if (!c)
72 return res+1;
73 res++;
74 s++;
75 }
76}
77EXPORT_SYMBOL(__strnlen_user);
78
79long strnlen_user(const char __user *s, long n)
80{
81 if (!access_ok(VERIFY_READ, s, 1))
82 return 0;
83 return __strnlen_user(s, n);
84}
85EXPORT_SYMBOL(strnlen_user);
86
87long strlen_user(const char __user *s)
88{
89 long res = 0;
90 char c;
91
92 for (;;) {
93 if (get_user(c, s))
94 return 0;
95 if (!c)
96 return res+1;
97 res++;
98 s++;
99 }
100}
101EXPORT_SYMBOL(strlen_user);
102
103unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len) 55unsigned long copy_in_user(void __user *to, const void __user *from, unsigned len)
104{ 56{
105 if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) { 57 if (access_ok(VERIFY_WRITE, to, len) && access_ok(VERIFY_READ, from, len)) {
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-21 19:42:04 -0500