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-rw-r--r--recipes-core/busybox/busybox/0001-Turn-ptr_to_globals-and-bb_errno-to-be-non-const.patch172
1 files changed, 0 insertions, 172 deletions
diff --git a/recipes-core/busybox/busybox/0001-Turn-ptr_to_globals-and-bb_errno-to-be-non-const.patch b/recipes-core/busybox/busybox/0001-Turn-ptr_to_globals-and-bb_errno-to-be-non-const.patch
deleted file mode 100644
index 468a32d..0000000
--- a/recipes-core/busybox/busybox/0001-Turn-ptr_to_globals-and-bb_errno-to-be-non-const.patch
+++ /dev/null
@@ -1,172 +0,0 @@
1From d941b59087d34cb93053b638c066bf080122e7bb Mon Sep 17 00:00:00 2001
2From: Khem Raj <raj.khem@gmail.com>
3Date: Wed, 16 Jan 2019 22:39:24 -0800
4Subject: [PATCH] Turn ptr_to_globals and bb_errno to be non const
5
6writing to a const variable is undefined behavior
7
8This is undefined as per (C99 6.7.3 paragraph 5) see [1]
9
10errno and ptr_to_globals is written to in code, this fails with
11segfaults when compiled with clang
12
13unsigned FAST_FUNC bb_strtou(const char *arg, char **endp, int base)
14{
15 unsigned long v;
16 char *endptr;
17
18 if (!endp) endp = &endptr;
19 *endp = (char*) arg;
20
21 if (!isalnum(arg[0])) return ret_ERANGE();
22 errno = 0;
23 v = strtoul(arg, endp, base);
24 if (v > UINT_MAX) return ret_ERANGE();
25 return handle_errors(v, endp);
26 }
27
28without 'const' ( working code )
29
30Dump of assembler code for function bb_strtou:
31 0x0000555555568298 <+0>: push %rbx
32 0x0000555555568299 <+1>: sub $0x10,%rsp
33 0x000055555556829d <+5>: test %rsi,%rsi
34 0x00005555555682a0 <+8>: lea 0x8(%rsp),%rbx
35 0x00005555555682a5 <+13>: cmovne %rsi,%rbx
36 0x00005555555682a9 <+17>: mov %rdi,(%rbx)
37 0x00005555555682ac <+20>: mov (%rdi),%al
38 0x00005555555682ae <+22>: lea -0x30(%rax),%ecx
39 0x00005555555682b1 <+25>: cmp $0xa,%cl
40 0x00005555555682b4 <+28>: jb 0x5555555682be <bb_strtou+38>
41 0x00005555555682b6 <+30>: or $0x20,%al
42 0x00005555555682b8 <+32>: add $0x9f,%al
43 0x00005555555682ba <+34>: cmp $0x1a,%al
44 0x00005555555682bc <+36>: jae 0x5555555682dc <bb_strtou+68>
45 0x00005555555682be <+38>: mov 0x107da3(%rip),%rax # 0x555555670068 <bb_errno>
46=> 0x00005555555682c5 <+45>: movl $0x0,(%rax)
47 0x00005555555682cb <+51>: mov %rbx,%rsi
48 0x00005555555682ce <+54>: callq 0x555555564310 <strtoul@plt>
49 0x00005555555682d3 <+59>: mov %rax,%rcx
50 0x00005555555682d6 <+62>: shr $0x20,%rcx
51 0x00005555555682da <+66>: je 0x5555555682f0 <bb_strtou+88>
52 0x00005555555682dc <+68>: mov 0x107d85(%rip),%rax # 0x555555670068 <bb_errno>
53 0x00005555555682e3 <+75>: movl $0x22,(%rax)
54 0x00005555555682e9 <+81>: mov $0xffffffff,%eax
55 0x00005555555682ee <+86>: jmp 0x5555555682fb <bb_strtou+99>
56 0x00005555555682f0 <+88>: mov %rax,%rdi
57 0x00005555555682f3 <+91>: mov %rbx,%rsi
58 0x00005555555682f6 <+94>: callq 0x5555555681e8 <handle_errors>
59 0x00005555555682fb <+99>: add $0x10,%rsp
60 0x00005555555682ff <+103>: pop %rbx
61 0x0000555555568300 <+104>: retq
62
63here address of bb_errno is valid rax = 0x7ffff7cac6c0
64
65with 'const' ( non-working code )
66
67Dump of assembler code for function bb_strtou:
68 0x00005555555682a4 <+0>: push %r14
69 0x00005555555682a6 <+2>: push %rbx
70 0x00005555555682a7 <+3>: push %rax
71 0x00005555555682a8 <+4>: test %rsi,%rsi
72 0x00005555555682ab <+7>: mov %rsp,%rbx
73 0x00005555555682ae <+10>: cmovne %rsi,%rbx
74 0x00005555555682b2 <+14>: mov %rdi,(%rbx)
75 0x00005555555682b5 <+17>: mov (%rdi),%al
76 0x00005555555682b7 <+19>: lea -0x30(%rax),%ecx
77 0x00005555555682ba <+22>: cmp $0xa,%cl
78 0x00005555555682bd <+25>: jb 0x5555555682d6 <bb_strtou+50>
79 0x00005555555682bf <+27>: or $0x20,%al
80 0x00005555555682c1 <+29>: add $0x9f,%al
81 0x00005555555682c3 <+31>: cmp $0x1a,%al
82 0x00005555555682c5 <+33>: jb 0x5555555682d6 <bb_strtou+50>
83 0x00005555555682c7 <+35>: mov 0x107d9a(%rip),%rax # 0x555555670068 <bb_errno>
84 0x00005555555682ce <+42>: movl $0x22,(%rax)
85 0x00005555555682d4 <+48>: jmp 0x5555555682fc <bb_strtou+88>
86 0x00005555555682d6 <+50>: mov 0x107d8b(%rip),%r14 # 0x555555670068 <bb_errno>
87=> 0x00005555555682dd <+57>: movl $0x0,(%r14)
88 0x00005555555682e4 <+64>: mov %rbx,%rsi
89 0x00005555555682e7 <+67>: callq 0x555555564300 <strtoul@plt>
90 0x00005555555682ec <+72>: mov %rax,%rcx
91 0x00005555555682ef <+75>: shr $0x20,%rcx
92 0x00005555555682f3 <+79>: je 0x555555568303 <bb_strtou+95>
93 0x00005555555682f5 <+81>: movl $0x22,(%r14)
94 0x00005555555682fc <+88>: mov $0xffffffff,%eax
95 0x0000555555568301 <+93>: jmp 0x55555556830e <bb_strtou+106>
96 0x0000555555568303 <+95>: mov %rax,%rdi
97 0x0000555555568306 <+98>: mov %rbx,%rsi
98 0x0000555555568309 <+101>: callq 0x5555555681f4 <handle_errors>
99 0x000055555556830e <+106>: add $0x8,%rsp
100 0x0000555555568312 <+110>: pop %rbx
101 0x0000555555568313 <+111>: pop %r14
102 0x0000555555568315 <+113>: retq
103
104r14 is 0x0 and writing to this ofcourse ends up in segfault
105
106[1] https://bugs.llvm.org/show_bug.cgi?id=39919
107
108Signed-off-by: Khem Raj <raj.khem@gmail.com>
109---
110 coreutils/test.c | 2 +-
111 include/libbb.h | 4 ++--
112 libbb/lineedit.c | 2 +-
113 shell/ash.c | 5 ++---
114 4 files changed, 6 insertions(+), 7 deletions(-)
115
116--- a/coreutils/test.c
117+++ b/coreutils/test.c
118@@ -435,7 +435,7 @@ struct test_statics {
119 };
120
121 /* See test_ptr_hack.c */
122-extern struct test_statics *const test_ptr_to_statics;
123+extern struct test_statics *test_ptr_to_statics;
124
125 #define S (*test_ptr_to_statics)
126 #define args (S.args )
127--- a/include/libbb.h
128+++ b/include/libbb.h
129@@ -342,7 +342,7 @@ struct BUG_off_t_size_is_misdetected {
130 #if defined(errno)
131 /* If errno is a define, assume it's "define errno (*__errno_location())"
132 * and we will cache it's result in this variable */
133-extern int *const bb_errno;
134+extern int *bb_errno;
135 #undef errno
136 #define errno (*bb_errno)
137 #define bb_cached_errno_ptr 1
138@@ -2228,7 +2228,7 @@ struct globals;
139 /* '*const' ptr makes gcc optimize code much better.
140 * Magic prevents ptr_to_globals from going into rodata.
141 * If you want to assign a value, use SET_PTR_TO_GLOBALS(x) */
142-extern struct globals *const ptr_to_globals;
143+extern struct globals *ptr_to_globals;
144
145 #if defined(__clang_major__) && __clang_major__ >= 9
146 /* Clang/llvm drops assignment to "constant" storage. Silently.
147--- a/libbb/lineedit.c
148+++ b/libbb/lineedit.c
149@@ -192,7 +192,7 @@ struct lineedit_statics {
150 };
151
152 /* See lineedit_ptr_hack.c */
153-extern struct lineedit_statics *const lineedit_ptr_to_statics;
154+extern struct lineedit_statics * lineedit_ptr_to_statics;
155
156 #define S (*lineedit_ptr_to_statics)
157 #define state (S.state )
158--- a/shell/ash.c
159+++ b/shell/ash.c
160@@ -300,10 +300,9 @@ typedef long arith_t;
161 * set "-DBB_GLOBAL_CONST=''" in CONFIG_EXTRA_CFLAGS to disable
162 * this optimization.
163 */
164-#ifndef BB_GLOBAL_CONST
165-# define BB_GLOBAL_CONST const
166-#endif
167
168+#undef BB_GLOBAL_CONST
169+#define BB_GLOBAL_CONST
170
171 /* ============ Hash table sizes. Configurable. */
172
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-06-09 07:44:28 +0000