Mercurial > hg > nginx
annotate src/os/unix/rfork_thread.S @ 5356:acd51b0f6fd4
Disable symlinks: use O_PATH to open path components.
It was introduced in Linux 2.6.39, glibc 2.14 and allows to obtain
file descriptors without actually opening files. Thus made it possible
to traverse path with openat() syscalls without the need to have read
permissions for path components. It is effectively emulates O_SEARCH
which is missing on Linux.
O_PATH is used in combination with O_RDONLY. The last one is ignored
if O_PATH is used, but it allows nginx to not fail when it was built on
modern system (i.e. glibc 2.14+) and run with a kernel older than 2.6.39.
Then O_PATH is unknown to the kernel and ignored, while O_RDONLY is used.
Sadly, fstat() is not working with O_PATH descriptors till Linux 3.6.
As a workaround we fallback to fstatat() with the AT_EMPTY_PATH flag
that was introduced at the same time as O_PATH.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Mon, 02 Sep 2013 08:07:59 +0400 |
parents | d620f497c50f |
children |
rev | line source |
---|---|
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
267
diff
changeset
|
1 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
267
diff
changeset
|
2 /* |
444
42d11f017717
nginx-0.1.0-2004-09-29-20:00:49 import; remove years from copyright
Igor Sysoev <igor@sysoev.ru>
parents:
441
diff
changeset
|
3 * Copyright (C) Igor Sysoev |
4412 | 4 * Copyright (C) Nginx, Inc. |
441
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
267
diff
changeset
|
5 */ |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
267
diff
changeset
|
6 |
da8c5707af39
nginx-0.1.0-2004-09-28-12:34:51 import; set copyright and remove unused files
Igor Sysoev <igor@sysoev.ru>
parents:
267
diff
changeset
|
7 |
267
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
8 #include <sys/syscall.h> |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
9 #include <machine/asm.h> |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
10 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
11 /* |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
12 * rfork_thread(3) - rfork_thread(flags, stack, func, arg); |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
13 */ |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
14 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
15 #define KERNCALL int $0x80 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
16 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
17 ENTRY(rfork_thread) |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
18 push %ebp |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
19 mov %esp, %ebp |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
20 push %esi |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
21 |
483 | 22 mov 12(%ebp), %esi # the thread stack address |
267
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
23 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
24 sub $4, %esi |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
25 mov 20(%ebp), %eax # the thread argument |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
26 mov %eax, (%esi) |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
27 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
28 sub $4, %esi |
483 | 29 mov 16(%ebp), %eax # the thread start address |
267
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
30 mov %eax, (%esi) |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
31 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
32 push 8(%ebp) # rfork(2) flags |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
33 push $0 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
34 mov $SYS_rfork, %eax |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
35 KERNCALL |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
36 jc error |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
37 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
38 cmp $0, %edx |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
39 jne child |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
40 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
41 parent: |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
42 add $8, %esp |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
43 pop %esi |
483 | 44 leave |
267
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
45 ret |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
46 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
47 child: |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
48 mov %esi, %esp |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
49 pop %eax |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
50 call *%eax # call a thread start address ... |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
51 add $4, %esp |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
52 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
53 push %eax |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
54 push $0 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
55 mov $SYS_exit, %eax # ... and exit(2) after a thread would return |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
56 KERNCALL |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
57 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
58 error: |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
59 add $8, %esp |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
60 pop %esi |
483 | 61 leave |
267
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
62 PIC_PROLOGUE |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
63 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
64 /* libc's cerror: jmp PIC_PLT(HIDENAME(cerror)) */ |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
65 |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
66 push %eax |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
67 call PIC_PLT(CNAME(__error)) |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
68 pop %ecx |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
69 PIC_EPILOGUE |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
70 mov %ecx, (%eax) |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
71 mov $-1, %eax |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
72 mov $-1, %edx |
83205e0b5522
nginx-0.0.2-2004-02-24-20:31:46 import
Igor Sysoev <igor@sysoev.ru>
parents:
diff
changeset
|
73 ret |