Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(637)

Side by Side Diff: services/service_manager/embedder/set_process_title_linux.cc

Issue 2613653003: Move some basic early process init into Service Manager (Closed)
Patch Set: fix mac shutdown order Created 3 years, 9 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch
OLDNEW
1 // Copyright (c) 2009 The Chromium Authors. All rights reserved. 1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be 2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. 3 // found in the LICENSE file.
4 4
5 // This file implements BSD-style setproctitle() for Linux. 5 // This file implements BSD-style setproctitle() for Linux.
6 // It is written such that it can easily be compiled outside Chromium. 6 // It is written such that it can easily be compiled outside Chromium.
7 // 7 //
8 // The Linux kernel sets up two locations in memory to pass arguments and 8 // The Linux kernel sets up two locations in memory to pass arguments and
9 // environment variables to processes. First, there are two char* arrays stored 9 // environment variables to processes. First, there are two char* arrays stored
10 // one after another: argv and environ. A pointer to argv is passed to main(), 10 // one after another: argv and environ. A pointer to argv is passed to main(),
(...skipping 19 matching lines...) Expand all
30 // of the way to make room for a potentially longer title, and then overwrite 30 // of the way to make room for a potentially longer title, and then overwrite
31 // the memory pointed to by argv[0] with a single replacement string, making 31 // the memory pointed to by argv[0] with a single replacement string, making
32 // sure its size does not exceed the available space. 32 // sure its size does not exceed the available space.
33 // 33 //
34 // It is perhaps worth noting that patches to add a system call to Linux for 34 // It is perhaps worth noting that patches to add a system call to Linux for
35 // this, like in BSD, have never made it in: this is the "official" way to do 35 // this, like in BSD, have never made it in: this is the "official" way to do
36 // this on Linux. Presumably it is not in glibc due to some disagreement over 36 // this on Linux. Presumably it is not in glibc due to some disagreement over
37 // this position within the glibc project, leaving applications caught in the 37 // this position within the glibc project, leaving applications caught in the
38 // middle. (Also, only a very few applications need or want this anyway.) 38 // middle. (Also, only a very few applications need or want this anyway.)
39 39
40 #include "content/common/set_process_title_linux.h" 40 #include "services/service_manager/embedder/set_process_title_linux.h"
41 41
42 #include <stdarg.h> 42 #include <stdarg.h>
43 #include <stddef.h> 43 #include <stddef.h>
44 #include <stdint.h> 44 #include <stdint.h>
45 #include <stdio.h> 45 #include <stdio.h>
46 #include <string.h> 46 #include <string.h>
47 #include <unistd.h> 47 #include <unistd.h>
48 48
49 extern char** environ; 49 extern char** environ;
50 50
51 static char** g_main_argv = NULL; 51 static char** g_main_argv = NULL;
52 static char* g_orig_argv0 = NULL; 52 static char* g_orig_argv0 = NULL;
53 53
54 void setproctitle(const char* fmt, ...) { 54 void setproctitle(const char* fmt, ...) {
55 va_list ap; 55 va_list ap;
56 size_t i, avail_size; 56 size_t i, avail_size;
57 uintptr_t page_size, page, page_end; 57 uintptr_t page_size, page, page_end;
58 // Sanity check before we try and set the process title. 58 // Sanity check before we try and set the process title.
59 // The BSD version allows fmt == NULL to restore the original title. 59 // The BSD version allows fmt == NULL to restore the original title.
60 if (!g_main_argv || !environ || !fmt) 60 if (!g_main_argv || !environ || !fmt)
61 return; 61 return;
62 if (!g_orig_argv0) { 62 if (!g_orig_argv0) {
63 // Save the original argv[0]. 63 // Save the original argv[0].
64 g_orig_argv0 = strdup(g_main_argv[0]); 64 g_orig_argv0 = strdup(g_main_argv[0]);
65 if (!g_orig_argv0) 65 if (!g_orig_argv0)
66 return; 66 return;
67 } 67 }
68 page_size = sysconf(_SC_PAGESIZE); 68 page_size = sysconf(_SC_PAGESIZE);
69 // Get the page on which the argument list and environment live. 69 // Get the page on which the argument list and environment live.
70 page = (uintptr_t) g_main_argv[0]; 70 page = (uintptr_t)g_main_argv[0];
71 page -= page % page_size; 71 page -= page % page_size;
72 page_end = page + page_size; 72 page_end = page + page_size;
73 // Move the environment out of the way. Note that we are moving the values, 73 // Move the environment out of the way. Note that we are moving the values,
74 // not the environment array itself (which may not be on the page we need 74 // not the environment array itself (which may not be on the page we need
75 // to overwrite anyway). 75 // to overwrite anyway).
76 for (i = 0; environ[i]; ++i) { 76 for (i = 0; environ[i]; ++i) {
77 uintptr_t env_i = (uintptr_t) environ[i]; 77 uintptr_t env_i = (uintptr_t)environ[i];
78 // Only move the value if it's actually in the way. This avoids 78 // Only move the value if it's actually in the way. This avoids
79 // leaking copies of the values if this function is called again. 79 // leaking copies of the values if this function is called again.
80 if (page <= env_i && env_i < page_end) { 80 if (page <= env_i && env_i < page_end) {
81 char* copy = strdup(environ[i]); 81 char* copy = strdup(environ[i]);
82 // Be paranoid. Check for allocation failure and bail out. 82 // Be paranoid. Check for allocation failure and bail out.
83 if (!copy) 83 if (!copy)
84 return; 84 return;
85 environ[i] = copy; 85 environ[i] = copy;
86 } 86 }
87 } 87 }
88 // Put the title in argv[0]. We have to zero out the space first since the 88 // Put the title in argv[0]. We have to zero out the space first since the
89 // kernel doesn't actually look for a null terminator unless we make the 89 // kernel doesn't actually look for a null terminator unless we make the
90 // argument list longer than it started. 90 // argument list longer than it started.
91 avail_size = page_end - (uintptr_t) g_main_argv[0]; 91 avail_size = page_end - (uintptr_t)g_main_argv[0];
92 memset(g_main_argv[0], 0, avail_size); 92 memset(g_main_argv[0], 0, avail_size);
93 va_start(ap, fmt); 93 va_start(ap, fmt);
94 if (fmt[0] == '-') { 94 if (fmt[0] == '-') {
95 vsnprintf(g_main_argv[0], avail_size, &fmt[1], ap); 95 vsnprintf(g_main_argv[0], avail_size, &fmt[1], ap);
96 } else { 96 } else {
97 size_t size = snprintf(g_main_argv[0], avail_size, "%s ", g_orig_argv0); 97 size_t size = snprintf(g_main_argv[0], avail_size, "%s ", g_orig_argv0);
98 if (size < avail_size) 98 if (size < avail_size)
99 vsnprintf(g_main_argv[0] + size, avail_size - size, fmt, ap); 99 vsnprintf(g_main_argv[0] + size, avail_size - size, fmt, ap);
100 } 100 }
101 va_end(ap); 101 va_end(ap);
102 g_main_argv[1] = NULL; 102 g_main_argv[1] = NULL;
103 } 103 }
104 104
105 // A version of this built into glibc would not need this function, since 105 // A version of this built into glibc would not need this function, since
106 // it could stash the argv pointer in __libc_start_main(). But we need it. 106 // it could stash the argv pointer in __libc_start_main(). But we need it.
107 void setproctitle_init(const char** main_argv) { 107 void setproctitle_init(const char** main_argv) {
108 if (g_main_argv) 108 if (g_main_argv)
109 return; 109 return;
110 110
111 uintptr_t page_size = sysconf(_SC_PAGESIZE); 111 uintptr_t page_size = sysconf(_SC_PAGESIZE);
112 // Check that the argv array is in fact on the same page of memory 112 // Check that the argv array is in fact on the same page of memory
113 // as the environment array just as an added measure of protection. 113 // as the environment array just as an added measure of protection.
114 if (((uintptr_t) environ) / page_size == ((uintptr_t) main_argv) / page_size) 114 if (((uintptr_t)environ) / page_size == ((uintptr_t)main_argv) / page_size)
115 g_main_argv = const_cast<char**>(main_argv); 115 g_main_argv = const_cast<char**>(main_argv);
116 } 116 }
OLDNEW
« no previous file with comments | « services/service_manager/embedder/set_process_title_linux.h ('k') | services/service_manager/embedder/shared_file_util.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698