xref: /aosp_15_r20/external/cronet/base/process/set_process_title.cc (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "build/build_config.h"
6 
7 // Define _GNU_SOURCE to ensure that <errno.h> defines
8 // program_invocation_short_name. Keep this at the top of the file since some
9 // system headers might include <errno.h> and the header could be skipped on
10 // subsequent includes.
11 #if (BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)) && !defined(_GNU_SOURCE)
12 #define _GNU_SOURCE
13 #endif
14 
15 #include "base/process/set_process_title.h"
16 
17 #include <stddef.h>
18 
19 #if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_MAC) && !BUILDFLAG(IS_SOLARIS)
20 #include <limits.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 
24 #include <string>
25 
26 #include "base/command_line.h"
27 #endif  // BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_MAC) && !BUILDFLAG(IS_SOLARIS)
28 
29 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
30 #include <errno.h>  // Get program_invocation_short_name declaration.
31 #include <sys/prctl.h>
32 
33 #include "base/files/file_path.h"
34 #include "base/files/file_util.h"
35 #include "base/no_destructor.h"
36 #include "base/process/process_metrics.h"
37 #include "base/strings/string_util.h"
38 #include "base/threading/platform_thread.h"
39 // Linux/glibc doesn't natively have setproctitle().
40 #include "base/process/set_process_title_linux.h"
41 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
42 
43 namespace base {
44 
45 // TODO(jrg): Find out if setproctitle or equivalent is available on Android.
46 #if BUILDFLAG(IS_POSIX) && !BUILDFLAG(IS_APPLE) && !BUILDFLAG(IS_SOLARIS) && \
47     !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_FUCHSIA) && !BUILDFLAG(IS_NACL)
48 
SetProcessTitleFromCommandLine(const char ** main_argv)49 void SetProcessTitleFromCommandLine(const char** main_argv) {
50   // Build a single string which consists of all the arguments separated
51   // by spaces. We can't actually keep them separate due to the way the
52   // setproctitle() function works.
53   std::string title;
54   bool have_argv0 = false;
55 
56 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
57   DCHECK_EQ(base::PlatformThread::CurrentId(), getpid());
58 
59   if (main_argv)
60     setproctitle_init(main_argv);
61 
62   // In Linux we sometimes exec ourselves from /proc/self/exe, but this makes us
63   // show up as "exe" in process listings. Read the symlink /proc/self/exe and
64   // use the path it points at for our process title. Note that this is only for
65   // display purposes and has no TOCTTOU security implications.
66   base::FilePath target;
67   base::FilePath self_exe(base::kProcSelfExe);
68   if (base::ReadSymbolicLink(self_exe, &target)) {
69     have_argv0 = true;
70     title = target.value();
71     // If the binary has since been deleted, Linux appends " (deleted)" to the
72     // symlink target. Remove it, since this is not really part of our name.
73     const std::string kDeletedSuffix = " (deleted)";
74     if (base::EndsWith(title, kDeletedSuffix, base::CompareCase::SENSITIVE))
75       title.resize(title.size() - kDeletedSuffix.size());
76 
77     base::FilePath::StringType base_name =
78         base::FilePath(title).BaseName().value();
79     // PR_SET_NAME is available in Linux 2.6.9 and newer.
80     // When available at run time, this sets the short process name that shows
81     // when the full command line is not being displayed in most process
82     // listings.
83     prctl(PR_SET_NAME, base_name.c_str());
84 
85     // This prevents program_invocation_short_name from being broken by
86     // setproctitle().
87     static base::NoDestructor<base::FilePath::StringType> base_name_storage;
88     *base_name_storage = std::move(base_name);
89     program_invocation_short_name = &(*base_name_storage)[0];
90   }
91 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
92 
93   const base::CommandLine* command_line =
94       base::CommandLine::ForCurrentProcess();
95   for (size_t i = 1; i < command_line->argv().size(); ++i) {
96     if (!title.empty())
97       title += " ";
98     title += command_line->argv()[i];
99   }
100   // Disable prepending argv[0] with '-' if we prepended it ourselves above.
101   setproctitle(have_argv0 ? "-%s" : "%s", title.c_str());
102 }
103 
104 #else
105 
106 // All other systems (basically Windows & Mac) have no need or way to implement
107 // this function.
108 void SetProcessTitleFromCommandLine(const char** /* main_argv */) {}
109 
110 #endif
111 
112 }  // namespace base
113