Index: services/service_manager/embedder/set_process_title_linux.cc |
diff --git a/services/service_manager/embedder/set_process_title_linux.cc b/services/service_manager/embedder/set_process_title_linux.cc |
deleted file mode 100644 |
index e0a5f3b79996d02e0b6fc36ea383fa60c92bbcc3..0000000000000000000000000000000000000000 |
--- a/services/service_manager/embedder/set_process_title_linux.cc |
+++ /dev/null |
@@ -1,116 +0,0 @@ |
-// Copyright (c) 2009 The Chromium Authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-// This file implements BSD-style setproctitle() for Linux. |
-// It is written such that it can easily be compiled outside Chromium. |
-// |
-// The Linux kernel sets up two locations in memory to pass arguments and |
-// environment variables to processes. First, there are two char* arrays stored |
-// one after another: argv and environ. A pointer to argv is passed to main(), |
-// while glibc sets the global variable |environ| to point at the latter. Both |
-// of these arrays are terminated by a NULL pointer; the environment array is |
-// also followed by some empty space to allow additional variables to be added. |
-// |
-// These arrays contain pointers to a second location in memory, where the |
-// strings themselves are stored one after another: first all the arguments, |
-// then the environment variables. The kernel will allocate a single page of |
-// memory for this purpose, so the end of the page containing argv[0] is the |
-// end of the storage potentially available to store the process title. |
-// |
-// When the kernel reads the command line arguments for a process, it looks at |
-// the range of memory within this page that it initially used for the argument |
-// list. If the terminating '\0' character is still where it expects, nothing |
-// further is done. If it has been overwritten, the kernel will scan up to the |
-// size of a page looking for another. (Note, however, that in general not that |
-// much space is actually mapped, since argv[0] is rarely page-aligned and only |
-// one page is mapped.) |
-// |
-// Thus to change the process title, we must move any environment variables out |
-// of the way to make room for a potentially longer title, and then overwrite |
-// the memory pointed to by argv[0] with a single replacement string, making |
-// sure its size does not exceed the available space. |
-// |
-// It is perhaps worth noting that patches to add a system call to Linux for |
-// this, like in BSD, have never made it in: this is the "official" way to do |
-// this on Linux. Presumably it is not in glibc due to some disagreement over |
-// this position within the glibc project, leaving applications caught in the |
-// middle. (Also, only a very few applications need or want this anyway.) |
- |
-#include "services/service_manager/embedder/set_process_title_linux.h" |
- |
-#include <stdarg.h> |
-#include <stddef.h> |
-#include <stdint.h> |
-#include <stdio.h> |
-#include <string.h> |
-#include <unistd.h> |
- |
-extern char** environ; |
- |
-static char** g_main_argv = NULL; |
-static char* g_orig_argv0 = NULL; |
- |
-void setproctitle(const char* fmt, ...) { |
- va_list ap; |
- size_t i, avail_size; |
- uintptr_t page_size, page, page_end; |
- // Sanity check before we try and set the process title. |
- // The BSD version allows fmt == NULL to restore the original title. |
- if (!g_main_argv || !environ || !fmt) |
- return; |
- if (!g_orig_argv0) { |
- // Save the original argv[0]. |
- g_orig_argv0 = strdup(g_main_argv[0]); |
- if (!g_orig_argv0) |
- return; |
- } |
- page_size = sysconf(_SC_PAGESIZE); |
- // Get the page on which the argument list and environment live. |
- page = (uintptr_t)g_main_argv[0]; |
- page -= page % page_size; |
- page_end = page + page_size; |
- // Move the environment out of the way. Note that we are moving the values, |
- // not the environment array itself (which may not be on the page we need |
- // to overwrite anyway). |
- for (i = 0; environ[i]; ++i) { |
- uintptr_t env_i = (uintptr_t)environ[i]; |
- // Only move the value if it's actually in the way. This avoids |
- // leaking copies of the values if this function is called again. |
- if (page <= env_i && env_i < page_end) { |
- char* copy = strdup(environ[i]); |
- // Be paranoid. Check for allocation failure and bail out. |
- if (!copy) |
- return; |
- environ[i] = copy; |
- } |
- } |
- // Put the title in argv[0]. We have to zero out the space first since the |
- // kernel doesn't actually look for a null terminator unless we make the |
- // argument list longer than it started. |
- avail_size = page_end - (uintptr_t)g_main_argv[0]; |
- memset(g_main_argv[0], 0, avail_size); |
- va_start(ap, fmt); |
- if (fmt[0] == '-') { |
- vsnprintf(g_main_argv[0], avail_size, &fmt[1], ap); |
- } else { |
- size_t size = snprintf(g_main_argv[0], avail_size, "%s ", g_orig_argv0); |
- if (size < avail_size) |
- vsnprintf(g_main_argv[0] + size, avail_size - size, fmt, ap); |
- } |
- va_end(ap); |
- g_main_argv[1] = NULL; |
-} |
- |
-// A version of this built into glibc would not need this function, since |
-// it could stash the argv pointer in __libc_start_main(). But we need it. |
-void setproctitle_init(const char** main_argv) { |
- if (g_main_argv) |
- return; |
- |
- uintptr_t page_size = sysconf(_SC_PAGESIZE); |
- // Check that the argv array is in fact on the same page of memory |
- // as the environment array just as an added measure of protection. |
- if (((uintptr_t)environ) / page_size == ((uintptr_t)main_argv) / page_size) |
- g_main_argv = const_cast<char**>(main_argv); |
-} |