binutils-gdb/gdb/common/linux-osdata.c
Pedro Alves e5798bef38 2011-08-26 Pedro Alves <pedro@codesourcery.com>
gdb/
	* common/linux-osdata.c (get_cores_used_by_process): Don't assume
	opening /proc/PID/task always succeeds.
2011-08-26 18:58:04 +00:00

589 lines
13 KiB
C

/* Linux-specific functions to retrieve OS data.
Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifdef GDBSERVER
#include "server.h"
#else
#include "defs.h"
#endif
#include "linux-osdata.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <utmp.h>
#include <time.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "xml-utils.h"
#include "buffer.h"
#include "gdb_assert.h"
#include "gdb_dirent.h"
int
linux_common_core_of_thread (ptid_t ptid)
{
char filename[sizeof ("/proc//task//stat")
+ 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
+ 1];
FILE *f;
char *content = NULL;
char *p;
char *ts = 0;
int content_read = 0;
int i;
int core;
sprintf (filename, "/proc/%d/task/%ld/stat",
ptid_get_pid (ptid), ptid_get_lwp (ptid));
f = fopen (filename, "r");
if (!f)
return -1;
for (;;)
{
int n;
content = xrealloc (content, content_read + 1024);
n = fread (content + content_read, 1, 1024, f);
content_read += n;
if (n < 1024)
{
content[content_read] = '\0';
break;
}
}
p = strchr (content, '(');
/* Skip ")". */
if (p != NULL)
p = strchr (p, ')');
if (p != NULL)
p++;
/* If the first field after program name has index 0, then core number is
the field with index 36. There's no constant for that anywhere. */
if (p != NULL)
p = strtok_r (p, " ", &ts);
for (i = 0; p != NULL && i != 36; ++i)
p = strtok_r (NULL, " ", &ts);
if (p == NULL || sscanf (p, "%d", &core) == 0)
core = -1;
xfree (content);
fclose (f);
return core;
}
static void
command_from_pid (char *command, int maxlen, pid_t pid)
{
char *stat_path = xstrprintf ("/proc/%d/stat", pid);
FILE *fp = fopen (stat_path, "r");
command[0] = '\0';
if (fp)
{
/* sizeof (cmd) should be greater or equal to TASK_COMM_LEN (in
include/linux/sched.h in the Linux kernel sources) plus two
(for the brackets). */
char cmd[32];
pid_t stat_pid;
int items_read = fscanf (fp, "%d %32s", &stat_pid, cmd);
if (items_read == 2 && pid == stat_pid)
{
cmd[strlen (cmd) - 1] = '\0'; /* Remove trailing parenthesis. */
strncpy (command, cmd + 1, maxlen); /* Ignore leading parenthesis. */
}
fclose (fp);
}
else
{
/* Return the PID if a /proc entry for the process cannot be found. */
snprintf (command, maxlen, "%d", pid);
}
command[maxlen - 1] = '\0'; /* Ensure string is null-terminated. */
xfree (stat_path);
}
/* Returns the command-line of the process with the given PID. The returned
string needs to be freed using xfree after use. */
static char *
commandline_from_pid (pid_t pid)
{
char *pathname = xstrprintf ("/proc/%d/cmdline", pid);
char *commandline = NULL;
FILE *f = fopen (pathname, "r");
if (f)
{
size_t len = 0;
while (!feof (f))
{
char buf[1024];
size_t read_bytes = fread (buf, 1, sizeof (buf), f);
if (read_bytes)
{
commandline = (char *) xrealloc (commandline, len + read_bytes + 1);
memcpy (commandline + len, buf, read_bytes);
len += read_bytes;
}
}
fclose (f);
if (commandline)
{
size_t i;
/* Replace null characters with spaces. */
for (i = 0; i < len; ++i)
if (commandline[i] == '\0')
commandline[i] = ' ';
commandline[len] = '\0';
}
else
{
/* Return the command in square brackets if the command-line is empty. */
commandline = (char *) xmalloc (32);
commandline[0] = '[';
command_from_pid (commandline + 1, 31, pid);
len = strlen (commandline);
if (len < 31)
strcat (commandline, "]");
}
}
xfree (pathname);
return commandline;
}
static void
user_from_uid (char *user, int maxlen, uid_t uid)
{
struct passwd *pwentry = getpwuid (uid);
if (pwentry)
{
strncpy (user, pwentry->pw_name, maxlen);
user[maxlen - 1] = '\0'; /* Ensure that the user name is null-terminated. */
}
else
user[0] = '\0';
}
static int
get_process_owner (uid_t *owner, pid_t pid)
{
struct stat statbuf;
char procentry[sizeof ("/proc/4294967295")];
sprintf (procentry, "/proc/%d", pid);
if (stat (procentry, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
{
*owner = statbuf.st_uid;
return 0;
}
else
return -1;
}
static int
get_number_of_cpu_cores (void)
{
int cores = 0;
FILE *f = fopen ("/proc/cpuinfo", "r");
while (!feof (f))
{
char buf[512];
char *p = fgets (buf, sizeof (buf), f);
if (p && strncmp (buf, "processor", 9) == 0)
++cores;
}
fclose (f);
return cores;
}
/* CORES points to an array of at least get_number_of_cpu_cores () elements. */
static int
get_cores_used_by_process (pid_t pid, int *cores)
{
char taskdir[sizeof ("/proc/4294967295/task")];
DIR *dir;
struct dirent *dp;
int task_count = 0;
sprintf (taskdir, "/proc/%d/task", pid);
dir = opendir (taskdir);
if (dir)
{
while ((dp = readdir (dir)) != NULL)
{
pid_t tid;
int core;
if (!isdigit (dp->d_name[0])
|| NAMELEN (dp) > sizeof ("4294967295") - 1)
continue;
tid = atoi (dp->d_name);
core = linux_common_core_of_thread (ptid_build (pid, tid, 0));
if (core >= 0)
{
++cores[core];
++task_count;
}
}
closedir (dir);
}
return task_count;
}
static LONGEST
linux_xfer_osdata_processes (gdb_byte *readbuf,
ULONGEST offset, LONGEST len)
{
/* We make the process list snapshot when the object starts to be read. */
static const char *buf;
static LONGEST len_avail = -1;
static struct buffer buffer;
if (offset == 0)
{
DIR *dirp;
if (len_avail != -1 && len_avail != 0)
buffer_free (&buffer);
len_avail = 0;
buf = NULL;
buffer_init (&buffer);
buffer_grow_str (&buffer, "<osdata type=\"processes\">\n");
dirp = opendir ("/proc");
if (dirp)
{
const int num_cores = get_number_of_cpu_cores ();
struct dirent *dp;
while ((dp = readdir (dirp)) != NULL)
{
pid_t pid;
uid_t owner;
char user[UT_NAMESIZE];
char *command_line;
int *cores;
int task_count;
char *cores_str;
int i;
if (!isdigit (dp->d_name[0])
|| NAMELEN (dp) > sizeof ("4294967295") - 1)
continue;
sscanf (dp->d_name, "%d", &pid);
command_line = commandline_from_pid (pid);
if (get_process_owner (&owner, pid) == 0)
user_from_uid (user, sizeof (user), owner);
else
strcpy (user, "?");
/* Find CPU cores used by the process. */
cores = (int *) xcalloc (num_cores, sizeof (int));
task_count = get_cores_used_by_process (pid, cores);
cores_str = (char *) xcalloc (task_count, sizeof ("4294967295") + 1);
for (i = 0; i < num_cores && task_count > 0; ++i)
if (cores[i])
{
char core_str[sizeof ("4294967205")];
sprintf (core_str, "%d", i);
strcat (cores_str, core_str);
task_count -= cores[i];
if (task_count > 0)
strcat (cores_str, ",");
}
xfree (cores);
buffer_xml_printf (
&buffer,
"<item>"
"<column name=\"pid\">%d</column>"
"<column name=\"user\">%s</column>"
"<column name=\"command\">%s</column>"
"<column name=\"cores\">%s</column>"
"</item>",
pid,
user,
command_line ? command_line : "",
cores_str);
xfree (command_line);
xfree (cores_str);
}
closedir (dirp);
}
buffer_grow_str0 (&buffer, "</osdata>\n");
buf = buffer_finish (&buffer);
len_avail = strlen (buf);
}
if (offset >= len_avail)
{
/* Done. Get rid of the buffer. */
buffer_free (&buffer);
buf = NULL;
len_avail = 0;
return 0;
}
if (len > len_avail - offset)
len = len_avail - offset;
memcpy (readbuf, buf + offset, len);
return len;
}
static LONGEST
linux_xfer_osdata_threads (gdb_byte *readbuf,
ULONGEST offset, LONGEST len)
{
/* We make the process list snapshot when the object starts to be read. */
static const char *buf;
static LONGEST len_avail = -1;
static struct buffer buffer;
if (offset == 0)
{
DIR *dirp;
if (len_avail != -1 && len_avail != 0)
buffer_free (&buffer);
len_avail = 0;
buf = NULL;
buffer_init (&buffer);
buffer_grow_str (&buffer, "<osdata type=\"threads\">\n");
dirp = opendir ("/proc");
if (dirp)
{
struct dirent *dp;
while ((dp = readdir (dirp)) != NULL)
{
struct stat statbuf;
char procentry[sizeof ("/proc/4294967295")];
if (!isdigit (dp->d_name[0])
|| NAMELEN (dp) > sizeof ("4294967295") - 1)
continue;
sprintf (procentry, "/proc/%s", dp->d_name);
if (stat (procentry, &statbuf) == 0
&& S_ISDIR (statbuf.st_mode))
{
DIR *dirp2;
char *pathname;
pid_t pid;
char command[32];
pathname = xstrprintf ("/proc/%s/task", dp->d_name);
pid = atoi (dp->d_name);
command_from_pid (command, sizeof (command), pid);
dirp2 = opendir (pathname);
if (dirp2)
{
struct dirent *dp2;
while ((dp2 = readdir (dirp2)) != NULL)
{
pid_t tid;
int core;
if (!isdigit (dp2->d_name[0])
|| NAMELEN (dp2) > sizeof ("4294967295") - 1)
continue;
tid = atoi (dp2->d_name);
core = linux_common_core_of_thread (ptid_build (pid, tid, 0));
buffer_xml_printf (
&buffer,
"<item>"
"<column name=\"pid\">%d</column>"
"<column name=\"command\">%s</column>"
"<column name=\"tid\">%d</column>"
"<column name=\"core\">%d</column>"
"</item>",
pid,
command,
tid,
core);
}
closedir (dirp2);
}
xfree (pathname);
}
}
closedir (dirp);
}
buffer_grow_str0 (&buffer, "</osdata>\n");
buf = buffer_finish (&buffer);
len_avail = strlen (buf);
}
if (offset >= len_avail)
{
/* Done. Get rid of the buffer. */
buffer_free (&buffer);
buf = NULL;
len_avail = 0;
return 0;
}
if (len > len_avail - offset)
len = len_avail - offset;
memcpy (readbuf, buf + offset, len);
return len;
}
struct osdata_type {
char *type;
char *description;
LONGEST (*getter) (gdb_byte *readbuf, ULONGEST offset, LONGEST len);
} osdata_table[] = {
{ "processes", "Listing of all processes", linux_xfer_osdata_processes },
{ "threads", "Listing of all threads", linux_xfer_osdata_threads },
{ NULL, NULL, NULL }
};
LONGEST
linux_common_xfer_osdata (const char *annex, gdb_byte *readbuf,
ULONGEST offset, LONGEST len)
{
if (!annex || *annex == '\0')
{
static const char *buf;
static LONGEST len_avail = -1;
static struct buffer buffer;
if (offset == 0)
{
int i;
if (len_avail != -1 && len_avail != 0)
buffer_free (&buffer);
len_avail = 0;
buf = NULL;
buffer_init (&buffer);
buffer_grow_str (&buffer, "<osdata type=\"types\">\n");
for (i = 0; osdata_table[i].type; ++i)
buffer_xml_printf (
&buffer,
"<item>"
"<column name=\"Type\">%s</column>"
"<column name=\"Description\">%s</column>"
"</item>",
osdata_table[i].type,
osdata_table[i].description);
buffer_grow_str0 (&buffer, "</osdata>\n");
buf = buffer_finish (&buffer);
len_avail = strlen (buf);
}
if (offset >= len_avail)
{
/* Done. Get rid of the buffer. */
buffer_free (&buffer);
buf = NULL;
len_avail = 0;
return 0;
}
if (len > len_avail - offset)
len = len_avail - offset;
memcpy (readbuf, buf + offset, len);
return len;
}
else
{
int i;
for (i = 0; osdata_table[i].type; ++i)
{
if (strcmp (annex, osdata_table[i].type) == 0)
{
gdb_assert (readbuf);
return (osdata_table[i].getter) (readbuf, offset, len);
}
}
return 0;
}
}