[RFA] New command "info proc" for Linux

[RFA] New command "info proc" for Linux

[Michael Snyder]

What do you Linux guys think of this?  It's modelled after the info
proc command from procfs.c, but uses/exposes the /proc information
available on Linux.  Do you see any architecture/portability issues?

Thanks
Michael

2002-01-10  Michael Snyder  <msnyder@redhat.com>

	* linux-proc.c: Add "info proc" command, a la procfs.c.
	(read_mapping): New function, abstract and re-use code.
	(linux_find_memory_regions): Use new func read_mapping.
	(linux_info_proc_cmd): New function, implement "info proc".
	(_initialize_linux_proc): Add new command "info proc".

Index: linux-proc.c
===================================================================
RCS file: /cvs/src/src/gdb/linux-proc.c,v
retrieving revision 1.3
diff -c -3 -p -r1.3 linux-proc.c
*** linux-proc.c	2002/01/09 02:21:25	1.3
--- linux-proc.c	2002/01/10 20:04:03
***************
*** 22,31 ****
--- 22,34 ----
  #include "inferior.h"
  #include <sys/param.h>	/* for MAXPATHLEN */
  #include <sys/procfs.h>
+ #include <sys/stat.h>	/* for struct stat */
+ #include <ctype.h>	/* for isdigit */
  #include "gregset.h"	/* for gregset */
  #include "gdbcore.h"	/* for get_exec_file */
  #include "gdbthread.h"	/* for struct thread_info etc. */
  #include "elf-bfd.h"
+ #include "cli/cli-decode.h"
  
  /* Function: child_pid_to_exec_file
   *
*************** child_pid_to_exec_file (int pid)
*** 52,57 ****
--- 55,90 ----
      return name1;
  }
  
+ /* Function: read_mappings
+  *
+  * Service function for corefiles and info proc.
+  */
+ 
+ static int 
+ read_mapping (FILE *mapfile, 
+ 	      long long *addr, 
+ 	      long long *endaddr, 
+ 	      char *permissions, 
+ 	      long long *offset, 
+ 	      char *device, 
+ 	      long long *inode, 
+ 	      char *filename)
+ {
+   int ret = fscanf (mapfile,  "%llx-%llx %s %llx %s %llx", 
+ 		    addr, endaddr, permissions, offset, device, inode);
+ 
+   if (ret > 0 && ret != EOF && *inode != 0)
+     {
+       ret += fscanf (mapfile, "%s\n", filename);
+     }
+   else
+     {
+       filename[0] = '\0';	/* no filename */
+       fscanf (mapfile, "\n");
+     }
+   return (ret != 0 && ret != EOF);
+ }
+ 
  /* Function: linux_find_memory_regions
   *
   * Fills the "to_find_memory_regions" target vector.
*************** linux_find_memory_regions (int (*func) (
*** 66,107 ****
  			   void *obfd)
  {
    long long pid = PIDGET (inferior_ptid);
!   char procfilename[MAXPATHLEN];
!   FILE *procfile;
    long long addr, endaddr, size, offset, inode;
!   char perms[8], dev[8], filename[MAXPATHLEN];
    int read, write, exec;
    int ret;
  
    /* Compose the filename for the /proc memory map, and open it. */
!   sprintf (procfilename, "/proc/%lld/maps", pid);
!   if ((procfile = fopen (procfilename, "r")) == NULL)
!     error ("Could not open %s\n", procfilename);
  
    if (info_verbose)
      fprintf_filtered (gdb_stdout, 
! 		      "Reading memory regions from %s\n", procfilename);
! 
!   /* Read the first memory segment descriptor from the maps file.  */
!   ret = fscanf (procfile, "%llx-%llx %s %llx %s %llx", 
! 		&addr, &endaddr, perms, &offset, dev, &inode);
!   if (inode)
!     fscanf (procfile, " %s\n", filename);
!   else
!     {
!       filename[0] = '\0';
!       fscanf (procfile, "\n");
!     }
  
    /* Now iterate until end-of-file. */
!   while (ret > 0 && ret != EOF)
      {
        size = endaddr - addr;
  
        /* Get the segment's permissions.  */
!       read  = (strchr (perms, 'r') != 0);
!       write = (strchr (perms, 'w') != 0);
!       exec  = (strchr (perms, 'x') != 0);
  
        if (info_verbose)
  	{
--- 99,130 ----
  			   void *obfd)
  {
    long long pid = PIDGET (inferior_ptid);
!   char mapsfilename[MAXPATHLEN];
!   FILE *mapsfile;
    long long addr, endaddr, size, offset, inode;
!   char permissions[8], device[8], filename[MAXPATHLEN];
    int read, write, exec;
    int ret;
  
    /* Compose the filename for the /proc memory map, and open it. */
!   sprintf (mapsfilename, "/proc/%lld/maps", pid);
!   if ((mapsfile = fopen (mapsfilename, "r")) == NULL)
!     error ("Could not open %s\n", mapsfilename);
  
    if (info_verbose)
      fprintf_filtered (gdb_stdout, 
! 		      "Reading memory regions from %s\n", mapsfilename);
  
    /* Now iterate until end-of-file. */
!   while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0], 
! 		       &offset, &device[0], &inode, &filename[0]))
      {
        size = endaddr - addr;
  
        /* Get the segment's permissions.  */
!       read  = (strchr (permissions, 'r') != 0);
!       write = (strchr (permissions, 'w') != 0);
!       exec  = (strchr (permissions, 'x') != 0);
  
        if (info_verbose)
  	{
*************** linux_find_memory_regions (int (*func) (
*** 119,139 ****
  
        /* Invoke the callback function to create the corefile segment. */
        func (addr, size, read, write, exec, obfd);
- 
-       /* Read the next memory region.  */
-       filename[0] = '\0';
-       ret = fscanf (procfile, "%llx-%llx %s %llx %s %llx", 
- 		    &addr, &endaddr, perms, &offset, dev, &inode);
-       if (inode)
- 	fscanf (procfile, " %s\n", filename);
-       else
- 	{
- 	  filename[0] = '\0';
- 	  fscanf (procfile, "\n");
- 	}
      }
! 
!   fclose (procfile);
    return 0;
  }
  
--- 142,149 ----
  
        /* Invoke the callback function to create the corefile segment. */
        func (addr, size, read, write, exec, obfd);
      }
!   fclose (mapsfile);
    return 0;
  }
  
*************** linux_make_note_section (bfd *obfd, int 
*** 268,273 ****
--- 278,550 ----
    return note_data;
  }
  
+ /*
+  * Function: linux_info_proc_cmd
+  *
+  * Implement the "info proc" command.
+  */
+ 
+ static void
+ linux_info_proc_cmd (char *args, int from_tty)
+ {
+   long long pid = PIDGET (inferior_ptid);
+   FILE *procfile;
+   char **argv = NULL;
+   char buffer[MAXPATHLEN];
+   char fname1[MAXPATHLEN], fname2[MAXPATHLEN];
+   int cmdline_f = 1;
+   int cwd_f = 1;
+   int exe_f = 1;
+   int mappings_f = 0;
+   int environ_f = 0;
+   int status_f = 0;
+   int stat_f = 0;
+   int all = 0;
+   struct stat dummy;
+ 
+   if (args)
+     {
+       /* Break up 'args' into an argv array. */
+       if ((argv = buildargv (args)) == NULL)
+ 	nomem (0);
+       else
+ 	make_cleanup_freeargv (argv);
+     }
+   while (argv != NULL && *argv != NULL)
+     {
+       if (isdigit (argv[0][0]))
+ 	{
+ 	  pid = strtoul (argv[0], NULL, 10);
+ 	}
+       else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0)
+ 	{
+ 	  mappings_f = 1;
+ 	}
+       else if (strcmp (argv[0], "status") == 0)
+ 	{
+ 	  status_f = 1;
+ 	}
+       else if (strcmp (argv[0], "stat") == 0)
+ 	{
+ 	  stat_f = 1;
+ 	}
+       else if (strcmp (argv[0], "cmd") == 0)
+ 	{
+ 	  cmdline_f = 1;
+ 	}
+       else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0)
+ 	{
+ 	  exe_f = 1;
+ 	}
+       else if (strcmp (argv[0], "cwd") == 0)
+ 	{
+ 	  cwd_f = 1;
+ 	}
+       else if (strncmp (argv[0], "all", strlen (argv[0])) == 0)
+ 	{
+ 	  all = 1;
+ 	}
+       else
+ 	{
+ 	  /* [...] (future options here) */
+ 	}
+       argv++;
+     }
+   if (pid == 0)
+     error ("No current process: you must name one.");
+ 
+   sprintf (fname1, "/proc/%lld", pid);
+   if (stat (fname1, &dummy) != 0)
+     error ("No /proc directory: '%s'", fname1);
+ 
+   printf_filtered ("process %lld\n", pid);
+   if (cmdline_f || all)
+     {
+       sprintf (fname1, "/proc/%lld/cmdline", pid);
+       if ((procfile = fopen (fname1, "r")) > 0)
+ 	{
+ 	  fgets (buffer, sizeof (buffer), procfile);
+ 	  printf_filtered ("cmdline = '%s'\n", buffer);
+ 	  fclose (procfile);
+ 	}
+       else
+ 	warning ("unable to open /proc file '%s'", fname1);
+     }
+   if (cwd_f || all)
+     {
+       sprintf (fname1, "/proc/%lld/cwd", pid);
+       memset (fname2, 0, sizeof (fname2));
+       if (readlink (fname1, fname2, sizeof (fname2)) > 0)
+ 	printf_filtered ("cwd = '%s'\n", fname2);
+       else
+ 	warning ("unable to read link '%s'", fname1);
+     }
+   if (exe_f || all)
+     {
+       sprintf (fname1, "/proc/%lld/exe", pid);
+       memset (fname2, 0, sizeof (fname2));
+       if (readlink (fname1, fname2, sizeof (fname2)) > 0)
+ 	printf_filtered ("exe = '%s'\n", fname2);
+       else
+ 	warning ("unable to read link '%s'", fname1);
+     }
+   if (mappings_f || all)
+     {
+       sprintf (fname1, "/proc/%lld/maps", pid);
+       if ((procfile = fopen (fname1, "r")) > 0)
+ 	{
+ 	  long long addr, endaddr, size, offset, inode;
+ 	  char permissions[8], device[8], filename[MAXPATHLEN];
+ 	  char *header_fmt_string, *data_fmt_string;
+ 
+ 	  if (TARGET_ADDR_BIT == 32)
+ 	    {
+ 	      header_fmt_string = "\t%10s %10s %10s %10s %7s\n";
+ 	      data_fmt_string   = "\t%#10lx %#10lx %#10x %#10x %7s\n";
+ 	    }
+ 	  else
+ 	    {
+ 	      header_fmt_string = "  %18s %18s %10s %10s %7s\n";
+ 	      data_fmt_string   = "  %#18lx %#18lx %#10x %#10x %7s\n";
+ 	    }
+ 
+ 	  printf_filtered ("Mapped address spaces:\n\n");
+ 	  printf_filtered (header_fmt_string, 
+ 			   "Start Addr",
+ 			   "  End Addr",
+ 			   "      Size",
+ 			   "    Offset",
+ 			   "objfile");
+ 	  
+ 	  while (read_mapping (procfile, &addr, &endaddr, &permissions[0], 
+ 			       &offset, &device[0], &inode, &filename[0]))
+ 	    {
+ 	      size = endaddr - addr;
+ 	      printf_filtered (data_fmt_string, 
+ 			       (unsigned long) addr, /* FIXME: pr_addr */
+ 			       (unsigned long) endaddr, 
+ 			       (int) size, 
+ 			       (unsigned int) offset, 
+ 			       filename[0] ? filename : "");
+ 	      
+ 	    }
+ 
+ 	  fclose (procfile);
+ 	}
+       else
+ 	warning ("unable to open /proc file '%s'", fname1);
+     }
+   if (status_f || all)
+     {
+       sprintf (fname1, "/proc/%lld/status", pid);
+       if ((procfile = fopen (fname1, "r")) > 0)
+ 	{
+ 	  while (fgets (buffer, sizeof (buffer), procfile) != NULL)
+ 	    printf_filtered (buffer);
+ 	  fclose (procfile);
+ 	}
+       else 
+ 	warning ("unable to open /proc file '%s'", fname1);
+     }
+   if (stat_f || all)
+     {
+       sprintf (fname1, "/proc/%lld/stat", pid);
+       if ((procfile = fopen (fname1, "r")) > 0)
+ 	{
+ 	  int itmp;
+ 	  char ctmp;
+ 
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Process: %d\n", itmp);
+ 	  if (fscanf (procfile, "%s ", &buffer[0]) > 0)
+ 	    printf_filtered ("Exec file: %s\n", buffer);
+ 	  if (fscanf (procfile, "%c ", &ctmp) > 0)
+ 	    printf_filtered ("State: %c\n", ctmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Parent process: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Process group: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Session id: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("TTY: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("TTY owner process group: %d\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Flags: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Minor faults (no memory page): %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Minor faults, children: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Major faults (memory page faults): %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Major faults, children: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("utime: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("stime: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("utime, children: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("stime, children: %d\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("jiffies remaining in current time slice: %d\n", 
+ 			     itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("'nice' value: %d\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("jiffies until next timeout: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("jiffies until next SIGALRM: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("start time (jiffies since system boot): %d\n", 
+ 			     itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Virtual memory size: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Resident set size: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("rlim: %u\n", 
+ 			     (unsigned int) itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Start of text: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("End of text: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)
+ 	    printf_filtered ("Start of stack: 0x%x\n", itmp);
+ #if 0	/* Don't know how architecture-dependent the rest is... 
+ 	   Anyway the signal bitmap info is available from "status".  */
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)	/* FIXME arch? */
+ 	    printf_filtered ("Kernel stack pointer: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)	/* FIXME arch? */
+ 	    printf_filtered ("Kernel instr pointer: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Pending signals bitmap: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Blocked signals bitmap: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Ignored signals bitmap: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%d ", &itmp) > 0)
+ 	    printf_filtered ("Catched signals bitmap: 0x%x\n", itmp);
+ 	  if (fscanf (procfile, "%u ", &itmp) > 0)	/* FIXME arch? */
+ 	    printf_filtered ("wchan (system call): 0x%x\n", itmp);
+ #endif
+ 	  fclose (procfile);
+ 	}
+       else
+ 	warning ("unable to open /proc file '%s'", fname1);
+     }
+ }
+ 
  void
  _initialize_linux_proc (void)
  {
*************** _initialize_linux_proc (void)
*** 276,279 ****
--- 553,565 ----
  
    inftarg_set_find_memory_regions (linux_find_memory_regions);
    inftarg_set_make_corefile_notes (linux_make_note_section);
+ 
+   add_info ("proc", linux_info_proc_cmd, 
+ 	    "Show /proc process information about any running process.\n\
+ Specify any process id, or use the program being debugged by default.\n\
+ Specify any of the following keywords for detailed info:\n\
+   mappings -- list of mapped memory regions.\n\
+   stat     -- list a bunch of random process info.\n\
+   status   -- list a different bunch of random process info.\n\
+   all      -- list all available /proc info.");
  }

Re: [RFA] New command "info proc" for Linux

[Daniel Jacobowitz]

On Thu, Jan 10, 2002 at 12:08:51PM -0800, Michael Snyder wrote:
> 
> What do you Linux guys think of this?  It's modelled after the info
> proc command from procfs.c, but uses/exposes the /proc information
> available on Linux.  Do you see any architecture/portability issues?

Not offhand - I like it.  Someday I hope to be able to get this from
gdbserver, too.  I would have killed for it over the past week.

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: [RFA] New command "info proc" for Linux

[Michael Snyder]

Daniel Jacobowitz wrote:
> 
> On Thu, Jan 10, 2002 at 12:08:51PM -0800, Michael Snyder wrote:
> >
> > What do you Linux guys think of this?  It's modelled after the info
> > proc command from procfs.c, but uses/exposes the /proc information
> > available on Linux.  Do you see any architecture/portability issues?
> 
> Not offhand - I like it.  Someday I hope to be able to get this from
> gdbserver, too.  I would have killed for it over the past week.

Committed.

Re: [RFA] New command "info proc" for Linux

[Eli Zaretskii]

On Tue, 15 Jan 2002, Michael Snyder wrote:

> Committed.

Michael, please don't forget the documentation.  Thanks.

Re: [RFA] New command "info proc" for Linux

[Michael Snyder]

Eli Zaretskii wrote:
> 
> On Tue, 15 Jan 2002, Michael Snyder wrote:
> 
> > Committed.
> 
> Michael, please don't forget the documentation.  Thanks.

Not straightforward.  Couple of issues:

1) The old implementation of the "info proc" command was 
poorly documented -- many of the documented sub-commands
were never implemented.  And the command was only available
on "/proc" systems (real ones, not Linux).

2) The stuff I've just added will ONLY work on Linux, 
not on other ("real") /proc systems.

Re: [RFA] New command "info proc" for Linux

[Eli Zaretskii]

> Date: Wed, 16 Jan 2002 09:07:39 -0800
> From: Michael Snyder <msnyder@redhat.com>
> > 
> > Michael, please don't forget the documentation.  Thanks.
> 
> Not straightforward.  Couple of issues:
> 
> 1) The old implementation of the "info proc" command was 
> poorly documented -- many of the documented sub-commands
> were never implemented.  And the command was only available
> on "/proc" systems (real ones, not Linux).
> 
> 2) The stuff I've just added will ONLY work on Linux, 
> not on other ("real") /proc systems.

Does that mean the functionality of this command differs on these two
classes of systems?  If so, we could:

 (a) document the functionality on both classes, telling which parts
 work on what systems;

or

 (b) document the GNU/Linux functionality that you just added, and
 leave the docs of what the command does on ``real'' /proc systems as
 it is now.

The latter will probably be easier for you (no need to figure out code
written by someone else ;-), and it doesn't make the situation worse
than it is now.  So I won't object if you do only (b).  (If you do, it
is possible that the Linux-specific docs could go into a new
subsection of the "Native" node, where system-specific features are
described.

Does that address your concerns?

Re: [RFA] New command "info proc" for Linux

[Michael Snyder]

Eli Zaretskii wrote:
> 
> > Date: Wed, 16 Jan 2002 09:07:39 -0800
> > From: Michael Snyder <msnyder@redhat.com>
> > >
> > > Michael, please don't forget the documentation.  Thanks.
> >
> > Not straightforward.  Couple of issues:
> >
> > 1) The old implementation of the "info proc" command was
> > poorly documented -- many of the documented sub-commands
> > were never implemented.  And the command was only available
> > on "/proc" systems (real ones, not Linux).
> >
> > 2) The stuff I've just added will ONLY work on Linux,
> > not on other ("real") /proc systems.
> 
> Does that mean the functionality of this command differs on these two
> classes of systems?  If so, we could:
> 
>  (a) document the functionality on both classes, telling which parts
>  work on what systems;
> 
> or
> 
>  (b) document the GNU/Linux functionality that you just added, and
>  leave the docs of what the command does on ``real'' /proc systems as
>  it is now.
> 
> The latter will probably be easier for you (no need to figure out code
> written by someone else ;-), and it doesn't make the situation worse
> than it is now.  So I won't object if you do only (b).  (If you do, it
> is possible that the Linux-specific docs could go into a new
> subsection of the "Native" node, where system-specific features are
> described.
> 
> Does that address your concerns?

Yeah, except I don't know how to make a nnew node, 
and I would have to think about where to put it.  ;-)

Re: [RFA] New command "info proc" for Linux

[Eli Zaretskii]

> Date: Wed, 16 Jan 2002 09:47:55 -0800
> From: Michael Snyder <msnyder@redhat.com>
> > 
> > Does that address your concerns?
> 
> Yeah, except I don't know how to make a nnew node, 
> and I would have to think about where to put it.  ;-)

Don't worry: just send me the Texinfo that needs to be added, and I
will do the boring part.