[PATCH][gdb] Make maint info sections print relocated addresses

[PATCH][gdb] Make maint info sections print relocated addresses

[Tom de Vries]

Hi,

When running gdb.base/compare-sections.exp with -fPIE/-pie, we get:
...
print /u *(unsigned char *) 0x00000238^M
Cannot access memory at address 0x238^M
(gdb) FAIL: gdb.base/compare-sections.exp: read-only: get value of read-only section
...

The problem is that that "maint info sections" prints an unrelocated address:
...
 [0]     0x00000238->0x00000254 at 0x00000238: .interp ALLOC LOAD READONLY \
                                                       DATA HAS_CONTENTS
...
while the test expects a relocated address.

Given that the documentation states that the command displays "the section
information displayed by info files", and that info files shows relocated
addresses:
...
        0x0000555555554238 - 0x0000555555554254 is .interp
...
fix this by showing relocated addresses for maint info sections as
well.

Build and tested on x86_64-linux.

OK for trunk?

Thanks,
- Tom

[gdb] Make maint info sections print relocated addresses

gdb/ChangeLog:

2019-08-14  Tom de Vries  <tdevries@suse.de>

	* maint.c (maintenance_info_sections): Also handle !ALLOBJ case using
	print_objfile_section_info.

---
 gdb/maint.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/gdb/maint.c b/gdb/maint.c
index f7485dc3ab..12262b14e5 100644
--- a/gdb/maint.c
+++ b/gdb/maint.c
@@ -329,33 +329,36 @@ maintenance_info_sections (const char *arg, int from_tty)
 {
   if (exec_bfd)
     {
+      struct obj_section *osect;
+      bool allobj = false;
+
       printf_filtered (_("Exec file:\n"));
       printf_filtered ("    `%s', ", bfd_get_filename (exec_bfd));
       wrap_here ("        ");
       printf_filtered (_("file type %s.\n"), bfd_get_target (exec_bfd));
-      if (arg && *arg && match_substring (arg, "ALLOBJ"))
-	{
-	  struct obj_section *osect;
 
-	  /* Only this function cares about the 'ALLOBJ' argument; 
-	     if 'ALLOBJ' is the only argument, discard it rather than
-	     passing it down to print_objfile_section_info (which 
-	     wouldn't know how to handle it).  */
-	  if (strcmp (arg, "ALLOBJ") == 0)
-	    arg = NULL;
+      /* Only this function cares about the 'ALLOBJ' argument;
+	 if 'ALLOBJ' is the only argument, discard it rather than
+	 passing it down to print_objfile_section_info (which
+	 wouldn't know how to handle it).  */
+      if (arg && strcmp (arg, "ALLOBJ") == 0)
+	{
+	  arg = NULL;
+	  allobj = true;
+	}
 
-	  for (objfile *ofile : current_program_space->objfiles ())
+      for (objfile *ofile : current_program_space->objfiles ())
+	{
+	  if (allobj)
+	    printf_filtered (_("  Object file: %s\n"), 
+			     bfd_get_filename (ofile->obfd));
+	  ALL_OBJFILE_OSECTIONS (ofile, osect)
 	    {
-	      printf_filtered (_("  Object file: %s\n"), 
-			       bfd_get_filename (ofile->obfd));
-	      ALL_OBJFILE_OSECTIONS (ofile, osect)
-		{
-		  print_objfile_section_info (ofile->obfd, osect, arg);
-		}
+	      if (!allobj && ofile->obfd != exec_bfd)
+		continue;
+	      print_objfile_section_info (ofile->obfd, osect, arg);
 	    }
 	}
-      else 
-	bfd_map_over_sections (exec_bfd, print_bfd_section_info, (void *) arg);
     }
 
   if (core_bfd)

Re: [PATCH][gdb] Make maint info sections print relocated addresses

[Tom Tromey]

>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:

Tom> gdb/ChangeLog:

Tom> 2019-08-14  Tom de Vries  <tdevries@suse.de>

Tom> 	* maint.c (maintenance_info_sections): Also handle !ALLOBJ case using
Tom> 	print_objfile_section_info.

Thanks.

Tom> +      if (arg && strcmp (arg, "ALLOBJ") == 0)
Tom> +	{
Tom> +	  arg = NULL;
Tom> +	  allobj = true;
Tom> +	}

It took me a minute to understand that this was equivalent to the old
code.  It looked like the intent was to use match_substring, but then
other code defeated that.  If this was more user-facing I'd say "ALLOBJ"
should be replaced with a real option; but since this is a maint command
I would not bother.

This patch is ok.  Thanks.

Tom