diff mbox series

[avr] Fix PR31687: Account for .rodata size in avr-objdump -P mem-usage

Message ID 39c6854c-ccc8-492e-86fd-57f01edb451c@gjlay.de
State New
Headers
Series [avr] Fix PR31687: Account for .rodata size in avr-objdump -P mem-usage |

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Commit Message

Georg-Johann Lay May 5, 2024, 7:30 p.m. UTC 
  AVR: binutils/31684 - Include .rodata size in avr-objdump -P mem-usage.

AVR emulations with a .rodata output section were missing the size
of that section in  avr-objdump -P mem-usage.  This are the emulations
that keep .rodata in program memory, which can be supported by devices
that see (a part of) the program memory in the RAM address space.

The patch also introduces a code clean-up related to PR 27283, which
was about broken binaries that lead to overflow / UB in size computation.
The section size is now just truncated, alongside with a diagnostic about
the truncation and *which* section length is being truncated.

binutils/
	PR binutils/31684
	* od-elf32_avr.c (elf32_avr_get_truncated_size): New static function.
	(elf32_avr_get_memory_usage): Use it to get (truncated) section sizes.

Comments

Georg-Johann Lay May 5, 2024, 7:46 p.m. UTC | #1 
Am 05.05.24 um 21:30 schrieb Georg-Johann Lay:
> AVR: binutils/31684 - Include .rodata size in avr-objdump -P mem-usage.
> 
> AVR emulations with a .rodata output section were missing the size
> of that section in  avr-objdump -P mem-usage.  This are the emulations
> that keep .rodata in program memory, which can be supported by devices
> that see (a part of) the program memory in the RAM address space.
> 
> The patch also introduces a code clean-up related to PR 27283, which
> was about broken binaries that lead to overflow / UB in size computation.
> The section size is now just truncated, alongside with a diagnostic about
> the truncation and *which* section length is being truncated.
> 
> binutils/
>      PR binutils/31684
>      * od-elf32_avr.c (elf32_avr_get_truncated_size): New static function.
>      (elf32_avr_get_memory_usage): Use it to get (truncated) section sizes.

There's a typo, it's PR31687 (not 31684)

Johann
diff mbox series

Patch

diff --git a/binutils/od-elf32_avr.c b/binutils/od-elf32_avr.c
index d32bd4fc049..1e7a8b49935 100644
--- a/binutils/od-elf32_avr.c
+++ b/binutils/od-elf32_avr.c
@@ -164,79 +164,55 @@  elf32_avr_get_device_info (bfd *abfd, char *description,
   device->name = str_table + device_name_index;
 }
 
-static void
-elf32_avr_get_memory_usage (bfd *abfd,
-			    bfd_size_type *text_usage,
-			    bfd_size_type *data_usage,
-			    bfd_size_type *eeprom_usage)
-{
 
-  bfd_size_type avr_datasize = 0;
-  bfd_size_type avr_textsize = 0;
-  bfd_size_type avr_bsssize = 0;
-  bfd_size_type bootloadersize = 0;
-  bfd_size_type noinitsize = 0;
-  bfd_size_type eepromsize = 0;
-  bfd_size_type res;
+/* Get the size of section *SECNAME, truncated to a reasonable value in
+   order to catch PR 27285 and dysfunctional binaries.  */
+
+static bfd_size_type
+elf32_avr_get_truncated_size (bfd *abfd, const char *secname)
+{
+  /* Max size of around 1 MiB is more than any reasonable AVR will
+     ever be able to swallow.  And it's small enough so that we won't
+     get overflows / UB as demonstrated in PR 27285.  */
+  const bfd_size_type max_size = 1000000;
+  bfd_size_type size = 0;
   asection *section;
 
-  if ((section = bfd_get_section_by_name (abfd, ".data")) != NULL)
-    avr_datasize = bfd_section_size (section);
-  if ((section = bfd_get_section_by_name (abfd, ".text")) != NULL)
-    avr_textsize = bfd_section_size (section);
-  if ((section = bfd_get_section_by_name (abfd, ".bss")) != NULL)
-    avr_bsssize = bfd_section_size (section);
-  if ((section = bfd_get_section_by_name (abfd, ".bootloader")) != NULL)
-    bootloadersize = bfd_section_size (section);
-  if ((section = bfd_get_section_by_name (abfd, ".noinit")) != NULL)
-    noinitsize = bfd_section_size (section);
-  if ((section = bfd_get_section_by_name (abfd, ".eeprom")) != NULL)
-    eepromsize = bfd_section_size (section);
-
-  /* PR 27285: Check for overflow.  */
-  res = avr_textsize + avr_datasize;
-  if (res < avr_textsize || res < avr_datasize)
-    {
-      fprintf (stderr, _("Warning: textsize (%#lx) + datasize (%#lx) overflows size type\n"),
-	       (long) avr_textsize, (long) avr_datasize);
-      res = (bfd_size_type) -1;
-    }
-  else
+  section = bfd_get_section_by_name (abfd, secname);
+
+  if (section != NULL)
     {
-      bfd_size_type res2;
-      res2 = res + bootloadersize;
-      if (res2 < bootloadersize || res2 < res)
+      size = bfd_section_size (section);
+      if (size > max_size)
 	{
-	  fprintf (stderr, _("Warning: textsize (%#lx) + datasize (%#lx) + bootloadersize (%#lx) overflows size type\n"),
-		   (long) avr_textsize, (long) avr_datasize, (long) bootloadersize);
-	  res2 = (bfd_size_type) -1;
+	  fprintf (stderr, _("Warning: section %s has an impossible size of"
+			     " %lu bytes, truncating to %lu bytes\n"),
+		   secname, (unsigned long) size, (unsigned long) max_size);
+	  size = max_size;
 	}
-      res = res2;
     }
-  *text_usage = res;
 
-  res = avr_datasize + avr_bsssize;
-  if (res < avr_datasize || res < avr_bsssize)
-    {
-      fprintf (stderr, _("Warning: datatsize (%#lx) + bssssize (%#lx) overflows size type\n"),
-	       (long) avr_datasize, (long) avr_bsssize);
-      res = (bfd_size_type) -1;
-    }
-  else
-    {
-      bfd_size_type res2;
+  return size;
+}
 
-      res2 = res + noinitsize;
-      if (res2 < res || res2 < noinitsize)
-	{
-	  fprintf (stderr, _("Warning: datasize (%#lx) + bsssize (%#lx) + noinitsize (%#lx) overflows size type\n"),
-		   (long) avr_datasize, (long) avr_bsssize, (long) noinitsize);
-	  res2 = (bfd_size_type) -1;
-	}
-      res = res2;
-    }
-  *data_usage = res;
 
+static void
+elf32_avr_get_memory_usage (bfd *abfd,
+			    bfd_size_type *text_usage,
+			    bfd_size_type *data_usage,
+			    bfd_size_type *eeprom_usage)
+{
+  bfd_size_type avr_textsize = elf32_avr_get_truncated_size (abfd, ".text");
+  bfd_size_type avr_datasize = elf32_avr_get_truncated_size (abfd, ".data");;
+  bfd_size_type avr_bsssize  = elf32_avr_get_truncated_size (abfd, ".bss");
+  bfd_size_type noinitsize = elf32_avr_get_truncated_size (abfd, ".noinit");
+  bfd_size_type rodatasize = elf32_avr_get_truncated_size (abfd, ".rodata");
+  bfd_size_type eepromsize = elf32_avr_get_truncated_size (abfd, ".eeprom");
+  bfd_size_type bootloadersize = elf32_avr_get_truncated_size (abfd,
+							       ".bootloader");
+
+  *text_usage = avr_textsize + avr_datasize + rodatasize + bootloadersize;
+  *data_usage = avr_datasize + avr_bsssize + noinitsize;
   *eeprom_usage = eepromsize;
 }
 
@@ -274,7 +250,7 @@  elf32_avr_dump_mem_usage (bfd *abfd)
   if (device.flash_size > 0)
     printf (" (%2.1f%% Full)", (double) text_usage / device.flash_size * 100);
 
-  printf ("\n(.text + .data + .bootloader)\n\n");
+  printf ("\n(.text + .data + .rodata + .bootloader)\n\n");
 
   /* Data size */
   printf ("Data:   %8" PRIu64 " bytes", (uint64_t) data_usage);