Finish elflint .gnu.attributes checking

4 files changed, 427 insertions, 15 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index d3e49e41..f28c7006 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,21 @@
+2008-02-20  Roland McGrath  <[email protected]>
+
+	* readelf.c (print_attributes): New function.
+	(process_elf_file): Call it under -A.
+
+	* elflint.c (check_attributes): Implement it for real.
+
+2008-02-19  Roland McGrath  <[email protected]>
+
+	* elflint.c (special_sections): Handle .gnu.attributes section.
+	(check_sections): Likewise.
+	(check_attributes): New function.
+
+2008-02-10  Roland McGrath  <[email protected]>
+
+	* elfcmp.c (main): Ignore sh_offset differences in non-SHF_ALLOC
+	sections and ET_REL files.
+
 2008-02-02  Ulrich Drepper  <[email protected]>
 
 	* elf32-i386.script: Add .eh_frame_hdr, .tdata, and .tbss sections.
@@ -110,6 +128,12 @@
 
 2008-01-04  Roland McGrath  <[email protected]>
 
+	* readelf.c (handle_core_items): Take new arg DESCSZ; if nonzero,
+	a size greater than the items cover means multiple sets of items.
+	(handle_core_note): Update caller.
+
+2008-01-04  Roland McGrath  <[email protected]>
+
 	* strip.c (handle_elf): Move SHDRIDX defn to silence gcc warning.
 
 2008-01-03  Roland McGrath  <[email protected]>
diff --git a/src/elfcmp.c b/src/elfcmp.c
index be9aaccd..0e134df8 100644
--- a/src/elfcmp.c
+++ b/src/elfcmp.c
@@ -1,5 +1,5 @@
 /* Compare relevant content of two ELF files.
-   Copyright (C) 2005, 2006, 2007 Red Hat, Inc.
+   Copyright (C) 2005, 2006, 2007, 2008 Red Hat, Inc.
    This file is part of Red Hat elfutils.
    Written by Ulrich Drepper <[email protected]>, 2005.
 
@@ -259,7 +259,9 @@ main (int argc, char *argv[])
 	  // XXX Any flags which should be ignored?
 	  || shdr1->sh_flags != shdr2->sh_flags
 	  || shdr1->sh_addr != shdr2->sh_addr
-	  || shdr1->sh_offset != shdr2->sh_offset
+	  || (shdr1->sh_offset != shdr2->sh_offset
+	      && (shdr1->sh_flags & SHF_ALLOC)
+	      && ehdr1->e_type != ET_REL)
 	  || shdr1->sh_size != shdr2->sh_size
 	  || shdr1->sh_link != shdr2->sh_link
 	  || shdr1->sh_info != shdr2->sh_info
diff --git a/src/elflint.c b/src/elflint.c
index b65170ce..9a1a7179 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -46,7 +46,12 @@
 
 #include <elf-knowledge.h>
 #include <system.h>
+#include "../libelf/libelfP.h"
+#include "../libelf/common.h"
 #include "../libebl/libeblP.h"
+#include "../libdw/libdwP.h"
+#include "../libdwfl/libdwflP.h"
+#include "../libdw/memory-access.h"
 
 
 /* Name and version of program.  */
@@ -3099,6 +3104,194 @@ section [%2d] '%s': unknown parent version '%s'\n"),
     }
 }
 
+static void
+check_attributes (Ebl *ebl, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int idx)
+{
+  if (shdr->sh_size == 0)
+    {
+      ERROR (gettext ("section [%2d] '%s': empty object attributes section\n"),
+	     idx, section_name (ebl, idx));
+      return;
+    }
+
+  Elf_Data *data = elf_rawdata (elf_getscn (ebl->elf, idx), NULL);
+  if (data == NULL || data->d_size == 0)
+    {
+      ERROR (gettext ("section [%2d] '%s': cannot get section data\n"),
+	     idx, section_name (ebl, idx));
+      return;
+    }
+
+  inline size_t pos (const unsigned char *p)
+  {
+    return p - (const unsigned char *) data->d_buf;
+  }
+
+  const unsigned char *p = data->d_buf;
+  if (*p++ != 'A')
+    {
+      ERROR (gettext ("section [%2d] '%s': unrecognized attribute format\n"),
+	     idx, section_name (ebl, idx));
+      return;
+    }
+
+  inline size_t left (void)
+  {
+    return (const unsigned char *) data->d_buf + data->d_size - p;
+  }
+
+  while (left () >= 4)
+    {
+      uint32_t len;
+      memcpy (&len, p, sizeof len);
+
+      if (len == 0)
+	ERROR (gettext ("\
+section [%2d] '%s': offset %zu: zero length field in attribute section\n"),
+	       idx, section_name (ebl, idx), pos (p));
+
+      if (MY_ELFDATA != ehdr->e_ident[EI_DATA])
+	CONVERT (len);
+
+      if (len > left ())
+	{
+	  ERROR (gettext ("\
+section [%2d] '%s': offset %zu: invalid length in attribute section\n"),
+		 idx, section_name (ebl, idx), pos (p));
+	  break;
+	}
+
+      const unsigned char *name = p + sizeof len;
+      p += len;
+
+      unsigned const char *q = memchr (name, '\0', len);
+      if (q == NULL)
+	{
+	  ERROR (gettext ("\
+section [%2d] '%s': offset %zu: unterminated vendor name string\n"),
+		 idx, section_name (ebl, idx), pos (p));
+	  continue;
+	}
+      ++q;
+
+      if (q - name == sizeof "gnu" && !memcmp (name, "gnu", sizeof "gnu"))
+	while (q < p)
+	  {
+	    unsigned const char *chunk = q;
+
+	    unsigned int subsection_tag;
+	    get_uleb128 (subsection_tag, q);
+
+	    if (q >= p)
+	      {
+		ERROR (gettext ("\
+section [%2d] '%s': offset %zu: endless ULEB128 in attribute subsection tag\n"),
+		       idx, section_name (ebl, idx), pos (chunk));
+		break;
+	      }
+
+	    uint32_t subsection_len;
+	    if (p - q < (ptrdiff_t) sizeof subsection_len)
+	      {
+		ERROR (gettext ("\
+section [%2d] '%s': offset %zu: truncated attribute section\n"),
+		       idx, section_name (ebl, idx), pos (q));
+		break;
+	      }
+
+	    memcpy (&subsection_len, q, sizeof subsection_len);
+	    if (subsection_len == 0)
+	      {
+		ERROR (gettext ("\
+section [%2d] '%s': offset %zu: zero length field in attribute subsection\n"),
+		       idx, section_name (ebl, idx), pos (q));
+
+		q += sizeof subsection_len;
+		continue;
+	      }
+
+	    if (MY_ELFDATA != ehdr->e_ident[EI_DATA])
+	      CONVERT (subsection_len);
+
+	    if (p - chunk < subsection_len)
+	      {
+		ERROR (gettext ("\
+section [%2d] '%s': offset %zu: invalid length in attribute subsection\n"),
+		       idx, section_name (ebl, idx), pos (q));
+		break;
+	      }
+
+	    const unsigned char *subsection_end = chunk + subsection_len;
+	    chunk = q;
+	    q = subsection_end;
+
+	    if (subsection_tag != 1) /* Tag_File */
+	      ERROR (gettext ("\
+section [%2d] '%s': offset %zu: attribute subsection has unexpected tag %u\n"),
+		     idx, section_name (ebl, idx), pos (chunk), subsection_tag);
+	    else
+	      {
+		chunk += sizeof subsection_len;
+		while (chunk < q)
+		  {
+		    unsigned int tag;
+		    get_uleb128 (tag, chunk);
+
+		    uint64_t value = 0;
+		    const unsigned char *r = chunk;
+		    if (tag == 32 || (tag & 1) == 0)
+		      {
+			get_uleb128 (value, r);
+			if (r > q)
+			  {
+			    ERROR (gettext ("\
+section [%2d] '%s': offset %zu: endless ULEB128 in attribute tag\n"),
+				   idx, section_name (ebl, idx), pos (chunk));
+			    break;
+			  }
+		      }
+		    if (tag == 32 || (tag & 1) != 0)
+		      {
+			r = memchr (r, '\0', q - r);
+			if (r == NULL)
+			  {
+			    ERROR (gettext ("\
+section [%2d] '%s': offset %zu: unterminated string in attribute\n"),
+				   idx, section_name (ebl, idx), pos (chunk));
+			    break;
+			  }
+			++r;
+		      }
+
+		    const char *tag_name = NULL;
+		    const char *value_name = NULL;
+		    if (!ebl_check_object_attribute (ebl, (const char *) name,
+						     tag, value,
+						     &tag_name, &value_name))
+		      ERROR (gettext ("\
+section [%2d] '%s': offset %zu: unrecognized attribute tag %u\n"),
+			     idx, section_name (ebl, idx), pos (chunk), tag);
+		    else if ((tag & 1) == 0 && value_name == NULL)
+		      ERROR (gettext ("\
+section [%2d] '%s': offset %zu: unrecognized %s attribute value %" PRIu64 "\n"),
+			     idx, section_name (ebl, idx), pos (chunk),
+			     tag_name, value);
+
+		    chunk = r;
+		  }
+	      }
+	  }
+      else
+	ERROR (gettext ("\
+section [%2d] '%s': offset %zu: vendor '%s' unknown\n"),
+	       idx, section_name (ebl, idx), pos (p), name);
+    }
+
+  if (left () != 0)
+    ERROR (gettext ("\
+section [%2d] '%s': offset %zu: extra bytes after last attribute section\n"),
+	   idx, section_name (ebl, idx), pos (p));
+}
 
 static bool has_loadable_segment;
 static bool has_interp_segment;
@@ -3150,7 +3343,8 @@ static const struct
     /* The following are GNU extensions.  */
     { ".gnu.version", 13, SHT_GNU_versym, exact, SHF_ALLOC, 0 },
     { ".gnu.version_d", 15, SHT_GNU_verdef, exact, SHF_ALLOC, 0 },
-    { ".gnu.version_r", 15, SHT_GNU_verneed, exact, SHF_ALLOC, 0 }
+    { ".gnu.version_r", 15, SHT_GNU_verneed, exact, SHF_ALLOC, 0 },
+    { ".gnu.attributes", 16, SHT_GNU_ATTRIBUTES, exact, 0, 0 },
   };
 #define nspecial_sections \
   (sizeof (special_sections) / sizeof (special_sections[0]))
@@ -3365,6 +3559,7 @@ section [%2zu] '%s': size not multiple of entry size\n"),
 	ERROR (gettext ("cannot get section header\n"));
 
       if (shdr->sh_type >= SHT_NUM
+	  && shdr->sh_type != SHT_GNU_ATTRIBUTES
 	  && shdr->sh_type != SHT_GNU_LIBLIST
 	  && shdr->sh_type != SHT_CHECKSUM
 	  && shdr->sh_type != SHT_GNU_verdef
@@ -3557,6 +3752,10 @@ section [%2zu] '%s': relocatable files cannot have dynamic symbol tables\n"),
 	  check_verdef (ebl, shdr, cnt);
 	  break;
 
+	case SHT_GNU_ATTRIBUTES:
+	  check_attributes (ebl, ehdr, shdr, cnt);
+	  break;
+
 	default:
 	  /* Nothing.  */
 	  break;
diff --git a/src/readelf.c b/src/readelf.c
index 90c460f9..0f0773c8 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -1,5 +1,5 @@
 /* Print information from ELF file in human-readable form.
-   Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007 Red Hat, Inc.
+   Copyright (C) 1999,2000,2001,2002,2003,2004,2005,2006,2007,2008 Red Hat, Inc.
    This file is part of Red Hat elfutils.
    Written by Ulrich Drepper <[email protected]>, 1999.
 
@@ -52,6 +52,7 @@
 
 #include <system.h>
 #include "../libelf/libelfP.h"
+#include "../libelf/common.h"
 #include "../libebl/libeblP.h"
 #include "../libdw/libdwP.h"
 #include "../libdwfl/libdwflP.h"
@@ -221,6 +222,7 @@ static void print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr);
 static void handle_hash (Ebl *ebl);
 static void handle_notes (Ebl *ebl, GElf_Ehdr *ehdr);
 static void print_liblist (Ebl *ebl);
+static void print_attributes (Ebl *ebl, const GElf_Ehdr *ehdr);
 static void dump_data (Ebl *ebl);
 static void dump_strings (Ebl *ebl);
 static void print_strings (Ebl *ebl);
@@ -640,6 +642,8 @@ process_elf_file (Dwfl_Module *dwflmod, int fd)
     print_symtab (ebl, SHT_SYMTAB);
   if (print_arch)
     print_liblist (ebl);
+  if (print_arch)
+    print_attributes (ebl, ehdr);
   if (dump_data_sections != NULL)
     dump_data (pure_ebl);
   if (string_sections != NULL)
@@ -2777,6 +2781,166 @@ print_liblist (Ebl *ebl)
     }
 }
 
+static void
+print_attributes (Ebl *ebl, const GElf_Ehdr *ehdr)
+{
+  /* Find the object attributes sections.  For this we have to search
+     through the section table.  */
+  Elf_Scn *scn = NULL;
+
+  /* Get the section header string table index.  */
+  size_t shstrndx;
+  if (unlikely (elf_getshstrndx (ebl->elf, &shstrndx) < 0))
+    error (EXIT_FAILURE, 0,
+	   gettext ("cannot get section header string table index"));
+
+  while ((scn = elf_nextscn (ebl->elf, scn)) != NULL)
+    {
+      GElf_Shdr shdr_mem;
+      GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+
+      if (shdr == NULL || shdr->sh_type != SHT_GNU_ATTRIBUTES)
+	continue;
+
+      printf (gettext ("\
+\nObject attributes section [%2zu] '%s' of %" PRIu64
+		       " bytes at offset %#0" PRIx64 ":\n"),
+	      elf_ndxscn (scn),
+	      elf_strptr (ebl->elf, shstrndx, shdr->sh_name),
+	      shdr->sh_size, shdr->sh_offset);
+
+      Elf_Data *data = elf_rawdata (scn, NULL);
+      if (data == NULL)
+	return;
+
+      const unsigned char *p = data->d_buf;
+
+      if (unlikely (*p++ != 'A'))
+	return;
+
+      fputs_unlocked (gettext ("  Owner          Size\n"), stdout);
+
+      inline size_t left (void)
+      {
+	return (const unsigned char *) data->d_buf + data->d_size - p;
+      }
+
+      while (left () >= 4)
+	{
+	  uint32_t len;
+	  memcpy (&len, p, sizeof len);
+
+	  if (MY_ELFDATA != ehdr->e_ident[EI_DATA])
+	    CONVERT (len);
+
+	  if (unlikely (len > left ()))
+	    break;
+
+	  const unsigned char *name = p + sizeof len;
+	  p += len;
+
+	  unsigned const char *q = memchr (name, '\0', len);
+	  if (unlikely (q == NULL))
+	    continue;
+	  ++q;
+
+	  printf (gettext ("  %-13s  %4" PRIu32 "\n"), name, len);
+
+	  if (q - name == sizeof "gnu"
+	      && !memcmp (name, "gnu", sizeof "gnu"))
+	    while (q < p)
+	      {
+		const unsigned char *const sub = q;
+
+		unsigned int subsection_tag;
+		get_uleb128 (subsection_tag, q);
+		if (unlikely (q >= p))
+		  break;
+
+		uint32_t subsection_len;
+		if (unlikely (p - sub < (ptrdiff_t) sizeof subsection_len))
+		  break;
+
+		memcpy (&subsection_len, q, sizeof subsection_len);
+
+		if (MY_ELFDATA != ehdr->e_ident[EI_DATA])
+		  CONVERT (subsection_len);
+
+		if (unlikely (p - sub < subsection_len))
+		  break;
+
+		const unsigned char *r = q + sizeof subsection_len;
+		q = sub + subsection_len;
+
+		switch (subsection_tag)
+		  {
+		  default:
+		    printf (gettext ("    %-4u %12" PRIu32 "\n"),
+			    subsection_tag, subsection_len);
+		    break;
+
+		  case 1:	/* Tag_File */
+		    printf (gettext ("    File: %11" PRIu32 "\n"),
+			    subsection_len);
+
+		    while (r < q)
+		      {
+			unsigned int tag;
+			get_uleb128 (tag, r);
+			if (unlikely (r >= q))
+			  break;
+
+			uint64_t value = 0;
+			const char *string = NULL;
+			if (tag == 32 || (tag & 1) == 0)
+			  {
+			    get_uleb128 (value, r);
+			    if (r > q)
+			      break;
+			  }
+			if (tag == 32 || (tag & 1) != 0)
+			  {
+			    r = memchr (r, '\0', q - r);
+			    if (r == NULL)
+			      break;
+			    ++r;
+			  }
+
+			const char *tag_name = NULL;
+			const char *value_name = NULL;
+			ebl_check_object_attribute (ebl, (const char *) name,
+						    tag, value,
+						    &tag_name, &value_name);
+
+			if (tag_name != NULL)
+			  {
+			    if (tag == 32)
+			      printf (gettext ("      %s: %" PRId64 ", %s\n"),
+				      tag_name, value, string);
+			    else if (string == NULL && value_name == NULL)
+			      printf (gettext ("      %s: %" PRId64 "\n"),
+				      tag_name, value);
+			    else
+			      printf (gettext ("      %s: %s\n"),
+				      tag_name, string ?: value_name);
+			  }
+			else
+			  {
+			    assert (tag != 32);
+			    if (string == NULL)
+			      printf (gettext ("      %u: %" PRId64 "\n"),
+				      tag, value);
+			    else
+			      printf (gettext ("      %u: %s\n"),
+				      tag, string);
+			  }
+		      }
+		  }
+	      }
+	}
+    }
+}
+
 
 static char *
 format_dwarf_addr (Dwfl_Module *dwflmod,
@@ -5426,7 +5590,7 @@ compare_core_item_groups (const void *a, const void *b)
 }
 
 static unsigned int
-handle_core_items (Elf *core, const void *desc,
+handle_core_items (Elf *core, const void *desc, size_t descsz,
 		   const Ebl_Core_Item *items, size_t nitems)
 {
   if (nitems == 0)
@@ -5450,18 +5614,35 @@ handle_core_items (Elf *core, const void *desc,
 
   /* Write out all the groups.  */
   unsigned int colno = 0;
-  for (size_t i = 0; i < ngroups; ++i)
+
+  do
     {
-      for (const Ebl_Core_Item **item = groups[i];
-	   (item < &sorted_items[nitems]
-	    && ((*item)->group == groups[i][0]->group
-		|| !strcmp ((*item)->group, groups[i][0]->group)));
-	   ++item)
-	colno = handle_core_item (core, *item, desc, colno);
+      for (size_t i = 0; i < ngroups; ++i)
+	{
+	  for (const Ebl_Core_Item **item = groups[i];
+	       (item < &sorted_items[nitems]
+		&& ((*item)->group == groups[i][0]->group
+		    || !strcmp ((*item)->group, groups[i][0]->group)));
+	       ++item)
+	    colno = handle_core_item (core, *item, desc, colno);
+
+	  /* Force a line break at the end of the group.  */
+	  colno = ITEM_WRAP_COLUMN;
+	}
 
-      /* Force a line break at the end of the group.  */
-      colno = ITEM_WRAP_COLUMN;
+      if (descsz == 0)
+	break;
+
+      /* This set of items consumed a certain amount of the note's data.
+	 If there is more data there, we have another unit of the same size.
+	 Loop to print that out too.  */
+      const Ebl_Core_Item *item = &items[nitems - 1];
+      size_t eltsz = item->offset + gelf_fsize (core, item->type,
+						item->count ?: 1, EV_CURRENT);
+      descsz -= eltsz;
+      desc += eltsz;
     }
+  while (descsz > 0);
 
   return colno;
 }
@@ -5807,7 +5988,13 @@ handle_core_note (Ebl *ebl, const GElf_Nhdr *nhdr, const void *desc)
 		       &regs_offset, &nregloc, &reglocs, &nitems, &items))
     return;
 
-  unsigned int colno = handle_core_items (ebl->elf, desc, items, nitems);
+  /* Pass 0 for DESCSZ when there are registers in the note,
+     so that the ITEMS array does not describe the whole thing.
+     For non-register notes, the actual descsz might be a multiple
+     of the unit size, not just exactly the unit size.  */
+  unsigned int colno = handle_core_items (ebl->elf, desc,
+					  nregloc == 0 ? nhdr->n_descsz : 0,
+					  items, nitems);
   if (colno != 0)
     putchar_unlocked ('\n');