[patchv2 3/4] Provide elf_scnfindvma

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

Hi Mark,

jankratochvil/scnfindvma

On Wed, 13 Nov 2013 13:03:21 +0100, Mark Wielaard wrote:
> There are other implementation of libelf and gelf and we should try to
> keep them somewhat compatible.

OK, I didn't realize that.

OK this way?


Thanks,
Jan

Provide __libdwfl_scnfindvma

libdwfl/
2013-11-13  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Provide __libdwfl_scnfindvma.
	* Makefile.am (libdwfl_a_SOURCES): Add scnfindvma.c.
	* dwfl_module_addrsym.c (dwfl_module_addrsym) (same_section): Call
	__libdwfl_scnfindvma where is the code from here moved out.
	* libdwflP.h (__libdwfl_scnfindvma): New declaration.
	* scnfindvma.c: New file.

Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>

diff --git a/libdwfl/Makefile.am b/libdwfl/Makefile.am
index ce590da..a20d951 100644
--- a/libdwfl/Makefile.am
+++ b/libdwfl/Makefile.am
@@ -70,7 +70,8 @@ libdwfl_a_SOURCES = dwfl_begin.c dwfl_end.c dwfl_error.c dwfl_version.c \
 		    dwfl_segment_report_module.c \
 		    link_map.c core-file.c open.c image-header.c \
 		    dwfl_frame.c frame_unwind.c dwfl_frame_pc.c \
-		    linux-pid-attach.c linux-core-attach.c dwfl_frame_regs.c
+		    linux-pid-attach.c linux-core-attach.c dwfl_frame_regs.c \
+		    scnfindvma.c
 
 if ZLIB
 libdwfl_a_SOURCES += gzip.c
diff --git a/libdwfl/dwfl_module_addrsym.c b/libdwfl/dwfl_module_addrsym.c
index d9eb0a2..5e46608 100644
--- a/libdwfl/dwfl_module_addrsym.c
+++ b/libdwfl/dwfl_module_addrsym.c
@@ -53,21 +53,9 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
       if (addr_shndx == SHN_UNDEF || addr_symfile != symfile)
 	{
 	  GElf_Addr mod_addr = dwfl_deadjust_st_value (mod, symfile, addr);
-	  Elf_Scn *scn = NULL;
-	  addr_shndx = SHN_ABS;
+	  Elf_Scn *scn = __libdwfl_scnfindvma (symfile->elf, mod_addr);
+	  addr_shndx = scn == NULL ? SHN_ABS : elf_ndxscn (scn);
 	  addr_symfile = symfile;
-	  while ((scn = elf_nextscn (symfile->elf, scn)) != NULL)
-	    {
-	      GElf_Shdr shdr_mem;
-	      GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
-	      if (likely (shdr != NULL)
-		  && mod_addr >= shdr->sh_addr
-		  && mod_addr < shdr->sh_addr + shdr->sh_size)
-		{
-		  addr_shndx = elf_ndxscn (scn);
-		  break;
-		}
-	    }
 	}
 
       return shndx == addr_shndx && addr_symfile == symfile;
diff --git a/libdwfl/libdwflP.h b/libdwfl/libdwflP.h
index 0c862b3..ffe5752 100644
--- a/libdwfl/libdwflP.h
+++ b/libdwfl/libdwflP.h
@@ -531,6 +531,10 @@ extern GElf_Addr __libdwfl_segment_start (Dwfl *dwfl, GElf_Addr start)
 extern GElf_Addr __libdwfl_segment_end (Dwfl *dwfl, GElf_Addr end)
   internal_function;
 
+/* Get section containing VMA address.  Return NULL otherwise.  */
+extern Elf_Scn *__libdwfl_scnfindvma (Elf *elf, GElf_Addr vma)
+  internal_function;
+
 /* Decompression wrappers: decompress whole file into memory.  */
 extern Dwfl_Error __libdw_gunzip  (int fd, off64_t start_offset,
 				   void *mapped, size_t mapped_size,
diff --git a/libdwfl/scnfindvma.c b/libdwfl/scnfindvma.c
new file mode 100644
index 0000000..8db2e85
--- /dev/null
+++ b/libdwfl/scnfindvma.c
@@ -0,0 +1,47 @@
+/* Get section containing VMA address.  Return NULL otherwise.
+   Copyright (C) 2013 Red Hat, Inc.
+   This file is part of elfutils.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include "libdwflP.h"
+
+Elf_Scn *
+internal_function
+__libdwfl_scnfindvma (Elf *elf, GElf_Addr vma)
+{
+  Elf_Scn *scn = NULL;
+  while ((scn = elf_nextscn (elf, scn)) != NULL)
+    {
+      GElf_Shdr shdr_mem;
+      GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+      if (likely (shdr != NULL)
+	  && vma >= shdr->sh_addr
+	  && vma < shdr->sh_addr + shdr->sh_size)
+	break;
+    }
+  return scn;
+}