libdwfl: Revamp bias bookkeeping, account correctly for prelink REL->RELA segment inflation.

19 files changed, 172 insertions, 61 deletions

diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index cc6dfb5b..dd4eb10c 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,3 +1,51 @@
+2010-11-12  Roland McGrath  <roland@redhat.com>
+
+	* libdwflP.h (struct Dwfl_Module): New member main_bias.
+	(dwfl_adjusted_address, dwfl_deadjust_address): Use it.
+	* dwfl_module_getdwarf.c (__libdwfl_getelf): Initialize it.
+
+	* libdwflP.h (dwfl_deadjust_address): New function.
+	(dwfl_deadjust_dwarf_addr, dwfl_deadjust_st_value): New functions.
+	* cu.c (addrarange): Use dwfl_deadjust_dwarf_addr.
+	* dwfl_module_addrsym.c: Use dwfl_deadjust_st_value.
+
+2010-11-11  Roland McGrath  <roland@redhat.com>
+
+	* libdwflP.h (struct dwfl_file): Remove bias member.
+	Add vaddr and address_sync members instead.
+	(dwfl_adjusted_address): Calculate using vaddr.
+	(dwfl_adjusted_dwarf_addr): Calculate using address_sync and call that.
+	(dwfl_adjusted_st_value): Use one of those calls.
+	* dwfl_module_getdwarf.c (open_elf): Initialize vaddr and address_sync.
+	* dwfl_segment_report_module.c (dwfl_segment_report_module): Likewise.
+	* derelocate.c (dwfl_module_relocations): Update ET_EXEC assertions.
+	* link_map.c (consider_executable): Adjust only MOD->low_addr for
+	detected PIE bias change.
+
+	* libdwflP.h (dwfl_adjusted_dwarf_addr): New function.
+	* dwfl_module_info.c: Use it.
+	* cu.c (addrarange): Likewise.
+	* dwfl_dwarf_line.c: Likewise.
+	* dwfl_module_dwarf_cfi.c: Likewise.
+	* dwfl_lineinfo.c: Likewise.
+	* dwfl_nextcu.c: Likewise.
+	* dwfl_module_getdwarf.c (dwfl_module_getdwarf): Likewise.
+
+	* libdwflP.h (dwfl_adjusted_st_value): New function.
+	* relocate.c (resolve_symbol): Use it.
+	* dwfl_module_getsym.c: Likewise.
+	* dwfl_module_addrsym.c: Likewise.
+	* dwfl_module_info.c: Likewise.
+
+	* libdwflP.h (dwfl_adjusted_address): New function.
+	* dwfl_module_build_id.c (__libdwfl_find_build_id): Use it.
+	* relocate.c (__libdwfl_relocate_value): Likewise.
+	* derelocate.c (cache_sections): Likewise.
+	(dwfl_module_address_section): Likewise.
+	* dwfl_module_getelf.c: Likewise.
+	* dwfl_module_eh_cfi.c: Likewise.
+	* link_map.c (consider_executable): Likewise.
+
 2010-08-24  Roland McGrath  <roland@redhat.com>
 
 	* dwfl_dwarf_line.c: New file.
diff --git a/libdwfl/cu.c b/libdwfl/cu.c
index 5f73d2a3..515aff3b 100644
--- a/libdwfl/cu.c
+++ b/libdwfl/cu.c
@@ -106,7 +106,7 @@ addrarange (Dwfl_Module *mod, Dwarf_Addr addr, struct dwfl_arange **arange)
     }
 
   /* The address must be inside the module to begin with.  */
-  addr -= mod->debug.bias;
+  addr = dwfl_deadjust_dwarf_addr (mod, addr);
 
   /* The ranges are sorted by address, so we can use binary search.  */
   size_t l = 0, u = mod->naranges;
diff --git a/libdwfl/derelocate.c b/libdwfl/derelocate.c
index 56ba25af..483b75eb 100644
--- a/libdwfl/derelocate.c
+++ b/libdwfl/derelocate.c
@@ -134,7 +134,7 @@ cache_sections (Dwfl_Module *mod)
 	  newref->scn = scn;
 	  newref->relocs = NULL;
 	  newref->name = name;
-	  newref->start = shdr->sh_addr + mod->main.bias;
+	  newref->start = dwfl_adjusted_address (mod, shdr->sh_addr);
 	  newref->end = newref->start + shdr->sh_size;
 	  newref->next = refs;
 	  refs = newref;
@@ -239,8 +239,8 @@ dwfl_module_relocations (Dwfl_Module *mod)
       return 1;
 
     case ET_EXEC:
-      assert (mod->main.bias == 0);
-      assert (mod->debug.bias == 0);
+      assert (mod->main.vaddr == mod->low_addr);
+      assert (mod->debug.address_sync == mod->main.address_sync);
       break;
     }
 
@@ -406,7 +406,7 @@ dwfl_module_address_section (Dwfl_Module *mod, Dwarf_Addr *address,
 	}
     }
 
-  *bias = mod->main.bias;
+  *bias = dwfl_adjusted_address (mod, 0);
   return mod->reloc_info->refs[idx].scn;
 }
 INTDEF (dwfl_module_address_section)
diff --git a/libdwfl/dwfl_dwarf_line.c b/libdwfl/dwfl_dwarf_line.c
index ee522db4..eb085e4a 100644
--- a/libdwfl/dwfl_dwarf_line.c
+++ b/libdwfl/dwfl_dwarf_line.c
@@ -59,6 +59,6 @@ dwfl_dwarf_line (Dwfl_Line *line, Dwarf_Addr *bias)
   struct dwfl_cu *cu = dwfl_linecu (line);
   const Dwarf_Line *info = &cu->die.cu->lines->info[line->idx];
 
-  *bias = cu->mod->debug.bias;
+  *bias = dwfl_adjusted_dwarf_addr (cu->mod, 0);
   return (Dwarf_Line *) info;
 }
diff --git a/libdwfl/dwfl_lineinfo.c b/libdwfl/dwfl_lineinfo.c
index 0d8a6887..6049de84 100644
--- a/libdwfl/dwfl_lineinfo.c
+++ b/libdwfl/dwfl_lineinfo.c
@@ -1,5 +1,5 @@
 /* Get information from a source line record returned by libdwfl.
-   Copyright (C) 2005, 2006 Red Hat, Inc.
+   Copyright (C) 2005-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -61,7 +61,7 @@ dwfl_lineinfo (Dwfl_Line *line, Dwarf_Addr *addr, int *linep, int *colp,
   const Dwarf_Line *info = &cu->die.cu->lines->info[line->idx];
 
   if (addr != NULL)
-    *addr = info->addr + cu->mod->debug.bias;
+    *addr = dwfl_adjusted_dwarf_addr (cu->mod, info->addr);
   if (linep != NULL)
     *linep = info->line;
   if (colp != NULL)
diff --git a/libdwfl/dwfl_module_addrsym.c b/libdwfl/dwfl_module_addrsym.c
index 72280d11..a9f98f44 100644
--- a/libdwfl/dwfl_module_addrsym.c
+++ b/libdwfl/dwfl_module_addrsym.c
@@ -1,5 +1,5 @@
 /* Find debugging and symbol information for a module in libdwfl.
-   Copyright (C) 2005, 2006, 2007, 2008 Red Hat, Inc.
+   Copyright (C) 2005-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -71,7 +71,7 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
       /* Figure out what section ADDR lies in.  */
       if (addr_shndx == SHN_UNDEF)
 	{
-	  GElf_Addr mod_addr = addr - mod->symfile->bias;
+	  GElf_Addr mod_addr = dwfl_deadjust_st_value (mod, addr);
 	  Elf_Scn *scn = NULL;
 	  addr_shndx = SHN_ABS;
 	  while ((scn = elf_nextscn (mod->symfile->elf, scn)) != NULL)
diff --git a/libdwfl/dwfl_module_build_id.c b/libdwfl/dwfl_module_build_id.c
index 9dc7f678..f9888660 100644
--- a/libdwfl/dwfl_module_build_id.c
+++ b/libdwfl/dwfl_module_build_id.c
@@ -124,7 +124,7 @@ __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
 							phdr->p_offset,
 							phdr->p_filesz,
 							ELF_T_NHDR),
-				  phdr->p_vaddr + mod->main.bias);
+				  dwfl_adjusted_address (mod, phdr->p_vaddr));
 	}
     }
   else
@@ -139,7 +139,7 @@ __libdwfl_find_build_id (Dwfl_Module *mod, bool set, Elf *elf)
 	    if (!(shdr->sh_flags & SHF_ALLOC))
 	      vaddr = NO_VADDR;
 	    else if (mod->e_type != ET_REL)
-	      vaddr = shdr->sh_addr + mod->main.bias;
+	      vaddr = dwfl_adjusted_address (mod, shdr->sh_addr);
 	    else if (__libdwfl_relocate_value (mod, elf, &shstrndx,
 					       elf_ndxscn (scn), &vaddr))
 	      vaddr = NO_VADDR;
diff --git a/libdwfl/dwfl_module_dwarf_cfi.c b/libdwfl/dwfl_module_dwarf_cfi.c
index e851a1f4..96e60fbf 100644
--- a/libdwfl/dwfl_module_dwarf_cfi.c
+++ b/libdwfl/dwfl_module_dwarf_cfi.c
@@ -1,5 +1,5 @@
 /* Find DWARF CFI for a module in libdwfl.
-   Copyright (C) 2009 Red Hat, Inc.
+   Copyright (C) 2009-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -81,7 +81,7 @@ dwfl_module_dwarf_cfi (mod, bias)
 
   if (mod->dwarf_cfi != NULL)
     {
-      *bias = mod->debug.bias;
+      *bias = dwfl_adjusted_dwarf_addr (mod, 0);
       return mod->dwarf_cfi;
     }
 
diff --git a/libdwfl/dwfl_module_eh_cfi.c b/libdwfl/dwfl_module_eh_cfi.c
index 36a495f1..79c8279c 100644
--- a/libdwfl/dwfl_module_eh_cfi.c
+++ b/libdwfl/dwfl_module_eh_cfi.c
@@ -1,5 +1,5 @@
 /* Find EH CFI for a module in libdwfl.
-   Copyright (C) 2009 Red Hat, Inc.
+   Copyright (C) 2009-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -60,7 +60,7 @@ dwfl_module_eh_cfi (mod, bias)
 
   if (mod->eh_cfi != NULL)
     {
-      *bias = mod->main.bias;
+      *bias = dwfl_adjusted_address (mod, 0);
       return mod->eh_cfi;
     }
 
@@ -71,7 +71,7 @@ dwfl_module_eh_cfi (mod, bias)
       return NULL;
     }
 
-  *bias = mod->main.bias;
+  *bias = dwfl_adjusted_address (mod, 0);
   return __libdwfl_set_cfi (mod, &mod->eh_cfi,
 			    INTUSE(dwarf_getcfi_elf) (mod->main.elf));
 }
diff --git a/libdwfl/dwfl_module_getdwarf.c b/libdwfl/dwfl_module_getdwarf.c
index 41ed0730..d89081b7 100644
--- a/libdwfl/dwfl_module_getdwarf.c
+++ b/libdwfl/dwfl_module_getdwarf.c
@@ -93,35 +93,23 @@ open_elf (Dwfl_Module *mod, struct dwfl_file *file)
       return DWFL_E (LIBELF, elf_errno ());
     }
 
-  /* The addresses in an ET_EXEC file are absolute.  The lowest p_vaddr of
-     the main file can differ from that of the debug file due to prelink.
-     But that doesn't not change addresses that symbols, debuginfo, or
-     sh_addr of any program sections refer to.  */
-  file->bias = 0;
-  if (mod->e_type != ET_EXEC)
+  if (mod->e_type != ET_REL)
     {
       size_t phnum;
       if (unlikely (elf_getphdrnum (file->elf, &phnum) != 0))
 	goto elf_error;
 
+      file->vaddr = file->address_sync = 0;
       for (size_t i = 0; i < phnum; ++i)
 	{
 	  GElf_Phdr ph_mem;
 	  GElf_Phdr *ph = gelf_getphdr (file->elf, i, &ph_mem);
-	  if (ph == NULL)
+	  if (unlikely (ph == NULL))
 	    goto elf_error;
 	  if (ph->p_type == PT_LOAD)
 	    {
-	      GElf_Addr align = mod->dwfl->segment_align;
-	      if (align <= 1)
-		{
-		  if ((mod->low_addr & (ph->p_align - 1)) == 0)
-		    align = ph->p_align;
-		  else
-		    align = ((GElf_Addr) 1 << ffsll (mod->low_addr)) >> 1;
-		}
-
-	      file->bias = ((mod->low_addr & -align) - (ph->p_vaddr & -align));
+	      file->vaddr = ph->p_vaddr & -ph->p_align;
+	      file->address_sync = ph->p_vaddr + ph->p_memsz;
 	      break;
 	    }
 	}
@@ -130,7 +118,7 @@ open_elf (Dwfl_Module *mod, struct dwfl_file *file)
   mod->e_type = ehdr->e_type;
 
   /* Relocatable Linux kernels are ET_EXEC but act like ET_DYN.  */
-  if (mod->e_type == ET_EXEC && file->bias != 0)
+  if (mod->e_type == ET_EXEC && file->vaddr != mod->low_addr)
     mod->e_type = ET_DYN;
 
   return DWFL_E_NOERROR;
@@ -198,6 +186,8 @@ __libdwfl_getelf (Dwfl_Module *mod)
 	  mod->main.fd = -1;
 	}
     }
+
+  mod->main_bias = mod->e_type == ET_REL ? 0 : mod->low_addr - mod->main.vaddr;
 }
 
 /* Search an ELF file for a ".gnu_debuglink" section.  */
@@ -733,7 +723,7 @@ find_dw (Dwfl_Module *mod)
     {
     case DWFL_E_NOERROR:
       mod->debug.elf = mod->main.elf;
-      mod->debug.bias = mod->main.bias;
+      mod->debug.address_sync = mod->main.address_sync;
       return;
 
     case DWFL_E_NO_DWARF:
@@ -782,7 +772,7 @@ dwfl_module_getdwarf (Dwfl_Module *mod, Dwarf_Addr *bias)
 	    (void) __libdwfl_relocate (mod, mod->debug.elf, false);
 	}
 
-      *bias = mod->debug.bias;
+      *bias = dwfl_adjusted_dwarf_addr (mod, 0);
       return mod->dw;
     }
 
diff --git a/libdwfl/dwfl_module_getelf.c b/libdwfl/dwfl_module_getelf.c
index 6414a9d3..b4e4a2b7 100644
--- a/libdwfl/dwfl_module_getelf.c
+++ b/libdwfl/dwfl_module_getelf.c
@@ -1,5 +1,5 @@
 /* Find debugging and symbol information for a module in libdwfl.
-   Copyright (C) 2009 Red Hat, Inc.
+   Copyright (C) 2009-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -78,7 +78,7 @@ dwfl_module_getelf (Dwfl_Module *mod, GElf_Addr *loadbase)
 	    }
 	}
 
-      *loadbase = mod->main.bias;
+      *loadbase = dwfl_adjusted_address (mod, 0);
       return mod->main.elf;
     }
 
diff --git a/libdwfl/dwfl_module_getsym.c b/libdwfl/dwfl_module_getsym.c
index f78e6ec0..6bc063bb 100644
--- a/libdwfl/dwfl_module_getsym.c
+++ b/libdwfl/dwfl_module_getsym.c
@@ -1,5 +1,5 @@
 /* Find debugging and symbol information for a module in libdwfl.
-   Copyright (C) 2006,2007,2009 Red Hat, Inc.
+   Copyright (C) 2006-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -114,7 +114,7 @@ dwfl_module_getsym (Dwfl_Module *mod, int ndx,
 	}
       else if (alloc)
 	/* Apply the bias to the symbol value.  */
-	sym->st_value += mod->symfile->bias;
+	sym->st_value = dwfl_adjusted_st_value (mod, sym->st_value);
       break;
     }
 
diff --git a/libdwfl/dwfl_module_info.c b/libdwfl/dwfl_module_info.c
index 759cb621..bfde6fc1 100644
--- a/libdwfl/dwfl_module_info.c
+++ b/libdwfl/dwfl_module_info.c
@@ -1,5 +1,5 @@
 /* Return information about a module.
-   Copyright (C) 2005 Red Hat, Inc.
+   Copyright (C) 2005-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -66,9 +66,11 @@ dwfl_module_info (Dwfl_Module *mod, void ***userdata,
     *end = mod->high_addr;
 
   if (dwbias)
-    *dwbias = mod->debug.elf == NULL ? (Dwarf_Addr) -1 : mod->debug.bias;
+    *dwbias = (mod->debug.elf == NULL ? (Dwarf_Addr) -1
+	       : dwfl_adjusted_dwarf_addr (mod, 0));
   if (symbias)
-    *symbias = mod->symfile == NULL ? (Dwarf_Addr) -1 : mod->symfile->bias;
+    *symbias = (mod->symfile == NULL ? (Dwarf_Addr) -1
+		: dwfl_adjusted_st_value (mod, 0));
 
   if (mainfile)
     *mainfile = mod->main.name;
diff --git a/libdwfl/dwfl_nextcu.c b/libdwfl/dwfl_nextcu.c
index 6db3e0f1..90862d20 100644
--- a/libdwfl/dwfl_nextcu.c
+++ b/libdwfl/dwfl_nextcu.c
@@ -1,5 +1,5 @@
 /* Iterate through DWARF compilation units across all modules.
-   Copyright (C) 2005 Red Hat, Inc.
+   Copyright (C) 2005-2010 Red Hat, Inc.
    This file is part of Red Hat elfutils.
 
    Red Hat elfutils is free software; you can redistribute it and/or modify
@@ -75,7 +75,7 @@ dwfl_nextcu (Dwfl *dwfl, Dwarf_Die *lastcu, Dwarf_Addr *bias)
 
       if (cu != NULL)
 	{
-	  *bias = mod->debug.bias;
+	  *bias = dwfl_adjusted_dwarf_addr (mod, 0);
 	  return &cu->die;
 	}
 
diff --git a/libdwfl/dwfl_report_elf.c b/libdwfl/dwfl_report_elf.c
index 062a647f..4c4132b1 100644
--- a/libdwfl/dwfl_report_elf.c
+++ b/libdwfl/dwfl_report_elf.c
@@ -72,6 +72,8 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name,
       return NULL;
     }
 
+  GElf_Addr vaddr = 0;
+  GElf_Addr address_sync = 0;
   GElf_Addr start = 0, end = 0, bias = 0;
   switch (ehdr->e_type)
     {
@@ -198,13 +200,15 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name,
 	    goto elf_error;
 	  if (ph->p_type == PT_LOAD)
 	    {
+	      vaddr = ph->p_vaddr & -ph->p_align;
+	      address_sync = ph->p_vaddr + ph->p_memsz;
 	      if ((base & (ph->p_align - 1)) != 0)
 		base = (base + ph->p_align - 1) & -ph->p_align;
 	      start = base + (ph->p_vaddr & -ph->p_align);
 	      break;
 	    }
 	}
-      bias = base;
+      bias = start - vaddr;
 
       for (size_t i = phnum; i-- > 0;)
 	{
@@ -248,13 +252,16 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name,
       if (m->main.elf == NULL)
 	{
 	  m->main.elf = elf;
-	  m->main.bias = bias;
+	  m->main.vaddr = vaddr;
+	  m->main.address_sync = address_sync;
+	  m->main_bias = bias;
 	  m->e_type = ehdr->e_type;
 	}
       else
 	{
 	  elf_end (elf);
-	  if (m->main.bias != base)
+	  if (m->main_bias != bias
+	      || m->main.vaddr != vaddr || m->main.address_sync != address_sync)
 	    goto overlap;
 	}
     }
diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c
index 3f77cfc7..012a0fde 100644
--- a/libdwfl/dwfl_segment_report_module.c
+++ b/libdwfl/dwfl_segment_report_module.c
@@ -270,6 +270,7 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name,
   /* Collect the unbiased bounds of the module here.  */
   GElf_Addr module_start = -1l;
   GElf_Addr module_end = 0;
+  GElf_Addr module_address_sync = 0;
 
   /* If we see PT_DYNAMIC, record it here.  */
   GElf_Addr dyn_vaddr = 0;
@@ -400,9 +401,11 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name,
 	    found_bias = true;
 	  }
 
-	vaddr &= -align;
-	if (vaddr < module_start)
-	  module_start = vaddr;
+	if ((vaddr & -align) < module_start)
+	  {
+	    module_start = vaddr & -align;
+	    module_address_sync = vaddr + memsz;
+	  }
 
 	if (module_end < vaddr_end)
 	  module_end = vaddr_end;
@@ -662,7 +665,8 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name,
     {
       /* Install the file in the module.  */
       mod->main.elf = elf;
-      mod->main.bias = bias;
+      mod->main.vaddr = module_start - bias;
+      mod->main.address_sync = module_address_sync;
     }
 
   return finish ();
diff --git a/libdwfl/libdwflP.h b/libdwfl/libdwflP.h
index e4c7e7c8..1003b2d3 100644
--- a/libdwfl/libdwflP.h
+++ b/libdwfl/libdwflP.h
@@ -140,7 +140,22 @@ struct dwfl_file
   bool relocated;		/* Partial relocation of all sections done.  */
 
   Elf *elf;
-  GElf_Addr bias;		/* Actual load address - p_vaddr.  */
+
+  /* This is the lowest p_vaddr in this ELF file, aligned to p_align.
+     For a file without phdrs, this is zero.  */
+  GElf_Addr vaddr;
+
+  /* This is an address chosen for synchronization between the main file
+     and the debug file.  In a file without phdrs, this is zero.  In
+     other files it is the address at the end of the first PT_LOAD
+     segment.  When prelink converts REL to RELA in an ET_DYN file, it
+     expands the space between the beginning of the segment and the
+     actual code/data addresses.  Since that change wasn't made in the
+     debug file, the distance from p_vaddr to an address of interest (in
+     an st_value or DWARF data) now differs between the main and debug
+     files.  The distance from address_sync to an address of interest
+     remains consistent.  */
+  GElf_Addr address_sync;
 };
 
 struct Dwfl_Module
@@ -154,6 +169,7 @@ struct Dwfl_Module
   GElf_Addr low_addr, high_addr;
 
   struct dwfl_file main, debug;
+  GElf_Addr main_bias;
   Ebl *ebl;
   GElf_Half e_type;		/* GElf_Ehdr.e_type cache.  */
   Dwfl_Error elferr;		/* Previous failure to open main file.  */
@@ -236,6 +252,50 @@ dwfl_linecu_inline (const Dwfl_Line *line)
 }
 #define dwfl_linecu dwfl_linecu_inline
 
+static inline GElf_Addr
+dwfl_adjusted_address (Dwfl_Module *mod, GElf_Addr addr)
+{
+  return addr + mod->main_bias;
+}
+
+static inline GElf_Addr
+dwfl_deadjust_address (Dwfl_Module *mod, GElf_Addr addr)
+{
+  return addr - mod->main_bias;
+}
+
+static inline Dwarf_Addr
+dwfl_adjusted_dwarf_addr (Dwfl_Module *mod, Dwarf_Addr addr)
+{
+  return dwfl_adjusted_address (mod, (addr
+				      - mod->debug.address_sync
+				      + mod->main.address_sync));
+}
+
+static inline Dwarf_Addr
+dwfl_deadjust_dwarf_addr (Dwfl_Module *mod, Dwarf_Addr addr)
+{
+  return (dwfl_deadjust_address (mod, addr)
+	  - mod->main.address_sync
+	  + mod->debug.address_sync);
+}
+
+static inline GElf_Addr
+dwfl_adjusted_st_value (Dwfl_Module *mod, GElf_Addr addr)
+{
+  if (mod->symfile == &mod->main)
+    return dwfl_adjusted_address (mod, addr);
+  return dwfl_adjusted_dwarf_addr (mod, addr);
+}
+
+static inline GElf_Addr
+dwfl_deadjust_st_value (Dwfl_Module *mod, GElf_Addr addr)
+{
+  if (mod->symfile == &mod->main)
+    return dwfl_deadjust_address (mod, addr);
+  return dwfl_deadjust_dwarf_addr (mod, addr);
+}
+
 /* This describes a contiguous address range that lies in a single CU.
    We condense runs of Dwarf_Arange entries for the same CU into this.  */
 struct dwfl_arange
diff --git a/libdwfl/link_map.c b/libdwfl/link_map.c
index 8ec06269..05839b3a 100644
--- a/libdwfl/link_map.c
+++ b/libdwfl/link_map.c
@@ -515,11 +515,11 @@ consider_executable (Dwfl_Module *mod, GElf_Addr at_phdr, GElf_Addr at_entry,
 
 	      /* If we're changing the module's address range,
 		 we've just invalidated the module lookup table.  */
-	      if (bias != mod->main.bias)
+	      GElf_Addr mod_bias = dwfl_adjusted_address (mod, 0);
+	      if (bias != mod_bias)
 		{
-		  mod->low_addr -= mod->main.bias;
-		  mod->high_addr -= mod->main.bias;
-		  mod->main.bias = bias;
+		  mod->low_addr -= mod_bias;
+		  mod->high_addr -= mod_bias;
 		  mod->low_addr += bias;
 		  mod->high_addr += bias;
 
@@ -554,7 +554,7 @@ consider_executable (Dwfl_Module *mod, GElf_Addr at_phdr, GElf_Addr at_entry,
   if (d_val_vaddr != 0)
     {
       /* Now we have the final address from which to read &r_debug.  */
-      d_val_vaddr += mod->main.bias;
+      d_val_vaddr = dwfl_adjusted_address (mod, d_val_vaddr);
 
       void *buffer = NULL;
       size_t buffer_available = addrsize (ehdr.e_ident[EI_CLASS]);
diff --git a/libdwfl/relocate.c b/libdwfl/relocate.c
index 0075c7f9..95206f47 100644
--- a/libdwfl/relocate.c
+++ b/libdwfl/relocate.c
@@ -99,7 +99,7 @@ __libdwfl_relocate_value (Dwfl_Module *mod, Elf *elf, size_t *shstrndx,
 
   if (refshdr->sh_flags & SHF_ALLOC)
     /* Apply the adjustment.  */
-    *value += refshdr->sh_addr + mod->main.bias;
+    *value += dwfl_adjusted_address (mod, refshdr->sh_addr);
 
   return DWFL_E_NOERROR;
 }
@@ -275,7 +275,7 @@ resolve_symbol (Dwfl_Module *referer, struct reloc_symtab_cache *symtab,
 
 		if (m->e_type != ET_REL)
 		  {
-		    sym->st_value += m->symfile->bias;
+		    sym->st_value = dwfl_adjusted_st_value (m, sym->st_value);
 		    return DWFL_E_NOERROR;
 		  }