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[patch 1/4] Fix dwfl_module_addrsym for minidebuginfo
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: elfutils-devel at lists dot fedorahosted dot org
- Date: Wed, 06 Nov 2013 22:10:29 +0100
- Subject: [patch 1/4] Fix dwfl_module_addrsym for minidebuginfo
Hi Mark,
jankratochvil/xauxfile
the existing condition is clearly wrong:
((size_t) i < mod->syments ? mod->symfile : &mod->aux_sym)
Additionally same_section() cannot compare section number from file X with
section number from file Y, it is moreover done just for caching/performance
reasons. My fix there is performance-suboptimal but still only twice as slow
as it could be, I think.
The existing code worked due to a luck. This fix does not have a new testcase
but the later testcase for ppc64 .opd FAILs without this fix so it gets tested
somehow.
The added function i_to_symfile() is deleted in the next patch so its content
does not matter much I think.
Thanks,
Jan
commit 7a58010a1862eaa3f7292b387347ecae6178243a
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Wed Nov 6 20:23:44 2013 +0100
Fix dwfl_module_addrsym for minidebuginfo
libdwfl/
2013-11-06 Jan Kratochvil <jan.kratochvil@redhat.com>
Fix dwfl_module_addrsym for minidebuginfo.
* dwfl_module_addrsym.c (dwfl_module_addrsym): New variable
addr_symfile.
(dwfl_module_addrsym) (same_section): Use it.
(dwfl_module_addrsym) (i_to_symfile): New function.
(dwfl_module_addrsym) (search_table): Use it.
Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>
diff --git a/libdwfl/dwfl_module_addrsym.c b/libdwfl/dwfl_module_addrsym.c
index 732b698..3d19943 100644
--- a/libdwfl/dwfl_module_addrsym.c
+++ b/libdwfl/dwfl_module_addrsym.c
@@ -41,6 +41,7 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
/* Return true iff we consider ADDR to lie in the same section as SYM. */
GElf_Word addr_shndx = SHN_UNDEF;
+ struct dwfl_file *addr_symfile = NULL;
inline bool same_section (const GElf_Sym *sym, struct dwfl_file *symfile,
GElf_Word shndx)
{
@@ -49,11 +50,12 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
return sym->st_value == addr;
/* Figure out what section ADDR lies in. */
- if (addr_shndx == SHN_UNDEF)
+ 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;
+ addr_symfile = symfile;
while ((scn = elf_nextscn (symfile->elf, scn)) != NULL)
{
GElf_Shdr shdr_mem;
@@ -68,7 +70,7 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
}
}
- return shndx == addr_shndx;
+ return shndx == addr_shndx && addr_symfile == symfile;
}
/* Keep track of the closest symbol we have seen so far.
@@ -84,6 +86,20 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
/* Keep track of the lowest address a relevant sizeless symbol could have. */
GElf_Addr min_label = 0;
+ inline struct dwfl_file *i_to_symfile (int ndx)
+ {
+ int skip_aux_zero = (mod->syments > 0 && mod->aux_syments > 0) ? 1 : 0;
+ if (ndx < mod->first_global)
+ return mod->symfile; // main symbol table (locals).
+ else if (ndx < mod->first_global + mod->aux_first_global - skip_aux_zero)
+ return &mod->aux_sym; // aux symbol table (locals).
+ else if ((size_t) ndx
+ < mod->syments + mod->aux_first_global - skip_aux_zero)
+ return mod->symfile; // main symbol table (globals).
+ else
+ return &mod->aux_sym; // aux symbol table (globals).
+ }
+
/* Look through the symbol table for a matching symbol. */
inline void search_table (int start, int end)
{
@@ -136,11 +152,7 @@ dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
}
else if (closest_name == NULL
&& sym.st_value >= min_label
- && same_section (&sym,
- ((size_t) i < mod->syments
- ? mod->symfile
- : &mod->aux_sym),
- shndx))
+ && same_section (&sym, i_to_symfile (i), shndx))
{
/* Handwritten assembly symbols sometimes have no
st_size. If no symbol with proper size includes