Re: [PATCH V2] ctf: make libabigail::ctf_reader::read_corpus reentrant

[Dodji Seketeli <dodji@seketeli.org>]

"Jose E. Marchesi via Libabigail" <libabigail@sourceware.org> a écrit:

> [Changes from V1:
> - Make sure that the string table passed to libctf is the one related
>   to the symbol table.]


Pffft.

I mistakenly applied the V1 patch to master, sorry about that.

So I am providing below a "differential" patch that would bring master
to the level of this V2 patch.

Would you mind reviewing it, please, (and sign it off) so that I can
apply it master as well?

Thanks, and sorry again.

Cheers,

From b3e9ff53879939a3e0d4092ecd23cbd39393c268 Mon Sep 17 00:00:00 2001
From: Dodji Seketeli <dodji@redhat.com>
Date: Tue, 9 Nov 2021 11:24:16 +0100
Subject: [PATCH] ctf-reader: Use the string table related to the symtab

There can be several string tables in the ELF file.  The one we want
to use is the one related to the symbol table, referred to by its
sh_link property.

This patch ensures that.

	* src/abg-ctf-reader.cc (slurp_elf_info): Use the string table
	related to the symbol table.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>
---
 src/abg-ctf-reader.cc | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/abg-ctf-reader.cc b/src/abg-ctf-reader.cc
index 51fb2ed9..33642821 100644
--- a/src/abg-ctf-reader.cc
+++ b/src/abg-ctf-reader.cc
@@ -1037,12 +1037,20 @@ slurp_elf_info(read_context *ctxt, corpus_sptr corp)
                                 0 /* No suppressions.  */);
   corp->set_symtab(ctxt->symtab);
 
-  /* Get the raw ELF section contents for libctf.  */
+  /* Get the raw ELF section contents for libctf.  The .ctf section
+     and the symtab are straightforward enough.  */
   Elf_Scn *ctf_scn = elf_helpers::find_section(ctxt->elf_handler, ".ctf", SHT_PROGBITS);
   Elf_Scn *symtab_scn = elf_helpers::find_symbol_table_section(ctxt->elf_handler);
-  Elf_Scn *strtab_scn = elf_helpers::find_section(ctxt->elf_handler, SHT_STRTAB);
 
-  if (ctf_scn == NULL || symtab_scn == NULL || strtab_scn == NULL)
+  if (ctf_scn == NULL || symtab_scn == NULL)
+    return 0;
+
+  /* The string table that libctf expects is the one related to the
+     symbol table by virtue of sh_link.  */
+  GElf_Shdr symtab_shdr_mem, *symtab_shdr = gelf_getshdr(symtab_scn, &symtab_shdr_mem);
+  Elf_Scn *strtab_scn = elf_getscn(ctxt->elf_handler, symtab_shdr->sh_link);
+
+  if (strtab_scn == NULL)
     return 0;
 
   fill_ctf_section(ctxt, ctf_scn, &ctxt->ctf_sect);
-- 
2.32.0



-- 
		Dodji