[binutils-gdb] arc: Fix alignment of the TLS Translation Control Block

[binutils-gdb] arc: Fix alignment of the TLS Translation Control Block

[Claudiu Zissulescu]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=0a43fbaa23a5eaf4254a51fa43ef61a6e28c9bd6

commit 0a43fbaa23a5eaf4254a51fa43ef61a6e28c9bd6
Author: Claudiu Zissulescu <claziss@gmail.com>
Date:   Fri Sep 15 12:57:22 2023 +0300

    arc: Fix alignment of the TLS Translation Control Block
    
    The R_ARC_TLS_LE_32 is defined as S + A + TLS_TBSS - TLS_REL, where
    
      -  S is the base address of the symbol in the memory
      -  A is the symbol addendum
      -  TLS_TBSS is the TLS Translation Control Block size (aligned)
      -  TLS_REL is the base of the TLS section
    
    Given the next code snip:
    
    __thread int data_var = 12;
    __attribute__((__aligned__(128))) __thread int data_var_128 = 128;
    __thread int bss_var;
    __attribute__((__aligned__(256))) __thread int bss_var_256;
    
    int __start(void)
    {
            return data_var + data_var_128 + bss_var + bss_var_256;
    }
    
    The current code returns different TLS_TBSS values for .tdata and
    .tbss. This patch fixes this by using the linker provided tls_sec.
    
    bfd/
    
            * elf32-arc.c (TLS_REL): Clean up.
            (TLS_TBSS): Use tls_sec alignment.
            (arc_do_relocation): Check if we have valid tls_sec.
    
    Signed-off-by: Claudiu Zissulescu <claziss@gmail.com>

Diff:
---
 bfd/elf32-arc.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/bfd/elf32-arc.c b/bfd/elf32-arc.c
index 78dfd6eebbd..ac9970545c3 100644
--- a/bfd/elf32-arc.c
+++ b/bfd/elf32-arc.c
@@ -1226,10 +1226,8 @@ arc_special_overflow_checks (const struct arc_relocation_data reloc_data,
   (bfd_signed_vma) (reloc_data.sym_section->output_section->vma)
 #define JLI (bfd_signed_vma) (reloc_data.sym_section->output_section->vma)
 #define _SDA_BASE_ (bfd_signed_vma) (reloc_data.sdata_begin_symbol_vma)
-#define TLS_REL (bfd_signed_vma) \
-  ((elf_hash_table (info))->tls_sec->output_section->vma)
-#define TLS_TBSS (align_power(TCB_SIZE, \
-		  reloc_data.sym_section->alignment_power))
+#define TLS_REL (bfd_signed_vma)(tls_sec->output_section->vma)
+#define TLS_TBSS (align_power (TCB_SIZE, tls_sec->alignment_power))
 
 #define none (0)
 
@@ -1307,6 +1305,7 @@ arc_do_relocation (bfd_byte * contents,
   bfd * abfd = reloc_data.input_section->owner;
   struct elf_link_hash_table *htab ATTRIBUTE_UNUSED = elf_hash_table (info);
   bfd_reloc_status_type flag;
+  asection *tls_sec = htab->tls_sec;
 
   if (!reloc_data.should_relocate)
     return bfd_reloc_ok;
@@ -1336,6 +1335,20 @@ arc_do_relocation (bfd_byte * contents,
 
   orig_insn = insn;
 
+  /* If we resolve a TLS relocation, make sure we do have a valid TLS
+     section.  */
+  switch (reloc_data.howto->type)
+    {
+    case R_ARC_TLS_LE_32:
+      if (tls_sec == NULL)
+	return bfd_reloc_notsupported;
+      break;
+
+    default:
+      break;
+    }
+
+
   switch (reloc_data.howto->type)
     {
 #include "elf/arc-reloc.def"