From: Jan Beulich <jbeulich@suse.com>
Date: Thu, 6 Jan 2022 13:17:40 +0000 (+0100)
Subject: x86-64: restrict PC32 -> PLT32 conversion
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1ef3994a3740f657e9af9dc354962a2c093586df;p=binutils-gdb.git

x86-64: restrict PC32 -> PLT32 conversion

Neither non-64-bit code nor uses with a non-zero offset from a symbol
should be converted to PLT32, as an eventual PLT entry would not express
what was requested.
---

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 66a2e0f8e0a..387fa6074ef 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -8857,6 +8857,8 @@ output_branch (void)
       off = 0;
     }
 
+  frag_now->tc_frag_data.code64 = flag_code == CODE_64BIT;
+
   /* 1 possible extra opcode + 4 byte displacement go in var part.
      Pass reloc in fr_var.  */
   frag_var (rs_machine_dependent, 5, i.reloc[0], subtype, sym, off, p);
@@ -8985,8 +8987,8 @@ output_jump (void)
     }
 
 #if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
-  if (size == 4
-      && jump_reloc == NO_RELOC
+  if (flag_code == CODE_64BIT && size == 4
+      && jump_reloc == NO_RELOC && i.op[0].disps->X_add_number == 0
       && need_plt32_p (i.op[0].disps->X_add_symbol))
     jump_reloc = BFD_RELOC_X86_64_PLT32;
 #endif
@@ -12294,7 +12296,8 @@ md_estimate_size_before_relax (fragS *fragP, segT segment)
       else if (size == 2)
 	reloc_type = BFD_RELOC_16_PCREL;
 #if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
-      else if (need_plt32_p (fragP->fr_symbol))
+      else if (fragP->tc_frag_data.code64 && fragP->fr_offset == 0
+	       && need_plt32_p (fragP->fr_symbol))
 	reloc_type = BFD_RELOC_X86_64_PLT32;
 #endif
       else
diff --git a/gas/config/tc-i386.h b/gas/config/tc-i386.h
index 4d67ef5779e..603ae475bbc 100644
--- a/gas/config/tc-i386.h
+++ b/gas/config/tc-i386.h
@@ -283,6 +283,7 @@ struct i386_tc_frag_data
   unsigned int mf_type : 3;
   unsigned int classified : 1;
   unsigned int branch_type : 3;
+  unsigned int code64 : 1; /* Only set by output_branch for now.  */
 };
 
 /* We need to emit the right NOP pattern in .align frags.  This is