x86-64: Fix TLSDESC relaxation for x32
[deliverable/binutils-gdb.git] / bfd / elf64-x86-64.c
index 79e68ff47674220a1d8e9a6840b5a671e1f0cb40..014bea147541caf686d203f519f3adf616146411 100644 (file)
@@ -1223,7 +1223,8 @@ elf_x86_64_check_tls_transition (bfd *abfd,
 
     case R_X86_64_GOTPC32_TLSDESC:
       /* Check transition from GDesc access model:
-               leaq x@tlsdesc(%rip), %rax
+               leaq x@tlsdesc(%rip), %rax <--- LP64 mode.
+               rex leal x@tlsdesc(%rip), %eax <--- X32 mode.
 
         Make sure it's a leaq adding rip to a 32-bit offset
         into any register, although it's probably almost always
@@ -1233,7 +1234,8 @@ elf_x86_64_check_tls_transition (bfd *abfd,
        return FALSE;
 
       val = bfd_get_8 (abfd, contents + offset - 3);
-      if ((val & 0xfb) != 0x48)
+      val &= 0xfb;
+      if (val != 0x48 && (ABI_64_P (abfd) || val != 0x40))
        return FALSE;
 
       if (bfd_get_8 (abfd, contents + offset - 2) != 0x8d)
@@ -1244,13 +1246,26 @@ elf_x86_64_check_tls_transition (bfd *abfd,
 
     case R_X86_64_TLSDESC_CALL:
       /* Check transition from GDesc access model:
-               call *x@tlsdesc(%rax)
+               call *x@tlsdesc(%rax) <--- LP64 mode.
+               call *x@tlsdesc(%eax) <--- X32 mode.
        */
       if (offset + 2 <= sec->size)
        {
-         /* Make sure that it's a call *x@tlsdesc(%rax).  */
+         unsigned int prefix;
          call = contents + offset;
-         return call[0] == 0xff && call[1] == 0x10;
+         prefix = 0;
+         if (!ABI_64_P (abfd))
+           {
+             /* Check for call *x@tlsdesc(%eax).  */
+             if (call[0] == 0x67)
+               {
+                 prefix = 1;
+                 if (offset + 3 > sec->size)
+                   return FALSE;
+               }
+           }
+         /* Make sure that it's a call *x@tlsdesc(%rax).  */
+         return call[prefix] == 0xff && call[1 + prefix] == 0x10;
        }
 
       return FALSE;
@@ -3401,10 +3416,13 @@ corrupt_input:
                {
                  /* GDesc -> LE transition.
                     It's originally something like:
-                    leaq x@tlsdesc(%rip), %rax
+                    leaq x@tlsdesc(%rip), %rax <--- LP64 mode.
+                    rex leal x@tlsdesc(%rip), %eax <--- X32 mode.
 
                     Change it to:
-                    movl $x@tpoff, %rax.  */
+                    movq $x@tpoff, %rax <--- LP64 mode.
+                    rex movl $x@tpoff, %eax <--- X32 mode.
+                  */
 
                  unsigned int val, type;
 
@@ -3412,7 +3430,8 @@ corrupt_input:
                    goto corrupt_input;
                  type = bfd_get_8 (input_bfd, contents + roff - 3);
                  val = bfd_get_8 (input_bfd, contents + roff - 1);
-                 bfd_put_8 (output_bfd, 0x48 | ((type >> 2) & 1),
+                 bfd_put_8 (output_bfd,
+                            (type & 0x48) | ((type >> 2) & 1),
                             contents + roff - 3);
                  bfd_put_8 (output_bfd, 0xc7, contents + roff - 2);
                  bfd_put_8 (output_bfd, 0xc0 | ((val >> 3) & 7),
@@ -3426,11 +3445,30 @@ corrupt_input:
                {
                  /* GDesc -> LE transition.
                     It's originally:
-                    call *(%rax)
+                    call *(%rax) <--- LP64 mode.
+                    call *(%eax) <--- X32 mode.
                     Turn it into:
-                    xchg %ax,%ax.  */
-                 bfd_put_8 (output_bfd, 0x66, contents + roff);
-                 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
+                    xchg %ax,%ax <-- LP64 mode.
+                    nopl (%rax)  <-- X32 mode.
+                  */
+                 unsigned int prefix = 0;
+                 if (!ABI_64_P (input_bfd))
+                   {
+                     /* Check for call *x@tlsdesc(%eax).  */
+                     if (contents[roff] == 0x67)
+                       prefix = 1;
+                   }
+                 if (prefix)
+                   {
+                     bfd_put_8 (output_bfd, 0x0f, contents + roff);
+                     bfd_put_8 (output_bfd, 0x1f, contents + roff + 1);
+                     bfd_put_8 (output_bfd, 0x00, contents + roff + 2);
+                   }
+                 else
+                   {
+                     bfd_put_8 (output_bfd, 0x66, contents + roff);
+                     bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
+                   }
                  continue;
                }
              else if (r_type == R_X86_64_GOTTPOFF)
@@ -3741,13 +3779,18 @@ corrupt_input:
                {
                  /* GDesc -> IE transition.
                     It's originally something like:
-                    leaq x@tlsdesc(%rip), %rax
+                    leaq x@tlsdesc(%rip), %rax <--- LP64 mode.
+                    rex leal x@tlsdesc(%rip), %eax <--- X32 mode.
 
                     Change it to:
-                    movq x@gottpoff(%rip), %rax # before xchg %ax,%ax.  */
+                    # before xchg %ax,%ax in LP64 mode.
+                    movq x@gottpoff(%rip), %rax
+                    # before nopl (%rax) in X32 mode.
+                    rex movl x@gottpoff(%rip), %eax
+                 */
 
                  /* Now modify the instruction as appropriate. To
-                    turn a leaq into a movq in the form we use it, it
+                    turn a lea into a mov in the form we use it, it
                     suffices to change the second byte from 0x8d to
                     0x8b.  */
                  if (roff < 2)
@@ -3768,13 +3811,32 @@ corrupt_input:
                {
                  /* GDesc -> IE transition.
                     It's originally:
-                    call *(%rax)
+                    call *(%rax) <--- LP64 mode.
+                    call *(%eax) <--- X32 mode.
 
                     Change it to:
-                    xchg %ax, %ax.  */
+                    xchg %ax, %ax <-- LP64 mode.
+                    nopl (%rax)  <-- X32 mode.
+                  */
 
-                 bfd_put_8 (output_bfd, 0x66, contents + roff);
-                 bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
+                 unsigned int prefix = 0;
+                 if (!ABI_64_P (input_bfd))
+                   {
+                     /* Check for call *x@tlsdesc(%eax).  */
+                     if (contents[roff] == 0x67)
+                       prefix = 1;
+                   }
+                 if (prefix)
+                   {
+                     bfd_put_8 (output_bfd, 0x0f, contents + roff);
+                     bfd_put_8 (output_bfd, 0x1f, contents + roff + 1);
+                     bfd_put_8 (output_bfd, 0x00, contents + roff + 2);
+                   }
+                 else
+                   {
+                     bfd_put_8 (output_bfd, 0x66, contents + roff);
+                     bfd_put_8 (output_bfd, 0x90, contents + roff + 1);
+                   }
                  continue;
                }
              else
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