[Patch] Windows TLS enhancements

[Patch] Windows TLS enhancements

[Daniel Green]

[-- Attachment #1: Type: text/plain, Size: 396 bytes --]

Included are 2 patches to help support TLS on Windows.

secrel32.patch:
     Allows use of secrel32 as an operand in gas.  Such as "movl 
$symbol@secrel32, %eax"

pe_tls.patch:
     Convention requires that the symbols defining the start and end of 
the TLS section be within .tls$AAA and .tls$ZZZ.  The changes here 
ensure those sections appear at the start and end of the TLS section.

Daniel

[-- Attachment #2: secrel32.patch --]
[-- Type: text/plain, Size: 3305 bytes --]

Index: gas/config/tc-i386.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-i386.c,v
retrieving revision 1.480
diff -u -p -r1.480 tc-i386.c
--- gas/config/tc-i386.c	13 Jan 2012 22:19:31 -0000	1.480
+++ gas/config/tc-i386.c	16 Jan 2012 17:07:57 -0000
@@ -6685,6 +6685,105 @@ lex_got (enum bfd_reloc_code_real *rel,
 }
 #endif
 
+#ifdef TE_PE
+  #ifdef lex_got
+    #undef lex_got
+  #endif
+/* Parse operands of the form
+   <symbol>@SECREL32+<nnn>
+
+   If we find one, set up the correct relocation in RELOC and copy the
+   input string, minus the `@SECREL32' into a malloc'd buffer for
+   parsing by the calling routine.  Return this buffer, and if ADJUST
+   is non-null set it to the length of the string we removed from the
+   input line.  Otherwise return NULL.  
+   
+   This function is copied from the ELF version above adjusted for PE targets.
+   */
+static char *
+lex_got (enum bfd_reloc_code_real *rel ATTRIBUTE_UNUSED,
+	 int *adjust ATTRIBUTE_UNUSED,
+	 i386_operand_type *types ATTRIBUTE_UNUSED)
+{
+  static const struct {
+    const char *str;
+    int len;
+    const enum bfd_reloc_code_real rel[2];
+    const i386_operand_type types64;
+  } gotrel[] = {
+    { STRING_COMMA_LEN ("SECREL32"),    { BFD_RELOC_32_SECREL,
+				       BFD_RELOC_32_SECREL  },
+      OPERAND_TYPE_IMM32_32S_64_DISP32_64 },
+  };
+
+  char *cp;
+  unsigned j;
+
+  for (cp = input_line_pointer; *cp != '@'; cp++)
+    if (is_end_of_line[(unsigned char) *cp] || *cp == ',')
+      return NULL;
+
+  for (j = 0; j < ARRAY_SIZE (gotrel); j++)
+    {
+      int len = gotrel[j].len;
+      if (strncasecmp (cp + 1, gotrel[j].str, len) == 0)
+	{
+	  if (gotrel[j].rel[object_64bit] != 0)
+	    {
+	      int first, second;
+	      char *tmpbuf, *past_reloc;
+
+	      *rel = gotrel[j].rel[object_64bit];
+	      if (adjust)
+		*adjust = len;
+
+	      if (types)
+		{
+		  if (flag_code != CODE_64BIT)
+		    {
+		      types->bitfield.imm32 = 1;
+		      types->bitfield.disp32 = 1;
+		    }
+		  else
+		    *types = gotrel[j].types64;
+		}
+
+	      /* The length of the first part of our input line.  */
+	      first = cp - input_line_pointer;
+
+	      /* The second part goes from after the reloc token until
+		 (and including) an end_of_line char or comma.  */
+	      past_reloc = cp + 1 + len;
+	      cp = past_reloc;
+	      while (!is_end_of_line[(unsigned char) *cp] && *cp != ',')
+		++cp;
+	      second = cp + 1 - past_reloc;
+
+	      /* Allocate and copy string.  The trailing NUL shouldn't
+		 be necessary, but be safe.  */
+	      tmpbuf = (char *) xmalloc (first + second + 2);
+	      memcpy (tmpbuf, input_line_pointer, first);
+	      if (second != 0 && *past_reloc != ' ')
+		/* Replace the relocation token with ' ', so that
+		   errors like foo@SECLREL321 will be detected.  */
+		tmpbuf[first++] = ' ';
+	      memcpy (tmpbuf + first, past_reloc, second);
+	      tmpbuf[first + second] = '\0';
+	      return tmpbuf;
+	    }
+
+	  as_bad (_("@%s reloc is not supported with %d-bit output format"),
+		  gotrel[j].str, 1 << (5 + object_64bit));
+	  return NULL;
+	}
+    }
+
+  /* Might be a symbol version string.  Don't as_bad here.  */
+  return NULL;
+}
+#endif
+
+
 void
 x86_cons (expressionS *exp, int size)
 {

[-- Attachment #3: pe_tls.patch --]
[-- Type: text/plain, Size: 2106 bytes --]

Index: ld/scripttempl/pe.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/pe.sc,v
retrieving revision 1.29
diff -u -p -r1.29 pe.sc
--- ld/scripttempl/pe.sc	27 Sep 2011 15:59:55 -0000	1.29
+++ ld/scripttempl/pe.sc	16 Jan 2012 17:07:59 -0000
@@ -39,9 +39,11 @@ if test "${RELOCATING}"; then
   R_CRT_XP='*(SORT(.CRT$XP*))  /* Pre-termination */'
   R_CRT_XT='*(SORT(.CRT$XT*))  /* Termination */'
   R_TLS='
+    *(.tls$AAA)    
     *(.tls)
     *(.tls$)
-    *(SORT(.tls$*))'
+    *(SORT(.tls$*))
+    *(.tls$ZZZ)'
   R_RSRC='*(SORT(.rsrc$*))'
 else
   R_TEXT=
@@ -179,6 +181,10 @@ SECTIONS
     ${RELOCATING+___crt_xt_end__ = . ;}
   }
 
+  /* Windows TLS expects .tls\$AAA to be at the start and .tls\$ZZZ to be
+     at the end of section.  This is important because _tls_start MUST
+     be at the beginning of the section to enable SECREL32 relocations with TLS
+     data. */
   .tls ${RELOCATING+BLOCK(__section_alignment__)} :
   { 					
     ${RELOCATING+___tls_start__ = . ;}
Index: ld/scripttempl/pep.sc
===================================================================
RCS file: /cvs/src/src/ld/scripttempl/pep.sc,v
retrieving revision 1.18
diff -u -p -r1.18 pep.sc
--- ld/scripttempl/pep.sc	27 Sep 2011 15:59:55 -0000	1.18
+++ ld/scripttempl/pep.sc	16 Jan 2012 17:07:59 -0000
@@ -39,9 +39,11 @@ if test "${RELOCATING}"; then
   R_CRT_XP='*(SORT(.CRT$XP*))  /* Pre-termination */'
   R_CRT_XT='*(SORT(.CRT$XT*))  /* Termination */'
   R_TLS='
+    *(.tls$AAA)    
     *(.tls)
     *(.tls$)
-    *(SORT(.tls$*))'
+    *(SORT(.tls$*))
+    *(.tls$ZZZ)'
   R_RSRC='*(SORT(.rsrc$*))'
 else
   R_TEXT=
@@ -185,6 +187,10 @@ SECTIONS
     ${RELOCATING+___crt_xt_end__ = . ;}
   }
 
+  /* Windows TLS expects .tls\$AAA to be at the start and .tls\$ZZZ to be
+     at the end of the .tls section.  This is important because _tls_start MUST
+     be at the beginning of the section to enable SECREL32 relocations with TLS
+     data. */
   .tls ${RELOCATING+BLOCK(__section_alignment__)} :
   { 					
     ${RELOCATING+___tls_start__ = . ;}

Re: [Patch] Windows TLS enhancements

[NightStrike]

Ping

On Mon, Jan 16, 2012 at 7:26 AM, Daniel Green <venix1@gmail.com> wrote:
> Included are 2 patches to help support TLS on Windows.
>
> secrel32.patch:
>     Allows use of secrel32 as an operand in gas.  Such as "movl
> $symbol@secrel32, %eax"
>
> pe_tls.patch:
>     Convention requires that the symbols defining the start and end of the
> TLS section be within .tls$AAA and .tls$ZZZ.  The changes here ensure those
> sections appear at the start and end of the TLS section.
>
> Daniel


This email went unnoticed.  I contacted Daniel, and he never got a review.

Daniel, do you have a patch for GCC for this as well?  Also, are you
able to make this patch current, or do you need someone else to help
in that area?

I am CC'ing Kai for help on this.  Thanks, Kai!

Re: [Patch] Windows TLS enhancements

[nick clifton]

Hi Daniel,

> secrel32.patch:
>      Allows use of secrel32 as an operand in gas.  Such as "movl
> $symbol@secrel32, %eax"
>
> pe_tls.patch:
>      Convention requires that the symbols defining the start and end of
> the TLS section be within .tls$AAA and .tls$ZZZ.  The changes here
> ensure those sections appear at the start and end of the TLS section.

Approved and applied.

Note - I extended the gas/testsuite/gas/i386/secrel.[sd] testcase to 
include a check that the syntax is parsed correctly.

Cheers
   Nick

gas/ChangeLog
2012-08-07  Daniel Green  <venix1@gmail.com>

	* config/tc-i386.c (lex_got): Provide implementation for PE
	format.

ld/ChangeLog
2012-08-07  Daniel Green  <venix1@gmail.com>

	* scripttempl/pe.sc (R_TLS): Add .tls$AAA and .tls$ZZZ.
	* scripttempl/pep.sc (R_TLS): Add .tls$AAA and .tls$ZZZ.