commit bbe4bbb6e8997b5ff9843bd3f32ac77dbaec7284

Author: Fangrui Song <maskray@google.com>

Date:   Mon Aug 16 09:59:30 2021 -0700

    elf: Drop elf/tls-macros.h in favor of __thread and tls_model attributes [BZ #28152] [BZ #28205]

    elf/tls-macros.h was added for TLS testing when GCC did not support

    __thread. __thread and tls_model attributes are mature now and have been

    used by many newer tests.

    Also delete tst-tls2.c which tests .tls_common (unused by modern GCC and

    unsupported by Clang/LLD). .tls_common and .tbss definition are almost

    identical after linking, so the runtime test doesn't add additional

    coverage.  Assembler and linker tests should be on the binutils side.

    When LLD 13.0.0 is allowed in configure.ac

    (https://sourceware.org/pipermail/libc-alpha/2021-August/129866.html),

    `make check` result is on par with glibc built with GNU ld on aarch64

    and x86_64.

    As a future clean-up, TLS_GD/TLS_LD/TLS_IE/TLS_IE macros can be removed from

    sysdeps/*/tls-macros.h. We can add optional -mtls-dialect={gnu2,trad}

    tests to ensure coverage.

    Tested on aarch64-linux-gnu, powerpc64le-linux-gnu, and x86_64-linux-gnu.

    Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>

    (cherry picked from commit 33c50ef42878b07ee6ead8b3f1a81d8c2c74697c)

Conflicts:

	elf/Makefile

	  (different backport order)

diff --git a/elf/Makefile b/elf/Makefile

index feec365e4e5fe9b3..3a8590e0d3cc33ab 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -275,7 +275,6 @@ tests-static-internal := \

   tst-ptrguard1-static \

   tst-stackguard1-static \

   tst-tls1-static \

-  tst-tls2-static \

   tst-tls1-static-non-pie \

   # tests-static-internal

@@ -308,7 +307,6 @@ tests := \

 tests-internal := \

   $(tests-static-internal) \

   tst-tls1 \

-  tst-tls2 \

   # tests-internal

 tests-static := $(tests-static-normal) $(tests-static-internal)

diff --git a/elf/tls-macros.h b/elf/tls-macros.h

deleted file mode 100644

index e25e33b0f032099d..0000000000000000

--- a/elf/tls-macros.h

+++ /dev/null

@@ -1,25 +0,0 @@

-/* Macros to support TLS testing in times of missing compiler support.  */

-

-#define COMMON_INT_DEF(x) \

-  asm (".tls_common " #x ",4,4")

-/* XXX Until we get compiler support we don't need declarations.  */

-#define COMMON_INT_DECL(x)

-

-/* XXX This definition will probably be machine specific, too.  */

-#define VAR_INT_DEF(x) \

-  asm (".section .tdata\n\t"						      \

-       ".globl " #x "\n"						      \

-       ".balign 4\n"							      \

-       #x ":\t.long 0\n\t"						      \

-       ".size " #x ",4\n\t"						      \

-       ".previous")

-/* XXX Until we get compiler support we don't need declarations.  */

-#define VAR_INT_DECL(x)

-

-#include_next <tls-macros.h>

-

-  /* XXX Each architecture must have its own asm for now.  */

-#if !defined TLS_LE || !defined TLS_IE \

-      || !defined TLS_LD || !defined TLS_GD

-# error "No support for this architecture so far."

-#endif

diff --git a/elf/tst-tls1.c b/elf/tst-tls1.c

index c31da56ce9cb3e8f..b3412213ee9eaa7e 100644

--- a/elf/tst-tls1.c

+++ b/elf/tst-tls1.c

@@ -1,13 +1,14 @@

 /* glibc test for TLS in ld.so.  */

 #include <stdio.h>

-#include "tls-macros.h"

-

-

-/* Two common 'int' variables in TLS.  */

-COMMON_INT_DEF(foo);

-COMMON_INT_DEF(bar);

+__thread int foo, bar __attribute__ ((tls_model("local-exec")));

+extern __thread int foo_gd asm ("foo") __attribute__ ((tls_model("global-dynamic")));

+extern __thread int foo_ld asm ("foo") __attribute__ ((tls_model("local-dynamic")));

+extern __thread int foo_ie asm ("foo") __attribute__ ((tls_model("initial-exec")));

+extern __thread int bar_gd asm ("bar") __attribute__ ((tls_model("global-dynamic")));

+extern __thread int bar_ld asm ("bar") __attribute__ ((tls_model("local-dynamic")));

+extern __thread int bar_ie asm ("bar") __attribute__ ((tls_model("initial-exec")));

 static int

 do_test (void)

@@ -18,63 +19,48 @@ do_test (void)

   /* Set the variable using the local exec model.  */

   puts ("set bar to 1 (LE)");

-  ap = TLS_LE (bar);

-  *ap = 1;

+  bar = 1;

   /* Get variables using initial exec model.  */

   fputs ("get sum of foo and bar (IE)", stdout);

-  ap = TLS_IE (foo);

-  bp = TLS_IE (bar);

+  ap = &foo_ie;

+  bp = &bar_ie;

   printf (" = %d\n", *ap + *bp);

   result |= *ap + *bp != 1;

-  if (*ap != 0)

-    {

-      printf ("foo = %d\n", *ap);

-      result = 1;

-    }

-  if (*bp != 1)

+  if (*ap != 0 || *bp != 1)

     {

-      printf ("bar = %d\n", *bp);

+      printf ("foo = %d\nbar = %d\n", *ap, *bp);

       result = 1;

     }

-  /* Get variables using local dynamic model.  */

-  fputs ("get sum of foo and bar (LD)", stdout);

-  ap = TLS_LD (foo);

-  bp = TLS_LD (bar);

+  /* Get variables using local dynamic model or TLSDESC.  */

+  fputs ("get sum of foo and bar (LD or TLSDESC)", stdout);

+  ap = &foo_ld;

+  bp = &bar_ld;

   printf (" = %d\n", *ap + *bp);

   result |= *ap + *bp != 1;

-  if (*ap != 0)

-    {

-      printf ("foo = %d\n", *ap);

-      result = 1;

-    }

-  if (*bp != 1)

+  if (*ap != 0 || *bp != 1)

     {

-      printf ("bar = %d\n", *bp);

+      printf ("foo = %d\nbar = %d\n", *ap, *bp);

       result = 1;

     }

-  /* Get variables using generic dynamic model.  */

-  fputs ("get sum of foo and bar (GD)", stdout);

-  ap = TLS_GD (foo);

-  bp = TLS_GD (bar);

+  /* Get variables using general dynamic model or TLSDESC.  */

+  fputs ("get sum of foo and bar (GD or TLSDESC)", stdout);

+  ap = &foo_gd;

+  bp = &bar_gd;

   printf (" = %d\n", *ap + *bp);

   result |= *ap + *bp != 1;

-  if (*ap != 0)

-    {

-      printf ("foo = %d\n", *ap);

-      result = 1;

-    }

-  if (*bp != 1)

+  if (*ap != 0 || *bp != 1)

     {

-      printf ("bar = %d\n", *bp);

+      printf ("foo = %d\nbar = %d\n", *ap, *bp);

       result = 1;

     }

+

   return result;

 }

diff --git a/elf/tst-tls2.c b/elf/tst-tls2.c

deleted file mode 100644

index 963b8d6c88bba0b5..0000000000000000

--- a/elf/tst-tls2.c

+++ /dev/null

@@ -1,82 +0,0 @@

-/* glibc test for TLS in ld.so.  */

-#include <stdio.h>

-

-#include "tls-macros.h"

-

-

-/* Two 'int' variables in TLS.  */

-VAR_INT_DEF(foo);

-VAR_INT_DEF(bar);

-

-

-static int

-do_test (void)

-{

-  int result = 0;

-  int *ap, *bp;

-

-

-  /* Set the variable using the local exec model.  */

-  puts ("set bar to 1 (LE)");

-  ap = TLS_LE (bar);

-  *ap = 1;

-

-

-  /* Get variables using initial exec model.  */

-  fputs ("get sum of foo and bar (IE)", stdout);

-  ap = TLS_IE (foo);

-  bp = TLS_IE (bar);

-  printf (" = %d\n", *ap + *bp);

-  result |= *ap + *bp != 1;

-  if (*ap != 0)

-    {

-      printf ("foo = %d\n", *ap);

-      result = 1;

-    }

-  if (*bp != 1)

-    {

-      printf ("bar = %d\n", *bp);

-      result = 1;

-    }

-

-

-  /* Get variables using local dynamic model.  */

-  fputs ("get sum of foo and bar (LD)", stdout);

-  ap = TLS_LD (foo);

-  bp = TLS_LD (bar);

-  printf (" = %d\n", *ap + *bp);

-  result |= *ap + *bp != 1;

-  if (*ap != 0)

-    {

-      printf ("foo = %d\n", *ap);

-      result = 1;

-    }

-  if (*bp != 1)

-    {

-      printf ("bar = %d\n", *bp);

-      result = 1;

-    }

-

-

-  /* Get variables using generic dynamic model.  */

-  fputs ("get sum of foo and bar (GD)", stdout);

-  ap = TLS_GD (foo);

-  bp = TLS_GD (bar);

-  printf (" = %d\n", *ap + *bp);

-  result |= *ap + *bp != 1;

-  if (*ap != 0)

-    {

-      printf ("foo = %d\n", *ap);

-      result = 1;

-    }

-  if (*bp != 1)

-    {

-      printf ("bar = %d\n", *bp);

-      result = 1;

-    }

-

-  return result;

-}

-

-

-#include <support/test-driver.c>

diff --git a/elf/tst-tls3.c b/elf/tst-tls3.c

index 7e0abb4c58c8ff50..222b179626161897 100644

--- a/elf/tst-tls3.c

+++ b/elf/tst-tls3.c

@@ -1,13 +1,12 @@

 /* glibc test for TLS in ld.so.  */

 #include <stdio.h>

-#include "tls-macros.h"

-

-/* One define int variable, two externs.  */

-COMMON_INT_DECL(foo);

-VAR_INT_DECL(bar);

-VAR_INT_DEF(baz);

+__thread int foo, bar __attribute__ ((tls_model("initial-exec")));

+__thread int baz __attribute__ ((tls_model("local-exec")));

+extern __thread int foo_gd __attribute__ ((alias("foo"), tls_model("global-dynamic")));

+extern __thread int bar_gd __attribute__ ((alias("bar"), tls_model("global-dynamic")));

+extern __thread int baz_ld __attribute__ ((alias("baz"), tls_model("local-dynamic")));

 extern int in_dso (void);

@@ -22,23 +21,20 @@ do_test (void)

   /* Set the variable using the local exec model.  */

   puts ("set baz to 3 (LE)");

-  ap = TLS_LE (baz);

-  *ap = 3;

+  baz = 3;

   /* Get variables using initial exec model.  */

   puts ("set variables foo and bar (IE)");

-  ap = TLS_IE (foo);

-  *ap = 1;

-  bp = TLS_IE (bar);

-  *bp = 2;

+  foo = 1;

+  bar = 2;

   /* Get variables using local dynamic model.  */

   fputs ("get sum of foo, bar (GD) and baz (LD)", stdout);

-  ap = TLS_GD (foo);

-  bp = TLS_GD (bar);

-  cp = TLS_LD (baz);

+  ap = &foo_gd;

+  bp = &bar_gd;

+  cp = &baz_ld;

   printf (" = %d\n", *ap + *bp + *cp);

   result |= *ap + *bp + *cp != 6;

   if (*ap != 1)

diff --git a/elf/tst-tlsmod1.c b/elf/tst-tlsmod1.c

index 8d9156791be9eabf..a448c4dc37eaf01b 100644

--- a/elf/tst-tlsmod1.c

+++ b/elf/tst-tlsmod1.c

@@ -1,12 +1,12 @@

 #include <stdio.h>

-#include "tls-macros.h"

+__thread int foo, bar __attribute__ ((tls_model("global-dynamic")));

+extern __thread int baz __attribute__ ((tls_model("global-dynamic")));

+extern __thread int foo_ie asm ("foo") __attribute__ ((tls_model("initial-exec")));

+extern __thread int bar_ie asm ("bar") __attribute__ ((tls_model("initial-exec")));

+extern __thread int baz_ie asm ("baz") __attribute__ ((tls_model("initial-exec")));

-/* One define int variable, two externs.  */

-COMMON_INT_DEF(foo);

-VAR_INT_DEF(bar);

-VAR_INT_DECL(baz);

 extern int in_dso (void);

@@ -19,8 +19,8 @@ in_dso (void)

   /* Get variables using initial exec model.  */

   fputs ("get sum of foo and bar (IE)", stdout);

   asm ("" ::: "memory");

-  ap = TLS_IE (foo);

-  bp = TLS_IE (bar);

+  ap = &foo_ie;

+  bp = &bar_ie;

   printf (" = %d\n", *ap + *bp);

   result |= *ap + *bp != 3;

   if (*ap != 1)

@@ -35,11 +35,11 @@ in_dso (void)

     }

-  /* Get variables using generic dynamic model.  */

-  fputs ("get sum of foo and bar and baz (GD)", stdout);

-  ap = TLS_GD (foo);

-  bp = TLS_GD (bar);

-  cp = TLS_GD (baz);

+  /* Get variables using generic dynamic model or TLSDESC.  */

+  fputs ("get sum of foo and bar and baz (GD or TLSDESC)", stdout);

+  ap = &foo;

+  bp = &bar;

+  cp = &baz;

   printf (" = %d\n", *ap + *bp + *cp);

   result |= *ap + *bp + *cp != 6;

   if (*ap != 1)

diff --git a/elf/tst-tlsmod2.c b/elf/tst-tlsmod2.c

index 40eb1407f864f64a..3223fe494bb7e1f0 100644

--- a/elf/tst-tlsmod2.c

+++ b/elf/tst-tlsmod2.c

@@ -1,9 +1,7 @@

 #include <stdio.h>

-#include "tls-macros.h"

-

-COMMON_INT_DEF(foo);

+__thread int foo;

 int

@@ -15,7 +13,7 @@ in_dso (int n, int *caller_foop)

   puts ("foo");			/* Make sure PLT is used before macros.  */

   asm ("" ::: "memory");

-  foop = TLS_GD (foo);

+  foop = &foo;

   if (caller_foop != NULL && foop != caller_foop)

     {

diff --git a/elf/tst-tlsmod3.c b/elf/tst-tlsmod3.c

index 6d186c47ee6ba104..d6e7498fd8331cb7 100644

--- a/elf/tst-tlsmod3.c

+++ b/elf/tst-tlsmod3.c

@@ -1,10 +1,10 @@

 #include <stdio.h>

-#include "tls-macros.h"

 extern int in_dso (int n, int *caller_foop);

-COMMON_INT_DEF(comm_n);

+extern __thread int foo;

+__thread int comm_n;

@@ -20,8 +20,8 @@ in_dso2 (void)

   puts ("foo");			/* Make sure PLT is used before macros.  */

   asm ("" ::: "memory");

-  foop = TLS_GD (foo);

-  np = TLS_GD (comm_n);

+  foop = &foo;

+  np = &comm_;;

   if (n != *np)

     {

diff --git a/elf/tst-tlsmod4.c b/elf/tst-tlsmod4.c

index 86889aac7e58bcf5..f38919a8a94861c1 100644

--- a/elf/tst-tlsmod4.c

+++ b/elf/tst-tlsmod4.c

@@ -1,9 +1,7 @@

 #include <stdio.h>

-#include "tls-macros.h"

-

-COMMON_INT_DEF(baz);

+__thread int baz;

 int

@@ -15,7 +13,7 @@ in_dso (int n, int *caller_bazp)

   puts ("foo");			/* Make sure PLT is used before macros.  */

   asm ("" ::: "memory");

-  bazp = TLS_GD (baz);

+  bazp = &baz;

   if (caller_bazp != NULL && bazp != caller_bazp)

     {

diff --git a/elf/tst-tlsmod5.c b/elf/tst-tlsmod5.c

index a97c7e5e0c69de26..3f39c5bdb76e0b5c 100644

--- a/elf/tst-tlsmod5.c

+++ b/elf/tst-tlsmod5.c

@@ -1,3 +1 @@

-#include "tls-macros.h"

-

-COMMON_INT_DEF(foo);

+__thread int foo;

diff --git a/elf/tst-tlsmod6.c b/elf/tst-tlsmod6.c

index e968596dd4ef7756..7b3571f428b7243b 100644

--- a/elf/tst-tlsmod6.c

+++ b/elf/tst-tlsmod6.c

@@ -1,3 +1 @@

-#include "tls-macros.h"

-

-COMMON_INT_DEF(bar);

+__thread int bar;

diff --git a/sysdeps/powerpc/mod-tlsopt-powerpc.c b/sysdeps/powerpc/mod-tlsopt-powerpc.c

index 51cc502f2860e969..d941024963fc7e6a 100644

--- a/sysdeps/powerpc/mod-tlsopt-powerpc.c

+++ b/sysdeps/powerpc/mod-tlsopt-powerpc.c

@@ -1,11 +1,9 @@

 /* shared library to test for __tls_get_addr optimization.  */

 #include <stdio.h>

-#include "../../elf/tls-macros.h"

 #include "dl-tls.h"

-/* common 'int' variable in TLS.  */

-COMMON_INT_DEF(foo);

+__thread int foo __attribute__ ((tls_model("global-dynamic")));

 int

@@ -14,7 +12,7 @@ tls_get_addr_opt_test (void)

   int result = 0;

   /* Get variable using general dynamic model.  */

-  int *ap = TLS_GD (foo);

+  int *ap = &foo;

   if (*ap != 0)

     {

       printf ("foo = %d\n", *ap);

diff --git a/sysdeps/powerpc/tst-tlsifunc.c b/sysdeps/powerpc/tst-tlsifunc.c

index 3095d41a68320d72..c8c0bada4547e1a4 100644

--- a/sysdeps/powerpc/tst-tlsifunc.c

+++ b/sysdeps/powerpc/tst-tlsifunc.c

@@ -21,9 +21,9 @@

 #include <stdint.h>

 #include <inttypes.h>

 #include <libc-symbols.h>

-#include <tls-macros.h>

 __thread int bar;

+extern __thread int bar_gd asm ("bar") __attribute__ ((tls_model("global-dynamic")));

 static int *bar_ptr = NULL;

 static uint32_t resolver_platform = 0;

@@ -57,7 +57,7 @@ get_platform (void)

 void

 init_foo (void)

 {

-  bar_ptr = TLS_GD (bar);

+  bar_ptr = &bar_gd;

 }

 int