[PATCH] libc x86-64 __thread fix

[PATCH] libc x86-64 __thread fix

[Jakub Jelinek]

Hi!

2002-10-14  Jakub Jelinek  <jakub@redhat.com>

	* sysdeps/unix/sysv/linux/x86_64/sysdep.h: Include tls.h.
	(SYSCALL_ERROR_HANDLER): Use RTLD_PRIVATE_ERRNO sequence
	in ld.so even if __thread is supported.

--- libc/sysdeps/unix/sysv/linux/x86_64/sysdep.h.jj	2002-10-11 08:54:41.000000000 -0400
+++ libc/sysdeps/unix/sysv/linux/x86_64/sysdep.h	2002-10-14 08:16:36.000000000 -0400
@@ -23,6 +23,7 @@
 #include <sysdeps/unix/x86_64/sysdep.h>
 #include <bp-sym.h>
 #include <bp-asm.h>
+#include <tls.h>
 
 #ifdef IS_IN_rtld
 # include <dl-sysdep.h>		/* Defines RTLD_PRIVATE_ERRNO.  */
@@ -82,22 +83,22 @@
 
 #ifndef PIC
 #define SYSCALL_ERROR_HANDLER	/* Nothing here; code in sysdep.S is used.  */
-#elif USE___THREAD
+#elif RTLD_PRIVATE_ERRNO
 # define SYSCALL_ERROR_HANDLER			\
 0:						\
-  movq errno@GOTTPOFF(%rip), %rcx;		\
+  leaq errno(%rip), %rcx;			\
   xorq %rdx, %rdx;				\
   subq %rax, %rdx;				\
-  movl %edx, %fs:(%rcx);			\
+  movl %edx, (%rcx);				\
   orq $-1, %rax;				\
   jmp L(pseudo_end);
-#elif RTLD_PRIVATE_ERRNO
+#elif USE___THREAD
 # define SYSCALL_ERROR_HANDLER			\
 0:						\
-  leaq errno(%rip), %rcx;			\
+  movq errno@GOTTPOFF(%rip), %rcx;		\
   xorq %rdx, %rdx;				\
   subq %rax, %rdx;				\
-  movl %edx, (%rcx);				\
+  movl %edx, %fs:(%rcx);			\
   orq $-1, %rax;				\
   jmp L(pseudo_end);
 #elif defined _LIBC_REENTRANT

	Jakub

Re: [PATCH] libc x86-64 __thread fix

[Roland McGrath]

Something is wrong if you need that.  USE___THREAD != HAVE___THREAD.
Why is USE___THREAD defined in your rtld build?

Re: [PATCH] libc x86-64 __thread fix

[Jakub Jelinek]

On Mon, Oct 14, 2002 at 12:37:59PM -0700, Roland McGrath wrote:
> Something is wrong if you need that.  USE___THREAD != HAVE___THREAD.
> Why is USE___THREAD defined in your rtld build?

Actually, maybe just the #include <tls.h> is needed.
The problem was that without including tls.h uname.os etc. in libc-pic.a
was calling __errno_location(), which caused rtld-errno-loc.os to be
added into librtld.a. But rtld-errno-loc.os would not compile, because
errno was first defined as normal variable in include/errno.h and then
redefined as __thread variable in sysdeps/generic/errno-loc.c.
Though IMHO putting RTLD_PRIVATE_ERRNO case before USE__THREAD
shouldn't hurt.

	Jakub

Re: [PATCH] libc x86-64 __thread fix

[Roland McGrath]

> Actually, maybe just the #include <tls.h> is needed.

Yes, though that doesn't directly affect the build of the rtld modules.

> The problem was that without including tls.h uname.os etc. in libc-pic.a

Ah, I see.  I was confused as to how it could be losing even if
USE___THREAD was never defined at all, because !defined -> 0 is the right
default for the rtld build.  But that explains it, since it was the libc
build of the module that indirectly loused up the rtld build.

> Though IMHO putting RTLD_PRIVATE_ERRNO case before USE__THREAD
> shouldn't hurt.

Certainly.  I just don't like these things to be mysterious.