[v6,03/13] ARC: Thread Local Storage support
Commit Message
This includes all 4 TLS addressing models
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
sysdeps/arc/dl-tls.h | 30 +++++++
sysdeps/arc/libc-tls.c | 27 ++++++
sysdeps/arc/nptl/tcb-offsets.sym | 11 +++
sysdeps/arc/nptl/tls.h | 150 +++++++++++++++++++++++++++++++
sysdeps/arc/stackinfo.h | 33 +++++++
5 files changed, 251 insertions(+)
create mode 100644 sysdeps/arc/dl-tls.h
create mode 100644 sysdeps/arc/libc-tls.c
create mode 100644 sysdeps/arc/nptl/tcb-offsets.sym
create mode 100644 sysdeps/arc/nptl/tls.h
create mode 100644 sysdeps/arc/stackinfo.h
Comments
On 22/04/2020 22:41, Vineet Gupta via Libc-alpha wrote:
> This includes all 4 TLS addressing models
>
> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
As prior patch we do not use DCO, but rather copyright assignment.
Looks ok in general, with some comments below.
> ---
> sysdeps/arc/dl-tls.h | 30 +++++++
> sysdeps/arc/libc-tls.c | 27 ++++++
> sysdeps/arc/nptl/tcb-offsets.sym | 11 +++
> sysdeps/arc/nptl/tls.h | 150 +++++++++++++++++++++++++++++++
> sysdeps/arc/stackinfo.h | 33 +++++++
> 5 files changed, 251 insertions(+)
> create mode 100644 sysdeps/arc/dl-tls.h
> create mode 100644 sysdeps/arc/libc-tls.c
> create mode 100644 sysdeps/arc/nptl/tcb-offsets.sym
> create mode 100644 sysdeps/arc/nptl/tls.h
> create mode 100644 sysdeps/arc/stackinfo.h
>
> diff --git a/sysdeps/arc/dl-tls.h b/sysdeps/arc/dl-tls.h
> new file mode 100644
> index 000000000000..2269ac6c3daa
> --- /dev/null
> +++ b/sysdeps/arc/dl-tls.h
> @@ -0,0 +1,30 @@
> +/* Thread-local storage handling in the ELF dynamic linker. ARC version.
> + Copyright (C) 2012-2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library. If not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +
> +/* Type used for the representation of TLS information in the GOT. */
> +typedef struct
> +{
> + unsigned long int ti_module;
> + unsigned long int ti_offset;
> +} tls_index;
> +
> +extern void *__tls_get_addr (tls_index *ti);
> +
> +/* Value used for dtv entries for which the allocation is delayed. */
> +#define TLS_DTV_UNALLOCATED ((void *) -1l)
Ok.
> diff --git a/sysdeps/arc/libc-tls.c b/sysdeps/arc/libc-tls.c
> new file mode 100644
> index 000000000000..ec88282de60e
> --- /dev/null
> +++ b/sysdeps/arc/libc-tls.c
> @@ -0,0 +1,27 @@
> +/* Thread-local storage handling in the ELF dynamic linker. ARC version.
> + Copyright (C) 2005-2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library. If not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <csu/libc-tls.c>
> +#include <dl-tls.h>
> +
> +void *
> +__tls_get_addr (tls_index *ti)
> +{
> + dtv_t *dtv = THREAD_DTV ();
> + return (char *) dtv[1].pointer.val + ti->ti_offset;
> +}
Ok.
> diff --git a/sysdeps/arc/nptl/tcb-offsets.sym b/sysdeps/arc/nptl/tcb-offsets.sym
> new file mode 100644
> index 000000000000..64c432c22e76
> --- /dev/null
> +++ b/sysdeps/arc/nptl/tcb-offsets.sym
> @@ -0,0 +1,11 @@
> +#include <sysdep.h>
> +#include <tls.h>
> +
> +-- Derive offsets relative to the thread register.
> +#define thread_offsetof(mem) (long)(offsetof (struct pthread, mem) - sizeof (struct pthread))
> +
> +MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads)
> +TLS_PRE_TCB_SIZE sizeof (struct pthread)
> +TLS_TCB_SIZE sizeof (tcbhead_t)
> +
> +PTHREAD_TID offsetof (struct pthread, tid)
Ok.
> diff --git a/sysdeps/arc/nptl/tls.h b/sysdeps/arc/nptl/tls.h
> new file mode 100644
> index 000000000000..a836af121a85
> --- /dev/null
> +++ b/sysdeps/arc/nptl/tls.h
> @@ -0,0 +1,150 @@
> +/* Definition for thread-local data handling. NPTL/ARC version.
> + Copyright (C) 2012-2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library. If not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#ifndef _ARC_NPTL_TLS_H
> +#define _ARC_NPTL_TLS_H 1
> +
> +#include <dl-sysdep.h>
> +
> +#ifndef __ASSEMBLER__
> +# include <stdbool.h>
> +# include <stddef.h>
> +# include <stdint.h>
> +
> +#include <dl-dtv.h>
> +
> +/* Get system call information. */
> +# include <sysdep.h>
> +
> +/* The TLS blocks start right after the TCB. */
> +# define TLS_DTV_AT_TP 1
> +# define TLS_TCB_AT_TP 0
> +
> +/* Get the thread descriptor definition. */
> +# include <nptl/descr.h>
> +
> +typedef struct
> +{
> + dtv_t *dtv;
> + uintptr_t pointer_guard;
> +} tcbhead_t;
> +
> +register struct pthread *__thread_self __asm__("r25");
This is used on other ports, but I am not sure if this is a valid definition
for a global variable. Usually the register specifier is used as an input
for inline assembly. Do we really need this global on ARC port? Couldn't
we replace it with __builtin_thread_pointer where applicable?
> +
> +/* This is the size of the initial TCB. */
> +# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
> +
> +/* Alignment requirements for the initial TCB. */
> +# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
> +
> +/* This is the size of the TCB. */
> +#ifndef TLS_TCB_SIZE
> +# define TLS_TCB_SIZE sizeof (tcbhead_t)
> +#endif
> +
> +/* Alignment requirements for the TCB. */
> +# define TLS_TCB_ALIGN __alignof__ (struct pthread)
> +
> +/* This is the size we need before TCB. */
> +# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
> +
> +/* Install the dtv pointer. The pointer passed is to the element with
> + index -1 which contain the length. */
> +# define INSTALL_DTV(tcbp, dtvp) \
> + (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
> +
> +/* Install new dtv for current thread. */
> +# define INSTALL_NEW_DTV(dtv) \
> + (THREAD_DTV() = (dtv))
> +
> +/* Return dtv of given thread descriptor. */
> +# define GET_DTV(tcbp) \
> + (((tcbhead_t *) (tcbp))->dtv)
> +
> +/* Code to initially initialize the thread pointer. */
> +# define TLS_INIT_TP(tcbp) \
> + ({ \
> + long result_var; \
> + __builtin_set_thread_pointer (tcbp); \
> + result_var = INTERNAL_SYSCALL (arc_settls, 1, (tcbp)); \
> + INTERNAL_SYSCALL_ERROR_P (result_var) \
> + ? "settls syscall error" : NULL; \
> + })
> +
> +/* Value passed to 'clone' for initialization of the thread register. */
> +# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
> +
> +/* Return the address of the dtv for the current thread. */
> +# define THREAD_DTV() \
> + (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
> +
> +/* Return the thread descriptor for the current thread. */
> +# define THREAD_SELF \
> + ((struct pthread *)__builtin_thread_pointer () - 1)
> +
> +/* Magic for libthread_db to know how to do THREAD_SELF. */
> +# define DB_THREAD_SELF \
> + CONST_THREAD_AREA (32, sizeof (struct pthread))
> +
> +/* Access to data in the thread descriptor is easy. */
> +# define THREAD_GETMEM(descr, member) \
> + descr->member
> +# define THREAD_GETMEM_NC(descr, member, idx) \
> + descr->member[idx]
> +# define THREAD_SETMEM(descr, member, value) \
> + descr->member = (value)
> +# define THREAD_SETMEM_NC(descr, member, idx, value) \
> + descr->member[idx] = (value)
> +
> +/* Get and set the global scope generation counter in struct pthread. */
> +#define THREAD_GSCOPE_IN_TCB 1
> +#define THREAD_GSCOPE_FLAG_UNUSED 0
> +#define THREAD_GSCOPE_FLAG_USED 1
> +#define THREAD_GSCOPE_FLAG_WAIT 2
> +#define THREAD_GSCOPE_RESET_FLAG() \
> + do \
> + { int __res \
> + = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag, \
> + THREAD_GSCOPE_FLAG_UNUSED); \
> + if (__res == THREAD_GSCOPE_FLAG_WAIT) \
> + lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
> + } \
> + while (0)
> +#define THREAD_GSCOPE_SET_FLAG() \
> + do \
> + { \
> + THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
> + atomic_write_barrier (); \
> + } \
> + while (0)
> +#define THREAD_GSCOPE_WAIT() \
> + GL(dl_wait_lookup_done) ()
> +
> +#else
> +
> +# include <tcb-offsets.h>
> +
> +# r25 is dedicated TLS register for ARC
> +.macro THREAD_SELF reg
> + # struct pthread is just ahead of TCB
> + sub \reg, r25, TLS_PRE_TCB_SIZE
> +.endm
> +
> +#endif /* __ASSEMBLER__ */
> +
> +#endif /* tls.h */
Ok.
> diff --git a/sysdeps/arc/stackinfo.h b/sysdeps/arc/stackinfo.h
> new file mode 100644
> index 000000000000..911efd928675
> --- /dev/null
> +++ b/sysdeps/arc/stackinfo.h
> @@ -0,0 +1,33 @@
> +/* Stack environment definitions for ARC.
> + Copyright (C) 2012-2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library. If not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +/* This file contains a bit of information about the stack allocation
> + of the processor. */
> +
> +#ifndef _STACKINFO_H
> +#define _STACKINFO_H 1
> +
> +#include <elf.h>
> +
> +/* On ARC the stack grows down. */
> +#define _STACK_GROWS_DOWN 1
> +
> +/* Default to a non-executable stack. */
> +#define DEFAULT_STACK_PERMS (PF_R|PF_W)
> +
> +#endif /* stackinfo.h */
>
Ok.
On 5/27/20 12:17 PM, Adhemerval Zanella via Libc-alpha wrote:
>
>
> On 22/04/2020 22:41, Vineet Gupta via Libc-alpha wrote:
>> This includes all 4 TLS addressing models
>>
>> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
>
> As prior patch we do not use DCO, but rather copyright assignment.
>
> Looks ok in general, with some comments below.
>> +
>> +register struct pthread *__thread_self __asm__("r25");
>
> This is used on other ports, but I am not sure if this is a valid definition
> for a global variable.
Not valid from gcc implementation POV ? The syntax seems to work alright in ARC
linux kernel where we use r25 to cache the current task pointer.
> Usually the register specifier is used as an input
> for inline assembly. Do we really need this global on ARC port? Couldn't
> we replace it with __builtin_thread_pointer where applicable?
We do use __builtin_thread_pointer and actually __thread_self is not used in ARC
port :-) so I can just drop it
Many thx for reviewing.
-Vineet
On 27/05/2020 22:36, Vineet Gupta wrote:
> On 5/27/20 12:17 PM, Adhemerval Zanella via Libc-alpha wrote:
>>
>>
>> On 22/04/2020 22:41, Vineet Gupta via Libc-alpha wrote:
>>> This includes all 4 TLS addressing models
>>>
>>> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
>>
>> As prior patch we do not use DCO, but rather copyright assignment.
>>
>> Looks ok in general, with some comments below.
>
>>> +
>>> +register struct pthread *__thread_self __asm__("r25");
>>
>> This is used on other ports, but I am not sure if this is a valid definition
>> for a global variable.
>
> Not valid from gcc implementation POV ? The syntax seems to work alright in ARC
> linux kernel where we use r25 to cache the current task pointer.
The gcc documentation [1] does specify register global variables, but it
also states that
"[...] it is recommended that you choose a register that is normally saved and
restored by function calls on your machine, so that calls to library routines
will not clobber it."
So I see that the semantic of global register is kind fragile and since
it is usage is solely for asm inline argument I don't see a very compelling
reason to keep using it.
[1] https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html
>
>> Usually the register specifier is used as an input
>> for inline assembly. Do we really need this global on ARC port? Couldn't
>> we replace it with __builtin_thread_pointer where applicable?
>
> We do use __builtin_thread_pointer and actually __thread_self is not used in ARC
> port :-) so I can just drop it
Ack.
>
> Many thx for reviewing.
> -Vineet
>
new file mode 100644
@@ -0,0 +1,30 @@
+/* Thread-local storage handling in the ELF dynamic linker. ARC version.
+ Copyright (C) 2012-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+
+/* Type used for the representation of TLS information in the GOT. */
+typedef struct
+{
+ unsigned long int ti_module;
+ unsigned long int ti_offset;
+} tls_index;
+
+extern void *__tls_get_addr (tls_index *ti);
+
+/* Value used for dtv entries for which the allocation is delayed. */
+#define TLS_DTV_UNALLOCATED ((void *) -1l)
new file mode 100644
@@ -0,0 +1,27 @@
+/* Thread-local storage handling in the ELF dynamic linker. ARC version.
+ Copyright (C) 2005-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <csu/libc-tls.c>
+#include <dl-tls.h>
+
+void *
+__tls_get_addr (tls_index *ti)
+{
+ dtv_t *dtv = THREAD_DTV ();
+ return (char *) dtv[1].pointer.val + ti->ti_offset;
+}
new file mode 100644
@@ -0,0 +1,11 @@
+#include <sysdep.h>
+#include <tls.h>
+
+-- Derive offsets relative to the thread register.
+#define thread_offsetof(mem) (long)(offsetof (struct pthread, mem) - sizeof (struct pthread))
+
+MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads)
+TLS_PRE_TCB_SIZE sizeof (struct pthread)
+TLS_TCB_SIZE sizeof (tcbhead_t)
+
+PTHREAD_TID offsetof (struct pthread, tid)
new file mode 100644
@@ -0,0 +1,150 @@
+/* Definition for thread-local data handling. NPTL/ARC version.
+ Copyright (C) 2012-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _ARC_NPTL_TLS_H
+#define _ARC_NPTL_TLS_H 1
+
+#include <dl-sysdep.h>
+
+#ifndef __ASSEMBLER__
+# include <stdbool.h>
+# include <stddef.h>
+# include <stdint.h>
+
+#include <dl-dtv.h>
+
+/* Get system call information. */
+# include <sysdep.h>
+
+/* The TLS blocks start right after the TCB. */
+# define TLS_DTV_AT_TP 1
+# define TLS_TCB_AT_TP 0
+
+/* Get the thread descriptor definition. */
+# include <nptl/descr.h>
+
+typedef struct
+{
+ dtv_t *dtv;
+ uintptr_t pointer_guard;
+} tcbhead_t;
+
+register struct pthread *__thread_self __asm__("r25");
+
+/* This is the size of the initial TCB. */
+# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
+
+/* Alignment requirements for the initial TCB. */
+# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
+
+/* This is the size of the TCB. */
+#ifndef TLS_TCB_SIZE
+# define TLS_TCB_SIZE sizeof (tcbhead_t)
+#endif
+
+/* Alignment requirements for the TCB. */
+# define TLS_TCB_ALIGN __alignof__ (struct pthread)
+
+/* This is the size we need before TCB. */
+# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
+
+/* Install the dtv pointer. The pointer passed is to the element with
+ index -1 which contain the length. */
+# define INSTALL_DTV(tcbp, dtvp) \
+ (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
+
+/* Install new dtv for current thread. */
+# define INSTALL_NEW_DTV(dtv) \
+ (THREAD_DTV() = (dtv))
+
+/* Return dtv of given thread descriptor. */
+# define GET_DTV(tcbp) \
+ (((tcbhead_t *) (tcbp))->dtv)
+
+/* Code to initially initialize the thread pointer. */
+# define TLS_INIT_TP(tcbp) \
+ ({ \
+ long result_var; \
+ __builtin_set_thread_pointer (tcbp); \
+ result_var = INTERNAL_SYSCALL (arc_settls, 1, (tcbp)); \
+ INTERNAL_SYSCALL_ERROR_P (result_var) \
+ ? "settls syscall error" : NULL; \
+ })
+
+/* Value passed to 'clone' for initialization of the thread register. */
+# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
+
+/* Return the address of the dtv for the current thread. */
+# define THREAD_DTV() \
+ (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
+
+/* Return the thread descriptor for the current thread. */
+# define THREAD_SELF \
+ ((struct pthread *)__builtin_thread_pointer () - 1)
+
+/* Magic for libthread_db to know how to do THREAD_SELF. */
+# define DB_THREAD_SELF \
+ CONST_THREAD_AREA (32, sizeof (struct pthread))
+
+/* Access to data in the thread descriptor is easy. */
+# define THREAD_GETMEM(descr, member) \
+ descr->member
+# define THREAD_GETMEM_NC(descr, member, idx) \
+ descr->member[idx]
+# define THREAD_SETMEM(descr, member, value) \
+ descr->member = (value)
+# define THREAD_SETMEM_NC(descr, member, idx, value) \
+ descr->member[idx] = (value)
+
+/* Get and set the global scope generation counter in struct pthread. */
+#define THREAD_GSCOPE_IN_TCB 1
+#define THREAD_GSCOPE_FLAG_UNUSED 0
+#define THREAD_GSCOPE_FLAG_USED 1
+#define THREAD_GSCOPE_FLAG_WAIT 2
+#define THREAD_GSCOPE_RESET_FLAG() \
+ do \
+ { int __res \
+ = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag, \
+ THREAD_GSCOPE_FLAG_UNUSED); \
+ if (__res == THREAD_GSCOPE_FLAG_WAIT) \
+ lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
+ } \
+ while (0)
+#define THREAD_GSCOPE_SET_FLAG() \
+ do \
+ { \
+ THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED; \
+ atomic_write_barrier (); \
+ } \
+ while (0)
+#define THREAD_GSCOPE_WAIT() \
+ GL(dl_wait_lookup_done) ()
+
+#else
+
+# include <tcb-offsets.h>
+
+# r25 is dedicated TLS register for ARC
+.macro THREAD_SELF reg
+ # struct pthread is just ahead of TCB
+ sub \reg, r25, TLS_PRE_TCB_SIZE
+.endm
+
+#endif /* __ASSEMBLER__ */
+
+#endif /* tls.h */
new file mode 100644
@@ -0,0 +1,33 @@
+/* Stack environment definitions for ARC.
+ Copyright (C) 2012-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* This file contains a bit of information about the stack allocation
+ of the processor. */
+
+#ifndef _STACKINFO_H
+#define _STACKINFO_H 1
+
+#include <elf.h>
+
+/* On ARC the stack grows down. */
+#define _STACK_GROWS_DOWN 1
+
+/* Default to a non-executable stack. */
+#define DEFAULT_STACK_PERMS (PF_R|PF_W)
+
+#endif /* stackinfo.h */