diff mbox series

[v2,05/13] or1k: Thread Local Storage support

Message ID 20211113031639.2402161-6-shorne@gmail.com
State Superseded
Headers show
Series Glibc OpenRISC port | expand

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Stafford Horne Nov. 13, 2021, 3:16 a.m. UTC
OpenRISC includes 3 TLS addressing models.  Local Dynamic optimizations
are not done in the linker and therefore use the same code sequences as
Global Dynamic.
---
 sysdeps/or1k/dl-tls.h             |  26 ++++
 sysdeps/or1k/libc-tls.c           |  32 +++++
 sysdeps/or1k/nptl/tcb-offsets.sym |   6 +
 sysdeps/or1k/nptl/tls.h           | 189 ++++++++++++++++++++++++++++++
 sysdeps/or1k/stackinfo.h          |  33 ++++++
 5 files changed, 286 insertions(+)
 create mode 100644 sysdeps/or1k/dl-tls.h
 create mode 100644 sysdeps/or1k/libc-tls.c
 create mode 100644 sysdeps/or1k/nptl/tcb-offsets.sym
 create mode 100644 sysdeps/or1k/nptl/tls.h
 create mode 100644 sysdeps/or1k/stackinfo.h

Comments

Joseph Myers Nov. 18, 2021, 10:22 p.m. UTC | #1
On Sat, 13 Nov 2021, Stafford Horne via Libc-alpha wrote:

> diff --git a/sysdeps/or1k/dl-tls.h b/sysdeps/or1k/dl-tls.h
> new file mode 100644
> index 0000000000..f25645c715
> --- /dev/null
> +++ b/sysdeps/or1k/dl-tls.h
> @@ -0,0 +1,26 @@
> +/* Copyright (C) 2021 Free Software Foundation, Inc.

Each file should have a one-line description on the line before the 
copyright notice.

> diff --git a/sysdeps/or1k/libc-tls.c b/sysdeps/or1k/libc-tls.c
> new file mode 100644
> index 0000000000..43571944dd
> --- /dev/null
> +++ b/sysdeps/or1k/libc-tls.c
> @@ -0,0 +1,32 @@
> +/* Copyright (C) 2021 Free Software Foundation, Inc.

Likewise.

> diff --git a/sysdeps/or1k/stackinfo.h b/sysdeps/or1k/stackinfo.h
> new file mode 100644
> index 0000000000..14e767c5bf
> --- /dev/null
> +++ b/sysdeps/or1k/stackinfo.h
> @@ -0,0 +1,33 @@
> +/* Copyright (C) 2021 Free Software Foundation, Inc.

Likewise.

> +/* Default to an executable stack.  PF_X can be overridden if PT_GNU_STACK is
> + * present, but it is presumed absent.  */

We don't use '*' at the start of second and subsequent lines of comments.

(It seems unfortunate for a new port to default to executable stacks, but 
it looks like this is indeed what the Linux kernel port to OpenRISC does, 
given the lack of an override of the default VM_DATA_DEFAULT_FLAGS and 
VM_STACK_DEFAULT_FLAGS.)
Stafford Horne Nov. 19, 2021, 11:03 p.m. UTC | #2
On Thu, Nov 18, 2021 at 10:22:23PM +0000, Joseph Myers wrote:
> On Sat, 13 Nov 2021, Stafford Horne via Libc-alpha wrote:
> 
> > diff --git a/sysdeps/or1k/dl-tls.h b/sysdeps/or1k/dl-tls.h
> > new file mode 100644
> > index 0000000000..f25645c715
> > --- /dev/null
> > +++ b/sysdeps/or1k/dl-tls.h
> > @@ -0,0 +1,26 @@
> > +/* Copyright (C) 2021 Free Software Foundation, Inc.
> 
> Each file should have a one-line description on the line before the 
> copyright notice.

OK, I went through the patch's and made sure I have this on all .c .h and .S
files.

> > diff --git a/sysdeps/or1k/libc-tls.c b/sysdeps/or1k/libc-tls.c
> > new file mode 100644
> > index 0000000000..43571944dd
> > --- /dev/null
> > +++ b/sysdeps/or1k/libc-tls.c
> > @@ -0,0 +1,32 @@
> > +/* Copyright (C) 2021 Free Software Foundation, Inc.
> 
> Likewise.
> 
> > diff --git a/sysdeps/or1k/stackinfo.h b/sysdeps/or1k/stackinfo.h
> > new file mode 100644
> > index 0000000000..14e767c5bf
> > --- /dev/null
> > +++ b/sysdeps/or1k/stackinfo.h
> > @@ -0,0 +1,33 @@
> > +/* Copyright (C) 2021 Free Software Foundation, Inc.
> 
> Likewise.
> 
> > +/* Default to an executable stack.  PF_X can be overridden if PT_GNU_STACK is
> > + * present, but it is presumed absent.  */
> 
> We don't use '*' at the start of second and subsequent lines of comments.

OK, I went through the patch and tried to sort all of these occurances out.
Also there were a few where we didn't have two spaces after period ".". Also, a
few other similar issues.

> (It seems unfortunate for a new port to default to executable stacks, but 
> it looks like this is indeed what the Linux kernel port to OpenRISC does, 
> given the lack of an override of the default VM_DATA_DEFAULT_FLAGS and 
> VM_STACK_DEFAULT_FLAGS.)

Yes.

Thanks for reviewing.

-Stafford
diff mbox series

Patch

diff --git a/sysdeps/or1k/dl-tls.h b/sysdeps/or1k/dl-tls.h
new file mode 100644
index 0000000000..f25645c715
--- /dev/null
+++ b/sysdeps/or1k/dl-tls.h
@@ -0,0 +1,26 @@ 
+/* Copyright (C) 2021 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);
diff --git a/sysdeps/or1k/libc-tls.c b/sysdeps/or1k/libc-tls.c
new file mode 100644
index 0000000000..43571944dd
--- /dev/null
+++ b/sysdeps/or1k/libc-tls.c
@@ -0,0 +1,32 @@ 
+/* Copyright (C) 2021 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>
+
+/* On OpenRISC, linker optimizations are not required, so __tls_get_addr
+   can be called even in statically linked binaries.  In this case module
+   must be always 1 and PT_TLS segment exist in the binary, otherwise it
+   would not link.  */
+
+void *
+__tls_get_addr (tls_index *ti)
+{
+  dtv_t *dtv = THREAD_DTV ();
+  return (char *) dtv[1].pointer.val + ti->ti_offset;
+}
diff --git a/sysdeps/or1k/nptl/tcb-offsets.sym b/sysdeps/or1k/nptl/tcb-offsets.sym
new file mode 100644
index 0000000000..86025a402d
--- /dev/null
+++ b/sysdeps/or1k/nptl/tcb-offsets.sym
@@ -0,0 +1,6 @@ 
+#include <sysdep.h>
+#include <tls.h>
+
+MULTIPLE_THREADS_OFFSET         offsetof (struct pthread, header.multiple_threads)
+TID_OFFSET                      offsetof (struct pthread, tid)
+TP_TO_PTHREAD_OFFSET            -(sizeof (struct pthread) + sizeof (tcbhead_t))
diff --git a/sysdeps/or1k/nptl/tls.h b/sysdeps/or1k/nptl/tls.h
new file mode 100644
index 0000000000..7ad4d2c280
--- /dev/null
+++ b/sysdeps/or1k/nptl/tls.h
@@ -0,0 +1,189 @@ 
+/* Definition for thread-local data handling.  NPTL/OpenRISC version.
+   Copyright (C) 2021 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 _TLS_H
+#define _TLS_H  1
+
+#include <dl-sysdep.h>
+
+#ifndef __ASSEMBLER__
+# include <stdbool.h>
+# include <stddef.h>
+# include <stdint.h>
+# include <dl-dtv.h>
+
+typedef struct
+{
+  dtv_t *dtv;
+  void *__padding[3]; /* To maintain 16 byte padding, needed by STACK_ALIGN.  */
+} tcbhead_t;
+
+register tcbhead_t *__thread_self __asm__("r10");
+
+# define TLS_MULTIPLE_THREADS_IN_TCB 1
+
+#else /* __ASSEMBLER__ */
+# include <tcb-offsets.h>
+#endif /* __ASSEMBLER__ */
+
+#ifndef __ASSEMBLER__
+
+/* Get system call information.  */
+# include <sysdep.h>
+
+/* The TP points to the start of the TLS block.
+   As I understand it, this isn't strictly that "TP points to DTV" - it's
+   more where to place the TCB in the TLS block. This will place it in
+   the beginning.
+
+   Layout:
+    +-----+-----+----------------------+
+    | PRE | TCB | TLS MEMORY ..        |
+    +-----+-----+----------------------+
+		 ^ r10 / TP
+
+   PRE is the struct pthread described below
+   TCB is tcbhead_t
+   TLS memory is where the TLS program sections are loaded
+
+   See _dl_allocate_tls_storage and __libc_setup_tls for more information.  */
+
+# define TLS_DTV_AT_TP  1
+# define TLS_TCB_AT_TP  0
+
+/* Get the thread descriptor definition.  */
+# include <nptl/descr.h>
+
+/* Requirements for the TCB.  */
+# define TLS_INIT_TCB_SIZE    sizeof (tcbhead_t)
+# define TLS_INIT_TCB_ALIGN   __alignof__ (struct pthread)
+
+# define TLS_TCB_SIZE         sizeof (tcbhead_t)
+# define TLS_TCB_ALIGN        __alignof__ (struct pthread)
+
+/* This is the size of the TCB.  */
+
+/* This is the size we need before TCB.
+   To support THREAD_GETMEM with friends we want to have a
+   struct pthread available.
+   Yank it in infront of everything, I'm sure nobody will mind.
+
+   This memory is really allocated PRE the TLS block, so it's possible
+   to do ((char*)tlsblock) - TLS_PRE_TCB_SIZE to access it.
+   This is done for THREAD_SELF.  */
+
+# define TLS_PRE_TCB_SIZE sizeof (struct pthread)
+
+
+/* Install the dtv pointer.
+   When called, dtvp is a pointer not the DTV per say (which should start
+   with the generation counter) but to the length of the DTV.
+   We can always index with -1, so we store dtvp[1].  */
+
+# define INSTALL_DTV(tcbp, dtvp) \
+  (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
+
+/* Install new dtv for current thread
+   In a logicial world dtv here would also point to the length of the DTV.
+   However it does not, this time it points to the generation counter,
+   so just store it.
+
+   Note: -1 is still valid and contains the length.  */
+
+# 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.
+
+   Set TP to the address _after_ tcbhead_t. This will allow us
+   to change the size of tcbhead_t without having to re-link everything.
+
+   This has to return NULL on success (or a string with the failure text).
+   It's hard to fail this, so return NULL always.  */
+
+# define TLS_INIT_TP(tcbp) \
+  ({__thread_self = ((tcbhead_t *)tcbp + 1); NULL;})
+
+/* Value passed to 'clone' for initialization of the thread register.  */
+# define TLS_DEFINE_INIT_TP(tp, pd) \
+  void *tp = ((char *) pd + TLS_PRE_TCB_SIZE + TLS_INIT_TCB_SIZE)
+
+/* Return the address of the dtv for the current thread.
+
+   Dereference TP, offset to dtv - really straightforward.
+   Remember that we made TP point to after tcb, so we need to reverse that.  */
+
+#  define THREAD_DTV() \
+  ((((tcbhead_t *)__thread_self)-1)->dtv)
+
+/* Return the thread descriptor for the current thread.
+
+   Return a pointer to the TLS_PRE area where we allocated space for
+   a struct pthread. Again, TP points to after tcbhead_t, compensate with
+   TLS_INIT_TCB_SIZE.
+
+   I regard this is a seperate system from the "normal" TLS.  */
+
+# define THREAD_SELF \
+  ((struct pthread *) ((char *) __thread_self - TLS_INIT_TCB_SIZE \
+    - TLS_PRE_TCB_SIZE))
+
+/* Magic for libthread_db to know how to do THREAD_SELF.  */
+
+# define DB_THREAD_SELF \
+  REGISTER (32, 32, 10 * 4, - TLS_INIT_TCB_SIZE - TLS_PRE_TCB_SIZE)
+
+/* 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_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)
+
+#endif /* __ASSEMBLER__ */
+
+#endif  /* tls.h */
diff --git a/sysdeps/or1k/stackinfo.h b/sysdeps/or1k/stackinfo.h
new file mode 100644
index 0000000000..14e767c5bf
--- /dev/null
+++ b/sysdeps/or1k/stackinfo.h
@@ -0,0 +1,33 @@ 
+/* Copyright (C) 2021 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 or1k the stack grows down.  */
+#define _STACK_GROWS_DOWN	1
+
+/* Default to an executable stack.  PF_X can be overridden if PT_GNU_STACK is
+ * present, but it is presumed absent.  */
+#define DEFAULT_STACK_PERMS (PF_R|PF_W|PF_X)
+
+#endif /* stackinfo.h */