glibc/sysdeps/powerpc/nptl/tls.h
Alan Modra 31a9bc8c55 powerpc64: Set up thread register for _dl_relocate_static_pie
libgcc ifunc resolvers that access hwcap via a field in the tcb can't
be called until the thread pointer is set up.  Other ifunc resolvers
might need access to at_platform.  This patch sets up a fake thread
pointer early to a copy of tcbhead_t.  hwcapinfo.c already had local
variables for hwcap and at_platform, replace them with an entire
tcbhead_t.  It's not that large and this way we easily ensure hwcap
and at_platform are at the same relative offsets as they are in the
real thread block.

The patch also conditionally disables part of tst-tlsifunc-static,
"bar address read from IFUNC resolver is incorrect".  We can't get a
proper address for a thread variable before glibc initialises tls.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
2022-04-10 08:33:40 +09:30

234 lines
8.0 KiB
C

/* Definition for thread-local data handling. NPTL/PowerPC version.
Copyright (C) 2003-2022 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>
# include <thread_pointer.h>
#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
# define __ASSEMBLY__
# include <asm/ptrace.h>
#endif /* __ASSEMBLER__ */
#ifndef __powerpc64__
/* Register r2 (tp) is reserved by the ABI as "thread pointer". */
# define PT_THREAD_POINTER PT_R2
#else /* __powerpc64__ */
/* Register r13 (tp) is reserved by the ABI as "thread pointer". */
# define PT_THREAD_POINTER PT_R13
#endif /* __powerpc64__ */
#ifndef __ASSEMBLER__
/* Get system call information. */
# include <sysdep.h>
/* The TP points to the start of the thread blocks. */
# define TLS_DTV_AT_TP 1
# define TLS_TCB_AT_TP 0
/* We use the multiple_threads field in the pthread struct */
#define TLS_MULTIPLE_THREADS_IN_TCB 1
/* Get the thread descriptor definition. */
# include <nptl/descr.h>
/* The stack_guard is accessed directly by GCC -fstack-protector code,
so it is a part of public ABI. The dtv and pointer_guard fields
are private. */
typedef struct
{
/* Reservation for HWCAP data. To be accessed by GCC in
__builtin_cpu_supports(), so it is a part of public ABI. */
uint64_t hwcap;
/* Reservation for AT_PLATFORM data. To be accessed by GCC in
__builtin_cpu_is(), so it is a part of public ABI. Since there
are different ABIs for 32 and 64 bit, we put this field in a
previously empty padding space for powerpc64. */
#ifndef __powerpc64__
/* Padding to maintain alignment. */
uint32_t padding;
uint32_t at_platform;
#endif
uint32_t __unused;
/* Reservation for AT_PLATFORM data - powerpc64. */
#ifdef __powerpc64__
uint32_t at_platform;
#endif
/* Reservation for Dynamic System Optimizer ABI. */
uintptr_t dso_slot2;
uintptr_t dso_slot1;
/* Reservation for tar register (ISA 2.07). */
uintptr_t tar_save;
/* GCC split stack support. */
void *__private_ss;
/* Reservation for the Event-Based Branching ABI. */
uintptr_t ebb_handler;
uintptr_t ebb_ctx_pointer;
uintptr_t ebb_reserved1;
uintptr_t ebb_reserved2;
uintptr_t pointer_guard;
uintptr_t stack_guard;
dtv_t *dtv;
} tcbhead_t;
# include <hwcapinfo.h>
/* This is the size of the initial TCB. */
# define TLS_INIT_TCB_SIZE 0
/* This is the size of the TCB. */
# define TLS_TCB_SIZE 0
/* This is the size we need before TCB. */
# define TLS_PRE_TCB_SIZE \
(sizeof (struct pthread) \
+ ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1) \
& ~(__alignof (struct pthread) - 1)))
/* The following assumes that TP (R2 or R13) points to the end of the
TCB + 0x7000 (per the ABI). This implies that TCB address is
TP - 0x7000. As we define TLS_DTV_AT_TP we can
assume that the pthread struct is allocated immediately ahead of the
TCB. This implies that the pthread_descr address is
TP - (TLS_PRE_TCB_SIZE + 0x7000). */
# define TLS_TCB_OFFSET 0x7000
/* 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))[-1].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))[-1].dtv)
/* Code to initially initialize the thread pointer. This might need
special attention since 'errno' is not yet available and if the
operation can cause a failure 'errno' must not be touched. */
# define TLS_INIT_TP(tcbp) \
({ \
__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET; \
THREAD_SET_HWCAP (__tcb.hwcap); \
THREAD_SET_AT_PLATFORM (__tcb.at_platform); \
NULL; \
})
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \
void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE; \
(((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].hwcap) = \
THREAD_GET_HWCAP (); \
(((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].at_platform) = \
THREAD_GET_AT_PLATFORM ();
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \
(((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
/* Return the thread descriptor for the current thread. */
# define THREAD_SELF \
((struct pthread *) (__thread_register \
- TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
/* Magic for libthread_db to know how to do THREAD_SELF. */
# define DB_THREAD_SELF \
REGISTER (32, 32, PT_THREAD_POINTER * 4, \
- TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE) \
REGISTER (64, 64, PT_THREAD_POINTER * 8, \
- TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
# include <tcb-access.h>
/* Set the stack guard field in TCB head. */
# define THREAD_SET_STACK_GUARD(value) \
(((tcbhead_t *) ((char *) __thread_register \
- TLS_TCB_OFFSET))[-1].stack_guard = (value))
# define THREAD_COPY_STACK_GUARD(descr) \
(((tcbhead_t *) ((char *) (descr) \
+ TLS_PRE_TCB_SIZE))[-1].stack_guard \
= ((tcbhead_t *) ((char *) __thread_register \
- TLS_TCB_OFFSET))[-1].stack_guard)
/* Set the stack guard field in TCB head. */
# define THREAD_GET_POINTER_GUARD() \
(((tcbhead_t *) ((char *) __thread_register \
- TLS_TCB_OFFSET))[-1].pointer_guard)
# define THREAD_SET_POINTER_GUARD(value) \
(THREAD_GET_POINTER_GUARD () = (value))
# define THREAD_COPY_POINTER_GUARD(descr) \
(((tcbhead_t *) ((char *) (descr) \
+ TLS_PRE_TCB_SIZE))[-1].pointer_guard \
= THREAD_GET_POINTER_GUARD())
/* hwcap field in TCB head. */
# define THREAD_GET_HWCAP() \
(((tcbhead_t *) ((char *) __thread_register \
- TLS_TCB_OFFSET))[-1].hwcap)
# define THREAD_SET_HWCAP(value) \
(THREAD_GET_HWCAP () = (value))
/* at_platform field in TCB head. */
# define THREAD_GET_AT_PLATFORM() \
(((tcbhead_t *) ((char *) __thread_register \
- TLS_TCB_OFFSET))[-1].at_platform)
# define THREAD_SET_AT_PLATFORM(value) \
(THREAD_GET_AT_PLATFORM () = (value))
/* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
different value to mean unset l_tls_offset. */
# define NO_TLS_OFFSET -1
/* 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 */