elf: Introduce <dl-call_tls_init_tp.h> and call_tls_init_tp (bug 29249)

This makes it more likely that the compiler can compute the strlen
argument in _startup_fatal at compile time, which is required to
avoid a dependency on strlen this early during process startup.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
This commit is contained in:
Florian Weimer 2022-11-03 17:28:03 +01:00
parent fb6ee7ba81
commit 1f34a23288
25 changed files with 68 additions and 51 deletions

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@ -25,6 +25,7 @@
#include <sys/param.h>
#include <array_length.h>
#include <pthreadP.h>
#include <dl-call_tls_init_tp.h>
#ifdef SHARED
#error makefile bug, this file is for static only
@ -147,14 +148,14 @@ __libc_setup_tls (void)
tcb_offset = roundup (memsz + GLRO(dl_tls_static_surplus), max_align);
tlsblock = _dl_early_allocate (tcb_offset + TLS_INIT_TCB_SIZE + max_align);
if (tlsblock == NULL)
_startup_fatal ("Fatal glibc error: Cannot allocate TLS block\n");
_startup_fatal_tls_error ();
#elif TLS_DTV_AT_TP
tcb_offset = roundup (TLS_INIT_TCB_SIZE, align ?: 1);
tlsblock = _dl_early_allocate (tcb_offset + memsz + max_align
+ TLS_PRE_TCB_SIZE
+ GLRO(dl_tls_static_surplus));
if (tlsblock == NULL)
_startup_fatal ("Fatal glibc error: Cannot allocate TLS block\n");
_startup_fatal_tls_error ();
tlsblock += TLS_PRE_TCB_SIZE;
#else
/* In case a model with a different layout for the TCB and DTV
@ -191,16 +192,11 @@ __libc_setup_tls (void)
#if TLS_TCB_AT_TP
INSTALL_DTV ((char *) tlsblock + tcb_offset, _dl_static_dtv);
const char *lossage = TLS_INIT_TP ((char *) tlsblock + tcb_offset);
call_tls_init_tp ((char *) tlsblock + tcb_offset);
#elif TLS_DTV_AT_TP
INSTALL_DTV (tlsblock, _dl_static_dtv);
const char *lossage = TLS_INIT_TP (tlsblock);
#else
# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
call_tls_init_tp (tlsblock);
#endif
if (__builtin_expect (lossage != NULL, 0))
_startup_fatal (lossage);
__tls_init_tp ();
/* Update the executable's link map with enough information to make
the TLS routines happy. */

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@ -52,6 +52,7 @@
#include <dl-execve.h>
#include <dl-find_object.h>
#include <dl-audit-check.h>
#include <dl-call_tls_init_tp.h>
#include <assert.h>
@ -796,10 +797,7 @@ cannot allocate TLS data structures for initial thread\n");
GL(dl_initial_dtv) = GET_DTV (tcbp);
/* And finally install it for the main thread. */
const char *lossage = TLS_INIT_TP (tcbp);
if (__glibc_unlikely (lossage != NULL))
_dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
__tls_init_tp ();
call_tls_init_tp (tcbp);
__rtld_tls_init_tp_called = true;
return tcbp;
@ -2348,13 +2346,7 @@ dl_main (const ElfW(Phdr) *phdr,
/* And finally install it for the main thread. */
if (! __rtld_tls_init_tp_called)
{
const char *lossage = TLS_INIT_TP (tcbp);
if (__glibc_unlikely (lossage != NULL))
_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
lossage);
__tls_init_tp ();
}
call_tls_init_tp (tcbp);
/* Make sure no new search directories have been added. */
assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs));

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@ -72,7 +72,7 @@ typedef struct
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) \
({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; })
({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); true; })
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

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@ -69,7 +69,7 @@ typedef struct
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) \
(__builtin_set_thread_pointer ((void *)(tcbp)), NULL)
(__builtin_set_thread_pointer ((void *)(tcbp)), true)
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

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@ -75,8 +75,7 @@ typedef struct
long result_var; \
__builtin_set_thread_pointer (tcbp); \
result_var = INTERNAL_SYSCALL_CALL (arc_settls, (tcbp));\
INTERNAL_SYSCALL_ERROR_P (result_var) \
? "settls syscall error" : NULL; \
!INTERNAL_SYSCALL_ERROR_P (result_var); \
})
/* Value passed to 'clone' for initialization of the thread register. */

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@ -92,8 +92,7 @@ typedef struct
({ long int result_var; \
result_var = INTERNAL_SYSCALL_CALL (set_thread_area, \
(char *) (tcbp) + TLS_TCB_OFFSET); \
INTERNAL_SYSCALL_ERROR_P (result_var) \
? "unknown error" : NULL; })
!INTERNAL_SYSCALL_ERROR_P (result_var); })
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \

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@ -0,0 +1,34 @@
/* Invoke TLS_INIT_TP and __tls_init_tp with error handling.
Copyright (C) 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/>. */
#include <startup.h>
#include <tls.h>
static inline void
_startup_fatal_tls_error (void)
{
_startup_fatal ("Fatal glibc error: Cannot allocate TLS block\n");
}
static inline void
call_tls_init_tp (void *addr)
{
if (!TLS_INIT_TP (addr))
_startup_fatal_tls_error ();
__tls_init_tp ();
}

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@ -19,7 +19,7 @@
/* Targets should override this file if the default definitions below
will not work correctly very early before TLS is initialized. */
#include <unistd.h>
#include <stdio.h>
/* Use macro instead of inline function to avoid including <stdio.h>. */
#define _startup_fatal(message) __libc_fatal ((message))

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@ -74,7 +74,7 @@ typedef struct
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) \
({ __set_cr27(tcbp); NULL; })
({ __set_cr27(tcbp); true; })
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

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@ -203,8 +203,7 @@ tls_fill_user_desc (union user_desc_init *desc,
which is necessary since we have changed it. */ \
TLS_SET_GS (_segdescr.desc.entry_number * 8 + 3); \
\
_result == 0 ? NULL \
: "set_thread_area failed when setting up thread-local storage\n"; })
_result == 0; })
# define TLS_DEFINE_INIT_TP(tp, pd) \
union user_desc_init _segdescr; \

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@ -105,7 +105,7 @@ register struct pthread *__thread_self __asm__("r13");
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(thrdescr) \
(__thread_self = (thrdescr), INIT_SYSINFO, NULL)
(__thread_self = (thrdescr), INIT_SYSINFO, true)
/* Value passed to 'clone2' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \

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@ -83,7 +83,7 @@ typedef struct
#define TLS_INIT_TP(tcbp) \
({ \
__thread_self = (char *) tcbp + TLS_TCB_OFFSET; \
NULL; \
true; \
})
/* Return the address of the dtv for the current thread. */

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@ -90,7 +90,7 @@ typedef struct
\
_sys_result = INTERNAL_SYSCALL_CALL (set_thread_area, \
((void *) (tcbp)) + TLS_TCB_OFFSET); \
INTERNAL_SYSCALL_ERROR_P (_sys_result) ? "unknown error" : NULL; })
!INTERNAL_SYSCALL_ERROR_P (_sys_result); })
# define TLS_DEFINE_INIT_TP(tp, pd) \
void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE

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@ -117,12 +117,12 @@ extern unsigned short __init1_desc;
# define HURD_SEL_LDT(sel) (__builtin_expect ((sel) & 4, 0))
static inline const char * __attribute__ ((unused))
static inline bool __attribute__ ((unused))
_hurd_tls_init (tcbhead_t *tcb)
{
HURD_TLS_DESC_DECL (desc, tcb);
thread_t self = __mach_thread_self ();
const char *msg = NULL;
bool success = true;
/* This field is used by TLS accesses to get our "thread pointer"
from the TLS point of view. */
@ -141,14 +141,14 @@ _hurd_tls_init (tcbhead_t *tcb)
assert_perror (err);
if (err)
{
msg = "i386_set_ldt failed";
success = false;
goto out;
}
}
else if (err)
{
assert_perror (err); /* Separate from above with different line #. */
msg = "i386_set_gdt failed";
success = false;
goto out;
}
@ -157,7 +157,7 @@ _hurd_tls_init (tcbhead_t *tcb)
out:
__mach_port_deallocate (__mach_task_self (), self);
return msg;
return success;
}
/* Code to initially initialize the thread pointer. This might need

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@ -75,7 +75,7 @@ typedef struct
/* Code to initially initialize the thread pointer.
r21 is reserved for thread pointer. */
# define TLS_INIT_TP(tcbp) \
({ __asm __volatile ("or r21,r0,%0" : : "r" ((void *)tcbp)); NULL; })
({ __asm __volatile ("or r21,r0,%0" : : "r" ((void *)tcbp)); true; })
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

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@ -116,8 +116,7 @@ typedef struct
({ long int result_var; \
result_var = INTERNAL_SYSCALL_CALL (set_thread_area, \
(char *) (tcbp) + TLS_TCB_OFFSET); \
INTERNAL_SYSCALL_ERROR_P (result_var) \
? "unknown error" : NULL; })
!INTERNAL_SYSCALL_ERROR_P (result_var); })
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \

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@ -88,7 +88,7 @@ register struct pthread *__thread_self __asm__("r23");
/* Code to initially initialize the thread pointer. */
# define TLS_INIT_TP(tcbp) \
(__thread_self = (struct pthread *) ((char *) tcbp + TLS_TCB_OFFSET), NULL)
(__thread_self = (struct pthread *) ((char *) tcbp + TLS_TCB_OFFSET), true)
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \

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@ -112,7 +112,7 @@ register tcbhead_t *__thread_self __asm__("r10");
It's hard to fail this, so return NULL always. */
# define TLS_INIT_TP(tcbp) \
({__thread_self = ((tcbhead_t *)tcbp + 1); NULL;})
({__thread_self = ((tcbhead_t *)tcbp + 1); true;})
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \

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@ -139,7 +139,7 @@ typedef struct
__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET; \
THREAD_SET_HWCAP (__tcb.hwcap); \
THREAD_SET_AT_PLATFORM (__tcb.at_platform); \
NULL; \
true; \
})
/* Value passed to 'clone' for initialization of the thread register. */

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@ -79,7 +79,7 @@ typedef struct
/* Code to initially initialize the thread pointer. */
# define TLS_INIT_TP(tcbp) \
({ __thread_self = (char*)tcbp + TLS_TCB_OFFSET; NULL; })
({ __thread_self = (char*)tcbp + TLS_TCB_OFFSET; true; })
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \

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@ -112,7 +112,7 @@ typedef struct
INIT_SYSINFO; \
\
__builtin_set_thread_pointer (_thrdescr); \
NULL; \
true; \
})
/* Value passed to 'clone' for initialization of the thread register. */

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@ -83,7 +83,7 @@ typedef struct
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) \
({ __asm __volatile ("ldc %0,gbr" : : "r" (tcbp)); NULL; })
({ __asm __volatile ("ldc %0,gbr" : : "r" (tcbp)); true; })
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

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@ -89,7 +89,7 @@ register struct pthread *__thread_self __asm__("%g7");
/* Code to initially initialize the thread pointer. */
# define TLS_INIT_TP(descr) \
(__thread_self = (__typeof (__thread_self)) (descr), NULL)
(__thread_self = (__typeof (__thread_self)) (descr), true)
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)

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@ -33,8 +33,7 @@
# define TLS_INIT_TP(tcbp) \
({ long int result_var; \
result_var = INTERNAL_SYSCALL_CALL (set_tls, (tcbp)); \
INTERNAL_SYSCALL_ERROR_P (result_var) \
? "unknown error" : NULL; })
!INTERNAL_SYSCALL_ERROR_P (result_var); })
#endif /* __ASSEMBLER__ */

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@ -156,7 +156,7 @@ _Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,
"S" (_thrdescr) \
: "memory", "cc", "r11", "cx"); \
\
_result ? "cannot set %fs base address for thread-local storage" : 0; \
_result == 0; \
})
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)