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authorUlrich Drepper <drepper@redhat.com>2002-07-23 23:12:01 +0000
committerUlrich Drepper <drepper@redhat.com>2002-07-23 23:12:01 +0000
commit8a30f00fe8ea30054c2df183d34ef3ad8a522cc5 (patch)
tree4b34500fac3e847c4f98bec8ca6c0ab96f7704ba /sysdeps
parentfcda29e2604e941cbe9a9eb30c56b8b8fa607836 (diff)
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Update.
2002-07-23 Ulrich Drepper <drepper@redhat.com> * sysdeps/generic/libc-tls.c: New file. * csu/Makefile (routines): Add libc-tls. (static-only-routines): Add libc-tls. * elf/dl-support.c (_dl_phdr): New variable. (_dl_phnum): New variable. (_dl_aux_init): Initialize _dl_phdr and _dl_phnum from aux vector. * sysdeps/generic/libc-start.c (__libc_start_main): Reorganize code for !SHARED. First look through auxiliary vector. If TLS always call __pthread_initialize_minimal. * sysdeps/generic/dl-tls.c (_dl_allocate_tls): Make sure size argument in mmap call is never zero.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/generic/dl-tls.c2
-rw-r--r--sysdeps/generic/libc-start.c22
-rw-r--r--sysdeps/generic/libc-tls.c182
3 files changed, 197 insertions, 9 deletions
diff --git a/sysdeps/generic/dl-tls.c b/sysdeps/generic/dl-tls.c
index 0d6fcec..8877023 100644
--- a/sysdeps/generic/dl-tls.c
+++ b/sysdeps/generic/dl-tls.c
@@ -215,7 +215,7 @@ _dl_allocate_tls (void)
GL(dl_zerofd) = _dl_sysdep_open_zero_fill ();
# define MAP_ANON 0
# endif
- result = __mmap (0, GL(dl_tls_static_size), PROT_READ|PROT_WRITE,
+ result = __mmap (0, GL(dl_tls_static_size) ?: 1, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_PRIVATE, _dl_zerofd, 0);
/* We allocate a few more elements in the dtv than are needed for the
diff --git a/sysdeps/generic/libc-start.c b/sysdeps/generic/libc-start.c
index 4d17486..600136d 100644
--- a/sysdeps/generic/libc-start.c
+++ b/sysdeps/generic/libc-start.c
@@ -77,10 +77,23 @@ BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
__libc_stack_end = stack_end;
#ifndef SHARED
+# ifdef HAVE_AUX_VECTOR
+ /* First process the auxiliary vector since we need to find the
+ program header to locate an eventually present PT_TLS entry. */
+ for (auxvec = (void *__unbounded *__unbounded) ubp_ev;
+ *auxvec != NULL; ++auxvec);
+ ++auxvec;
+ _dl_aux_init ((ElfW(auxv_t) *) auxvec);
+# endif
+
/* Initialize the thread library at least a bit since the libgcc
functions are using thread functions if these are available and
- we need to setup errno. */
+ we need to setup errno. If there is no thread library and we
+ handle TLS the function is defined in the libc to initialized the
+ TLS handling. */
+# ifndef TLS
if (__pthread_initialize_minimal)
+# endif
__pthread_initialize_minimal ();
/* Some security at this point. Prevent starting a SUID binary where
@@ -89,13 +102,6 @@ BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
loader did the work already. */
if (__builtin_expect (__libc_enable_secure, 0))
__libc_check_standard_fds ();
-
-# ifdef HAVE_AUX_VECTOR
- for (auxvec = (void *__unbounded *__unbounded) ubp_ev;
- *auxvec != NULL; ++auxvec);
- ++auxvec;
- _dl_aux_init ((ElfW(auxv_t) *) auxvec);
-# endif
#endif
/* Register the destructor of the dynamic linker if there is any. */
diff --git a/sysdeps/generic/libc-tls.c b/sysdeps/generic/libc-tls.c
new file mode 100644
index 0000000..8c82040
--- /dev/null
+++ b/sysdeps/generic/libc-tls.c
@@ -0,0 +1,182 @@
+/* Initialization code for TLS in statically linked application.
+ Copyright (C) 2002 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <ldsodefs.h>
+#include <tls.h>
+#include <unistd.h>
+
+
+#ifdef USE_TLS
+extern ElfW(Phdr) *_dl_phdr;
+extern size_t _dl_phnum;
+
+
+/* DTV with just one element plus overhead. */
+static dtv_t static_dtv[3];
+
+
+static struct
+{
+ struct dtv_slotinfo_list si;
+ /* The dtv_slotinfo_list data structure does not include the actual
+ informatin since it is defined as an array of size zero. We
+ define here the necessary entries. Not that it is not important
+ whether there is padding or not since we will always access the
+ informatin through the 'si' element. */
+ struct dtv_slotinfo info[2 + TLS_SLOTINFO_SURPLUS];
+} static_slotinfo;
+
+/* Fake link map for the application. */
+static struct link_map static_map;
+
+
+void
+__libc_setup_tls (size_t tcbsize, size_t tcbalign)
+{
+ void *tlsblock;
+ size_t memsz = 0;
+ size_t filesz = 0;
+ off_t offset = 0;
+ size_t align = 0;
+ size_t max_align = tcbalign;
+ size_t loadaddr = ~0ul;
+ size_t tcb_offset;
+
+ /* Look through the TLS segment if there is any. */
+ if (_dl_phdr != NULL)
+ {
+ ElfW(Phdr) *phdr = _dl_phdr;
+ size_t phnum = _dl_phnum;
+
+ while (phnum-- > 0)
+ if (phdr->p_type == PT_TLS)
+ {
+ /* Remember the values we need. */
+ memsz = phdr->p_memsz;
+ filesz = phdr->p_filesz;
+ offset = phdr->p_offset;
+ align = phdr->p_align;
+ if (phdr->p_align > max_align)
+ max_align = phdr->p_align;
+ }
+ else if (phdr->p_type == PT_LOAD)
+ {
+ /* We have to find the load address which is not easy.
+ Look for the load segment with the lowest address. */
+ if (phdr->p_vaddr < loadaddr)
+ loadaddr = phdr->p_type;
+ }
+ }
+
+ if (memsz == 0 && tcbsize == 0)
+ /* We do not need a TLS block and no thread descriptor. */
+ return;
+
+ /* We have to set up the TCB block which also (possibly) contains
+ 'errno'. Therefore we avoid 'malloc' which might touch 'errno'.
+ Instead we use 'sbrk' which would only uses 'errno' if it fails.
+ In this case we are right away out of memory and the user gets
+ what she/he deserves. */
+# if TLS_TCB_AT_TP
+ tlsblock = __sbrk (roundup (memsz, tcbalign) + tcbsize + max_align);
+# elif TLS_DTV_AT_TP
+ tlsblock = __sbrk (roundup (tcbsize, align) + memsz + max_align);
+# else
+ /* In case a model with a different layout for the TCB and DTV
+ is defined add another #elif here and in the following #ifs. */
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+
+ /* Align the TLS block. */
+ tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
+ & ~(max_align - 1));
+
+ /* Initialize the dtv. [0] is the length, [1] the generation counter. */
+ static_dtv[0].counter = 1;
+ // static_dtv[1].counter = 0; would be needed if not already done
+
+ /* Initialize the TLS block. */
+# if TLS_TCB_AT_TP
+ static_dtv[2].pointer = tlsblock;
+# elif TLS_DTV_AT_TP
+ tcb_offset = roundup (tcbsize, align);
+ static_dtv[2].pointer = (char *) tlsblock + tcb_offset;
+# else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+ memset (__mempcpy (static_dtv[2].pointer, (char *) loadaddr + offset,
+ filesz),
+ '\0', memsz - filesz);
+
+ /* Install the pointer to the dtv. */
+
+ /* Initialize the thread pointer. */
+# if TLS_TCB_AT_TP
+ tcb_offset = roundup (memsz, tcbalign);
+
+ INSTALL_DTV ((char *) tlsblock + tcb_offset, static_dtv);
+
+ TLS_INIT_TP ((char *) tlsblock + tcb_offset);
+# elif TLS_DTV_AT_TP
+ INSTALL_DTV (tlsblock, static_dtv);
+ TLS_INIT_TP (tlsblock);
+# else
+# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+
+ /* We have to create a fake link map which normally would be created
+ by the dynamic linker. It just has to have enough informatino to
+ make the TLS routines happy. */
+ static_map.l_tls_align = align;
+ static_map.l_tls_blocksize = memsz;
+ static_map.l_tls_initimage_size = filesz;
+ static_map.l_tls_offset = offset;
+ static_map.l_type = lt_executable;
+ static_map.l_tls_modid = 1;
+
+ /* Create the slotinfo list. */
+ static_slotinfo.si.len = 1; /* Only one element. */
+ // static_slotinfo.si.next = NULL; already zero
+
+ static_slotinfo.si.slotinfo[1].gen = 0;
+ static_slotinfo.si.slotinfo[1].map = &static_map;
+
+ /* The slotinfo list. Will be extended by the code doing dynamic
+ linking. */
+ GL(dl_tls_max_dtv_idx) = 1;
+ GL(dl_tls_dtv_slotinfo_list) = &static_slotinfo.si;
+
+ /* That is the size of the TLS memory for this object. */
+# if TLS_TCB_AT_TP
+ GL(dl_tls_static_size) = roundup (memsz, align ?: 1) + tcbsize;
+#else
+ GL(dl_tls_static_size) = roundup (memsz, align ?: 1);
+#endif
+}
+
+
+/* This is the minimal initialization function used when libpthread is
+ not used. */
+void
+__attribute__ ((weak))
+__pthread_initialize_minimal (void)
+{
+ __libc_setup_tls (0, 1);
+}
+#endif