To support Intel Control-flow Enforcement Technology (CET) run-time
control:
1. An architecture specific field in the writable ld.so namespace is
needed to indicate if CET features are enabled at run-time.
2. An architecture specific field in struct link_map is needed if
CET features are enabled in an ELF module.
This patch adds dl-procruntime.c to the writable ld.so namespace and
link_map.h to struct link_map.
Tested with build-many-glibcs.py.
* elf/dl-support.c: Include <dl-procruntime.c>.
* include/link.h: Include <link_map.h>.
* sysdeps/generic/dl-procruntime.c: New file.
* sysdeps/generic/link_map.h: Likewise.
* sysdeps/generic/ldsodefs.h: Include <dl-procruntime.c> in
the writable ld.so namespace.
Drop _dl_hwcap_mask when building with tunables. This completes the
transition of hwcap_mask reading from _dl_hwcap_mask to tunables.
* elf/dl-hwcaps.h: New file.
* elf/dl-hwcaps.c: Include it.
(_dl_important_hwcaps)[HAVE_TUNABLES]: Read and update
glibc.tune.hwcap_mask.
* elf/dl-cache.c: Include dl-hwcaps.h.
(_dl_load_cache_lookup)[HAVE_TUNABLES]: Read
glibc.tune.hwcap_mask.
* sysdeps/sparc/sparc32/dl-machine.h: Likewise.
* elf/dl-support.c (_dl_hwcap2)[HAVE_TUNABLES]: Drop
_dl_hwcap_mask.
* elf/rtld.c (rtld_global_ro)[HAVE_TUNABLES]: Drop
_dl_hwcap_mask.
(process_envvars)[HAVE_TUNABLES]: Likewise.
* sysdeps/generic/ldsodefs.h (rtld_global_ro)[HAVE_TUNABLES]:
Likewise.
* sysdeps/x86/cpu-features.c (init_cpu_features): Don't
initialize dl_hwcap_mask when tunables are enabled.
The tunables framework allows us to uniformly manage and expose global
variables inside glibc as switches to users. tunables/README has
instructions for glibc developers to add new tunables.
Tunables support can be enabled by passing the --enable-tunables
configure flag to the configure script. This patch only adds a
framework and does not pose any limitations on how tunable values are
read from the user. It also adds environment variables used in malloc
behaviour tweaking to the tunables framework as a PoC of the
compatibility interface.
* manual/install.texi: Add --enable-tunables option.
* INSTALL: Regenerate.
* README.tunables: New file.
* Makeconfig (CPPFLAGS): Define TOP_NAMESPACE.
(before-compile): Generate dl-tunable-list.h early.
* config.h.in: Add HAVE_TUNABLES.
* config.make.in: Add have-tunables.
* configure.ac: Add --enable-tunables option.
* configure: Regenerate.
* csu/init-first.c (__libc_init_first): Move
__libc_init_secure earlier...
* csu/init-first.c (LIBC_START_MAIN):... to here.
Include dl-tunables.h, libc-internal.h.
(LIBC_START_MAIN) [!SHARED]: Initialize tunables for static
binaries.
* elf/Makefile (dl-routines): Add dl-tunables.
* elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE
namespace.
* elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_
only when !HAVE_TUNABLES.
* elf/rtld.c (process_envvars): Likewise.
* elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h
(_dl_sysdep_start): Call __tunables_init.
* elf/dl-tunable-types.h: New file.
* elf/dl-tunables.c: New file.
* elf/dl-tunables.h: New file.
* elf/dl-tunables.list: New file.
* malloc/tst-malloc-usable-static.c: New test case.
* malloc/Makefile (tests-static): Add it.
* malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h.
Define TUNABLE_NAMESPACE.
(DL_TUNABLE_CALLBACK (set_mallopt_check)): New function.
(DL_TUNABLE_CALLBACK_FNDECL): New macro. Use it to define
callback functions.
(ptmalloc_init): Set tunable values.
* scripts/gen-tunables.awk: New file.
* sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h.
(_dl_sysdep_start): Call __tunables_init.
Added AT_PLATFORM to _dl_aux_init () function to keep it in sync with
_dl_sysdep_start ().
* elf/dl-support.c (_dl_aux_init): Added AT_PLATFORM to the case
statement.
Fix a regression introduced with commit 0d23a5c1 [Static dlopen
correction fallout fixes] that caused the default library search path to
be ignored for modules loaded with dlopen from static executables.
[BZ #17250]
* elf/dl-support.c (_dl_main_map): Don't initialize l_flags_1
member.
Fixes to address issues from BZ #15022 resolution, as follows:
* TLS updates to csu/libc-tls.c -- we now have a proper main map, so
there's no longer a need to create a separate fake one to keep TLS
structures,
* random updates to elf/dl-close.c -- LM_ID_BASE is now a valid name
space ID for static executables as well, so assert that we don't
unload the main map. Similarly dl_nns isn't supposed to be 0 for
static executables anymore,
* actual BZ #16046 fix to elf/dl-iteratephdr.c -- the dl_iterate_phdr
special function for static executables isn't needed anymore, provided
that l_phdr and l_phnum members of the main map have been properly
initialized (done in _dl_non_dynamic_init in elf/dl-support.c now),
* ld.so.cache loader update to elf/dl-load.c --
GL(dl_ns)[LM_ID_BASE]._ns_loaded is now always initialized in static
executables so can become the fallback loader map to check for
DF_1_NODEFLIB, provided that the l_flags_1 member of the main map has
been properly initialized (done in elf/dl-support.c now); this also
ensures previous semantics elsewhere in elf/dl-load.c,
* matching updates to elf/dl-support.c -- to complement the two fixes
above.
Long ago static startup did not parse the auxiliary vector and therefore
could not get at any `AT_FPUCW' tag to check whether upon FPU context
allocation the kernel would use a FPU control word setting different to
that provided by the `__fpu_control' variable. Static startup therefore
always initialized the FPU control word, forcing immediate FPU context
allocation even for binaries that otherwise never used the FPU.
As from GIT commit f8f900ecb9 static
startup supports parsing the auxiliary vector, so now it can avoid
explicit initialization of the FPU control word, just as can dynamic
startup, in the usual case where the setting written to the FPU control
word would be the same as the kernel uses. This defers FPU context
allocation until the binary itself actually pokes at the FPU.
Note that the `AT_FPUCW' tag is usually absent from the auxiliary vector
in which case _FPU_DEFAULT is assumed to be the kernel default.
This change creates a link map in static executables to serve as the
global search list for dlopen. It fixes a problem with the inability
to access the global symbol object and a crash on an attempt to map a
DSO into the global scope. Some code that has become dead after the
addition of this link map is removed too and test cases are provided.
It may sometimes be desirable to make the dynamic linker only pick up
libraries from the library path and rpath and not look at the
ld.so.cache that ldconfig generates. An example of such a use case is
the glibc testsuite where the dynamic linker must not be influenced by
any external paths or caches.
This change adds a new option --inhibit-ldcache that when used, tells
the dynamic linker to not use ld.so.cache even if it is available.
change related to AT_EXECFN. We cannot use that string.
* sysdeps/generic/ldsodefs.h (struct rtld_global_ro): Remove
_dl_execfn member.
* elf/dl-support.c: Remove _dl_execfn variable.
(_dl_aux_init): Remove handling of AT_EXECFN.
* elf/dl-sysdep.c (_dl_sysdep_start): Remove handling of AT_EXECFN.
* elf/rtld.c (process_envvars): Remove use of __ASSUME_AT_EXECFN.
2007-06-13 Jakub Jelinek <jakub@redhat.com>
* include/link.h: Don't include rtld-lowlevel.h.
(struct link_map): Remove l_scope_lock.
* sysdeps/generic/ldsodefs.h: Don't include rtld-lowlevel.h.
(_dl_scope_free_list): New field (variable) in _rtld_global.
(DL_LOOKUP_SCOPE_LOCK): Remove.
(_dl_scope_free): New prototype.
* elf/dl-runtime.c (_dl_fixup): Don't use __rtld_mrlock_*lock.
Don't pass DL_LOOKUP_SCOPE_LOCK to _dl_lookup_symbol_x.
(_dl_profile_fixup): Likewise.
* elf/dl-sym.c (do_sym): Likewise. Use wrapped _dl_lookup_symbol_x
whenever !RTLD_SINGLE_THREAD_P, use THREAD_GSCOPE_SET_FLAG and
THREAD_GSCOPE_RESET_FLAG around it.
* elf/dl-close.c (_dl_close_worker): Don't use
__rtld_mrlock_{change,done}. Call _dl_scope_free on the old
scope. Make sure THREAD_GSCOPE_WAIT () happens if any old
scopes were queued or if l_scope_mem has been abandoned.
* elf/dl-open.c (_dl_scope_free): New function.
(dl_open_worker): Use it. Don't use __rtld_mrlock_{change,done}.
* elf/dl-support.c (_dl_scope_free_list): New variable.
* elf/dl-lookup.c (add_dependency): Remove flags argument.
Remove DL_LOOKUP_SCOPE_LOCK handling.
(_dl_lookup_symbol_x): Adjust caller. Remove DL_LOOKUP_SCOPE_LOCK
handling.
* elf/dl-object.c (_dl_new_object): Don't use
__rtld_mrlock_initialize.
2007-06-19 Ulrich Drepper <drepper@redhat.com>
global scope, wait for all lookups to finish afterwards.
* elf/dl-open.c (add_to_global): When global scope array must
grow, allocate a new one and free old array only after all
lookups finish.
* elf/dl-runtime.c (_dl_fixup): Protect using global scope.
(_dl_lookup_symbol_x): Likewise.
* elf/dl-support.c: Define _dl_wait_lookup_done.
* sysdeps/generic/ldsodefs.h (struct rtld_global): Add
_dl_wait_lookup_done.
* sysdeps/unix/sysv/linux/alpha/dl-auxv.h: New file.
* sysdeps/unix/sysv/linux/alpha/dl-support.c: New file.
* sysdeps/unix/sysv/linux/alpha/dl-sysdep.c (__libc_alpha_cache_shape):
Move to dl-auxv.h; initialize instead of extern weak.
(DL_PLATFORM_AUXV): Move to dl-auxv.h; don't test for undef
weak symbol.
* sysdeps/unix/sysv/linux/alpha/sysconf.c (__libc_alpha_cache_shape):
Extern instead of initialized.
* elf/dl-support.c (_dl_aux_init): Honor DL_PLATFORM_AUXV.
* sysdeps/unix/sysv/linux/alpha/dl-auxv.h: New file.
* sysdeps/unix/sysv/linux/alpha/dl-support.c: New file.
* sysdeps/unix/sysv/linux/alpha/dl-sysdep.c (__libc_alpha_cache_shape):
Move to dl-auxv.h; initialize instead of extern weak.
(DL_PLATFORM_AUXV): Move to dl-auxv.h; don't test for undef
weak symbol.
* sysdeps/unix/sysv/linux/alpha/sysconf.c (__libc_alpha_cache_shape):
Extern instead of initialized.
2007-03-13 Richard Henderson <rth@redhat.com>
[(NEED_DL_SYSINFO || NEED_DL_SYSINFO_DSO) && SHARED]: Scan
GLRO(dl_sysinfo_map) for PT_NOTE giving Linux kernel version,
we can skip the uname call if it's there.
* sysdeps/generic/dl-sysdep.c (_dl_sysdep_start): Don't use
DL_SYSDEP_OSCHECK here.
* elf/rtld.c (dl_main) [DL_SYSDEP_OSCHECK]: Do it here instead.
* sysdeps/generic/ldsodefs.h (struct rtld_global_ro):
Add _dl_sysinfo_map.
* elf/rtld.c (dl_main): Don't call _dl_init_paths early in the
rtld_is_main case. Call it unconditionally later.
Move GLRO(dl_sysinfo_dso) handling earlier, before _dl_init_paths call.
Initialize GLRO(dl_sysinfo_map).
* elf/dl-load.c (open_path): Bail out if _dl_init_paths wasn't called.
* sysdeps/generic/dl-sysdep.c (_DL_FIRST_EXTRA): New macro.
(_dl_important_hwcaps)
[(NEED_DL_SYSINFO || NEED_DL_SYSINFO_DSO) && SHARED]: Scan
GLRO(dl_sysinfo_map) for PT_NOTE giving synthetic hwcap names
and bit values.
* elf/ldconfig.c (_DL_FIRST_EXTRA): New macro.
(hwcap_extra): New static variable.
(is_hwcap_platform): Check hwcap_extra for a matching name.
Remove tls special case.
(path_hwcap): Likewise.
(parse_conf): Parse "hwcap" directive to define synthetic hwcap bits
and their names, stored in hwcap_extra.
(main) [USE_TLS]: Initialize final synthetic hwcap bit as "tls".
* sysdeps/generic/ldsodefs.h (struct rtld_global_ro): Use uint64_t for
_dl_hwcap and _dl_hwcap_mask.
* sysdeps/generic/dl-sysdep.c (_dl_sysdep_start): Cast a_val for
AT_HWCAP to unsigned long int.
* elf/dl-support.c (_dl_aux_init): Likewise.
(_dl_hwcap): Update defn.
* elf/cache.c (print_entry): Pad hwcap value with 0s in diagnostic.
* elf/ldconfig.c (search_dir): Likewise.
_dl_sysinfo_dso under [NEED_DL_SYSINFO_DSO] as well.
* elf/rtld.c (dl_main): Set up GLRO(dl_sysinfo_dso) under
[NEED_DL_SYSINFO_DSO] as well.
* sysdeps/generic/dl-sysdep.c (_dl_show_auxv): Always include
AT_SYSINFO and AT_SYSINFO_EHDR in name table.
(_dl_sysdep_start) [NEED_DL_SYSINFO_DSO]: Match AT_SYSINFO_EHDR.
* elf/dl-support.c (_dl_sysinfo_dso): Define also under
[NEED_DL_SYSINFO_DSO].
(_dl_aux_init) [NEED_DL_SYSINFO || NEED_DL_SYSINFO_DSO]:
Match AT_SYSINFO_EHDR and set GL(dl_sysinfo_dso).
2004-11-05 Roland McGrath <roland@redhat.com>
Update.
Add support for namespaces in the dynamic linker.
* dlfcn/Makefile (libdl-routines): Add dlmopen.
* dlfcn/Versions [libdl, GLIBC_2.3.4]: Add dlmopen.
* dlfcn/dlfcn.h: Define Lmid_t, LM_ID_BASE, and LM_ID_NEWLM.
Declare dlmopen. Document RTLD_DI_LMID.
* dlfcn/dlinfo.c: Handle RTLD_DI_LMID.
* dlfcn/dlmopen.c: New file.
* dlfcn/dlopen.c: Pass new parameter to _dl_open.
* dlfcn/dlopenold.c: Likewise.
* elf/dl-addr.c: Adjust for removal of GL(dl_loaded).
* elf/dl-caller.c: Likewise.
* elf/dl-close.c: Likewise.
* elf/dl-conflict.c: Likewise.
* elf/dl-debug.c: Likewise.
* elf/dl-lookup.c: Likewise.
* elf/dl-sym.c: Likewise.
* elf/dl-version.c: Likewise.
* elf/do-lookup.h: Likewise.
* elf/rtld.c: Likewise.
* sysdeps/unix/sysv/linux/i386/dl-librecon.h: Likewise.
* elf/dl-depsc: Likewise. Add new parameter to _dl_map_object.
* elf/dl-fini.c: Call destructors in all namespaces.
* elf/dl-iteratephdr.c: Compute total nloaded. Adjust for removal of
GL(dl_loaded).
* elf/dl-libc.c: Pass new parameter to _dl_open. Adjust for removal
of GL(dl_loaded).
* elf/dl-load.c (_dl_map_object_from_fd): Don't load ld.so a second
time. Reuse the one from the main namespace in all others.
Pass new parameter to _dl_new_object.
Adjust for removal of GL(dl_loaded).
* elf/dl-object.c: Take new parameter. Use it to initialize l_ns.
Adjust for removal of GL(dl_loaded).
* elf/dl-open.c (_dl_open): Take new parameter.
Adjust for removal of GL(dl_loaded).
* elf/dl-support.c: Replace global _dl_loaded etc variables with
_dl_ns variable.
* include/dlfcn.h: Adjust prototype of _dl_open.
Define __LM_ID_CALLER.
* include/link.h: Add l_real, l_ns, and l_direct_opencount elements.
* sysdeps/generic/dl-tls.c: Bump TLS_STATIC_SURPLUS. Since libc is
using TLS we need memory appropriate to the number of namespaces.
* sysdeps/generic/ldsodefs.h (struct rtld_global): Replace _dl_loaded,
_dl_nloaded, _dl_global_scope, _dl_main_searchlist, and
_dl_global_scope_alloc with _dl_ns element. Define DL_NNS.
Adjust prototypes of _dl_map_object and member in rtld_global_ro.
* malloc/malloc.c: Include <dlfcn.h>.
* malloc/arena.c (ptmalloc_init): If libc is not in primary namespace,
never use brk.
* elf/Makefile: Add rules to build and run tst-dlmopen1 and
tst-dlmopen2.
* elf/tst-dlmopen1.c: New file.
* elf/tst-dlmopen1mod.c: New file.
* elf/tst-dlmopen2.c: New file.
* elf/dl-close.c: Improve reference counting by tracking direct loads.
* elf/dl-lookup.c (add_dependency): Likewise.
* elf/dl-open.c (dl_open_worker): Likewise.
* elf/rtld.c (dl_main): Likewise.
2004-09-09 GOTO Masanori <gotom@debian.or.jp>
[BZ #77]
* elf/dl-close.c: Count down l_opencount to check not only for
l_reldeps, but also l_initfini.
2004-10-13 Ulrich Drepper <drepper@redhat.com>
