Commit Graph

1891 Commits

Author SHA1 Message Date
Florian Weimer
dfb3f101c5 elf: Add extension mechanism to ld.so.cache
A previously unused new-format header field is used to record
the address of an extension directory.

This change adds a demo extension which records the version of
ldconfig which builds a file.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:41 +01:00
Florian Weimer
84ba719b26 elf: Add endianness markup to ld.so.cache (bug 27008)
Use a reserved byte in the new format cache header to indicate whether
the file is in little endian or big endian format.  Eventually, this
information could be used to provide a unified cache for qemu-user
and similiar scenarios.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-12-04 09:16:30 +01:00
Florian Weimer
dad90d5282 elf: Add glibc-hwcaps support for LD_LIBRARY_PATH
This hacks non-power-set processing into _dl_important_hwcaps.
Once the legacy hwcaps handling goes away, the subdirectory
handling needs to be reworked, but it is premature to do this
while both approaches are still supported.

ld.so supports two new arguments, --glibc-hwcaps-prepend and
--glibc-hwcaps-mask.  Each accepts a colon-separated list of
glibc-hwcaps subdirectory names.  The prepend option adds additional
subdirectories that are searched first, in the specified order.  The
mask option restricts the automatically selected subdirectories to
those listed in the option argument.  For example, on systems where
/usr/lib64 is on the library search path,
--glibc-hwcaps-prepend=valgrind:debug causes the dynamic loader to
search the directories /usr/lib64/glibc-hwcaps/valgrind and
/usr/lib64/glibc-hwcaps/debug just before /usr/lib64 is searched.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-12-04 09:13:43 +01:00
Florian Weimer
db07fae825 elf: Introduce enum opt_format in the ldconfig implementation
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-11-26 18:26:52 +01:00
Florian Weimer
1daccf403b nptl: Move stack list variables into _rtld_global
Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-11-16 19:33:30 +01:00
Adhemerval Zanella
01bd62517c Remove tls.h inclusion from internal errno.h
The tls.h inclusion is not really required and limits possible
definition on more arch specific headers.

This is a cleanup to allow inline functions on sysdep.h, more
specifically on i386 and ia64 which requires to access some tls
definitions its own.

No semantic changes expected, checked with a build against all
affected ABIs.
2020-11-13 12:59:19 -03:00
Florian Weimer
30af7c7fa1 struct _Unwind_Exception alignment should not depend on compiler flags
__attribute__((__aligned__)) selects an alignment that depends on
the micro-architecture selected by GCC flags.  Enabling vector
extensions may increase the allignment.  This is a problem when
building glibc as a collection of ELF multilibs with different
GCC flags because ld.so and libc.so/libpthread.so/&c may end up
with a different layout of struct pthread because of the
changing offset of its struct _Unwind_Exception field.

Tested-By: Matheus Castanho <msc@linux.ibm.com>
2020-11-11 11:59:29 +01:00
Samuel Thibault
3d3316b1de hurd: keep only required PLTs in ld.so
We need NO_RTLD_HIDDEN because of the need for PLT calls in ld.so.
See Roland's comment in
https://sourceware.org/bugzilla/show_bug.cgi?id=15605
"in the Hurd it's crucial that calls like __mmap be the libc ones
instead of the rtld-local ones after the bootstrap phase, when the
dynamic linker is being used for dlopen and the like."

We used to just avoid all hidden use in the rtld ; this commit switches to
keeping only those that should use PLT calls, i.e. essentially those defined in
sysdeps/mach/hurd/dl-sysdep.c:

__assert_fail
__assert_perror_fail
__*stat64
_exit

This fixes a few startup issues, notably the call to __tunable_get_val that is
made before PLTs are set up.
2020-11-11 02:36:22 +01:00
Florian Weimer
de1a9197af elf: Unify old and new format cache handling code in ld.so
struct file_entry_new starts with the fields of struct file_entry,
so the code can be shared if the size computation is made dynamic.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-30 14:12:14 +01:00
Adhemerval Zanella
aa03f722f3 linux: Add {f}stat{at} y2038 support
A new struct __stat{64}_t64 type is added with the required
__timespec64 time definition.  Only LFS is added, 64-bit time with
32-bit offsets is not supposed to be supported (no existing glibc
configuration supports such a combination).  It is done with an extra
__NR_statx call plus a conversion to the new __stat{64}_t64 type.
The statx call is done only for 32-bit time_t ABIs.

Internally some extra routines to copy from/to struct stat{64}
to struct __stat{64} used on multiple implementations (stat, fstat,
lstat, and fstatat) are added on a extra implementation
(stat_t64_cp.c).  Alse some extra routines to copy from statx to
__stat{64} is added on statx_cp.c.

Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
2020-10-09 17:02:07 -03:00
Adhemerval Zanella
589260cef8 Remove mknod wrapper functions, move them to symbols
This patch removes the mknod and mknodat static wrapper and add the
symbols on the libc with the expected names.

Both the prototypes of the internal symbol linked by the static
wrappers and the inline redirectors are also removed from the installed
sys/stat.h header file.  The wrapper implementation license LGPL
exception is also removed since it is no longer statically linked to
binaries.

Internally the _STAT_VER* definitions are moved to the arch-specific
xstatver.h file.

Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
2020-10-09 17:02:06 -03:00
Adhemerval Zanella
8ed005daf0 Remove stat wrapper functions, move them to exported symbols
This patch removes the stat, stat64, lstat, lstat64, fstat, fstat64,
fstatat, and fstatat64 static wrapper and add the symbol on the libc
with the expected names.

Both the prototypes of the internal symbol linked by the static
wrappers and the inline redirectors are also removed from the installed
sys/stat.h header file.  The wrapper implementation license LGPL
exception is also removed since it is no longer statically linked to
binaries.

Internally the _STAT_VER* definitions are moved to a arch-specific
xstatver.h file.  The internal defines that redirects internals
{f}stat{at} to their {f}xstat{at} counterparts are removed for Linux
(!NO_RTLD_HIDDEN).  Hurd still requires them since {f}stat{at} pulls
extra objects that makes the loader build fail otherwise (I haven't
dig into why exactly).

Checked with a build for all affected ABIs. I also checked on x86_64,
i686, powerpc, powerpc64le, sparcv9, sparc64, s390, and s390x.

Reviewed-by: Lukasz Majewski <lukma@denx.de>
2020-10-09 17:02:06 -03:00
Florian Weimer
bb5fd5ce64 elf: Do not pass GLRO(dl_platform), GLRO(dl_platformlen) to _dl_important_hwcaps
In the current code, the function can easily obtain the information
on its own.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-10-09 10:22:19 +02:00
Florian Weimer
27316f4a23 elf: Record whether paths come from LD_LIBRARY_PATH or --library-path
This allows more precise LD_DEBUG diagnostics.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-08 14:29:49 +02:00
Florian Weimer
b31d4355ae elf: Implement _dl_write
The generic version is parallel to _dl_writev.  It cannot use
_dl_writev directly because the errno value needs to be obtained
under a lock.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-10-07 16:41:30 +02:00
Florian Weimer
efedd1ed3d Linux: Remove rseq support
The kernel ABI is not finalized, and there are now various proposals
to change the size of struct rseq, which would make the glibc ABI
dependent on the version of the kernels used for building glibc.
This is of course not acceptable.

This reverts commit 48699da1c4 ("elf:
Support at least 32-byte alignment in static dlopen"), commit
8f4632deb3 ("Linux: rseq registration
tests"), commit 6e29cb3f61 ("Linux: Use
rseq in sched_getcpu if available"), and commit
0c76fc3c2b ("Linux: Perform rseq
registration at C startup and thread creation"), resolving the conflicts
introduced by the ARC port and the TLS static surplus changes.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-16 17:55:35 +02:00
Szabolcs Nagy
ffb17e7ba3 rtld: Avoid using up static TLS surplus for optimizations [BZ #25051]
On some targets static TLS surplus area can be used opportunistically
for dynamically loaded modules such that the TLS access then becomes
faster (TLSDESC and powerpc TLS optimization). However we don't want
all surplus TLS to be used for this optimization because dynamically
loaded modules with initial-exec model TLS can only use surplus TLS.

The new contract for surplus static TLS use is:

- libc.so can have up to 192 bytes of IE TLS,
- other system libraries together can have up to 144 bytes of IE TLS.
- Some "optional" static TLS is available for opportunistic use.

The optional TLS is now tunable: rtld.optional_static_tls, so users
can directly affect the allocated static TLS size. (Note that module
unloading with dlclose does not reclaim static TLS. After the optional
TLS runs out, TLS access is no longer optimized to use static TLS.)

The default setting of rtld.optional_static_tls is 512 so the surplus
TLS is 3*192 + 4*144 + 512 = 1664 by default, the same as before.

Fixes BZ #25051.

Tested on aarch64-linux-gnu and x86_64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-08 17:32:56 +01:00
Szabolcs Nagy
17796419b5 rtld: Account static TLS surplus for audit modules
The new static TLS surplus size computation is

  surplus_tls = 192 * (nns-1) + 144 * nns + 512

where nns is controlled via the rtld.nns tunable. This commit
accounts audit modules too so nns = rtld.nns + audit modules.

rtld.nns should only include the namespaces required by the
application, namespaces for audit modules are accounted on top
of that so audit modules don't use up the static TLS that is
reserved for the application. This allows loading many audit
modules without tuning rtld.nns or using up static TLS, and it
fixes

FAIL: elf/tst-auditmany

Note that DL_NNS is currently a hard upper limit for nns, and
if rtld.nns + audit modules go over the limit that's a fatal
error. By default rtld.nns is 4 which allows 12 audit modules.

Counting the audit modules is based on existing audit string
parsing code, we cannot use GLRO(dl_naudit) before the modules
are actually loaded.
2020-07-08 17:32:56 +01:00
Szabolcs Nagy
0c7b002fac rtld: Add rtld.nns tunable for the number of supported namespaces
TLS_STATIC_SURPLUS is 1664 bytes currently which is not enough to
support DL_NNS (== 16) number of dynamic link namespaces, if we
assume 192 bytes of TLS are reserved for libc use and 144 bytes
are reserved for other system libraries that use IE TLS.

A new tunable is introduced to control the number of supported
namespaces and to adjust the surplus static TLS size as follows:

surplus_tls = 192 * (rtld.nns-1) + 144 * rtld.nns + 512

The default is rtld.nns == 4 and then the surplus TLS size is the
same as before, so the behaviour is unchanged by default. If an
application creates more namespaces than the rtld.nns setting
allows, then it is not guaranteed to work, but the limit is not
checked. So existing usage will continue to work, but in the
future if an application creates more than 4 dynamic link
namespaces then the tunable will need to be set.

In this patch DL_NNS is a fixed value and provides a maximum to
the rtld.nns setting.

Static linking used fixed 2048 bytes surplus TLS, this is changed
so the same contract is used as for dynamic linking.  With static
linking DL_NNS == 1 so rtld.nns tunable is forced to 1, so by
default the surplus TLS is reduced to 144 + 512 = 656 bytes. This
change is not expected to cause problems.

Tested on aarch64-linux-gnu and x86_64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-08 17:32:56 +01:00
Szabolcs Nagy
c7aa8596de rtld: Clean up PT_NOTE and add PT_GNU_PROPERTY handling
Add generic code to handle PT_GNU_PROPERTY notes. Invalid
content is ignored, _dl_process_pt_gnu_property is always called
after PT_LOAD segments are mapped and it has no failure modes.
Currently only one NT_GNU_PROPERTY_TYPE_0 note is handled, which
contains target specific properties: the _dl_process_gnu_property
hook is called for each property.

The old _dl_process_pt_note and _rtld_process_pt_note differ in how
the program header is read.  The old _dl_process_pt_note is called
before PT_LOAD segments are mapped and _rtld_process_pt_note is called
after PT_LOAD segments are mapped. The old _rtld_process_pt_note is
removed and _dl_process_pt_note is always called after PT_LOAD
segments are mapped and now it has no failure modes.

The program headers are scanned backwards so that PT_NOTE can be
skipped if PT_GNU_PROPERTY exists.

Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-07-08 14:28:53 +01:00
Adhemerval Zanella
725eeb4af1 string: Use tls-internal on strerror_l
The buffer allocation uses the same strategy of strsignal.

Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-07 14:10:58 -03:00
Adhemerval Zanella
9deec7c8ba string: Remove old TLS usage on strsignal
The per-thread state is refactored two use two strategies:

  1. The default one uses a TLS structure, which will be placed in the
     static TLS space (using __thread keyword).

  2. Linux allocates via struct pthread and access it through THREAD_*
     macros.

The default strategy has the disadvantage of increasing libc.so static
TLS consumption and thus decreasing the possible surplus used in
some scenarios (which might be mitigated by BZ#25051 fix).

It is used only on Hurd, where accessing the thread storage in the in
single thread case is not straightforward (afaiu, Hurd developers could
correct me here).

The fallback static allocation used for allocation failure is also
removed: defining its size is problematic without synchronizing with
translated messages (to avoid partial translation) and the resulting
usage is not thread-safe.

Checked on x86-64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu,
and s390x-linux-gnu.

Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-07 14:10:58 -03:00
Adhemerval Zanella
b1ccfc061f signal: Move sys_siglist to a compat symbol
The symbol was deprecated by strsignal and its usage imposes issues
such as copy relocations.

Its internal name is changed to __sys_siglist and __sys_sigabbrev to
avoid static linking usage.  The compat code is also refactored, since
both Linux and Hurd usage the same strategy: export the same array with
different object sizes.

The libSegfault change avoids calling strsignal on the SIGFAULT signal
handler (the current usage is already sketchy, adding a call that
potentially issue locale internal function is even sketchier).

Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi
on all affected platforms.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-07-07 14:10:58 -03:00
Florian Weimer
706ad1e7af Add the __libc_single_threaded variable
The variable is placed in libc.so, and it can be true only in
an outer libc, not libcs loaded via dlmopen or static dlopen.
Since thread creation from inner namespaces does not work,
pthread_create can update __libc_single_threaded directly.

Using __libc_early_init and its initial flag, implementation of this
variable is very straightforward.  A future version may reset the flag
during fork (but not in an inner namespace), or after joining all
threads except one.

Reviewed-by: DJ Delorie <dj@redhat.com>
2020-07-06 11:15:58 +02:00
Mathieu Desnoyers
0c76fc3c2b Linux: Perform rseq registration at C startup and thread creation
Register rseq TLS for each thread (including main), and unregister for
each thread (excluding main).  "rseq" stands for Restartable Sequences.

See the rseq(2) man page proposed here:
  https://lkml.org/lkml/2018/9/19/647

Those are based on glibc master branch commit 3ee1e0ec5c.
The rseq system call was merged into Linux 4.18.

The TLS_STATIC_SURPLUS define is increased to leave additional room for
dlopen'd initial-exec TLS, which keeps elf/tst-auditmany working.

The increase (76 bytes) is larger than 32 bytes because it has not been
increased in quite a while.  The cost in terms of additional TLS storage
is quite significant, but it will also obscure some initial-exec-related
dlopen failures.
2020-07-06 10:21:16 +02:00
Florian Weimer
2034c70e64 elf: Include <stddef.h> (for size_t), <sys/stat.h> in <ldconfig.h>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-06-25 16:51:03 +02:00
Adhemerval Zanella
e80501a5c9 math: Decompose math-use-builtins.h
Each symbol definitions are moved on a separated file and it
cover all symbol type definitions (float, double, long double,
and float128).

It allows to set support for architectures without the boiler
place of copying default values.

Checked with a build on the affected ABIs.
2020-06-22 11:09:45 -03:00
H.J. Lu
f607047668 Update HP_TIMING_NOW for _ISOMAC in sysdeps/generic/hp-timing.h
commit e9698175b0
Author: Lukasz Majewski <lukma@denx.de>
Date:   Mon Mar 16 08:31:41 2020 +0100

    y2038: Replace __clock_gettime with __clock_gettime64

breaks benchtests with sysdeps/generic/hp-timing.h:

In file included from ./bench-timing.h:23,
                 from ./bench-skeleton.c:25,
                 from
/export/build/gnu/tools-build/glibc-gitlab/build-x86_64-linux/benchtests/bench-rint.c:45:
./bench-skeleton.c: In function ‘main’:
../sysdeps/generic/hp-timing.h:37:23: error: storage size of ‘tv’ isn’t known
   37 |   struct __timespec64 tv;      \
      |                       ^~

Define HP_TIMING_NOW with clock_gettime in sysdeps/generic/hp-timing.h
if _ISOMAC is defined.  Don't define __clock_gettime in bench-timing.h
since it is no longer needed.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-06-05 09:44:06 -07:00
Vineet Gupta
628d90c5f9 ieee754: provide gcc builtins based generic fma functions
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-06-03 10:23:28 -07:00
Vineet Gupta
3374868668 ieee754: provide gcc builtins based generic sqrt functions
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-06-03 10:23:22 -07:00
Florian Weimer
a9175662f8 Hurd: Use __sigmask in favor of deprecated sigmask
This fixes various build errors due to deprecation warnings.

Fixes commit 02802fafcf
("signal: Deprecate additional legacy signal handling functions").

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2020-05-28 11:40:13 +02:00
Florian Weimer
de42613540 elf: Turn _dl_printf, _dl_error_printf, _dl_fatal_printf into functions
This change makes it easier to set a breakpoint on these calls.

This also addresses the issue that including <ldsodefs.h> without
<unistd.h> does not result usable _dl_*printf macros because of the
use of the STD*_FILENO macros there.

(The private symbol for _dl_fatal_printf will go away again
once the exception handling implementation is unified between
libc and ld.so.)

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2020-05-25 18:17:27 +02:00
Lukasz Majewski
e9698175b0 y2038: Replace __clock_gettime with __clock_gettime64
The __clock_gettime internal function is not supporting 64 bit time on
architectures with __WORDSIZE == 32 and __TIMESIZE != 64 (like e.g. ARM 32
bit).

The __clock_gettime64 function shall be used instead in the glibc itself as
it supports 64 bit time on those systems.
This patch does not bring any changes to systems with __WORDSIZE == 64 as
for them the __clock_gettime64 is aliased to __clock_gettime (in
./include/time.h).
2020-05-20 16:45:16 +02:00
Florian Weimer
ec935dea63 elf: Implement __libc_early_init
This function is defined in libc.so, and the dynamic loader calls
right after relocation has been finished, before any ELF constructors
or the preinit function is invoked.  It is also used in the static
build for initializing parts of the static libc.

To locate __libc_early_init, a direct symbol lookup function is used,
_dl_lookup_direct.  It does not search the entire symbol scope and
consults merely a single link map.  This function could also be used
to implement lookups in the vDSO (as an optimization).

A per-namespace variable (libc_map) is added for locating libc.so,
to avoid repeated traversals of the search scope.  It is similar to
GL(dl_initfirst).  An alternative would have been to thread a context
argument from _dl_open down to _dl_map_object_from_fd (where libc.so
is identified).  This could have avoided the global variable, but
the change would be larger as a result.  It would not have been
possible to use this to replace GL(dl_initfirst) because that global
variable is used to pass the function pointer past the stack switch
from dl_main to the main program.  Replacing that requires adding
a new argument to _dl_init, which in turn needs changes to the
architecture-specific libc.so startup code written in assembler.

__libc_early_init should not be used to replace _dl_var_init (as
it exists today on some architectures).  Instead, _dl_lookup_direct
should be used to look up a new variable symbol in libc.so, and
that should then be initialized from the dynamic loader, immediately
after the object has been loaded in _dl_map_object_from_fd (before
relocation is run).  This way, more IFUNC resolvers which depend on
these variables will work.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-24 22:32:09 +02:00
Florian Weimer
50a2d83c08 elf: Introduce <elf_machine_sym_no_match.h>
MIPS needs to ignore certain existing symbols during symbol lookup.
The old scheme uses the ELF_MACHINE_SYM_NO_MATCH macro, with an
inline function, within its own header, with a sysdeps override for
MIPS.  This allows re-use of the function from another file (without
having to include <dl-machine.h> or providing the default definition
for ELF_MACHINE_SYM_NO_MATCH).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-04-24 22:13:03 +02:00
Tulio Magno Quites Machado Filho
218dad29e8 ldbl-128ibm-compat: Provide ieee128 symbols to narrow functions
Move the narrow math aliasing macros into a new sysdep header file
math-narrow-alias-float128.h.  Then, provide an override header
to supply the necessary changes to supply the *ieee128 aliases of
these symbols.

This adds ieee128 aliases for faddl, fdivl, fmull, fsubl, daddl, ddivl,
dmull, dsubl.
2020-02-20 17:12:14 -06:00
Florian Weimer
f4349837d9 Introduce <elf-initfini.h> and ELF_INITFINI for all architectures
This supersedes the init_array sysdeps directory.  It allows us to
check for ELF_INITFINI in both C and assembler code, and skip DT_INIT
and DT_FINI processing completely on newer architectures.

A new header file is needed because <dl-machine.h> is incompatible
with assembler code.  <sysdep.h> is compatible with assembler code,
but it cannot be included in all assembler files because on some
architectures, it redefines register names, and some assembler files
conflict with that.

<elf-initfini.h> is replicated for legacy architectures which need
DT_INIT/DT_FINI support.  New architectures follow the generic default
and disable it.
2020-02-18 15:12:25 +01:00
Adhemerval Zanella
6e05978f0c mips: Fix bracktrace result for signal frames
MIPS fallback code handle a frame where its FDE can not be obtained
(for instance a signal frame) by reading the kernel allocated signal frame
and adding '2' to the value of 'sc_pc' [1].  The added value is used to
recognize an end of an EH region on mips16 [2].

The fix adjust the obtained signal frame value and remove the libgcc added
value by checking if the previous frame is a signal frame one.

Checked with backtrace and tst-sigcontext-get_pc tests on mips-linux-gnu
and mips64-linux-gnu.

[1] libgcc/config/mips/linux-unwind.h from gcc code.
[2] gcc/config/mips/mips.h from gcc code.  */
2020-02-18 10:39:03 -03:00
Florian Weimer
fa185f0d45 <fd_to_filename.h>: Add type safety and port to Hurd
The new type struct fd_to_filename makes the allocation of the
backing storage explicit.

Hurd uses /dev/fd, not /proc/self/fd.

Co-Authored-By: Paul Eggert <eggert@cs.ucla.edu>
2020-02-18 13:42:29 +01:00
Florian Weimer
3a0ecccb59 ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]
Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.

This commit replaces one magic mechanism (symbol interposition) with
another one (preprocessor-/compiler-based redirection).  This makes
the hand-over from the minimal malloc to the full malloc more
explicit.

Removing the ABI symbols is backwards-compatible because libc.so is
always in scope, and the dynamic loader will find the malloc-related
symbols there since commit f0b2132b35
("ld.so: Support moving versioned symbols between sonames
[BZ #24741]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-02-15 11:01:23 +01:00
Tulio Magno Quites Machado Filho
18363b4f01 powerpc: Move cache line size to rtld_global_ro
GCC 10.0 enabled -fno-common by default and this started to point that
__cache_line_size had been implemented in 2 different places: loader and
libc.

In order to avoid this duplication, the libc variable has been removed
and the loader variable is moved to rtld_global_ro.

File sysdeps/unix/sysv/linux/powerpc/dl-auxv.h has been added in order
to reuse code for both static and dynamic linking scenarios.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-01-17 09:05:03 -03:00
Adhemerval Zanella
1bdda52fe9 elf: Move vDSO setup to rtld (BZ#24967)
This patch moves the vDSO setup from libc to loader code, just after
the vDSO link_map setup.  For static case the initialization
is moved to _dl_non_dynamic_init instead.

Instead of using the mangled pointer, the vDSO data is set as
attribute_relro (on _rtld_global_ro for shared or _dl_vdso_* for
static).  It is read-only even with partial relro.

It fixes BZ#24967 now that the vDSO pointer is setup earlier than
malloc interposition is called.

Also, vDSO calls should not be a problem for static dlopen as
indicated by BZ#20802.  The vDSO pointer would be zero-initialized
and the syscall will be issued instead.

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc64-linux-gnu,
powerpc-linux-gnu, s390x-linux-gnu, sparc64-linux-gnu, and
sparcv9-linux-gnu.  I also run some tests on mips.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-03 11:22:07 -03:00
Wilco Dijkstra
220622dde5 Add libm_alias_finite for _finite symbols
This patch adds a new macro, libm_alias_finite, to define all _finite
symbol.  It sets all _finite symbol as compat symbol based on its first
version (obtained from the definition at built generated first-versions.h).

The <fn>f128_finite symbols were introduced in GLIBC 2.26 and so need
special treatment in code that is shared between long double and float128.
It is done by adding a list, similar to internal symbol redifinition,
on sysdeps/ieee754/float128/float128_private.h.

Alpha also needs some tricky changes to ensure we still emit 2 compat
symbols for sqrt(f).

Passes buildmanyglibc.

Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2020-01-03 10:02:04 -03:00
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Adhemerval Zanella
58bd592536 Fix return code for __libc_signal_* functions
The functions do not fail regardless of the argument value.  Also, for
Linux the return value is not correct on some platforms due the missing
usage of INTERNAL_SYSCALL_ERROR_P / INTERNAL_SYSCALL_ERRNO macros.

Checked on x86_64-linux-gnu, i686-linux-gnu, and sparc64-linux-gnu.
2019-12-27 11:18:23 -03:00
Adhemerval Zanella
478f70780f Remove __waitpid_nocancel
It enables and disables cancellation with pthread_setcancelstate
before calling the waitpid.  It simplifies the waitpid implementation
for architectures that do not provide either __NR_waitpid or
__NR_wait4.

Checked on x86_64-linux-gnu.
2019-12-19 16:11:09 -03:00
Stefan Liebler
f818afdd3b Use GCC builtins for copysign functions if desired.
This patch is always using the corresponding GCC builtin for copysignf, copysign,
and is using the builtin for copysignl, copysignf128 if the USE_FUNCTION_BUILTIN
macros are defined to one in math-use-builtins.h.

Altough the long double version is enabled by default we still need
the macro and the alternative implementation as the _Float128 version
of the builtin is not available with all supported GCC versions.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-12-11 15:12:19 +01:00
Stefan Liebler
f82996f815 Use GCC builtins for round functions if desired.
This patch is using the corresponding GCC builtin for roundf, round,
roundl and roundf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.

This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used.  The code of the generic
implementation is not changed.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-12-11 15:12:18 +01:00
Stefan Liebler
1ac9c1cf87 Use GCC builtins for trunc functions if desired.
This patch is using the corresponding GCC builtin for truncf, trunc,
truncl and truncf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.

This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used.  The code of the generic
implementation is not changed.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-12-11 15:12:17 +01:00
Stefan Liebler
62560ee840 Use GCC builtins for ceil functions if desired.
This patch is using the corresponding GCC builtin for ceilf, ceil,
ceill and ceilf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.

This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used.  The code of the generic
implementation is not changed.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-12-11 15:12:17 +01:00