Commit Graph

212 Commits

Author SHA1 Message Date
Florian Weimer
1f34a23288 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>
2022-11-03 17:28:03 +01:00
John David Anglin
b7bd94068e hppa: Fix initialization of dp register [BZ 29635]
After upgrading glibc to Debian 2.35-1, gdb faulted on
startup and dropped core in a function call in the main
application.  This was caused by not initializing the
global dp register for the main application early enough.

Restore the code to initialize dp in _dl_start_user.
It was removed when code was added to initialize dp in
elf_machine_runtime_setup.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
2022-10-01 19:49:25 +00:00
Wilco Dijkstra
22f4ab2d20 Use atomic_exchange_release/acquire
Rename atomic_exchange_rel/acq to use atomic_exchange_release/acquire
since these map to the standard C11 atomic builtins.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-09-26 16:58:08 +01:00
Adhemerval Zanella
6242602273 hppa: Remove _dl_skip_args usage (BZ# 29165)
Different than other architectures, hppa creates an unrelated stack
frame where ld.so argc/argv adjustments done by ad43cac44a
is not done on the argc/argv saved/restore by _dl_start_user.

Instead load _dl_argc and _dl_argv directlty instead of adjust them
using _dl_skip_args value.

Checked on hppa-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-05-30 16:32:35 -03:00
Fangrui Song
098a657fe4 elf: Replace PI_STATIC_AND_HIDDEN with opposite HIDDEN_VAR_NEEDS_DYNAMIC_RELOC
PI_STATIC_AND_HIDDEN indicates whether accesses to internal linkage
variables and hidden visibility variables in a shared object (ld.so)
need dynamic relocations (usually R_*_RELATIVE). PI (position
independent) in the macro name is a misnomer: a code sequence using GOT
is typically position-independent as well, but using dynamic relocations
does not meet the requirement.

Not defining PI_STATIC_AND_HIDDEN is legacy and we expect that all new
ports will define PI_STATIC_AND_HIDDEN. Current ports defining
PI_STATIC_AND_HIDDEN are more than the opposite. Change the configure
default.

No functional change.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-04-26 09:26:22 -07:00
Fangrui Song
3ee318c923 Remove -z combreloc and HAVE_Z_COMBRELOC
-z combreloc has been the default regadless of the architecture since
binutils commit f4d733664aabd7bd78c82895e030ec9779a92809 (2002). The
configure check added in commit fdde83499a (2001) has long been
unneeded.

We can therefore treat HAVE_Z_COMBRELOC as always 1 and delete dead code
paths in dl-machine.h files (many were copied from commit a711b01d34
and ee0cb67ec2).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-04-04 17:19:07 -07:00
John David Anglin
d2224ffbdd hppa: Fix warnings from _dl_lookup_address
This change fixes two warnings from _dl_lookup_address.

The first warning comes from dropping the volatile keyword from
desc in the call to _dl_read_access_allowed.  We now have a full
atomic barrier between loading desc[0] and the access check, so
desc no longer needs to be declared as volatile.

The second warning comes from the implicit declaration of
_dl_fix_reloc_arg.  This is fixed by including dl-runtime.h and
declaring _dl_fix_reloc_arg in dl-runtime.h.
2022-02-22 18:51:35 +00:00
John David Anglin
17c57d70bd hppa: Fix typo 2022-02-14 17:41:59 +00:00
John David Anglin
2e20cd63c9 Fix elf/tst-audit2 on hppa
The test elf/tst-audit2 fails on hppa with a segmentation fault in the
long branch stub used to call malloc from calloc.  This occurs because
the test is not a PIC executable and calloc is called from the dynamic
linker before the dp register is initialized in _dl_start_user.

The fix is to move the dp register initialization into
elf_machine_runtime_setup.  Since the address of $global$ can't be
loaded directly, we continue to use the DT_PLTGOT value from the
the main_map to initialize dp.
2022-02-14 15:14:49 +00:00
Adhemerval Zanella
9e94f57484 hppa: Fix bind-now audit (BZ #28857)
On hppa, a function pointer returned by la_symbind is actually a function
descriptor has the plabel bit set (bit 30).  This must be cleared to get
the actual address of the descriptor.  If the descriptor has been bound,
the first word of the descriptor is the physical address of theA function,
otherwise, the first word of the descriptor points to a trampoline in the
PLT.

This patch also adds a workaround on tests because on hppa (and it seems
to be the only ABI I have see it), some shared library adds a dynamic PLT
relocation to am empty symbol name:

$ readelf -r elf/tst-audit25mod1.so
[...]
Relocation section '.rela.plt' at offset 0x464 contains 6 entries:
 Offset     Info    Type            Sym.Value  Sym. Name + Addend
00002008  00000081 R_PARISC_IPLT                508
[...]

It breaks some assumptions on the test, where a symbol with an empty
name ("") is passed on la_symbind.

Checked on x86_64-linux-gnu and hppa-linux-gnu.
2022-02-09 08:47:42 -03:00
Adhemerval Zanella
32612615c5 elf: Issue la_symbind for bind-now (BZ #23734)
The audit symbind callback is not called for binaries built with
-Wl,-z,now or when LD_BIND_NOW=1 is used, nor the PLT tracking callbacks
(plt_enter and plt_exit) since this would change the expected
program semantics (where no PLT is expected) and would have performance
implications (such as for BZ#15533).

LAV_CURRENT is also bumped to indicate the audit ABI change (where
la_symbind flags are set by the loader to indicate no possible PLT
trace).

To handle powerpc64 ELFv1 function descriptor, _dl_audit_symbind
requires to know whether bind-now is used so the symbol value is
updated to function text segment instead of the OPD (for lazy binding
this is done by PPC64_LOAD_FUNCPTR on _dl_runtime_resolve).

Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu,
powerpc64-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-02-01 14:49:46 -03:00
Florian Weimer
6b0978c14a Restore ENTRY_POINT definition on hppa, ia64 (bug 28749)
ENTRY_POINT is still needed for elf/rtld.c.  Fixes commit 4fb4e7e821
("csu: Always use __executable_start in gmon-start.c").
2022-01-07 14:47:31 +01:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Adhemerval Zanella
83b8d5027d malloc: Remove memusage.h
And use machine-sp.h instead.  The Linux implementation is based on
already provided CURRENT_STACK_FRAME (used on nptl code) and
STACK_GROWS_UPWARD is replaced with _STACK_GROWS_UP.
2021-12-28 14:57:57 -03:00
Adhemerval Zanella
8c0664e2b8 elf: Add _dl_audit_pltexit
It consolidates the code required to call la_pltexit audit
callback.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2021-12-28 08:40:38 -03:00
Adhemerval Zanella
691d9ae9e6 Remove ununsed tcb-offset
Some architectures do not use the auto-generated tcb-offsets.h.
2021-12-17 17:47:29 -03:00
Siddhesh Poyarekar
23645707f1 Replace --enable-static-pie with --disable-default-pie
Build glibc programs and tests as PIE by default and enable static-pie
automatically if the architecture and toolchain supports it.

Also add a new configuration option --disable-default-pie to prevent
building programs as PIE.

Only the following architectures now have PIE disabled by default
because they do not work at the moment.  hppa, ia64, alpha and csky
don't work because the linker is unable to handle a pcrel relocation
generated from PIE objects.  The microblaze compiler is currently
failing with an ICE.  GNU hurd tries to enable static-pie, which does
not work and hence fails.  All these targets have default PIE disabled
at the moment and I have left it to the target maintainers to enable PIE
on their targets.

build-many-glibcs runs clean for all targets.  I also tested x86_64 on
Fedora and Ubuntu, to verify that the default build as well as
--disable-default-pie work as expected with both system toolchains.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2021-12-13 08:08:59 +05:30
Florian Weimer
627f5ede70 Remove TLS_TCB_ALIGN and TLS_INIT_TCB_ALIGN
TLS_INIT_TCB_ALIGN is not actually used.  TLS_TCB_ALIGN was likely
introduced to support a configuration where the thread pointer
has not the same alignment as THREAD_SELF.  Only ia64 seems to use
that, but for the stack/pointer guard, not for storing tcbhead_t.
Some ports use TLS_TCB_OFFSET and TLS_PRE_TCB_SIZE to shift
the thread pointer, potentially landing in a different residue class
modulo the alignment, but the changes should not impact that.

In general, given that TLS variables have their own alignment
requirements, having different alignment for the (unshifted) thread
pointer and struct pthread would potentially result in dynamic
offsets, leading to more complexity.

hppa had different values before: __alignof__ (tcbhead_t), which
seems to be 4, and __alignof__ (struct pthread), which was 8
(old default) and is now 32.  However, it defines THREAD_SELF as:

/* Return the thread descriptor for the current thread.  */
# define THREAD_SELF \
  ({ struct pthread *__self;			\
	__self = __get_cr27();			\
	__self - 1;				\
   })

So the thread pointer points after struct pthread (hence __self - 1),
and they have to have the same alignment on hppa as well.

Similarly, on ia64, the definitions were different.  We have:

# define TLS_PRE_TCB_SIZE \
  (sizeof (struct pthread)						\
   + (PTHREAD_STRUCT_END_PADDING < 2 * sizeof (uintptr_t)		\
      ? ((2 * sizeof (uintptr_t) + __alignof__ (struct pthread) - 1)	\
	 & ~(__alignof__ (struct pthread) - 1))				\
      : 0))
# define THREAD_SELF \
  ((struct pthread *) ((char *) __thread_self - TLS_PRE_TCB_SIZE))

And TLS_PRE_TCB_SIZE is a multiple of the struct pthread alignment
(confirmed by the new _Static_assert in sysdeps/ia64/libc-tls.c).

On m68k, we have a larger gap between tcbhead_t and struct pthread.
But as far as I can tell, the port is fine with that.  The definition
of TCB_OFFSET is sufficient to handle the shifted TCB scenario.

This fixes commit 23c77f6018
("nptl: Increase default TCB alignment to 32").

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-09 23:47:49 +01:00
Florian Weimer
ce2248ab91 nptl: Introduce <tcb-access.h> for THREAD_* accessors
These are common between most architectures.  Only the x86 targets
are outliers.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00
Florian Weimer
4fb4e7e821 csu: Always use __executable_start in gmon-start.c
Current binutils defines __executable_start as the lowest text
address, so using the entry point address as a fallback is no
longer necessary.  As a result, overriding <entry.h> is only
necessary if the entry point is not called _start.

The previous approach to define __ASSEMBLY__ to suppress the
declaration breaks if headers included by <entry.h> are not
compatible with __ASSEMBLY__.  This happens with rseq integration
because it is necessary to include kernel headers in more places.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-05 13:50:21 +01:00
Adhemerval Zanella
d6d89608ac elf: Fix dynamic-link.h usage on rtld.c
The 4af6982e4c fix does not fully handle RTLD_BOOTSTRAP usage on
rtld.c due two issues:

  1. RTLD_BOOTSTRAP is also used on dl-machine.h on various
     architectures and it changes the semantics of various machine
     relocation functions.

  2. The elf_get_dynamic_info() change was done sideways, previously
     to 490e6c62aa get-dynamic-info.h was included by the first
     dynamic-link.h include *without* RTLD_BOOTSTRAP being defined.
     It means that the code within elf_get_dynamic_info() that uses
     RTLD_BOOTSTRAP is in fact unused.

To fix 1. this patch now includes dynamic-link.h only once with
RTLD_BOOTSTRAP defined.  The ELF_DYNAMIC_RELOCATE call will now have
the relocation fnctions with the expected semantics for the loader.

And to fix 2. part of 4af6982e4c is reverted (the check argument
elf_get_dynamic_info() is not required) and the RTLD_BOOTSTRAP
pieces are removed.

To reorganize the includes the static TLS definition is moved to
its own header to avoid a circular dependency (it is defined on
dynamic-link.h and dl-machine.h requires it at same time other
dynamic-link.h definition requires dl-machine.h defitions).

Also ELF_MACHINE_NO_REL, ELF_MACHINE_NO_RELA, and ELF_MACHINE_PLT_REL
are moved to its own header.  Only ancient ABIs need special values
(arm, i386, and mips), so a generic one is used as default.

The powerpc Elf64_FuncDesc is also moved to its own header, since
csu code required its definition (which would require either include
elf/ folder or add a full path with elf/).

Checked on x86_64, i686, aarch64, armhf, powerpc64, powerpc32,
and powerpc64le.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-10-14 14:52:07 -03:00
Fangrui Song
490e6c62aa elf: Avoid nested functions in the loader [BZ #27220]
dynamic-link.h is included more than once in some elf/ files (rtld.c,
dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested
functions. This harms readability and the nested functions usage
is the biggest obstacle prevents Clang build (Clang doesn't support GCC
nested functions).

The key idea for unnesting is to add extra parameters (struct link_map
*and struct r_scope_elm *[]) to RESOLVE_MAP,
ELF_MACHINE_BEFORE_RTLD_RELOC, ELF_DYNAMIC_RELOCATE, elf_machine_rel[a],
elf_machine_lazy_rel, and elf_machine_runtime_setup. (This is inspired
by Stan Shebs' ppc64/x86-64 implementation in the
google/grte/v5-2.27/master which uses mixed extra parameters and static
variables.)

Future simplification:
* If mips elf_machine_runtime_setup no longer needs RESOLVE_GOTSYM,
  elf_machine_runtime_setup can drop the `scope` parameter.
* If TLSDESC no longer need to be in elf_machine_lazy_rel,
  elf_machine_lazy_rel can drop the `scope` parameter.

Tested on aarch64, i386, x86-64, powerpc64le, powerpc64, powerpc32,
sparc64, sparcv9, s390x, s390, hppa, ia64, armhf, alpha, and mips64.
In addition, tested build-many-glibcs.py with {arc,csky,microblaze,nios2}-linux-gnu
and riscv64-linux-gnu-rv64imafdc-lp64d.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-07 11:55:02 -07:00
Sergey Bugaev
c484da9087 elf: Remove THREAD_GSCOPE_IN_TCB
All the ports now have THREAD_GSCOPE_IN_TCB set to 1. Remove all
support for !THREAD_GSCOPE_IN_TCB, along with the definition itself.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20210915171110.226187-4-bugaevc@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2021-09-16 01:04:20 +02:00
John David Anglin
d8cf84ac7e Update hppa libm-test-ulps 2021-09-06 17:37:29 +00:00
Siddhesh Poyarekar
30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30
Fangrui Song
710ba420fd Remove sysdeps/*/tls-macros.h
They provide TLS_GD/TLS_LD/TLS_IE/TLS_IE macros for TLS testing.  Now
that we have migrated to __thread and tls_model attributes, these macros
are unused and the tls-macros.h files can retire.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-08-18 09:15:20 -07:00
Florian Weimer
ce4b3b7bef nptl: Move pthread_spin_init, Move pthread_spin_unlock into libc
For some architectures, the two functions are aliased, so these
symbols need to be moved at the same time.

The symbols were moved using scripts/move-symbol-to-libc.py.
2021-04-23 17:06:44 +02:00
John David Anglin
e9eeeb3a58 Update hppa libm-test-ulps 2021-04-06 18:55:58 +00:00
John David Anglin
60167dc24b Update hppa libm-test-ulps 2021-03-07 17:23:34 +00:00
Florian Weimer
035c012e32 Reduce the statically linked startup code [BZ #23323]
It turns out the startup code in csu/elf-init.c has a perfect pair of
ROP gadgets (see Marco-Gisbert and Ripoll-Ripoll, "return-to-csu: A
New Method to Bypass 64-bit Linux ASLR").  These functions are not
needed in dynamically-linked binaries because DT_INIT/DT_INIT_ARRAY
are already processed by the dynamic linker.  However, the dynamic
linker skipped the main program for some reason.  For maximum
backwards compatibility, this is not changed, and instead, the main
map is consulted from __libc_start_main if the init function argument
is a NULL pointer.

For statically linked binaries, the old approach based on linker
symbols is still used because there is nothing else available.

A new symbol version __libc_start_main@@GLIBC_2.34 is introduced because
new binaries running on an old libc would not run their ELF
constructors, leading to difficult-to-debug issues.
2021-02-25 12:13:02 +01:00
John David Anglin
f678099de9 Update hppa libm-test-ulps 2021-01-18 14:23:10 +00:00
Paul Eggert
2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00
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
Szabolcs Nagy
238032ead6 aarch64: enforce >=64K guard size [BZ #26691]
There are several compiler implementations that allow large stack
allocations to jump over the guard page at the end of the stack and
corrupt memory beyond that. See CVE-2017-1000364.

Compilers can emit code to probe the stack such that the guard page
cannot be skipped, but on aarch64 the probe interval is 64K by default
instead of the minimum supported page size (4K).

This patch enforces at least 64K guard on aarch64 unless the guard
is disabled by setting its size to 0.  For backward compatibility
reasons the increased guard is not reported, so it is only observable
by exhausting the address space or parsing /proc/self/maps on linux.

On other targets the patch has no effect. If the stack probe interval
is larger than a page size on a target then ARCH_MIN_GUARD_SIZE can
be defined to get large enough stack guard on libc allocated stacks.

The patch does not affect threads with user allocated stacks.

Fixes bug 26691.
2020-10-02 09:57:44 +01:00
Vineet Gupta
8dbb7a08ec dl-runtime: reloc_{offset,index} now functions arch overide'able
The existing macros are fragile and expect local variables with a
certain name. Fix this by defining them as functions with default
implementation in a new header dl-runtime.h which arches can override
if need be.

This came up during ARC port review, hence the need for argument pltgot
in reloc_index() which is not needed by existing ports.

This patch potentially only affects hppa/x86 ports,
build tested for both those configs and a few more.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-06-05 13:45:46 -07:00
Vineet Gupta
1270fbaaee semaphore: consolidate arch headers into a generic one
This consolidates the copy-pasted arch specific semaphore header into
single version (based on s390) which suffices 32-bit and and 64-bit
arch/ABI based on the canonical WORDSIZE.

For now I've left out arches which use alternate defines to choose for
32 vs 64-bit builds (aarch64, mips) which in theory can also use the same
header.

Passes build-many for
  aarch64-linux-gnu arm-linux-gnueabi arm-linux-gnueabihf
  riscv64-linux-gnu-rv64imac-lp64 riscv64-linux-gnu-rv64imafdc-lp64
  x86_64-linux-gnu microblaze-linux-gnu nios2-linux-gnu

Suggested-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2020-05-06 13:07:12 -07:00
John David Anglin
a8d74ee47b Update hppa libm-test-ulps 2020-04-06 22:19:03 +00:00
John David Anglin
acdcca7294 Add new file missed in previous hppa commit. 2020-03-30 21:58:06 +00:00
John David Anglin
1a044511a3 Fix data race in setting function descriptors during lazy binding on hppa.
This addresses an issue that is present mainly on SMP machines running
threaded code.  In a typical indirect call or PLT import stub, the
target address is loaded first.  Then the global pointer is loaded into
the PIC register in the delay slot of a branch to the target address.
During lazy binding, the target address is a trampoline which transfers
to _dl_runtime_resolve().

_dl_runtime_resolve() uses the relocation offset stored in the global
pointer and the linkage map stored in the trampoline to find the
relocation.  Then, the function descriptor is updated.

In a multi-threaded application, it is possible for the global pointer
to be updated between the load of the target address and the global
pointer.  When this happens, the relocation offset has been replaced
by the new global pointer.  The function pointer has probably been
updated as well but there is no way to find the address of the function
descriptor and to transfer to the target.  So, _dl_runtime_resolve()
typically crashes.

HP-UX addressed this problem by adding an extra pc-relative branch to
the trampoline.  The descriptor is initially setup to point to the
branch.  The branch then transfers to the trampoline.  This allowed
the trampoline code to figure out which descriptor was being used
without any modification to user code.  I didn't use this approach
as it is more complex and changes function pointer canonicalization.

The order of loading the target address and global pointer in
indirect calls was not consistent with the order used in import stubs.
In particular, $$dyncall and some inline versions of it loaded the
global pointer first.  This was inconsistent with the global pointer
being updated first in dl-machine.h.  Assuming the accesses are
ordered, we want elf_machine_fixup_plt() to store the global pointer
first and calls to load it last.  Then, the global pointer will be
correct when the target function is entered.

However, just to make things more fun, HP added support for
out-of-order execution of accesses in PA 2.0.  The accesses used by
calls are weakly ordered. So, it's possibly under some circumstances
that a function might be entered with the wrong global pointer.
However, HP uses weakly ordered accesses in 64-bit HP-UX, so I assume
that loading the global pointer in the delay slot of the branch must
work consistently.

The basic fix for the race is a combination of modifying user code to
preserve the address of the function descriptor in register %r22 and
setting the least-significant bit in the relocation offset.  The
latter was suggested by Carlos as a way to distinguish relocation
offsets from global pointer values.  Conventionally, %r22 is used
as the address of the function descriptor in calls to $$dyncall.
So, it wasn't hard to preserve the address in %r22.

I have updated gcc trunk and gcc-9 branch to not clobber %r22 in
$$dyncall and inline indirect calls.  I have also modified the import
stubs in binutils trunk and the 2.33 branch to preserve %r22.  This
required making the stubs one instruction longer but we save one
relocation.  I also modified binutils to align the .plt section on
a 8-byte boundary.  This allows descriptors to be updated atomically
with a floting-point store.

With these changes, _dl_runtime_resolve() can fallback to an alternate
mechanism to find the relocation offset when it has been clobbered.
There's just one additional instruction in the fast path. I tested
the fallback function, _dl_fix_reloc_arg(), by changing the branch to
always use the fallback.  Old code still runs as it did before.

Fixes bug 23296.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-03-30 20:36:49 +00:00
Adhemerval Zanella
1c15464ca0 math: Remove inline math tests
With mathinline removal there is no need to keep building and testing
inline math tests.

The gen-libm-tests.py support to generate ULP_I_* is removed and all
libm-test-ulps files are updated to longer have the
i{float,double,ldouble} entries.  The support for no-test-inline is
also removed from both gen-auto-libm-tests and the
auto-libm-test-out-* were regenerated.

Checked on x86_64-linux-gnu and i686-linux-gnu.
2020-03-19 11:45:44 -03:00
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
Joseph Myers
d614a75396 Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
Adhemerval Zanella
7df8af43ad nptl: Add struct_rwlock.h
This patch adds a new generic __pthread_rwlock_arch_t definition meant
to be used by new ports.  Its layout mimics the current usage on some
64 bits ports and it allows some ports to use the generic definition.
The arch __pthread_rwlock_arch_t definition is moved from
pthreadtypes-arch.h to another arch-specific header (struct_rwlock.h).

Also the static intialization macro for pthread_rwlock_t is set to use
an arch defined on (__PTHREAD_RWLOCK_INITIALIZER) which simplifies its
implementation.

The default pthread_rwlock_t layout differs from current ports with:

  1. Internal layout is the same for 32 bits and 64 bits.

  2. Internal flag is an unsigned short so it should not required
     additional padding to align for word boundary (if it is the case
     for the ABI).

Checked with a build on affected abis.

Change-Id: I776a6a986c23199929d28a3dcd30272db21cd1d0
2019-11-26 13:53:36 +00:00
Adhemerval Zanella
1c3f9acf1f nptl: Add struct_mutex.h
The current way of defining the common mutex definition for POSIX and
C11 on pthreadtypes-arch.h (added by commit 06be6368da) is
not really the best options for newer ports.  It requires define some
misleading flags that should be always defined as 0
(__PTHREAD_COMPAT_PADDING_MID and __PTHREAD_COMPAT_PADDING_END), it
exposes options used solely for linuxthreads compat mode
(__PTHREAD_MUTEX_USE_UNION and __PTHREAD_MUTEX_NUSERS_AFTER_KIND), and
requires newer ports to explicit define them (adding more boilerplate
code).

This patch adds a new default __pthread_mutex_s definition meant to
be used by newer ports.  Its layout mimics the current usage on both
32 and 64 bits ports and it allows most ports to use the generic
definition.  Only ports that use some arch-specific definition (such
as hardware lock-elision or linuxthreads compat) requires specific
headers.

For 32 bit, the generic definitions mimic the other 32-bit ports
of using an union to define the fields uses on adaptive and robust
mutexes (thus not allowing both usage at same time) and by using a
single linked-list for robust mutexes.  Both decisions seemed to
follow what recent ports have done and make the resulting
pthread_mutex_t/mtx_t object smaller.

Also the static intialization macro for pthread_mutex_t is set to use
a macro __PTHREAD_MUTEX_INITIALIZER where the architecture can redefine
in its struct_mutex.h if it requires additional fields to be
initialized.

Checked with a build on affected abis.

Change-Id: I30a22c3e3497805fd6e52994c5925897cffcfe13
2019-11-26 13:53:36 +00:00
Adhemerval Zanella
0377a7fde6 nptl: Remove rwlock elision definitions
The new rwlock implementation added by cc25c8b4c1 (2.25) removed
support for lock-elision.  This patch removes remaining the
arch-specific unused definitions.

Checked with a build against all affected ABIs.

Change-Id: I5dec8af50e3cd56d7351c52ceff4aa3771b53cd6
2019-11-26 13:53:36 +00:00
Adhemerval Zanella
48dbce60cf nptl: Add tests for internal pthread_rwlock_t offsets
This patch new build tests to check for internal fields offsets for
internal pthread_rwlock_t definition.  Althoug the '__data.__flags'
field layout should be preserved due static initializators, the patch
also adds tests for the futexes that may be used in a shared memory
(although using different libc version in such scenario is not really
supported).

Checked with a build against all affected ABIs.

Change-Id: Iccc103d557de13d17e4a3f59a0cad2f4a640c148
2019-11-26 13:53:36 +00:00
Adhemerval Zanella
71d260c107 nptl: Cleanup mutex internal offset tests
The offsets of pthread_mutex_t __data.__nusers, __data.__spins,
__data.elision, __data.list are not required to be constant over
the releases.  Only the __data.__kind is used for static
initializers.

This patch also adds an additional size check for __data.__kind.

Checked with a build against affected ABIs.

Change-Id: I7a4e48cc91b4c4ada57e9a5d1b151fb702bfaa9f
2019-11-26 13:53:36 +00:00
Alistair Francis
aa706e13f4 Split up endian.h to minimize exposure of BYTE_ORDER.
With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.

This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR.  It only defines macros in the implementation
namespace.

The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h.  I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture.  Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.

endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines.  (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)

A few changes to specific bits/endian(ness).h variants deserve
mention:

 - sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
   sysdeps/ia64/bits/endianness.h.  If I remember correctly, ia64 did
   have selectable endianness, but we have assembly code in
   sysdeps/ia64 that assumes it’s little-endian, so there is no reason
   to treat the ia64 endianness.h as linux-specific.

 - The C-SKY port does not fully support big-endian mode, the compile
   will error out if __CSKYBE__ is defined.

 - The PowerPC port had extra logic in its bits/endian.h to detect a
   broken compiler, which strikes me as unnecessary, so I removed it.

 - The only files that defined __FLOAT_WORD_ORDER always defined it to
   the same value as __BYTE_ORDER, so I removed those definitions.
   The SH bits/endian(ness).h had comments inconsistent with the
   actual setting of __FLOAT_WORD_ORDER, which I also removed.

 - I *removed* copyright boilerplate from the few bits/endian(ness).h
   headers that had it; these files record a single fact in a fashion
   dictated by an external spec, so I do not think they are copyrightable.

As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double.  This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.

	* string/endian.h: Unconditionally define LITTLE_ENDIAN,
	BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER.	 Condition byteswapping
	macros only on !__ASSEMBLER__.	Move the definitions of
	__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
	and __LONG_LONG_PAIR to...
	* string/bits/endian.h: ...this new file, which includes
	the renamed header bits/endianness.h for the definition of
	__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.

	* string/Makefile: Install bits/endianness.h.
	* include/bits/endian.h: New wrapper.

	* bits/endian.h: Rename to bits/endianness.h.
	Add multiple-include guard.  Rewrite the comment explaining what
	the machine-specific variants of this file should do.

	* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
	Move to sysdeps/ia64.

	* sysdeps/aarch64/bits/endian.h
	* sysdeps/alpha/bits/endian.h
	* sysdeps/arm/bits/endian.h
	* sysdeps/csky/bits/endian.h
	* sysdeps/hppa/bits/endian.h
	* sysdeps/ia64/bits/endian.h
	* sysdeps/m68k/bits/endian.h
	* sysdeps/microblaze/bits/endian.h
	* sysdeps/mips/bits/endian.h
	* sysdeps/nios2/bits/endian.h
	* sysdeps/powerpc/bits/endian.h
	* sysdeps/riscv/bits/endian.h
	* sysdeps/s390/bits/endian.h
	* sysdeps/sh/bits/endian.h
	* sysdeps/sparc/bits/endian.h
	* sysdeps/x86/bits/endian.h:
	Rename to endianness.h; canonicalize form of file; remove
	redundant definitions of __FLOAT_WORD_ORDER.

	* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
	broken compilers.

	* ctype/ctype.h
	* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
	* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
	* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
	* sysdeps/ia64/ieee754.h
	* sysdeps/ieee754/ieee754.h
	* sysdeps/ieee754/ldbl-128/ieee754.h
	* sysdeps/ieee754/ldbl-128ibm/ieee754.h
	* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
	* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
	* sysdeps/mips/ieee754/ieee754.h
	* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
	* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
	* sysdeps/nptl/pthread.h
	* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
	* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
	* sysdeps/sparc/sparc32/ieee754.h
	* sysdeps/unix/sysv/linux/generic/bits/stat.h
	* sysdeps/unix/sysv/linux/generic/bits/statfs.h
	* sysdeps/unix/sysv/linux/sys/acct.h
	* wctype/bits/wctype-wchar.h:
	Include bits/endian.h, not endian.h.

	* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.

	* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
	in ifdefs, instead of LDBL_MANT_DIG.  Only include float.h
	when __LDBL_MANT_DIG__ is not predefined, in which case
	define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.
2019-10-01 14:54:46 -07:00
Paul Eggert
5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00
Joseph Myers
0175c9e9be Declare most TS 18661-1 interfaces for C2X.
C2X adds the interfaces from TS 18661-1, and all except a handful in
Annex F are unconditionally visible in C2X rather than only visible
when __STDC_WANT_IEC_60559_BFP_EXT__ is defined.  This patch updates
glibc headers accordingly: most uses of __GLIBC_USE
(IEC_60559_BFP_EXT) are changed to a new __GLIBC_USE
(IEC_60559_BFP_EXT_C2X).  (Regarding totalorder and totalordermag, the
type-generic macros in tgmath.h will go away when the functions are
changed to take pointer arguments.)

	* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_BFP_EXT): Update
	comment.
	(__GLIBC_USE_IEC_60559_BFP_EXT_C2X): New macro.
	* bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Change to
	[__GLIBC_USE (IEC_60559_BFP_EXT_C2X)].
	* include/limits.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* math/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* math/math.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* stdlib/bits/stdlib-ldbl.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* stdlib/stdint.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* stdlib/stdlib.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise.
	* sysdeps/aarch64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/alpha/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/arm/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/csky/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/hppa/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/ia64/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/m68k/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/microblaze/bits/fenv.h [__GLIBC_USE
	(IEC_60559_BFP_EXT)]: Likewise.
	* sysdeps/mips/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/nios2/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/powerpc/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/riscv/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/s390/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/sh/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/sparc/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* sysdeps/x86/fpu/bits/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise.
	* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_BFP_EXT)]:
	Likewise, except for totalorder, totalordermag, getpayload,
	setpayload and setpayloadsig.
	* math/tgmath.h [__GLIBC_USE (IEC_60559_BFP_EXT)]: Likewise,
	except for totalorder and totalordermag.
2019-08-13 11:28:51 +00:00