Commit Graph

38865 Commits

Author SHA1 Message Date
Florian Weimer
fe8ca369ad stdio-common: Simplify printf_unknown interface in vfprintf-internal.c
The called function does not use the args array, so there is no need
to produce it.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-24 08:03:11 +02:00
Florian Weimer
46db978347 stdio-common: Move union printf_arg int <printf.h>
The type does not depend on wide vs narrow preprocessor macros,
so it does not need to be customized in stdio-common/printf-parse.h.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-24 08:03:11 +02:00
Florian Weimer
800d535504 stdio-common: Add printf specifier registry to <printf.h>
Add  __printf_arginfo_table, __printf_function_table,
__printf_va_arg_table, __register_printf_specifier to
include/printf.h.
2022-05-24 08:03:11 +02:00
Fangrui Song
36c1dbaedd elf/dl-reloc.c: Copyright The GNU Toolchain Authors
by following 3.5. Update copyright information
on https://sourceware.org/glibc/wiki/Contribution%20checklist .
The change is advised by Carlos O'Donell.

Note: commit a8b11bd1f8 missed Signed-off-by tag
from Nicholas Guriev <nicholas@guriev.su>.
2022-05-23 19:16:05 -07:00
Noah Goldstein
a01a13601c benchtests: Improve bench-strnlen.c
1. Output results in json format so its easier to parse
2. Increase max alignment to `getpagesize () - 1` to make it possible
   to test page cross cases.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2022-05-23 18:14:06 -05:00
Adhemerval Zanella
efeb2bd1ab math: Add math-use-builtins-fabs (BZ#29027)
Both float, double, and _Float128 are assumed to be supported
(float and double already only uses builtins).  Only long double
is parametrized due GCC bug 29253 which prevents its usage on
powerpc.

It allows to remove i686, ia64, x86_64, powerpc, and sparc arch
specific implementation.

On ia64 it also fixes the sNAN handling:

  math/test-float64x-fabs
  math/test-ldouble-fabs

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc-linux-gnu,
powerpc64-linux-gnu, sparc64-linux-gnu, and ia64-linux-gnu.
2022-05-23 17:49:18 -03:00
Adhemerval Zanella
04b30fe4f8 linux: Add CLONE_NEWTIME from Linux 5.6 to bits/sched.h
It was added in commit 769071ac9f20b6a447410c7eaa55d1a5233ef40c.
2022-05-23 17:49:18 -03:00
Fangrui Song
a7629b1c1b Revert "[ARM][BZ #17711] Fix extern protected data handling"
This reverts commit 3bcea719dd.

Similar to commit e555954e02 for aarch64.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2022-05-23 13:42:10 -07:00
Fangrui Song
e555954e02 Revert "[AArch64][BZ #17711] Fix extern protected data handling"
This reverts commit 0910702c4d.

Say both a.so and b.so define protected data symbol `var` and the executable
copy relocates var.  ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA has strange
semantics: a.so accesses the copy in the executable while b.so accesses its
own.  This behavior requires that (a) the compiler emits GOT-generating
relocations (b) the linker produces GLOB_DAT instead of RELATIVE.

Without the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA code, b.so's GLOB_DAT
will bind to the executable (normal behavior).

For aarch64 it makes sense to restore the original behavior and don't
pay the ELF_RTYPE_CLASS_EXTERN_PROTECTED_DATA cost.  The behavior is very
unlikely used by anyone.

* Clang code generator treats STV_PROTECTED the same way as STV_HIDDEN:
  no GOT-generating relocation in the first place.
* gold and lld reject copy relocation on a STV_PROTECTED symbol.
* Nowadays -fpie/-fpic modes are popular.  GCC/Clang's codegen uses
  GOT-generating relocation when accessing an default visibility
  external symbol which avoids copy relocation.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2022-05-23 13:37:05 -07:00
Nicholas Guriev
a8b11bd1f8 elf: Rewrite long RESOLVE_MAP macro to an always_inline static function
An __always_inline static function is better to find where exactly a
crash happens, so one can step into the function with GDB.

Reviewed-by: Fangrui Song <maskray@google.com>
2022-05-23 12:06:44 -07:00
Fangrui Song
748df8126a dlfcn: Move RTLD_DEFAULT/RTLD_NEXT outside __USE_GNU
POSIX reserves the RTLD_ namespace, and this is already reflected in our
conform tests.
Note: RTLD_DEFAULT and RTLD_NEXT appear in IEEE Std 1003.1-2004.  Many
systems (e.g. FreeBSD, musl) just define the macros unconditionally.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Tested-by: Florian Weimer <fweimer@redhat.com>
2022-05-23 10:23:23 -07:00
Noah Goldstein
9a421348cd elf: Optimize _dl_new_hash in dl-new-hash.h
Unroll slightly and enforce good instruction scheduling. This improves
performance on out-of-order machines. The unrolling allows for
pipelined multiplies.

As well, as an optional sysdep, reorder the operations and prevent
reassosiation for better scheduling and higher ILP. This commit
only adds the barrier for x86, although it should be either no
change or a win for any architecture.

Unrolling further started to induce slowdowns for sizes [0, 4]
but can help the loop so if larger sizes are the target further
unrolling can be beneficial.

Results for _dl_new_hash
Benchmarked on Tigerlake: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz

Time as Geometric Mean of N=30 runs
Geometric of all benchmark New / Old: 0.674
  type, length, New Time, Old Time, New Time / Old Time
 fixed,      0,    2.865,     2.72,               1.053
 fixed,      1,    3.567,    2.489,               1.433
 fixed,      2,    2.577,    3.649,               0.706
 fixed,      3,    3.644,    5.983,               0.609
 fixed,      4,    4.211,    6.833,               0.616
 fixed,      5,    4.741,    9.372,               0.506
 fixed,      6,    5.415,    9.561,               0.566
 fixed,      7,    6.649,   10.789,               0.616
 fixed,      8,    8.081,   11.808,               0.684
 fixed,      9,    8.427,   12.935,               0.651
 fixed,     10,    8.673,   14.134,               0.614
 fixed,     11,    10.69,   15.408,               0.694
 fixed,     12,   10.789,   16.982,               0.635
 fixed,     13,   12.169,   18.411,               0.661
 fixed,     14,   12.659,   19.914,               0.636
 fixed,     15,   13.526,   21.541,               0.628
 fixed,     16,   14.211,   23.088,               0.616
 fixed,     32,   29.412,   52.722,               0.558
 fixed,     64,    65.41,  142.351,               0.459
 fixed,    128,  138.505,  295.625,               0.469
 fixed,    256,  291.707,  601.983,               0.485
random,      2,   12.698,   12.849,               0.988
random,      4,   16.065,   15.857,               1.013
random,      8,   19.564,   21.105,               0.927
random,     16,   23.919,   26.823,               0.892
random,     32,   31.987,   39.591,               0.808
random,     64,   49.282,   71.487,               0.689
random,    128,    82.23,  145.364,               0.566
random,    256,  152.209,  298.434,                0.51

Co-authored-by: Alexander Monakov <amonakov@ispras.ru>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
3d155d4b6c nss: Optimize nss_hash in nss_hash.c
The prior unrolling didn't really do much as it left the dependency
chain between iterations. Unrolled the loop for 4 so 4x multiplies
could be pipelined in out-of-order machines.

Results for __nss_hash
Benchmarked on Tigerlake: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz

Time as Geometric Mean of N=25 runs
Geometric of all benchmark New / Old: 0.845
  type, length, New Time, Old Time, New Time / Old Time
 fixed,      0,    4.019,    3.729,               1.078
 fixed,      1,     4.95,    5.707,               0.867
 fixed,      2,    5.152,    5.657,               0.911
 fixed,      3,    4.641,    5.721,               0.811
 fixed,      4,    5.551,     5.81,               0.955
 fixed,      5,    6.525,    6.552,               0.996
 fixed,      6,    6.711,    6.561,               1.023
 fixed,      7,    6.715,    6.767,               0.992
 fixed,      8,    7.874,    7.915,               0.995
 fixed,      9,    8.888,    9.767,                0.91
 fixed,     10,    8.959,    9.762,               0.918
 fixed,     11,    9.188,    9.987,                0.92
 fixed,     12,    9.708,   10.618,               0.914
 fixed,     13,   10.393,    11.14,               0.933
 fixed,     14,   10.628,   12.097,               0.879
 fixed,     15,   10.982,   12.965,               0.847
 fixed,     16,   11.851,   14.429,               0.821
 fixed,     32,   24.334,   34.414,               0.707
 fixed,     64,   55.618,   86.688,               0.642
 fixed,    128,  118.261,   224.36,               0.527
 fixed,    256,  256.183,  538.629,               0.476
random,      2,   11.194,   11.556,               0.969
random,      4,   17.516,   17.205,               1.018
random,      8,   23.501,   20.985,                1.12
random,     16,   28.131,   29.212,               0.963
random,     32,   35.436,   38.662,               0.917
random,     64,    45.74,   58.868,               0.777
random,    128,   75.394,  121.963,               0.618
random,    256,  139.524,  260.726,               0.535
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
319dddc143 benchtests: Add benchtests for dl_elf_hash, dl_new_hash and nss_hash
Benchtests are for throughput and include random / fixed size
benchmarks.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
5f2f0f6977 nss: Add tests for the nss_hash in nss_hash.h
If we want to further optimize the function tests are needed.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
6fd435485f elf: Add tests for the dl hash funcs (_dl_new_hash and _dl_elf_hash)
If we want to further optimize the functions tests are needed.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Noah Goldstein
c4bd509d47 elf: Refactor dl_new_hash so it can be tested / benchmarked
No change to the code other than moving the function to
dl-new-hash.h. Changed name so its now in the reserved namespace.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 10:38:40 -05:00
Florian Weimer
93ec1cf0fe locale: Add more cached data to LC_CTYPE
This data will be used in number formatting.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
7ee41feba6 locale: Remove private union from struct __locale_data
This avoids an alias violation later.  This commit also fixes
an incorrect double-checked locking idiom in _nl_init_era_entries.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
bbebe83a28 locale: Remove cleanup function pointer from struct __localedata
We can call the cleanup functions directly from _nl_unload_locale
if we pass the category to it.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
0b6342e769 locale: Call _nl_unload_locale from _nl_archive_subfreeres
The function performs the same steps for ld_archive locales
(mapped from an archive), and this code is not performance-critical,
so the specialization does not add value.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
0060a6de54 stdio-common: Add tst-memstream-string for open_memstream overflow
This code path is exercised indirectly by some of the DNS stub
resolver tests, via their own use of xopen_memstream for constructing
strings describing result data.  The relative lack of test suite
coverage became apparent when these tests starting failing after a
printf changes uncovered bug 28949.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
b094c52b1b __printf_fphex always uses LC_NUMERIC
There is no hexadecimal currency printing.  strfmon uses
__printf_fp_l exclusively.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
859e7a00af vfprintf: Consolidate some multibyte/wide character processing
form_character and form_string processing a sufficiently similar
that the logic can be shared.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
5442ea7ffe vfprintf: Move argument processing into vfprintf-process-arg.c
This simplies formatting and helps with debugging.  It also allows
the use of localized COMPILE_WPRINTF preprocessor conditionals.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Florian Weimer
21bb8382b6 stdio-common: Add tst-vfprintf-width-i18n to cover numeric field width
Related to bug 28943 and bug 28944.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-23 11:06:31 +02:00
Sergei Trofimovich
5a5f94af05 string.h: fix __fortified_attr_access macro call [BZ #29162]
commit e938c0274 "Don't add access size hints to fortifiable functions"
converted a few '__attr_access ((...))' into '__fortified_attr_access (...)'
calls.

But one of conversions had double parentheses of '__fortified_attr_access (...)'.

Noticed as a gnat6 build failure:

    /<<NIX>>-glibc-2.34-210-dev/include/bits/string_fortified.h:110:50: error: macro "__fortified_attr_access" requires 3 arguments, but only 1 given

The change fixes parentheses.

This is seen when using compilers that do not support
__builtin___stpncpy_chk, e.g. gcc older than 4.7, clang older than 2.6
or some compiler not derived from gcc or clang.

Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-23 13:56:43 +05:30
H.J. Lu
2d5ec6692f Enable DT_RELR in glibc shared libraries and PIEs automatically
Enable DT_RELR in glibc shared libraries and position independent
executables (PIE) automatically if linker supports -z pack-relative-relocs.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-05-18 13:04:13 -07:00
Stefan Liebler
728894dba4 S390: Enable static PIE
This commit enables static PIE on 64bit.  On 31bit, static PIE is
not supported.

A new configure check in sysdeps/s390/s390-64/configure.ac also performs
a minimal test for requirements in ld:
Ensure you also have those patches for:
- binutils (ld)
  - "[PR ld/22263] s390: Avoid dynamic TLS relocs in PIE"
    https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=26b1426577b5dcb32d149c64cca3e603b81948a9
    (Tested by configure check above)
    Otherwise there will be a R_390_TLS_TPOFF relocation, which fails to
    be processed in _dl_relocate_static_pie() as static TLS map is not setup.
  - "s390: Add DT_JMPREL pointing to .rela.[i]plt with static-pie"
    https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d942d8db12adf4c9e5c7d9ed6496a779ece7149e
    (We can't test it in configure as we are not able to link a static PIE
    executable if the system glibc lacks static PIE support)
    Otherwise there won't be DT_JMPREL, DT_PLTRELA, DT_PLTRELASZ entries
    and the IFUNC symbols are not processed, which leads to crashes.

- kernel (the mentioned links to the commits belong to 5.19 merge window):
  - "s390/mmap: increase stack/mmap gap to 128MB"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=f2f47d0ef72c30622e62471903ea19446ea79ee2
  - "s390/vdso: move vdso mapping to its own function"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=57761da4dc5cd60bed2c81ba0edb7495c3c740b8
  - "s390/vdso: map vdso above stack"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=9e37a2e8546f9e48ea76c839116fa5174d14e033
  - "s390/vdso: add vdso randomization"
    https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/commit/?h=features&id=41cd81abafdc4e58a93fcb677712a76885e3ca25
  (We can't test the kernel of the target system)
  Otherwise if /proc/sys/kernel/randomize_va_space is turned off (0),
  static PIE executables like ldconfig will crash.  While startup sbrk is
  used to enlarge the HEAP.  Unfortunately the underlying brk syscall fails
  as there is not enough space after the HEAP.  Then the address of the TLS
  image is invalid and the following memcpy in __libc_setup_tls() leads
  to a segfault.
  If /proc/sys/kernel/randomize_va_space is activated (default: 2), there
  is enough space after HEAP.

- glibc
  - "Linux: Define MMAP_CALL_INTERNAL"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=c1b68685d438373efe64e5f076f4215723004dfb
  - "i386: Remove OPTIMIZE_FOR_GCC_5 from Linux libc-do-syscall.S"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=6e5c7a1e262961adb52443ab91bd2c9b72316402
  - "i386: Honor I386_USE_SYSENTER for 6-argument Linux system calls"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=60f0f2130d30cfd008ca39743027f1e200592dff
  - "ia64: Always define IA64_USE_NEW_STUB as a flag macro"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=18bd9c3d3b1b6a9182698c85354578d1d58e9d64
  - "Linux: Implement a useful version of _startup_fatal"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=a2a6bce7d7e52c1c34369a7da62c501cc350bc31
  - "Linux: Introduce __brk_call for invoking the brk system call"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=b57ab258c1140bc45464b4b9908713e3e0ee35aa
  - "csu: Implement and use _dl_early_allocate during static startup"
    https://sourceware.org/git/?p=glibc.git;a=commit;h=f787e138aa0bf677bf74fa2a08595c446292f3d7
  The mentioned patch series by Florian Weimer avoids the mentioned failing
  sbrk syscall by falling back to mmap.

This commit also adjusts startup code in start.S to be ready for static PIE.
We have to add a wrapper function for main as we are not allowed to use
GOT relocations before __libc_start_main is called.
(Compare also to:
- commit 14d886edbd
  "aarch64: fix start code for static pie"
- commit 3d1d79283e
  "aarch64: fix static pie enabled libc when main is in a shared library"
)
2022-05-18 14:31:26 +02:00
Adhemerval Zanella
d2a1ec2097 linux: Add tst-pidfd.c
To check for the pidfd functions pidfd_open, pidfd_getfd, pid_send_signal,
and waitid with P_PIDFD.

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

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-05-17 10:36:59 -03:00
Adhemerval Zanella
b3528b0048 linux: Add P_PIDFD
It was added on Linux 5.4 (3695eae5fee0605f316fbaad0b9e3de791d7dfaf)
to extend waitid to wait on pidfd.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-05-17 10:34:36 -03:00
Adhemerval Zanella
56cf9e8eec linux: Add pidfd_send_signal
This was added on Linux 5.1(3eb39f47934f9d5a3027fe00d906a45fe3a15fad)
as a way to avoid the race condition of using kill (where PID might be
reused by the kernel between between obtaining the pid and sending the
signal).

If the siginfo_t argument is NULL then pidfd_send_signal is equivalent
to kill.  If it is not NULL pidfd_send_signal is equivalent to
rt_sigqueueinfo.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-05-17 10:33:46 -03:00
Adhemerval Zanella
32dd8c251a linux: Add pidfd_getfd
This was added on Linux 5.6 (8649c322f75c96e7ced2fec201e123b2b073bf09)
as a way to retrieve a file descriptors for another process though
pidfd (created either with CLONE_PIDFD or pidfd_getfd).  The
functionality is similar to recvmmsg SCM_RIGHTS.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-05-17 10:33:07 -03:00
Adhemerval Zanella
97f5d19c45 linux: Add pidfd_open
This was added on Linux 5.3 (32fcb426ec001cb6d5a4a195091a8486ea77e2df)
as a way to retrieve a pid file descriptors for process that has not
been created CLONE_PIDFD (by usual fork/clone).

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-05-17 10:32:28 -03:00
Szabolcs Nagy
1da064c015 aarch64: Move ld.so _start to separate file and drop _dl_skip_args
A separate asm file is easier to maintain than a macro that expands to
inline asm.

The RTLD_START macro is only needed now because _dl_start is local in
rtld.c, but _start has to call it, if _dl_start was made hidden then it
could be empty.

_dl_skip_args is no longer needed.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2022-05-17 10:14:03 +01:00
Szabolcs Nagy
9faf5262c7 linux: Add a getauxval test [BZ #23293]
This is for bug 23293 and it relies on the glibc test system running
tests via explicit ld.so invokation by default.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2022-05-17 10:14:03 +01:00
Szabolcs Nagy
86147bbeec rtld: Remove DL_ARGV_NOT_RELRO and make _dl_skip_args const
_dl_skip_args is always 0, so the target specific code that modifies
argv after relro protection is applied is no longer used.

After the patch relro protection is applied to _dl_argv consistently
on all targets.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2022-05-17 10:14:03 +01:00
Szabolcs Nagy
ad43cac44a rtld: Use generic argv adjustment in ld.so [BZ #23293]
When an executable is invoked as

  ./ld.so [ld.so-args] ./exe [exe-args]

then the argv is adujusted in ld.so before calling the entry point of
the executable so ld.so args are not visible to it.  On most targets
this requires moving argv, env and auxv on the stack to ensure correct
stack alignment at the entry point.  This had several issues:

- The code for this adjustment on the stack is written in asm as part
  of the target specific ld.so _start code which is hard to maintain.

- The adjustment is done after _dl_start returns, where it's too late
  to update GLRO(dl_auxv), as it is already readonly, so it points to
  memory that was clobbered by the adjustment. This is bug 23293.

- _environ is also wrong in ld.so after the adjustment, but it is
  likely not used after _dl_start returns so this is not user visible.

- _dl_argv was updated, but for this it was moved out of relro, which
  changes security properties across targets unnecessarily.

This patch introduces a generic _dl_start_args_adjust function that
handles the argument adjustments after ld.so processed its own args
and before relro protection is applied.

The same algorithm is used on all targets, _dl_skip_args is now 0, so
existing target specific adjustment code is no longer used.  The bug
affects aarch64, alpha, arc, arm, csky, ia64, nios2, s390-32 and sparc,
other targets don't need the change in principle, only for consistency.

The GNU Hurd start code relied on _dl_skip_args after dl_main returned,
now it checks directly if args were adjusted and fixes the Hurd startup
data accordingly.

Follow up patches can remove _dl_skip_args and DL_ARGV_NOT_RELRO.

Tested on aarch64-linux-gnu and cross tested on i686-gnu.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-17 10:14:03 +01:00
Florian Weimer
d055481ce3 scripts/glibcelf.py: Add *T_RISCV_* constants
SHT_RISCV_ATTRIBUTES, PT_RISCV_ATTRIBUTES, DT_RISCV_VARIANT_CC were
added in commit 0b6c675073
("Update RISC-V specific ELF definitions").  This caused the
elf/tst-glibcelf consistency check to fail.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-16 22:22:38 +02:00
Adhemerval Zanella
d2db60d8d8 Remove dl-librecon.h header.
The Linux version used by i686 and m68k provide three overrrides for
generic code:

  1. DISTINGUISH_LIB_VERSIONS to print additional information when
     libc5 is used by a dependency.

  2. EXTRA_LD_ENVVARS to that enabled LD_LIBRARY_VERSION environment
     variable.

  3. EXTRA_UNSECURE_ENVVARS to add two environment variables related
     to aout support.

None are really requires, it has some decades since libc5 or aout
suppported was removed and Linux even remove support for aout files.
The LD_LIBRARY_VERSION is also dead code, dl_correct_cache_id is not
used anywhere.

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

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-05-16 15:03:49 -03:00
Adhemerval Zanella
c628c22963 elf: Remove ldconfig kernel version check
Now that it was removed on libc.so.
2022-05-16 15:03:49 -03:00
Adhemerval Zanella
b46d250656 Remove kernel version check
The kernel version check is used to avoid glibc to run on older
kernels where some syscall are not available and fallback code are
not enabled to handle graciously fail.  However, it does not prevent
if the kernel does not correctly advertise its version through
vDSO note, uname or procfs.

Also kernel version checks are sometime not desirable by users,
where they want to deploy on different system with different kernel
version knowing the minimum set of syscall is always presented on
such systems.

The kernel version check has been removed along with the
LD_ASSUME_KERNEL environment variable.  The minimum kernel used to
built glibc is still provided through NT_GNU_ABI_TAG ELF note and
also printed when libc.so is issued.

Checked on x86_64-linux-gnu.
2022-05-16 15:03:49 -03:00
Adhemerval Zanella
97a912f7a8 linux: Use /sys/devices/system/cpu on __get_nprocs_conf (BZ#28991)
Currently on Linux __get_nprocs_conf first tries to enumerate the
cpus present in the system by iterating on /sys/devices/system/cpuX
directories.  This only enumerates the CPUs that are present in
system (but possibly offline), not taking in account possible CPU
that might added in the system through hotplugging.

Linux provides the maximum number of configured cpus on the
/sys/devices/system/cpu file.  Although it might present a larger
value of possible active CPUs on some system (where kernel either
get the information from firmaware or is configured at boot time),
the information is what kernel presents to userland.

This also change the returned value of _SC_NPROCESSORS_CONF, which
aligns as the maximum configure cpu in the system.

Checked on x86_64-linux-gnu.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2022-05-16 14:26:49 -03:00
Florian Weimer
f787e138aa csu: Implement and use _dl_early_allocate during static startup
This implements mmap fallback for a brk failure during TLS
allocation.

scripts/tls-elf-edit.py is updated to support the new patching method.
The script no longer requires that in the input object is of ET_DYN
type.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-16 18:42:03 +02:00
Florian Weimer
b57ab258c1 Linux: Introduce __brk_call for invoking the brk system call
Alpha and sparc can now use the generic implementation.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-05-16 18:41:52 +02:00
Jonathan Wakely
21244c70c2 sys/cdefs.h: Do not require C++ compilers to define __STDC__
The check for an ISO C compiler assumes that anything GCC-like will
define __STDC__, even if it's actually a C++ compiler. That's currently
true for G++ and compilers like clang++ that also define __GNUC__, but
it might not always be true.

The C++ standard leaves it implementation-defined whether or not
__STDC__ is defined by C++ compilers. And really the check should be
"ISO C or ISO C++ conforming compiler" anyway. So only give an error if
__GNUC__ is defined and neither __STDC__ nor __cplusplus is defined.

Reviewed-by: Fangrui Song <maskray@google.com>
2022-05-16 16:48:51 +01:00
Siddhesh Poyarekar
61a8753010 fortify: Ensure that __glibc_fortify condition is a constant [BZ #29141]
The fix c8ee1c85 introduced a -1 check for object size without also
checking that object size is a constant.  Because of this, the tree
optimizer passes in gcc fail to fold away one of the branches in
__glibc_fortify and trips on a spurious Wstringop-overflow.  The warning
itself is incorrect and the branch does go away eventually in DCE in the
rtl passes in gcc, but the constant check is a helpful hint to simplify
code early, so add it in.

Resolves: BZ #29141
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2022-05-16 20:10:08 +05:30
Andreas Schwab
0b6c675073 Update RISC-V specific ELF definitions
The definitions are taken from the 1.0-rc2 version of the ELF psABI.
2022-05-16 15:51:57 +02:00
Adhemerval Zanella
9403b71ae9 x86_64: Remove bzero optimization
Both symbols are marked as legacy in POSIX.1-2001 and removed on
POSIX.1-2008, although the prototypes are defined for _GNU_SOURCE
or _DEFAULT_SOURCE.

GCC also replaces bcopy with a memmove and bzero with memset on default
configuration (to actually get a bzero libc call the code requires
to omit string.h inclusion and built with -fno-builtin), so it is
highly unlikely programs are actually calling libc bzero symbol.

On a recent Linux distro (Ubuntu 22.04), there is no bzero calls
by the installed binaries.

  $ cat count_bstring.sh
  #!/bin/bash

  files=`IFS=':';for i in $PATH; do test -d "$i" && find "$i" -maxdepth 1 -executable -type f; done`
  total=0
  for file in $files; do
    symbols=`objdump -R $file 2>&1`
    if [ $? -eq 0 ]; then
      ncalls=`echo $symbols | grep -w $1 | wc -l`
      ((total=total+ncalls))
      if [ $ncalls -gt 0 ]; then
        echo "$file: $ncalls"
      fi
    fi
  done
  echo "TOTAL=$total"
  $ ./count_bstring.sh bzero
  TOTAL=0

Checked on x86_64-linux-gnu.
2022-05-16 09:36:06 -03:00
Maciej W. Rozycki
7b1cfba79e RISC-V: Use an autoconf template to produce `preconfigure'
Avoid fiddling with autoconf internals and use AC_DEFINE_UNQUOTED to
define macros in the configuration headers rather than handcoding an
equivalent shell sequence with the use of the `as_echo' undocumented
variable.

Switch to using AC_MSG_ERROR rather than `echo' and `exit' directly for
error handling.  Owing to the lack of any kind of error annotation it
makes it difficult to spot the message in the flood in a parallel build
and neither it is logged in `config.log'.

Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-05-13 17:07:23 +01:00