Commit Graph

2261 Commits

Author SHA1 Message Date
Siddhesh Poyarekar
f7a79879c0 realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770]
realpath returns an allocated string when the result exceeds PATH_MAX,
which is unexpected when its second argument is not NULL.  This results
in the second argument (resolved) being uninitialized and also results
in a memory leak since the caller expects resolved to be the same as the
returned value.

Return NULL and set errno to ENAMETOOLONG if the result exceeds
PATH_MAX.  This fixes [BZ #28770], which is CVE-2021-3998.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit ee8d5e33ad)
2022-01-24 11:36:19 +05:30
Aurelien Jarno
1d401d1fcc x86: use default cache size if it cannot be determined [BZ #28784]
In some cases (e.g QEMU, non-Intel/AMD CPU) the cache information can
not be retrieved and the corresponding values are set to 0.

Commit 2d651eb926 ("x86: Move x86 processor cache info to
cpu_features") changed the behaviour in such case by defining the
__x86_shared_cache_size and __x86_data_cache_size variables to 0 instead
of using the default values. This cause an issue with the i686 SSE2
optimized bzero/routine which assumes that the cache size is at least
128 bytes, and otherwise tries to zero/set the whole address space minus
128 bytes.

Fix that by restoring the original code to only update
__x86_shared_cache_size and __x86_data_cache_size variables if the
corresponding cache sizes are not zero.

Fixes bug 28784
Fixes commit 2d651eb926

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit c242fcce06)
2022-01-17 19:46:24 +01:00
Florian Weimer
6890b8a3ae CVE-2022-23218: Buffer overflow in sunrpc svcunix_create (bug 28768)
The sunrpc function svcunix_create suffers from a stack-based buffer
overflow with overlong pathname arguments.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit f545ad4928)
2022-01-17 11:49:25 +01:00
Florian Weimer
7b5d433fd0 CVE-2022-23219: Buffer overflow in sunrpc clnt_create for "unix" (bug 22542)
Processing an overlong pathname in the sunrpc clnt_create function
results in a stack-based buffer overflow.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 226b46770c)
2022-01-17 11:48:59 +01:00
Florian Weimer
2fe2af88ab i386: Remove broken CAN_USE_REGISTER_ASM_EBP (bug 28771)
The configure check for CAN_USE_REGISTER_ASM_EBP tried to compile a
simple function that uses %ebp as an inline assembly operand.  If
compilation failed, CAN_USE_REGISTER_ASM_EBP was set 0, which
eventually had these consequences:

(1) %ebx was avoided as an inline assembly operand, with an
    assembler macro hack to avoid unnecessary register moves.
(2) %ebp was avoided as an inline assembly operand, using an
    out-of-line syscall function for 6-argument system calls.

(1) is no longer needed for any GCC version that is supported for
building glibc.  %ebx can be used directly as a register operand.
Therefore, this commit removes the %ebx avoidance completely.  This
avoids the assembler macro hack, which turns out to be incompatible
with the current Systemtap probe macros (which switch to .altmacro
unconditionally).

(2) is still needed in many build configurations.  The existing
configure check cannot really capture that because the simple function
succeeds to compile, while the full glibc build still fails.
Therefore, this commit removes the check, the CAN_USE_REGISTER_ASM_EBP
macro, and uses the out-of-line syscall function for 6-argument system
calls unconditionally.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit a78e6a10d0)
2022-01-13 15:21:32 +01:00
Hans-Peter Nilsson
85b24f9694 timezone: handle truncated timezones from tzcode-2021d and later (BZ #28707)
When using a timezone file with a truncated starting time,
generated by the zic in IANA tzcode-2021d a.k.a. tzlib-2021d
(also in tzlib-2021e; current as of this writing), glibc
asserts in __tzfile_read (on e.g. tzset() for this file) and
you may find lines matching "tzfile.c:435: __tzfile_read:
Assertion `num_types == 1' failed" in your syslog.

One example of such a file is the tzfile for Asuncion
generated by tzlib-2021e as follows, using the tzlib-2021e zic:
"zic -d DEST -r @1546300800 -L /dev/null -b slim
SOURCE/southamerica".  Note that in its type 2 header, it has
two entries in its "time-types" array (types), but only one
entry in its "transition types" array (type_idxs).

This is valid and expected already in the published RFC8536, and
not even frowned upon: "Local time for timestamps before the
first transition is specified by the first time type (time type
0)" ... "every nonzero local time type index SHOULD appear at
least once in the transition type array".  Note the "nonzero ...
index".  Until the 2021d zic, index 0 has been shared by the
first valid transition but with 2021d it's separate, set apart
as a placeholder and only "implicitly" indexed.  (A draft update
of the RFC mandates that the entry at index 0 is a placeholder
in this case, hence can no longer be shared.)

	* time/tzfile.c (__tzfile_read): Don't assert when no transitions
	are found.

Co-authored-by: Christopher Wong <Christopher.Wong@axis.com>
(cherry picked from commit c36f64aa6d)
2022-01-07 10:20:58 +01:00
Paul Eggert
515a6f53cd Fix subscript error with odd TZif file [BZ #28338]
* time/tzfile.c (__tzfile_compute): Fix unlikely off-by-one bug
that accessed before start of an array when an oddball-but-valid
TZif file was queried with an unusual time_t value.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit 645277434a)
2022-01-07 10:20:02 +01:00
Wilco Dijkstra
217b84127b AArch64: Check for SVE in ifuncs [BZ #28744]
Add a check for SVE in the A64FX ifuncs for memcpy, memset and memmove.
This fixes BZ #28744.

(cherry picked from commit e5fa62b8db)
2022-01-07 10:10:27 +01:00
Aurelien Jarno
aa3a97496c riscv: align stack before calling _dl_init [BZ #28703]
Align the stack pointer to 128 bits during the call to _dl_init() as
specified by the RISC-V ABI [1]. This fixes the elf/tst-align2 test.

Fixes bug 28703.

[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc

(cherry picked from commit 225da459ce)
2021-12-17 22:50:13 +01:00
Aurelien Jarno
9de8011c32 riscv: align stack in clone [BZ #28702]
The RISC-V ABI [1] mandates that "the stack pointer shall be aligned to
a 128-bit boundary upon procedure entry". This as not the case in clone.

This fixes the misc/tst-misalign-clone-internal and
misc/tst-misalign-clone tests.

Fixes bug 28702.

[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc

(cherry picked from commit d2e594d715)
2021-12-17 22:48:41 +01:00
Aurelien Jarno
03de6917bd elf: Fix tst-cpu-features-cpuinfo for KVM guests on some AMD systems [BZ #28704]
On KVM guests running on some AMD systems, the IBRS feature is reported
as a synthetic feature using the Intel feature, while the cpuinfo entry
keeps the same. Handle that by first checking the presence of the Intel
feature on AMD systems.

Fixes bug 28704.

(cherry picked from commit 94058f6cde)
2021-12-17 20:35:45 +01:00
Florian Weimer
dc9b69d533 nss: Use "files dns" as the default for the hosts database (bug 28700)
This matches what is currently in nss/nsswitch.conf.  The new ordering
matches what most distributions use in their installed configuration
files.

It is common to add localhost to /etc/hosts because the name does not
exist in the DNS, but is commonly used as a host name.

With the built-in "dns [!UNAVAIL=return] files" default, dns is
searched first and provides an answer for "localhost" (NXDOMAIN).
We never look at the files database as a result, so the contents of
/etc/hosts is ignored.  This means that "getent hosts localhost"
fail without a /etc/nsswitch.conf file, even though the host name
is listed in /etc/hosts.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit b99b0f93ee)
2021-12-17 12:17:18 +01:00
Xi Ruoyao
7af07fe795 mips: align stack in clone [BZ #28223]
The MIPS O32 ABI requires 4 byte aligned stack, and the MIPS N64 and N32
ABI require 8 byte aligned stack.  Previously if the caller passed an
unaligned stack to clone the the child misbehaved.

Fixes bug 28223.

(cherry picked from commit 1f51cd9a86)
2021-12-14 22:57:39 +01:00
Florian Weimer
e9f81c261a nptl: Add one more barrier to nptl/tst-create1
Without the bar_ctor_finish barrier, it was possible that thread2
re-locked user_lock before ctor had a chance to lock it.  ctor then
blocked in its locking operation, xdlopen from the main thread
did not return, and thread2 was stuck waiting in bar_dtor:

thread 1: started.
thread 2: started.
thread 2: locked user_lock.
constructor started: 0.
thread 1: in ctor: started.
thread 3: started.
thread 3: done.
thread 2: unlocked user_lock.
thread 2: locked user_lock.

Fixes the test in commit 83b5323261
("elf: Avoid deadlock between pthread_create and ctors [BZ #28357]").

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
(cherry picked from commit 5cc3385654)
2021-12-10 11:56:06 +01:00
Matheus Castanho
387bff63dc powerpc64[le]: Fix CFI and LR save address for asm syscalls [BZ #28532]
Syscalls based on the assembly templates are missing CFI for r31, which gets
clobbered when scv is used, and info for LR is inaccurate, placed in the wrong
LOC and not using the proper offset. LR was also being saved to the callee's
frame, while the ABI mandates it to be saved to the caller's frame. These are
fixed by this commit.

After this change:

$ readelf -wF libc.so.6 | grep 0004b9d4.. -A 7 && objdump --disassemble=kill libc.so.6
00004a48 0000000000000020 00004a4c FDE cie=00000000 pc=000000000004b9d4..000000000004ba3c
   LOC           CFA      r31   ra
000000000004b9d4 r1+0     u     u
000000000004b9e4 r1+48    u     u
000000000004b9e8 r1+48    c-16  u
000000000004b9fc r1+48    c-16  c+16
000000000004ba08 r1+48    c-16
000000000004ba18 r1+48    u
000000000004ba1c r1+0     u

libc.so.6:     file format elf64-powerpcle

Disassembly of section .text:

000000000004b9d4 <kill>:
   4b9d4:       1f 00 4c 3c     addis   r2,r12,31
   4b9d8:       2c c3 42 38     addi    r2,r2,-15572
   4b9dc:       25 00 00 38     li      r0,37
   4b9e0:       d1 ff 21 f8     stdu    r1,-48(r1)
   4b9e4:       20 00 e1 fb     std     r31,32(r1)
   4b9e8:       98 8f ed eb     ld      r31,-28776(r13)
   4b9ec:       10 00 ff 77     andis.  r31,r31,16
   4b9f0:       1c 00 82 41     beq     4ba0c <kill+0x38>
   4b9f4:       a6 02 28 7d     mflr    r9
   4b9f8:       40 00 21 f9     std     r9,64(r1)
   4b9fc:       01 00 00 44     scv     0
   4ba00:       40 00 21 e9     ld      r9,64(r1)
   4ba04:       a6 03 28 7d     mtlr    r9
   4ba08:       08 00 00 48     b       4ba10 <kill+0x3c>
   4ba0c:       02 00 00 44     sc
   4ba10:       00 00 bf 2e     cmpdi   cr5,r31,0
   4ba14:       20 00 e1 eb     ld      r31,32(r1)
   4ba18:       30 00 21 38     addi    r1,r1,48
   4ba1c:       18 00 96 41     beq     cr5,4ba34 <kill+0x60>
   4ba20:       01 f0 20 39     li      r9,-4095
   4ba24:       40 48 23 7c     cmpld   r3,r9
   4ba28:       20 00 e0 4d     bltlr+
   4ba2c:       d0 00 63 7c     neg     r3,r3
   4ba30:       08 00 00 48     b       4ba38 <kill+0x64>
   4ba34:       20 00 e3 4c     bnslr+
   4ba38:       c8 32 fe 4b     b       2ed00 <__syscall_error>
        ...
   4ba44:       40 20 0c 00     .long 0xc2040
   4ba48:       68 00 00 00     .long 0x68
   4ba4c:       06 00 5f 5f     rlwnm   r31,r26,r0,0,3
   4ba50:       6b 69 6c 6c     xoris   r12,r3,26987

(cherry picked from commit d120fb9941)
2021-11-30 15:34:03 -03:00
Florian Weimer
bfe68fe3c4 nptl: Do not set signal mask on second setjmp return [BZ #28607]
__libc_signal_restore_set was in the wrong place: It also ran
when setjmp returned the second time (after pthread_exit or
pthread_cancel).  This is observable with blocked pending
signals during thread exit.

Fixes commit b3cae39dcb
("nptl: Start new threads with all signals blocked [BZ #25098]").

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit e186fc5a31)
2021-11-24 09:22:10 +01:00
Nikita Popov
f411207a83 gconv: Do not emit spurious NUL character in ISO-2022-JP-3 (bug 28524)
Bugfix 27256 has introduced another issue:
In conversion from ISO-2022-JP-3 encoding, it is possible
to force iconv to emit extra NUL character on internal state reset.
To do this, it is sufficient to feed iconv with escape sequence
which switches active character set.
The simplified check 'data->__statep->__count != ASCII_set'
introduced by the aforementioned bugfix picks that case and
behaves as if '\0' character has been queued thus emitting it.

To eliminate this issue, these steps are taken:
* Restore original condition
'(data->__statep->__count & ~7) != ASCII_set'.
It is necessary since bits 0-2 may contain
number of buffered input characters.
* Check that queued character is not NUL.
Similar step is taken for main conversion loop.

Bundled test case follows following logic:
* Try to convert ISO-2022-JP-3 escape sequence
switching active character set
* Reset internal state by providing NULL as input buffer
* Ensure that nothing has been converted.

Signed-off-by: Nikita Popov <npv1310@gmail.com>
(cherry picked from commit ff012870b2)
2021-11-04 21:28:43 +01:00
H.J. Lu
f42373f911 ld.so: Replace DL_RO_DYN_SECTION with dl_relocate_ld [BZ #28340]
We can't relocate entries in dynamic section if it is readonly:

1. Add a l_ld_readonly field to struct link_map to indicate if dynamic
section is readonly and set it based on p_flags of PT_DYNAMIC segment.
2. Replace DL_RO_DYN_SECTION with dl_relocate_ld to decide if dynamic
section should be relocated.
3. Remove DL_RO_DYN_TEMP_CNT.
4. Don't use a static dynamic section to make readonly dynamic section
in vDSO writable.
5. Remove the temp argument from elf_get_dynamic_info.

This fixes BZ #28340.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit b413280cfb)
2021-11-03 07:50:30 +01:00
Szabolcs Nagy
024a7640ab elf: Avoid deadlock between pthread_create and ctors [BZ #28357]
The fix for bug 19329 caused a regression such that pthread_create can
deadlock when concurrent ctors from dlopen are waiting for it to finish.
Use a new GL(dl_load_tls_lock) in pthread_create that is not taken
around ctors in dlopen.

The new lock is also used in __tls_get_addr instead of GL(dl_load_lock).

The new lock is held in _dl_open_worker and _dl_close_worker around
most of the logic before/after the init/fini routines.  When init/fini
routines are running then TLS is in a consistent, usable state.
In _dl_open_worker the new lock requires catching and reraising dlopen
failures that happen in the critical section.

The new lock is reinitialized in a fork child, to keep the existing
behaviour and it is kept recursive in case malloc interposition or TLS
access from signal handlers can retake it.  It is not obvious if this
is necessary or helps, but avoids changing the preexisting behaviour.

The new lock may be more appropriate for dl_iterate_phdr too than
GL(dl_load_write_lock), since TLS state of an incompletely loaded
module may be accessed.  If the new lock can replace the old one,
that can be a separate change.

Fixes bug 28357.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit 83b5323261)
2021-10-19 14:21:14 +02:00
Adhemerval Zanella
822662cf2a linux: Revert the use of sched_getaffinity on get_nproc (BZ #28310)
The use of sched_getaffinity on get_nproc and
sysconf (_SC_NPROCESSORS_ONLN) done in 903bc7dcc2 (BZ #27645)
breaks the top command in common hypervisor configurations and also
other monitoring tools.

The main issue using sched_getaffinity changed the symbols semantic
from system-wide scope of online CPUs to per-process one (which can
be changed with kernel cpusets or book parameters in VM).

This patch reverts mostly of the 903bc7dcc2, with the
exceptions:

  * No more cached values and atomic updates, since they are inherent
    racy.

  * No /proc/cpuinfo fallback, since /proc/stat is already used and
    it would require to revert more arch-specific code.

  * The alloca is replace with a static buffer of 1024 bytes.

So the implementation first consult the sysfs, and fallbacks to procfs.

Checked on x86_64-linux-gnu.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 342298278e)
2021-10-01 18:19:45 +02:00
Florian Weimer
40bade26d5 nptl: pthread_kill must send signals to a specific thread [BZ #28407]
The choice between the kill vs tgkill system calls is not just about
the TID reuse race, but also about whether the signal is sent to the
whole process (and any thread in it) or to a specific thread.

This was caught by the openposix test suite:

  LTP: openposix test suite - FAIL: SIGUSR1 is member of new thread pendingset.
  <https://gitlab.com/cki-project/kernel-tests/-/issues/764>

Fixes commit 526c3cf11e ("nptl: Fix race
between pthread_kill and thread exit (bug 12889)").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit eae81d7057)
2021-10-01 18:18:15 +02:00
Florian Weimer
33adeaa3e2 nptl: Avoid setxid deadlock with blocked signals in thread exit [BZ #28361]
As part of the fix for bug 12889, signals are blocked during
thread exit, so that application code cannot run on the thread that
is about to exit.  This would cause problems if the application
expected signals to be delivered after the signal handler revealed
the thread to still exist, despite pthread_kill can no longer be used
to send signals to it.  However, glibc internally uses the SIGSETXID
signal in a way that is incompatible with signal blocking, due to the
way the setxid handshake delays thread exit until the setxid operation
has completed.  With a blocked SIGSETXID, the handshake can never
complete, causing a deadlock.

As a band-aid, restore the previous handshake protocol by not blocking
SIGSETXID during thread exit.

The new test sysdeps/pthread/tst-pthread-setuid-loop.c is based on
a downstream test by Martin Osvald.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 2849e2f533)
2021-09-23 11:02:19 +02:00
Florian Weimer
8b8a1d0b73 nptl: Fix type of pthread_mutexattr_getrobust_np, pthread_mutexattr_setrobust_np (bug 28036)
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit f3e6645633)
2021-09-21 07:15:25 +02:00
Florian Weimer
a8ac8c4725 nptl: Fix race between pthread_kill and thread exit (bug 12889)
A new thread exit lock and flag are introduced.  They are used to
detect that the thread is about to exit or has exited in
__pthread_kill_internal, and the signal is not sent in this case.

The test sysdeps/pthread/tst-pthread_cancel-select-loop.c is derived
from a downstream test originally written by Marek Polacek.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit 526c3cf11e)
2021-09-13 13:38:51 +02:00
Florian Weimer
3abf3bd4ed nptl: pthread_kill, pthread_cancel should not fail after exit (bug 19193)
This closes one remaining race condition related to bug 12889: if
the thread already exited on the kernel side, returning ESRCH
is not correct because that error is reserved for the thread IDs
(pthread_t values) whose lifetime has ended.  In case of a
kernel-side exit and a valid thread ID, no signal needs to be sent
and cancellation does not have an effect, so just return 0.

sysdeps/pthread/tst-kill4.c triggers undefined behavior and is
removed with this commit.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
(cherry picked from commit 8af8456004)
2021-09-13 13:38:51 +02:00
Florian Weimer
31902ae639 Linux: Fix fcntl, ioctl, prctl redirects for _TIME_BITS=64 (bug 28182)
__REDIRECT and __THROW are not compatible with C++ due to the ordering of the
__asm__ alias and the throw specifier. __REDIRECT_NTH has to be used
instead.

Fixes commit 8a40aff86b ("io: Add time64 alias
for fcntl"), commit 82c395d91e ("misc: Add
time64 alias for ioctl"), commit b39ffab860
("Linux: Add time64 alias for prctl").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit c87fcacc50)
2021-08-06 16:42:40 +02:00
Carlos O'Donell
2e2c08aa4d Update NEWS.
Suggestions by Florian Weimer, Andreas Schwab, and Alexander Monakov.

See:
https://sourceware.org/pipermail/libc-alpha/2021-July/129356.html
https://sourceware.org/pipermail/libc-alpha/2021-July/129357.html
https://sourceware.org/pipermail/libc-alpha/2021-July/129361.html
2021-08-01 16:47:56 -04:00
Mark Harris
cfdaa29f66 NEWS: Fix typos, grammar, and missing words
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-08-01 00:51:22 -04:00
Siddhesh Poyarekar
1e5a5866cb Remove malloc hooks [BZ #23328]
Make malloc hooks symbols compat-only so that new applications cannot
link against them and remove the declarations from the API.  Also
remove the unused malloc-hooks.h.

Finally, mark all symbols in libc_malloc_debug.so as compat so that
the library cannot be linked against.

Add a note about the deprecation in NEWS.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:12 +05:30
Siddhesh Poyarekar
0552fd2c7d Move malloc_{g,s}et_state to libc_malloc_debug
These deprecated functions are only safe to call from
__malloc_initialize_hook and as a result, are not useful in the
general case.  Move the implementations to libc_malloc_debug so that
existing binaries that need it will now have to preload the debug DSO
to work correctly.

This also allows simplification of the core malloc implementation by
dropping all the undumping support code that was added to make
malloc_set_state work.

One known breakage is that of ancient emacs binaries that depend on
this.  They will now crash when running with this libc.  With
LD_BIND_NOW=1, it will terminate immediately because of not being able
to find malloc_set_state but with lazy binding it will crash in
unpredictable ways.  It will need a preloaded libc_malloc_debug.so so
that its initialization hook is executed to allow its malloc
implementation to work properly.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:38:10 +05:30
Siddhesh Poyarekar
2d2d9f2b48 Move malloc hooks into a compat DSO
Remove all malloc hook uses from core malloc functions and move it
into a new library libc_malloc_debug.so.  With this, the hooks now no
longer have any effect on the core library.

libc_malloc_debug.so is a malloc interposer that needs to be preloaded
to get hooks functionality back so that the debugging features that
depend on the hooks, i.e. malloc-check, mcheck and mtrace work again.
Without the preloaded DSO these debugging features will be nops.
These features will be ported away from hooks in subsequent patches.

Similarly, legacy applications that need hooks functionality need to
preload libc_malloc_debug.so.

The symbols exported by libc_malloc_debug.so are maintained at exactly
the same version as libc.so.

Finally, static binaries will no longer be able to use malloc
debugging features since they cannot preload the debugging DSO.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:37:59 +05:30
Siddhesh Poyarekar
55a4dd3930 Remove __morecore and __default_morecore
Make the __morecore and __default_morecore symbols compat-only and
remove their declarations from the API.  Also, include morecore.c
directly into malloc.c; this should ideally get merged into malloc in
a future cleanup.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-07-22 18:37:57 +05:30
Florian Weimer
248dbed118 resolv: Deprecate legacy interfaces in libresolv
Debugging interfaces: p_*, fp_*, and sym_* could conceivably be
used to produce debug out, but these functions have not been
updated to parse more resource records, so they are not very useful
today.  Likewise for ns_sprintrr and ns_sprintrrf.  ns_format_ttl and
ns_parse_ttl are related to these.

Internal implementation details: res_isourserver is probably only
useful in the implementation of a stub resolver, and so is
res_nameinquery.

Unclear semantics and bad performance: ns_samedomain, ns_subdomain,
ns_makecanon, ns_samename do textual converions & copies instead of
checking equivalence of the wire format.

inet_neta cannot handle IPv6 addresses.

res_hostalias has been superseded by getaddrinfo with AI_CANONNAME.
hostalias is not thread-safe.

Some functions have int as size arguments instead of size_t, so they
do not follow current coding practices.  However, dn_expand and
b64_ntop are somewhat widely used (to name just two examples), so
deprecating them seems problematic.

Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
2021-07-19 07:55:42 +02:00
H.J. Lu
5d98a7dae9 Define PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN)
The constant PTHREAD_STACK_MIN may be too small for some processors.
Rename _SC_SIGSTKSZ_SOURCE to _DYNAMIC_STACK_SIZE_SOURCE.  When
_DYNAMIC_STACK_SIZE_SOURCE or _GNU_SOURCE are defined, define
PTHREAD_STACK_MIN to sysconf(_SC_THREAD_STACK_MIN) which is changed
to MIN (PTHREAD_STACK_MIN, sysconf(_SC_MINSIGSTKSZ)).

Consolidate <bits/local_lim.h> with <bits/pthread_stack_min.h> to
provide a constant target specific PTHREAD_STACK_MIN value.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-09 15:10:35 -07:00
Adhemerval Zanella
882d6e17bc posix: Add posix_spawn_file_actions_addclosefrom_np
This patch adds a way to close a range of file descriptors on
posix_spawn as a new file action.  The API is similar to the one
provided by Solaris 11 [1], where the file action causes the all open
file descriptors greater than or equal to input on to be closed when
the new process is spawned.

The function posix_spawn_file_actions_addclosefrom_np is safe to be
implemented by iterating over /proc/self/fd, since the Linux spawni.c
helper process does not use CLONE_FILES, so its has own file descriptor
table and any failure (in /proc operation) aborts the process creation
and returns an error to the caller.

I am aware that this file action might be redundant to the current
approach of POSIX in promoting O_CLOEXEC in more interfaces. However
O_CLOEXEC is still not the default and for some specific usages, the
caller needs to close all possible file descriptors to avoid them
leaking.  Some examples are CPython (discussed in BZ#10353) and OpenJDK
jspawnhelper [2] (where OpenJDK spawns a helper process to exactly
closes all file descriptors).  Most likely any environment which calls
functions that might open file descriptor under the hood and aim to use
posix_spawn might face the same requirement.

Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15.

[1] https://docs.oracle.com/cd/E36784_01/html/E36874/posix-spawn-file-actions-addclosefrom-np-3c.html
[2] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
2021-07-08 14:08:15 -03:00
Adhemerval Zanella
607449506f io: Add closefrom [BZ #10353]
The function closes all open file descriptors greater than or equal to
input argument.  Negative values are clamped to 0, i.e, it will close
all file descriptors.

As indicated by the bug report, this is a common symbol provided by
different systems (Solaris, OpenBSD, NetBSD, FreeBSD) and, although
its has inherent issues with not taking in consideration internal libc
file descriptors (such as syslog), this is also a common feature used
in multiple projects [1][2][3][4][5].

The Linux fallback implementation iterates over /proc and close all
file descriptors sequentially.  Although it was raised the questioning
whether getdents on /proc/self/fd might return disjointed entries
when file descriptor are closed; it does not seems the case on my
testing on multiple kernel (v4.18, v5.4, v5.9) and the same strategy
is used on different projects [1][2][3][5].

Also, the interface is set a fail-safe meaning that a failure in the
fallback results in a process abort.

Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15.

[1] 5238e95759/src/basic/fd-util.c (L217)
[2] ddf4b77e11/src/lxc/start.c (L236)
[3] 9e4f2f3a6b/Modules/_posixsubprocess.c (L220)
[4] 5f47c0613e/src/libstd/sys/unix/process2.rs (L303-L308)
[5] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
2021-07-08 14:08:14 -03:00
Adhemerval Zanella
286286283e linux: Add close_range
It was added on Linux 5.9 (278a5fbaed89) with CLOSE_RANGE_CLOEXEC
added on 5.11 (582f1fb6b721f).  Although FreeBSD has added the same
syscall, this only adds the symbol on Linux ports.  This syscall is
required to provided a fail-safe way to implement the closefrom
symbol (BZ #10353).

Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15.
2021-07-08 14:08:13 -03:00
Siddhesh Poyarekar
00d28960c5 mtrace: Deprecate mallwatch and tr_break
The variable and function pair appear to provide a way for users to
set conditional breakpoints in mtrace when a specific address is
returned by the allocator.  This can be achieved by using conditional
breakpoints in gdb so it is redundant.  There is no documentation of
this interface in the manual either, so it appears to have been a hack
that got added to debug malloc.  Deprecate these symbols and do not
call tr_break anymore.

Reviewed-by: DJ Delorie <dj@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-07-03 00:47:34 +05:30
Adhemerval Zanella
c32c868ab8 posix: Add _Fork [BZ #4737]
Austin Group issue 62 [1] dropped the async-signal-safe requirement
for fork and provided a async-signal-safe _Fork replacement that
does not run the atfork handlers.  It will be included in the next
POSIX standard.

It allow to close a long standing issue to make fork AS-safe (BZ#4737).
As indicated on the bug, besides the internal lock for the atfork
handlers itself; there is no guarantee that the handlers itself will
not introduce more AS-safe issues.

The idea is synchronize fork with the required internal locks to allow
children in multithread processes to use mostly of standard function
(even though POSIX states only AS-safe function should be used).  On
signal handles, _Fork should be used intead and only AS-safe functions
should be used.

For testing, the new tst-_Fork only check basic usage.  I also added
a new tst-mallocfork3 which uses the same strategy to check for
deadlock of tst-mallocfork2 but using threads instead of subprocesses
(and it does deadlock if it replaces _Fork with fork).

[1] https://austingroupbugs.net/view.php?id=62
2021-06-28 15:55:56 -03:00
Florian Weimer
dd45734e32 nptl: Add glibc.pthread.stack_cache_size tunable
The valgrind/helgrind test suite needs a way to make stack dealloction
more prompt, and this feature seems to be generally useful.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-06-28 16:41:58 +02:00
Florian Weimer
8208be389b Install shared objects under their ABI names
Previously, the installed objects were named like libc-2.33.so,
and the ABI soname libc.so.6 was just a symbolic link.

The Makefile targets to install these symbolic links are no longer
needed after this, so they are removed with this commit.  The more
general $(make-link) command (which invokes scripts/rellns-sh) is
retained because other symbolic links are still needed.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@rehdat.com>
2021-06-28 08:33:57 +02:00
Paul Eggert
ac3babc394 * NEWS: Clarify _TIME_BITS change. 2021-06-24 21:12:19 -07:00
Adhemerval Zanella
bf6749a7f8 nptl: Use SA_RESTART for SIGCANCEL handler
The usage of signals to implementation pthread cancellation is an
implementation detail and should not be visible through cancellation
entrypoints.

However now that pthread_cancel always send the SIGCANCEL, some
entrypoint might be interruptable and return EINTR to the caller
(for instance on sem_wait).

Using SA_RESTART hides this, since the cancellation handler should
either act uppon cancellation (if asynchronous cancellation is enable)
or ignore the cancellation internal signal.

Checked on x86_64-linux-gnu and i686-linux-gnu.
2021-06-23 13:45:13 -03:00
Paul Eggert
03caacbc7f doc: _TIME_BITS defaults may change
* NEWS: Don't imply the default will always be 32-bit.
* manual/creature.texi (Feature Test Macros):
Say that _TIME_BITS and _FILE_OFFSET_BITS defaults
may change in future releases.
2021-06-23 09:04:22 -07:00
Siddhesh Poyarekar
7b54aaf2ce Add NEWS item for gconv-modules.d change
Reviewed-by: DJ Delorie <dj@redhat.com>
2021-06-23 08:54:13 +05:30
Adhemerval Zanella
47f24c21ee y2038: Add support for 64-bit time on legacy ABIs
A new build flag, _TIME_BITS, enables the usage of the newer 64-bit
time symbols for legacy ABI (where 32-bit time_t is default).  The 64
bit time support is only enabled if LFS (_FILE_OFFSET_BITS=64) is
also used.

Different than LFS support, the y2038 symbols are added only for the
required ABIs (armhf, csky, hppa, i386, m68k, microblaze, mips32,
mips64-n32, nios2, powerpc32, sparc32, s390-32, and sh).  The ABIs with
64-bit time support are unchanged, both for symbol and types
redirection.

On Linux the full 64-bit time support requires a minimum of kernel
version v5.1.  Otherwise, the 32-bit fallbacks are used and might
results in error with overflow return code (EOVERFLOW).

The i686-gnu does not yet support 64-bit time.

This patch exports following rediretions to support 64-bit time:

  * libc:
    adjtime
    adjtimex
    clock_adjtime
    clock_getres
    clock_gettime
    clock_nanosleep
    clock_settime
    cnd_timedwait
    ctime
    ctime_r
    difftime
    fstat
    fstatat
    futimens
    futimes
    futimesat
    getitimer
    getrusage
    gettimeofday
    gmtime
    gmtime_r
    localtime
    localtime_r
    lstat_time
    lutimes
    mktime
    msgctl
    mtx_timedlock
    nanosleep
    nanosleep
    ntp_gettime
    ntp_gettimex
    ppoll
    pselec
    pselect
    pthread_clockjoin_np
    pthread_cond_clockwait
    pthread_cond_timedwait
    pthread_mutex_clocklock
    pthread_mutex_timedlock
    pthread_rwlock_clockrdlock
    pthread_rwlock_clockwrlock
    pthread_rwlock_timedrdlock
    pthread_rwlock_timedwrlock
    pthread_timedjoin_np
    recvmmsg
    sched_rr_get_interval
    select
    sem_clockwait
    semctl
    semtimedop
    sem_timedwait
    setitimer
    settimeofday
    shmctl
    sigtimedwait
    stat
    thrd_sleep
    time
    timegm
    timerfd_gettime
    timerfd_settime
    timespec_get
    utime
    utimensat
    utimes
    utimes
    wait3
    wait4

  * librt:
    aio_suspend
    mq_timedreceive
    mq_timedsend
    timer_gettime
    timer_settime

  * libanl:
    gai_suspend

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2021-06-15 10:42:11 -03:00
Matheus Castanho
ebae2f5a6f Add build option to disable usage of scv on powerpc
Commit 68ab82f566 added support for the scv
syscall ABI on powerpc.  Since then systems that have kernel and processor
support started using scv.  However adding the proper support for a new syscall
ABI requires changes to several other projects (e.g. qemu, valgrind, strace,
kernel), which are gradually receiving support.

Meanwhile, having a way to disable scv on glibc at build time can be useful for
distros that may encounter conflicts with projects that still do not support the
scv ABI, buying time until proper support is added.

This commit adds a --disable-scv option that disables scv support and uses sc
for all syscalls, like before commit 68ab82f566.

Reviewed-by: Raphael M Zinsly <rzinsly@linux.ibm.com>
2021-06-10 16:23:25 -03:00
Andreas Schwab
42d3593505 Use __pthread_attr_copy in mq_notify (bug 27896)
Make a deep copy of the pthread attribute object to remove a potential
use-after-free issue.
2021-06-01 17:12:33 +02:00
Joseph Myers
858045ad1c Update floating-point feature test macro handling for C2X
ISO C2X has made some changes to the handling of feature test macros
related to features from the floating-point TSes, and to exactly what
such features are present in what headers, that require corresponding
changes in glibc.

* For the few features that were controlled by
  __STDC_WANT_IEC_60559_BFP_EXT__ (and the corresponding DFP macro) in
  C2X, there is now instead a new feature test macro
  __STDC_WANT_IEC_60559_EXT__ covering both binary and decimal FP.
  This controls CR_DECIMAL_DIG in <float.h> (provided by GCC; I
  implemented support for the new feature test macro for GCC 11) and
  the totalorder and payload functions in <math.h>.  C2X no longer
  says anything about __STDC_WANT_IEC_60559_BFP_EXT__ (so it's
  appropriate for that macro to continue to enable exactly the
  features from TS 18661-1).

* The SNAN macros for each floating-point type have moved to <float.h>
  (and been renamed in the process).  Thus, the copies in <math.h>
  should only be defined for __STDC_WANT_IEC_60559_BFP_EXT__, not for
  C2X.

* The fmaxmag and fminmag functions have been removed (replaced by new
  functions for the new min/max operations in IEEE 754-2019).  Thus
  those should also only be declared for
  __STDC_WANT_IEC_60559_BFP_EXT__.

* The _FloatN / _FloatNx handling for the last two points in glibc is
  trickier, since __STDC_WANT_IEC_60559_TYPES_EXT__ is still in C2X
  (the integration of TS 18661-3 as an Annex, that is, which hasn't
  yet been merged into the C standard git repository but has been
  accepted by WG14), so C2X with that macro should not declare some
  things that are declared for older standards with that macro.  The
  approach taken here is to provide the declarations (when
  __STDC_WANT_IEC_60559_TYPES_EXT__ is enabled) only when (defined
  __USE_GNU || !__GLIBC_USE (ISOC2X)), so if C2X features are enabled
  then those declarations (that are only in TS 18661-3 and not in C2X)
  will only be provided if _GNU_SOURCE is defined as well.  Thus
  _GNU_SOURCE remains a superset of the TS features as well as of C2X.

Some other somewhat related changes in C2X are not addressed here.
There's an open proposal not to include the fmin and fmax functions
for the _FloatN / _FloatNx types, given the new min/max operations,
which could be handled like the previous point if adopted.  And the
fromfp functions have been changed to return a result in floating type
rather than intmax_t / uintmax_t; my inclination there is to treat
that like that change of totalorder type (new symbol versions etc. for
the ABI change; old versions become compat symbols and are no longer
supported as an API).

Tested for x86_64 and x86.
2021-06-01 14:22:06 +00:00
Joseph Myers
e5ac7bd679 Add C2X timespec_getres
ISO C2X adds a timespec_getres function alongside the C11
timespec_get, with functionality similar to that of POSIX clock_getres
(including allowing a NULL pointer to be passed to the function).
Implement this function for glibc, similarly to the implementation of
timespec_get.

This includes a basic test like that of timespec_get, but no
documentation in the manual, given that TIME_UTC and timespec_get
aren't documented in the manual at all.  The handling of 64-bit time
follows that in timespec_get; people maintaining patch series for
64-bit time will need to update them accordingly (to export
__timespec_getres64, redirect calls in time.h and run the test for
_TIME_BITS=64).

Tested for x86_64 and x86, and (previous version; only testcase
differs) with build-many-glibcs.py.
2021-05-17 20:55:21 +00:00