The inline and library functions that the CMSG_NXTHDR macro may expand
to increment the pointer to the header before checking the stride of
the increment against available space. Since C only allows incrementing
pointers to one past the end of an array, the increment must be done
after a length check. This commit fixes that and includes a regression
test for CMSG_FIRSTHDR and CMSG_NXTHDR.
The Linux, Hurd, and generic headers are all changed.
Tested on Linux on armv7hl, i686, x86_64, aarch64, ppc64le, and s390x.
[BZ #28846]
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit 9c443ac455)
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>
(cherry picked from commit ad43cac44a)
After 73fc4e28b9,
__libc_enable_secure_decided is always 0 and a statically linked
executable may overwrite __libc_enable_secure without considering
AT_SECURE.
The __libc_enable_secure has been correctly initialized in _dl_aux_init,
so just remove __libc_enable_secure_decided and __libc_init_secure.
This allows us to remove some startup_get*id functions from
22b79ed7f4.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 3e9acce8c5)
5bf07e1b3a ("Linux: Simplify __opensock and fix race condition [BZ #28353]")
made __opensock try NETLINK then UNIX then INET. On the Hurd, only INET
knows about network interfaces, so better actually specify that in
if_index.
(cherry picked from commit 1d3decee99)
The glibc 2.34 release really should have added a GLIBC_2.34
symbol to the dynamic loader. With it, we could move functions such
as dlopen or pthread_key_create that work on process-global state
into the dynamic loader (once we have fixed a longstanding issue
with static linking). Without the GLIBC_2.34 symbol, yet another
new symbol version would be needed because old glibc will fail to
load binaries due to the missing symbol version in ld.so that newly
linked programs will require.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
(cherry picked from commit af121ae3e7)
This is an internal function meant to return the number of avaliable
processor where the process can scheduled, different than the
__get_nprocs which returns a the system available online CPU.
The Linux implementation currently only calls __get_nprocs(), which
in tuns calls sched_getaffinity.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit 11a02b035b)
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>
The malloc-check debugging feature is tightly integrated into glibc
malloc, so thanks to an idea from Florian Weimer, much of the malloc
implementation has been moved into libc_malloc_debug.so to support
malloc-check. Due to this, glibc malloc and malloc-check can no
longer work together; they use altogether different (but identical)
structures for heap management. This should not make a difference
though since the malloc check hook is not disabled anywhere.
malloc_set_state does, but it does so early enough that it shouldn't
cause any problems.
The malloc check tunable is now in the debug DSO and has no effect
when the DSO is not preloaded.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Wean mtrace away from the malloc hooks and move them into the debug
DSO. Split the API away from the implementation so that we can add
the API to libc.so as well as libc_malloc_debug.so, with the libc
implementations being empty.
Update localplt data since memalign no longer has any callers after
this change.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Split the mcheck implementation into the debugging hooks and API so
that the API can be replicated in libc and libc_malloc_debug.so. The
libc APIs always result in failure.
The mcheck implementation has also been moved entirely into
libc_malloc_debug.so and with it, all of the hook initialization code
can now be moved into the debug library. Now the initialization can
be done independently of libc internals.
With this patch, libc_malloc_debug.so can no longer be used with older
libcs, which is not its goal anyway. tst-vfork3 breaks due to this
since it spawns shell scripts, which in turn execute using the system
glibc. Move the test to tests-container so that only the built glibc
is used.
This move also fixes bugs in the mcheck version of memalign and
realloc, thus allowing removal of the tests from tests-mcheck
exclusion list.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
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>
This switches to public symbols without __ prefixes, due to improved
namespace management in glibc.
The script was used with --no-new-version to move the symbols
__res_nquery, __res_nquerydomain, __res_nsearch, __res_query,
__res_querydomain, __res_search, res_query, res_querydomain,
res_search. The public symbols res_nquery, res_nquerydomain,
res_nsearch, res_ownok, res_query, res_querydomain, res_search
were added with make update-all-abi.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This switches to public symbols without __ prefixes, due to improved
namespace management in glibc.
The symbols res_mkquery, __res_mkquery, __res_nmkquery were
moved with the script (using --no-new-version).
res_mkquery@@GLIBC_2.34, res_nmkquery@@GLIBC_2.34 were added using
make update-all-abi.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Switch to public symbols without __ prefix (due to improved
namespace management).
__res_send, __res_nsend were moved using the script (with
--no-new-version). res_send@@GLIBC_2.34 and res_nsend@@GLIBC_2.34
were added using make update-all-abi.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This reflects what the remaining functions in the file do.
The __res_dnok, __res_hnok, __res_mailok, __res_ownok were moved
with the script, using --no-new-version, and turned into compat
symbols. __libc_res_dnok@@GLIBC_PRIVATE and
__libc_res_hnok@@GLIBC_PRIVATE are added for internal use, to avoid
accidentally binding to compatibility symbols. The new public
symbols res_dnok, res_hnok, res_mailok, res_ownok were added using
make update-all-abi.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat it to GNU style.
dn_skipname is used outside glibc, so do not deprecate it,
and export it as dn_skipname (not __dn_skipname). Due to internal
users, provide a __libc_dn_skipname alias, and keep __dn_skipname
as a pure compatibility symbol.
__dn_skipname@GLIBC_2.0 was moved using the script, and
dn_skipname@@GLIBC_2.34 was added using make update-all-abi.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat it to GNU style.
dn_comp is used in various programs, so keep it as a non-deprecated
symbol. Switch to dn_comp (not __dn_comp) for the ABI name. There
are no internal users, so interposition is not a problem.
The __dn_comp symbol was moved with scripts/move-symbol-to-libc.py
--no-new-version. dn_comp@@GLIBC_2.34 was added with
make update-all-abi.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat to GNU style.
This switches back to the dn_expand name for the ABI symbol and turns
__dn_expand into a compatibility symbol. With the improved namespace
management in current glibc, it is no longer necessary to use a
private namespace symbol. To avoid old code binding to a
GLIBC_PRIVATE symbol by accident, use __libc_dn_expand for the
internal symbol name.
The symbols dn_expand, __dnexpand were moved using
scripts/move-symbol-to-libc.py, followed by an adjustment to make
dn_expand the only GLIBC_2.34 symbol.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat to GNU style.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat to GNU style, and eliminate the labellen function.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat to GNU style, and eliminate the digits variable.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat to GNU style. Check for negative error returns
(instead of -1).
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
And reformat to GNU style. Avoid out-of-bounds pointer arithmetic.
This also results in a fix of bug 28091 due to the additional packet
length checks.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@systemhalted.org>
Reformat to GNU style. Avoid out-of-bounds buffer arithmetic.
Eliminate the labellen function.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reformat to GNU style. Avoid out-of-bounds pointer arithmetic
(e.g., use eom - dn < 2 instead of dn + 1 >= eom). Inline the
labellen function and fold the compression pointer check into
the length check (l >= 64). Assume ASCII encoding.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This was put in __libc_fork by c32c868ab8 ("posix: Add _Fork [BZ #4737]")
so we need to avoid locking them again in _Fork called by __libc_lock, otherwise
we deadlock.
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
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
The symbols forkpty, login, login_tty, logout, logwtmp, openpty
were moved using scripts/move-symbol-to-libc.py.
This is a single commit because most of the symbols are tied together
via forkpty, for example.
Several changes to use hidden prototypes are needed. This commit
also updates pseudoterminal terminology on modified lines.
For 390 (31-bit), this commit follows the existing style for the
compat symbol version creation.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
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
The Linux nptl implementation is used as base for generic fork
implementation to handle the internal locks and mutexes. The
system specific bits are moved a new internal _Fork symbol.
(This new implementation will be used to provide a async-signal-safe
_Fork now that POSIX has clarified that fork might not be
async-signal-safe [1]).
For Hurd it means that the __nss_database_fork_prepare_parent and
__nss_database_fork_subprocess will be run in a slight different
order.
[1] https://austingroupbugs.net/view.php?id=62
This function has no dependency on libpthread, so the move is also
applied to Hurd.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This function has no dependency on libpthread, so the move is also
applied to Hurd.
To avoid localplt failures, use __open64_nocancel instead of
pthread_setcancelstate and open.
The symbol was moved using scripts/move-symbol-to-libc.py.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch replaced obsolete AC_TRY_COMPILE to AC_COMPILE_IFELSE or
AC_PREPROC_IFELSE.
It has been confirmed that GNU 'autoconf' 2.69 suppressed obsolete
warnings, updated the following files:
- configure
- sysdeps/mach/configure
- sysdeps/mach/hurd/configure
- sysdeps/s390/configure
- sysdeps/unix/sysv/linux/configure
and didn't change the following files:
- sysdeps/ieee754/ldbl-opt/configure
- sysdeps/unix/sysv/linux/powerpc/configure
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
In elf/Makefile, remove the $(libdl) dependency from testobj1.so
because it the unused libdl DSO now causes elf/tst-unused-deps to
fail.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The symbol was moved using scripts/move-symbol-to-libc.py.
There is a minor functionality enhancement: dlerror now sets
errno if it was set as part of the exception. (This is the result
of using %m in asprintf, to avoid the strerror PLT call.) The
previous errno value upon function return was unpredictable.
Documenting this as a feature is premature; we need to make sure
that the error codes are meaningful when they are set by the dynamic
loader.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
