Allocate a working buffer before calling `fork()` to avoid calling
`malloc()` in the async-signal-safe context between `fork()` and
`exec()`, where it’s not safe to use.
In this case, the buffer is used to assemble a wrapper around `argv` so
it can be run under `/bin/sh`.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #2140
Allocate a working buffer before calling `fork()` to avoid calling
`malloc()` in the async-signal-safe context between `fork()` and
`exec()`, where it’s not safe to use.
In this case, the buffer is used to assemble elements from `PATH` with
the binary from `argv[0]` to try executing them.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
Query the environment before calling `fork()` so that it doesn’t have to
be called in the async-signal-safe context between `fork()` and
`exec()`.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
They’re not safe to call in an async-signal-safe context on Linux.
`sysconf()` is safe to call on FreeBSD and OpenBSD (at least), so
continue doing that.
This will reduce performance in the (already low performance) fallback
case where `/proc` is inaccessible to a forked process on Linux, while
spawning a subprocess.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
Use the error handling infrastructure which already exists for other
failures in the async-signal-safe context.
`g_assert()` is unlikely to have caused problems in practice because it
is only async-signal-unsafe when the assertion condition fails.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
While `g_ascii_isdigit()` *is* currently async-signal-safe, it’s going
to be hard to remember to keep it that way if the implementation changes
in future.
It seems more robust to just reimplement it here, given that it’s not
much code.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
Use normal `close()` instead, which is guaranteed to be
async-signal-safe.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
Functions called between `fork()` and `exec()` have to be
async-signal-safe.
Add a comment to each function which is called in that context, and
`FIXME` comments to the non-async-signal-safe functions which end up
being called as leaves of the call graph.
The following commits will fix those `FIXME`s.
See `man 7 signal-safety`.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #2140
While these assertions look right at the first glance,
they actually crash the program. That's because GObject
insists on initializing all construct-only properties
to their default values, which results in
g_win32_registry_key_set_property() being called multiple
times with NULL string, once for each unset property.
If "path" is actually set by the caller, a subsequent
call to set "path-utf16" to NULL will fail an assertion,
since absolute_path is already non-NULL.
With assertions moved the set-to-NULL calls bail out before
an assertion is made.
Have the generated .c code decorate the prototypes with "G_MODULE_EXPORT"
instead of "extern" when --internal is not being used, so that we also
export the symbols from the generated code on Visual Studio-style
compilers. If --internal is used, we decorate the prototypes with
"G_GNUC_INTERNAL", as we did before.
Note that since the generated .c code does not attempt to include the
generated headers (if one is also generated), the gnerated headers are
still generated as they were before.
When timeout grater than 0 in g_poll function, the WaitForMultipleObjects
call will wait for all the threads to return, but when only one thread
got an event the others will sleep until the timeout elapses, and causes
a stall. Triggering the stop event in g_poll in this case is useless as
it is triggered when all the threads where already signaled or timed-out.
Closes: https://gitlab.gnome.org/GNOME/glib/issues/2107
With a trivial file that just includes glib.h:
#include <glib.h>
Compiled with:
gcc -c test.c \
-I /tmp/glib/include/glib-2.0/ \
-I /tmp/glib/lib/x86_64-linux-gnu/glib-2.0/include \
-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_28 \
-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_28 \
-fmax-errors=1 \
-Werror
We get:
In file included from /tmp/glib/include/glib-2.0/glib/gasyncqueue.h:32,
from /tmp/glib/include/glib-2.0/glib.h:32,
from test.c:1:
/tmp/glib/include/glib-2.0/glib/gthread.h: In function ‘g_rec_mutex_locker_new’:
/tmp/glib/include/glib-2.0/glib/gthread.h:396:3: error: ‘g_rec_mutex_lock’ is deprecated: Not available before 2.32 [-Werror=deprecated-declarations]
396 | g_rec_mutex_lock (rec_mutex);
| ^~~~~~~~~~~~~~~~
/tmp/glib/include/glib-2.0/glib/gthread.h:196:17: note: declared here
196 | void g_rec_mutex_lock (GRecMutex *rec_mutex);
| ^~~~~~~~~~~~~~~~
compilation terminated due to -fmax-errors=1.
The problem is that the code in the static inline functions uses
g_rec_mutex_lock, introduced after 2.28. This code is compiled
regardless of if it's actually used or not.
Suppress the warning by using G_GNUC_BEGIN_IGNORE_DEPRECATIONS /
G_GNUC_END_IGNORE_DEPRECATIONS. There are precedents for doing that,
for example g_main_context_pusher_new in gmain.h.
Tested by building with all variations of GLIB_VERSION_MIN_REQUIRED /
GLIB_VERSION_MAX_ALLOWED:
for i in $(seq 26 2 64); do
gcc -c test.c \
-I/tmp/glib/include/glib-2.0 \
-I/tmp/glib/lib/x86_64-linux-gnu/glib-2.0/include \
-DGLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_$i \
-DGLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_$i \
-fmax-errors=1 \
-Werror
done
Fixes: #2094
pip in MSYS2 seems to install scripts into $USERPROFILE instead of $HOME
which means the MSYS2 meson, which is newer, wins. Make sure $USERPROFILE
is in PATH as well.
g_ptr_array_extend_and_steal() leaves the GPtrArray in an invalid state,
so if you would try to append another pointer, it leads to a crash.
Also adjust the test case so that it would result in the crash (without
the fix).
Fixes: 0675703af08d ('Adding g_ptr_array_extend_and_steal() function to glib/garray.c')
There’s no need to call `access()` and then `stat()` on the keyring
directory to check that it exists, is a directory, and has the right
permissions. Just call `stat()`.
This eliminates one potential TOCTTOU race in this code.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Helps: #1954
There was a time-of-check-to-time-of-use (TOCTTOU) race in the keyring
lock code, where it would check the existence of the lock file using
`access()`, then proceed to call `open(O_CREAT | O_EXCL)` to try and
create the lock file once `access()` showed that it didn’t exist.
The problem is that, because this is happening in a shared directory
(`~/.dbus-keyrings`), another process could quite legitimately create
the lock file in the meantime.
Instead, unconditionally call `open()` and ignore errors from it (which
will be returned if the lock file already exists) until it succeeds (or
the code times out).
This eliminates the TOCTTOU race, and simplifies the timeout behaviour
so there aren’t two loops (check for existence, try to create)
happening. It brings this code in line with what dbus.git does (see
`_dbus_keyring_lock()`).
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1954
When multiple tests were run in parallel, this would race on its access
to `~/.dbus-keyrings` to authenticate with the D-Bus server, since the
keyring directory was not appropriately sandboxed to the unit test.
Use `G_TEST_OPTION_ISOLATE_DIRS` to automatically isolate each unit
test’s directory usage.
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Fixes: #1954
gitlab will drop cmd.exe support with GitLab 13 so I took the opportunity to
add new runners with Windows 2016 and powershell as default.
These runners are tagged with win32-ps instead of win32. The old runners
will be switched off in the coming weeks.
The main difference is that all commands and env expansions use powershell
and Windows 2016 instead of 2012r2.
The GIO tests memory-monitor-dbus and memory-monitor-portal use a number
of third party Python modules that may not be present when running the
test case.
Instead of failing due to missing imports, catch the ImportError and
mock a test case that skips. This can't use the usual unittest.skip
logic because the test case class itself uses a 3rd party module.
Closes#2083.
There are two memory monitor tests that use Python's unittest module directly,
but GLib tests should be outputting TAP. Use the embedded TAPTestRunner to
ensure that TAP is output for these tests too.
By default, meson builds glib with -Werror=format=2, which
implies -Werror=format-nonliteral. With these flags, clang errors
out on e.g. the g_message_win32_error function, due to "format
string is not a string literal". This function takes a format
string, and passes the va_list of the arguments onwards to
g_strdup_vprintf, which is annotated with printf attributes.
When passing a string+va_list to another function, GCC doesn't warn
with -Wformat-nonliteral. Clang however does warn, unless the
functions themselves (g_message_win32_error and set_error) are decorated
with similar printf attributes (to force the same checks upon the
caller) - see
https://clang.llvm.org/docs/AttributeReference.html#format
for reference.
Adding these attributes revealed one existing mismatched format string
(fixed in the preceding commit).
