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Merged
merged 4 commits into from
Jun 27, 2024
Merged

posix: add stubs for signal.h functions that need process support #74436

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85b29a5
posix: procN: add missing alias for getpid()
cfriedt Jun 17, 2024
0f00efa
posix: add stubs for signal.h functions that need process support
cfriedt Jun 17, 2024
9616c43
tests: posix: headers: add checks for posix signals option group
cfriedt Jun 17, 2024
4bd5b2c
doc: posix: mark posix signals supported with undefined behaviour
cfriedt Jun 17, 2024
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4 changes: 2 additions & 2 deletions doc/services/portability/posix/aep/index.rst
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Expand Up @@ -50,8 +50,8 @@ The *Minimal Realtime System Profile* (PSE51) includes all of the

:ref:`POSIX_C_LANG_JUMP <posix_option_group_c_lang_jump>`, yes,
:ref:`POSIX_C_LANG_SUPPORT <posix_option_group_c_lang_support>`, yes,
:ref:`POSIX_DEVICE_IO <posix_option_group_device_io>`, yes, :kconfig:option:`CONFIG_POSIX_DEVICE_IO`
:ref:`POSIX_SIGNALS <posix_option_group_signals>`,, :kconfig:option:`CONFIG_POSIX_SIGNALS`
:ref:`POSIX_DEVICE_IO <posix_option_group_device_io>`,yes, :kconfig:option:`CONFIG_POSIX_DEVICE_IO`
:ref:`POSIX_SIGNALS <posix_option_group_signals>`, yes, :kconfig:option:`CONFIG_POSIX_SIGNALS` :ref:`†<posix_undefined_behaviour>`
:ref:`POSIX_SINGLE_PROCESS <posix_option_group_single_process>`, yes, :kconfig:option:`CONFIG_POSIX_SINGLE_PROCESS`
:ref:`XSI_THREADS_EXT <posix_option_group_xsi_threads_ext>`, yes, :kconfig:option:`CONFIG_XSI_THREADS_EXT`

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28 changes: 18 additions & 10 deletions doc/services/portability/posix/option_groups/index.rst
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Expand Up @@ -244,26 +244,34 @@ POSIX_SIGNALS
Signal services are a basic mechanism within POSIX-based systems and are
required for error and event handling.

.. note::
As processes are not yet supported in Zephyr, the ISO C functions ``abort()``, ``signal()``,
and ``raise()``, as well as the other POSIX functions listed below, may exhibit undefined
behaviour. The POSIX functions ``kill()``, ``pause()``, ``sigaction()``, ``sigpending()``,
``sigsuspend()``, and ``sigwait()`` are implemented to ensure that conformant applications can
link, but they are expected to fail, setting errno to ``ENOSYS``
:ref:`†<posix_undefined_behaviour>`.

.. csv-table:: POSIX_SIGNALS
:header: API, Supported
:widths: 50,10

abort(),yes
alarm(),
kill(),
pause(),
raise(),
sigaction(),
abort(),yes :ref:`†<posix_undefined_behaviour>`
alarm(),yes :ref:`†<posix_undefined_behaviour>`
kill(),yes :ref:`†<posix_undefined_behaviour>`
pause(),yes :ref:`†<posix_undefined_behaviour>`
raise(),yes :ref:`†<posix_undefined_behaviour>`
sigaction(),yes :ref:`†<posix_undefined_behaviour>`
sigaddset(),yes
sigdelset(),yes
sigemptyset(),yes
sigfillset(),yes
sigismember(),yes
signal(),
sigpending(),
signal(),yes :ref:`†<posix_undefined_behaviour>`
sigpending(),yes :ref:`†<posix_undefined_behaviour>`
sigprocmask(),yes
sigsuspend(),
sigwait(),
sigsuspend(),yes :ref:`†<posix_undefined_behaviour>`
sigwait(),yes :ref:`†<posix_undefined_behaviour>`
strsignal(),yes

.. _posix_option_group_device_io:
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32 changes: 32 additions & 0 deletions include/zephyr/posix/signal.h
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Expand Up @@ -77,6 +77,16 @@ typedef struct {
#define SIG_UNBLOCK 2
#endif

#define SIG_DFL ((void *)0)
#define SIG_IGN ((void *)1)
#define SIG_ERR ((void *)-1)

#define SI_USER 1
#define SI_QUEUE 2
#define SI_TIMER 3
#define SI_ASYNCIO 4
#define SI_MESGQ 5

typedef int sig_atomic_t; /* Atomic entity type (ANSI) */

union sigval {
Expand All @@ -92,12 +102,34 @@ struct sigevent {
int sigev_signo;
};

typedef struct {
int si_signo;
int si_code;
union sigval si_value;
} siginfo_t;

struct sigaction {
void (*sa_handler)(int signno);
sigset_t sa_mask;
int sa_flags;
void (*sa_sigaction)(int signo, siginfo_t *info, void *context);
};
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Shouldn't it be

struct sigaction {
	void (*sa_handler)(int signno);
	void (*sa_sigaction)(int signo, siginfo_t *info, void *context);
	sigset_t sa_mask;
	int sa_flags;
};

to avoid possible hole in the struct.

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Fixed!


unsigned int alarm(unsigned int seconds);
int kill(pid_t pid, int sig);
int pause(void);
int raise(int signo);
int sigaction(int sig, const struct sigaction *ZRESTRICT act, struct sigaction *ZRESTRICT oact);
int sigpending(sigset_t *set);
int sigsuspend(const sigset_t *sigmask);
int sigwait(const sigset_t *ZRESTRICT set, int *ZRESTRICT signo);
char *strsignal(int signum);
int sigemptyset(sigset_t *set);
int sigfillset(sigset_t *set);
int sigaddset(sigset_t *set, int signo);
int sigdelset(sigset_t *set, int signo);
int sigismember(const sigset_t *set, int signo);
void (*signal(int signo, void (*)(int signo)))(int signo);
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GNU extension is so much clear :)

typedef void (*sighandler_t)(int);

sighandler_t signal(int signum, sighandler_t handler);

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It is convenient, but also a gnu-ism.

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yep :)

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I haven't seen any conflicts when using the typedef, even when building using native_sim, so I'll add it as well.

int sigprocmask(int how, const sigset_t *ZRESTRICT set, sigset_t *ZRESTRICT oset);

int pthread_sigmask(int how, const sigset_t *ZRESTRICT set, sigset_t *ZRESTRICT oset);
Expand Down
1 change: 1 addition & 0 deletions lib/libc/Kconfig
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Expand Up @@ -105,6 +105,7 @@ config NEWLIB_LIBC
imply POSIX_FD_MGMT_ALIAS_LSEEK
imply POSIX_FILE_SYSTEM_ALIAS_FSTAT
imply POSIX_MULTI_PROCESS_ALIAS_GETPID
imply POSIX_SIGNALS_ALIAS_KILL
help
Build with newlib library. The newlib library is expected to be
part of the SDK in this case.
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7 changes: 7 additions & 0 deletions lib/posix/options/Kconfig.signal
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Expand Up @@ -24,6 +24,7 @@ endif # POSIX_REALTIME_SIGNALS
config POSIX_SIGNALS
bool "POSIX signals [EXPERIMENTAL]"
select EXPERIMENTAL
select POSIX_MULTI_PROCESS
help
Enable support for POSIX signals.

Expand All @@ -36,6 +37,12 @@ config POSIX_SIGNAL_STRING_DESC
Use full description for the strsignal API.
Will use 256 bytes of ROM.

# These options are intended to be used for compatibility with external POSIX
# implementations such as those in Newlib or Picolibc.

config POSIX_SIGNALS_ALIAS_KILL
bool

endif

endmenu # "Signal support"
3 changes: 3 additions & 0 deletions lib/posix/options/multi_process.c
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Expand Up @@ -21,3 +21,6 @@ pid_t getpid(void)

return 42;
}
#ifdef CONFIG_POSIX_MULTI_PROCESS_ALIAS_GETPID
FUNC_ALIAS(getpid, _getpid, pid_t);
#endif /* CONFIG_POSIX_MULTI_PROCESS_ALIAS_GETPID */
59 changes: 59 additions & 0 deletions lib/posix/options/signal.c
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Expand Up @@ -118,3 +118,62 @@ int sigprocmask(int how, const sigset_t *ZRESTRICT set, sigset_t *ZRESTRICT oset
errno = ENOSYS;
return -1;
}

/*
* The functions below are provided so that conformant POSIX applications and libraries can still
* link.
*/

unsigned int alarm(unsigned int seconds)
{
ARG_UNUSED(seconds);
return 0;
}

int kill(pid_t pid, int sig)
{
ARG_UNUSED(pid);
ARG_UNUSED(sig);
errno = ENOSYS;
return -1;
}
#ifdef CONFIG_POSIX_SIGNALS_ALIAS_KILL
FUNC_ALIAS(kill, _kill, int);
#endif /* CONFIG_POSIX_SIGNALS_ALIAS_KILL */

int pause(void)
{
errno = ENOSYS;
return -1;
}

int sigaction(int sig, const struct sigaction *ZRESTRICT act, struct sigaction *ZRESTRICT oact)
{
ARG_UNUSED(sig);
ARG_UNUSED(act);
ARG_UNUSED(oact);
errno = ENOSYS;
return -1;
}

int sigpending(sigset_t *set)
{
ARG_UNUSED(set);
errno = ENOSYS;
return -1;
}

int sigsuspend(const sigset_t *sigmask)
{
ARG_UNUSED(sigmask);
errno = ENOSYS;
return -1;
}

int sigwait(const sigset_t *ZRESTRICT set, int *ZRESTRICT sig)
{
ARG_UNUSED(set);
ARG_UNUSED(sig);
errno = ENOSYS;
return -1;
}
65 changes: 38 additions & 27 deletions tests/posix/headers/src/signal_h.c
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Expand Up @@ -6,6 +6,8 @@

#include "_common.h"

#include <stdlib.h>

#ifdef CONFIG_POSIX_API
#include <signal.h>
#else
Expand All @@ -19,13 +21,17 @@
*/
ZTEST(posix_headers, test_signal_h)
{
/* zassert_not_equal(-1, SIG_DFL); */ /* not implemented */
/* zassert_not_equal(-1, SIG_ERR); */ /* not implemented */
typedef void *(*my_sig_handler_t)(int signo);

my_sig_handler_t handler;

handler = SIG_DFL;
handler = SIG_ERR;
handler = SIG_IGN;
/* zassert_not_equal(-1, SIG_HOLD); */ /* not implemented */
/* zassert_not_equal(-1, SIG_IGN); */ /* not implemented */

zassert_not_equal((sig_atomic_t)-1, (sig_atomic_t)0);
/* zassert_not_equal((pid_t)-1, (pid_t)0); */ /* not implemented */
zassert_not_equal((pid_t)-1, (pid_t)0);

zassert_not_equal(-1, offsetof(struct sigevent, sigev_notify));
zassert_not_equal(-1, offsetof(struct sigevent, sigev_signo));
Expand All @@ -47,6 +53,15 @@ ZTEST(posix_headers, test_signal_h)
zassert_not_equal(-1, SIG_UNBLOCK);
zassert_not_equal(-1, SIG_SETMASK);

zassert_not_equal(-1, offsetof(struct sigaction, sa_handler));
zassert_not_equal(-1, offsetof(struct sigaction, sa_mask));
zassert_not_equal(-1, offsetof(struct sigaction, sa_flags));
zassert_not_equal(-1, offsetof(struct sigaction, sa_sigaction));

zassert_not_equal(-1, offsetof(siginfo_t, si_signo));
zassert_not_equal(-1, offsetof(siginfo_t, si_code));
zassert_not_equal(-1, offsetof(siginfo_t, si_value));

/* zassert_not_equal(-1, SA_NOCLDSTOP); */ /* not implemented */
/* zassert_not_equal(-1, SA_ONSTACK); */ /* not implemented */
/* zassert_not_equal(-1, SA_RESETHAND); */ /* not implemented */
Expand Down Expand Up @@ -117,18 +132,11 @@ ZTEST(posix_headers, test_signal_h)
/* zassert_not_equal(-1, CLD_STOPPED); */ /* not implemented */
/* zassert_not_equal(-1, CLD_CONTINUED); */ /* not implemented */

/* zassert_not_equal(-1, POLL_IN); */ /* not implemented */
/* zassert_not_equal(-1, POLL_OUT); */ /* not implemented */
/* zassert_not_equal(-1, POLL_MSG); */ /* not implemented */
/* zassert_not_equal(-1, POLL_ERR); */ /* not implemented */
/* zassert_not_equal(-1, POLL_PRI); */ /* not implemented */
/* zassert_not_equal(-1, POLL_HUP); */ /* not implemented */

/* zassert_not_equal(-1, SI_USER); */ /* not implemented */
/* zassert_not_equal(-1, SI_QUEUE); */ /* not implemented */
/* zassert_not_equal(-1, SI_TIMER); */ /* not implemented */
/* zassert_not_equal(-1, SI_ASYNCIO); */ /* not implemented */
/* zassert_not_equal(-1, SI_MESGQ); */ /* not implemented */
zassert_not_equal(-1, SI_USER);
zassert_not_equal(-1, SI_QUEUE);
zassert_not_equal(-1, SI_TIMER);
zassert_not_equal(-1, SI_ASYNCIO);
zassert_not_equal(-1, SI_MESGQ);

#ifdef CONFIG_POSIX_SIGNALS
zassert_true(SIGRTMIN >= 0);
Expand Down Expand Up @@ -158,37 +166,40 @@ ZTEST(posix_headers, test_signal_h)
zassert_not_equal(-1, SIGXCPU);
zassert_not_equal(-1, SIGXFSZ);
zassert_not_equal(((sigset_t){.sig[0] = 0}).sig[0], ((sigset_t){.sig[0] = -1}).sig[0]);
zassert_not_null(sigemptyset);
zassert_not_null(sigfillset);
zassert_not_null(abort);
zassert_not_null(alarm);
zassert_not_null(kill);
zassert_not_null(pause);
zassert_not_null(pthread_sigmask);
zassert_not_null(raise);
zassert_not_null(sigaction);
zassert_not_null(sigaddset);
zassert_not_null(sigdelset);
zassert_not_null(sigemptyset);
zassert_not_null(sigfillset);
zassert_not_null(sigismember);
zassert_not_null(strsignal);
zassert_not_null(signal);
zassert_not_null(sigpending);
zassert_not_null(sigprocmask);
zassert_not_null(pthread_sigmask);
zassert_not_null(sigsuspend);
zassert_not_null(sigwait);
zassert_not_null(strsignal);
#endif /* CONFIG_POSIX_SIGNALS */

if (IS_ENABLED(CONFIG_POSIX_API)) {
/* zassert_not_null(kill); */ /* not implemented */
/* zassert_not_null(killpg); */ /* not implemented */
/* zassert_not_null(psiginfo); */ /* not implemented */
/* zassert_not_null(psignal); */ /* not implemented */
/* zassert_not_null(pthread_kill); */ /* not implemented */
/* zassert_not_null(raise); */ /* not implemented */
/* zassert_not_null(sigaction); */ /* not implemented */
/* zassert_not_null(sigaltstack); */ /* not implemented */
/* zassert_not_null(sighold); */ /* not implemented */
/* zassert_not_null(sigignore); */ /* not implemented */
/* zassert_not_null(siginterrupt); */ /* not implemented */
/* zassert_not_null(signal); */ /* not implemented */
/* zassert_not_null(sigpause); */ /* not implemented */
/* zassert_not_null(sigpending); */ /* not implemented */
/* zassert_not_null(sigqueue); */ /* not implemented */
/* zassert_not_null(sigrelse); */ /* not implemented */
/* zassert_not_null(sigset); */ /* not implemented */
/* zassert_not_null(sigsuspend); */ /* not implemented */
/* zassert_not_null(sigtimedwait); */ /* not implemented */
/* zassert_not_null(sigwait); */ /* not implemented */
/* zassert_not_null(sigwaitinfo); */ /* not implemented */
}
}
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