Hi Thomas,
On Fri, 2025-08-01 at 17:09 +0200, Thomas Weißschuh wrote:
On 2025-07-31 22:12:25+0200, Benjamin Berg wrote:
From: Benjamin Berg benjamin.berg@intel.com
Add support for sigaction() using the rt_sigaction syscall and implement the normal sa_mask helpers.
For the uapi definitions, everything is copied into nolibc. This avoids issues with kernel architecture headers that are not usable with the rt_sigaction syscall.
Signed-off-by: Benjamin Berg benjamin.berg@intel.com
v3:
- put everything into signal.h and the new asm-signal.h
Hm, did we decide on that? We don't want the per-architecture include dance, but static overrides should still be fine I think. Keeping the architecture ifdeffery inside the respective arch header. And all the generic stuff in a shared header.
I probably just didn't really understand what you meant :-)
You are right, we can have the common definitions in signal.h and just skip them if the architecture header did already define them.
I think I'll also drop asm-signal.h again, see below.
- split out sigset_t tests
- actually mark signal_check static
- remove unused string.h include
- fix SIGUSR2 reset
- Use integer for signal_check as the signals are emitted from the
syscall context.
I don't understand this point, isn't it a signal handler?
My reasoning is, that the signal emission by the kernel happens from the kill syscall or function return. Both cases implicitly act as a memory barrier. So in this specific case we do not actually need an atomic variable.
v2:
- Use newly added macros to check signal emission order
- Add tests for sigset handling
- Restore the default handler after signal test
- make signal_check variable static
v1:
- Update architecture support (adding sh)
- Move sparc sys_rt_sigaction logic into its header
- Add sig_atomic_t
- Use new BITSET_* macros
- Move test into syscall suite
- Various other small changes
tools/include/nolibc/Makefile | 1 + tools/include/nolibc/arch-s390.h | 4 +- tools/include/nolibc/asm-signal.h | 237 +++++++++++++++++++ tools/include/nolibc/signal.h | 179 ++++++++++++++ tools/include/nolibc/sys.h | 2 +- tools/include/nolibc/sys/wait.h | 1 + tools/include/nolibc/time.h | 2 +- tools/include/nolibc/types.h | 9 + tools/testing/selftests/nolibc/nolibc-test.c | 134 +++++++++++ 9 files changed, 566 insertions(+), 3 deletions(-) create mode 100644 tools/include/nolibc/asm-signal.h
(...)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 295e71d34aba..a790e816565b 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -14,7 +14,6 @@ /* system includes */ #include <linux/unistd.h> -#include <linux/signal.h> /* for SIGCHLD */ #include <linux/termios.h> #include <linux/mman.h> #include <linux/fs.h> @@ -28,6 +27,7 @@ #include "errno.h" #include "stdarg.h" #include "types.h" +#include "asm-signal.h" /* for SIGCHLD */
#include "signal.h"
Right, this and asm-signal.h happened because signal.h uses sys_kill() for raise(), resulting in a circular dependency.
The simplest solution is probably to avoid the circular include by implementing raise() as:
int raise(int signal); __attribute__((weak,unused,section(".text.nolibc_raise"))) int raise(int signal) { return my_syscall2(__NR_kill, my_syscall0(__NR_getpid), signal); }
/* Syscall return helper: takes the syscall value in argument and checks for an diff --git a/tools/include/nolibc/sys/wait.h b/tools/include/nolibc/sys/wait.h index 56ddb806da7f..e2aa90cc3cf3 100644 --- a/tools/include/nolibc/sys/wait.h +++ b/tools/include/nolibc/sys/wait.h @@ -10,6 +10,7 @@ #ifndef _NOLIBC_SYS_WAIT_H #define _NOLIBC_SYS_WAIT_H +#include <asm/siginfo.h>
#include "signal.h"
The asm/ usage should be hidden.
#include "../arch.h" #include "../std.h" #include "../types.h"
(...)
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 180f0436127a..75b96eaa4c65 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -1269,6 +1269,138 @@ int test_namespace(void) return ret; } +int test_sigset_t(int test_idx) +{
- int llen;
- int ret = 0;
+#ifdef NOLIBC
- if (is_nolibc) {
This looks unnecessary. The #ifdef should be sufficient.
sigset_t sigset;(...)
Looks nice, thanks!
Great, thanks for the reviews!
Benjamin Intel Deutschland GmbH Registered Address: Am Campeon 10, 85579 Neubiberg, Germany Tel: +49 89 99 8853-0, www.intel.de Managing Directors: Sean Fennelly, Jeffrey Schneiderman, Tiffany Doon Silva Chairperson of the Supervisory Board: Nicole Lau Registered Office: Munich Commercial Register: Amtsgericht Muenchen HRB 186928