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author | Leonid Lisovskiy <lly.dev@gmail.com> | 2015-12-27 20:46:49 +0300 |
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committer | Waldemar Brodkorb <wbx@uclibc-ng.org> | 2016-01-01 19:48:17 +0100 |
commit | d1b1ccb72f4dee5728f0878054709721b1163f62 (patch) | |
tree | 862e6231c4472e83b911d6794f11ee6b4e84efe7 /test | |
parent | a65637cc30455841909b2676599589b702bd654e (diff) |
Fix "pselect: Use linux pselect6 syscall when available"
Commit e3c3bf2b58 introduce use of pselect6, but has following disadvantages:
* Use of userspace types in args67 structure - it breaks, for example,
configs when 32-bit uClibc-ng compiled against 64-bit kernel. Syscall
will always return EINVAL. We must use __kernel_* types and
__SYSCALL_SIGSET_T_SIZE.
* It have excess checks for NSEC_PER_SEC. Original code from select()
implementation has struct timeval => struct timespec conversion,
kernel select() syscall implementation do the same.
But none of libc versions (glibc, eglibc, musl) I know, perform similar
checks for pselect() - there is no structure fields conversions,
just struct timespec through all the calls.
To have such checks in uClibc-ng we need one example, at least.
* It is possible to avoid extra userspace reads from kernel code if
sigmask == NULL. I suggest to do it, for a few bytes cost.
* Commit didn't add test case to testsuite.
Signed-off-by: Leonid Lisovskiy <lly.dev@gmail.com>
Diffstat (limited to 'test')
-rw-r--r-- | test/unistd/tst-pselect.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/test/unistd/tst-pselect.c b/test/unistd/tst-pselect.c new file mode 100644 index 000000000..cab945119 --- /dev/null +++ b/test/unistd/tst-pselect.c @@ -0,0 +1,51 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/select.h> + +// our SIGALRM handler +void handler(int signum) { + (void)signum; + puts("got signal\n"); +} + +static int +do_test (void) +{ + int rc; + sigset_t wait_mask, mask_sigchld; + struct sigaction act; + + // block SIGALRM. We want to handle it only when we're ready + sigemptyset(&mask_sigchld); + sigaddset(&mask_sigchld, SIGALRM); + sigprocmask(SIG_BLOCK, &mask_sigchld, &wait_mask); + sigdelset(&wait_mask, SIGALRM); + + // register a signal handler so we can see when the signal arrives + memset(&act, 0, sizeof(act)); + sigemptyset(&act.sa_mask); // just in case an empty set isn't all 0's (total paranoia) + act.sa_handler = handler; + sigaction(SIGALRM, &act, NULL); + + // send ourselves a SIGARLM. It will pend until we unblock that signal in pselect() + printf("sending ourselves a signal\n"); + kill(getpid(), SIGALRM); + + printf("signal is pending; calling pselect()\n"); + rc = pselect(0, NULL, NULL, NULL, NULL, &wait_mask); + if (rc != -1 || errno != EINTR) { + int e = errno; + printf("pselect() returned %d, errno %d (%s)\n", rc, e, strerror(e)); + exit(1); + } + + return 0; +} + +#define TEST_FUNCTION do_test () +#include <test-skeleton.c> |