--- /dev/null
+// commit: 6871fd773dcedbf056317d5d5e87b4859e97c4a4 2011-03-10
+// commit: 9505bfbc40fec217820abad7142663eda60cd6be 2014-03-18
+// catching stackoverflow SIGSEGV using sigaltstack
+// mips stack_t is inconsistent with other archs
+#define _XOPEN_SOURCE 700
+#include <signal.h>
+#include <setjmp.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include "test.h"
+
+#define T(f) ((f)==0 || (t_error(#f " failed: %s\n", strerror(errno)),0))
+
+static char stack[SIGSTKSZ];
+static sigjmp_buf sbuf;
+static volatile sig_atomic_t state;
+
+static void handler(int sig)
+{
+ uintptr_t i;
+ stack_t ss;
+
+ if (state!=1)
+ t_error("handler is not invoked in fillstack (after sigsetjmp returned 0), "
+ "state is %d, want 1\n", state);
+ state++;
+
+ i = (uintptr_t)&i;
+ if (i < (uintptr_t)stack || i >= (uintptr_t)stack+SIGSTKSZ)
+ t_error("signal handler was not invoked on the altstack\n");
+
+ T(sigaltstack(0, &ss));
+ if (ss.ss_flags != SS_ONSTACK)
+ t_error("ss_flags is not SS_ONSTACK in the signal handler\n");
+
+ siglongjmp(sbuf, 1);
+}
+
+static unsigned fillstack(unsigned x)
+{
+ x++;
+ if (x==0) {
+ t_error("wrap around\n");
+ return x;
+ }
+ return fillstack(fillstack(x)) + 1;
+}
+
+int main(void)
+{
+ stack_t ss;
+ struct sigaction sa;
+
+ ss.ss_sp = stack;
+ ss.ss_size = sizeof stack;
+ ss.ss_flags = 0;
+ sa.sa_handler = handler;
+ sa.sa_flags = SA_ONSTACK;
+
+ T(sigaltstack(&ss, 0));
+ T(sigfillset(&sa.sa_mask));
+ T(sigaction(SIGSEGV, &sa, 0));
+ if (sigsetjmp(sbuf,0) == 0) {
+ state++;
+ fillstack(0);
+ t_error("infinite recursion finished\n");
+ }
+ if (state != 2)
+ t_error("sigsetjmp returned non-zero before running handler, "
+ "state is %d, want 2\n", state);
+
+ errno = 0;
+ ss.ss_size = MINSIGSTKSZ-1;
+ if (sigaltstack(&ss, 0) != -1 || errno != ENOMEM)
+ t_error("sigaltstack with stack size < MINSIGSTKSZ should have failed with ENOMEM, "
+ "got %s\n", strerror(errno));
+ errno = 0;
+ ss.ss_flags = -1;
+ ss.ss_size = MINSIGSTKSZ;
+ if (sigaltstack(&ss, 0) != -1 || errno != EINVAL)
+ t_error("sigaltstack with bad ss_flags should have failed with EINVAL, "
+ "got %s\n", strerror(errno));
+ errno = 0;
+ T(sigaltstack(0, 0));
+
+ return t_status;
+}