Harden the detection of broken makecontext: check that makecontext arguments can...

[simgrid.git] / acmacro / context.m4

diff --git a/acmacro/context.m4 b/acmacro/context.m4
index 152ed2d..604457e 100644 (file)
--- a/acmacro/context.m4
+++ b/acmacro/context.m4
@@ -1,7 +1,7 @@
 dnl AC_CHECK_UCONTEXT: Check whether ucontext are working
 
 dnl Most of the code is stolen from the GNU pth autoconf macros by
-dnl Ralf S. Engelschall. As 
+dnl Ralf S. Engelschall. 
 dnl # ``"Reuse an expert's code" is the right
 dnl #   advice for most people. But it's a useless
 dnl #   advice for the experts writing the code
@@ -67,7 +67,7 @@ dnl ##        ...stack grow up...
 dnl ##    #endif
 dnl ##
 
-AC_DEFUN(AC_CHECK_STACKGROWTH,[dnl
+AC_DEFUN([AC_CHECK_STACKGROWTH],[dnl
 AC_MSG_CHECKING(for direction of stack growth)
 AC_CACHE_VAL(ac_cv_check_stackgrowth, [
 cross_compiling=no
@@ -122,7 +122,7 @@ dnl ##  configure.ac:
 dnl ##     AC_CHECK_MCSC(<success-action>, <failure-action>)
 dnl ##
 
-AC_DEFUN(AC_CHECK_MCSC, [
+AC_DEFUN([AC_CHECK_MCSC], [
 AC_MSG_CHECKING(for usable SVR4/SUSv2 makecontext(2)/swapcontext(2))
 AC_CACHE_VAL(ac_cv_check_mcsc, [
 AC_TRY_RUN([
@@ -136,10 +136,10 @@ ucontext_t uc_main;
 
 void child(void *arg)
 {
-    if (arg != (void *)12345)
+    if (arg != (void *)2147483648)
         exit(1);
     if (swapcontext(&uc_child, &uc_main) != 0)
-        exit(1);
+        exit(2);
 }
 
 int main(int argc, char *argv[])
@@ -149,28 +149,28 @@ int main(int argc, char *argv[])
 
     /* the default is that it fails */
     if ((fp = fopen("conftestval", "w")) == NULL)
-        exit(1);
+        exit(3);
     fprintf(fp, "no\n");
     fclose(fp);
 
     /* configure a child user-space context */
     if ((stack = malloc(64*1024)) == NULL)
-        exit(1);
+        exit(4);
     if (getcontext(&uc_child) != 0)
-        exit(1);
+        exit(5);
     uc_child.uc_link = NULL;
     uc_child.uc_stack.ss_sp = (char *)stack+(32*1024);
     uc_child.uc_stack.ss_size = 32*1024;
     uc_child.uc_stack.ss_flags = 0;
-    makecontext(&uc_child, child, 2, (void *)12345);
+    makecontext(&uc_child, child, 2, (void *)2147483648);
 
     /* switch into the user context */
     if (swapcontext(&uc_main, &uc_child) != 0)
-        exit(1);
+        exit(6);
 
     /* Fine, child came home */
     if ((fp = fopen("conftestval", "w")) == NULL)
-        exit(1);
+        exit(7);
     fprintf(fp, "yes\n");
     fclose(fp);
 
@@ -209,7 +209,7 @@ dnl ##    xxx.sp_ss   = <macro-addr>(skaddr, sksize);
 dnl ##    xxx.sp_size = <macro-size>(skaddr, sksize);
 dnl ##
 
-AC_DEFUN(AC_CHECK_STACKSETUP,[dnl
+AC_DEFUN([AC_CHECK_STACKSETUP],[dnl
 dnl #   check for consistent usage
 ifelse($1,[sigstack],,[
 ifelse($1,[sigaltstack],,[