einj_mem_uc: Better handling of "-c" and copy-on-write test

If the copy-on-write test passes, then the child process gets a
SIGBUS and longjmp's back to the main loop. If "-c" had specified
to repeat the test, both parent and child will go back around.
Later loops will also include the grand-children and cousins!

Set a flag to break out of the loop for the child of a copy-on-write
test.

Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/einj_mem_uc.c b/einj_mem_uc.c
index 17567de..e394cb5 100644
--- a/einj_mem_uc.c
+++ b/einj_mem_uc.c
@@ -46,6 +46,8 @@ static int all_flag;
 static int Sflag;
 static long pagesize;
 static int *apicmap;
+static int child_process;
+
 #define	CACHE_LINE_SIZE	64
 
 #define EINJ_ETYPE "/sys/kernel/debug/apei/einj/error_type"
@@ -738,14 +740,19 @@ int trigger_copy_on_write(char *addr)
 		fprintf(stderr, "%s: fork failed\n", progname);
 		return -1;
 	case 0:
+		child_process = 1;
 		/* force kernel to copy this page */
+		PRINT_TRIGGERING;
 		*addr = '*';
 		exit(0);
 	}
 
+	fprintf(stderr, "%s: COW parent waiting for pid=%d\n", progname, pid);
 	while (wait(&status) != pid)
 		;
-	return 0;
+
+	PRINT_TRIGGERING;
+	return addr[0];
 }
 
 int trigger_patrol(char *addr)
@@ -1186,6 +1193,8 @@ skip2:
 				t = next_test(t);
 		}
 #endif
+		if (child_process)
+			break;
 	}
 
 	printf("Test passed\n");