PowerPC Linux support from ericvh.

Mainly adding va_copy/va_end.
Also fix bug in sprint wrapping
around top of memory.

1 files changed, 10 insertions, 1 deletions

diff --git a/src/lib9/fmt/sprint.c b/src/lib9/fmt/sprint.c
index 57150c36..ac68851b 100644
--- a/src/lib9/fmt/sprint.c
+++ b/src/lib9/fmt/sprint.c
@@ -18,10 +18,19 @@ int
 sprint(char *buf, char *fmt, ...)
 {
 	int n;
+	uint len;
 	va_list args;
 
+	len = 1<<30;  /* big number, but sprint is deprecated anyway */
+	/*
+	 * on PowerPC, the stack is near the top of memory, so
+	 * we must be sure not to overflow a 32-bit pointer.
+	 */
+	if(buf+len < buf)
+		len = -(uint)buf-1;
+
 	va_start(args, fmt);
-	n = vsnprint(buf, 65536, fmt, args);	/* big number, but sprint is deprecated anyway */
+	n = vsnprint(buf, len, fmt, args);
 	va_end(args);
 	return n;
 }