From: Denys Vlasenko <dvlasenk@redhat.com>
Date: Tue, 5 Nov 2013 15:20:16 +0000 (+0100)
Subject: Truncate arg[0] to int in select decoding.
X-Git-Tag: v4.9~177
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1f65c3cd2ac24c6fcc6a8eb3eb88cd6161c25c88;p=strace

Truncate arg[0] to int in select decoding.

This matches kernel's behavior.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
---

diff --git a/desc.c b/desc.c
index 384b1472..bbdc0872 100644
--- a/desc.c
+++ b/desc.c
@@ -481,16 +481,17 @@ static int
 decode_select(struct tcb *tcp, long *args, enum bitness_t bitness)
 {
 	int i, j;
-	unsigned nfds, fdsize;
+	int nfds, fdsize;
 	fd_set *fds;
 	const char *sep;
 	long arg;
 
-	fdsize = args[0];
+	/* Kernel truncates arg[0] to int, we do the same */
+	fdsize = (int)args[0];
 	/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
-	if (args[0] > 1024*1024)
+	if (fdsize > 1024*1024)
 		fdsize = 1024*1024;
-	if (args[0] < 0)
+	if (fdsize < 0)
 		fdsize = 0;
 	nfds = fdsize;
 	fdsize = (((fdsize + 7) / 8) + sizeof(long)-1) & -sizeof(long);