From: Dmitry V. Levin <ldv@altlinux.org>
Date: Fri, 19 Aug 2016 22:57:27 +0000 (+0000)
Subject: Fix decoding of indirect shmat's return code for non-native personalities
X-Git-Tag: v4.14~187
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3dfed0ef4e52d71d3bcad6127e1f6b78b9206721;p=strace

Fix decoding of indirect shmat's return code for non-native personalities

* ipc_shm.c (SYS_FUNC(shmat)): Fetch current_wordsize bytes of data
to obtain return code of indirect shmat subcall.
---

diff --git a/ipc_shm.c b/ipc_shm.c
index b2059c2b..e8a8206b 100644
--- a/ipc_shm.c
+++ b/ipc_shm.c
@@ -72,10 +72,14 @@ SYS_FUNC(shmat)
 		if (syserror(tcp))
 			return 0;
 		if (indirect_ipccall(tcp)) {
-			unsigned long raddr;
-			if (umove(tcp, tcp->u_arg[2], &raddr) < 0)
+			union {
+				uint64_t r64;
+				uint32_t r32;
+			} u;
+			if (umoven(tcp, tcp->u_arg[2], current_wordsize, &u) < 0)
 				return RVAL_NONE;
-			tcp->u_rval = raddr;
+			tcp->u_rval = (sizeof(u.r32) == current_wordsize)
+				      ? u.r32 : u.r64;
 		}
 		return RVAL_HEX;
 	}