From: Dmitry V. Levin <ldv@altlinux.org>
Date: Mon, 26 Dec 2016 11:19:18 +0000 (+0000)
Subject: lseek: simplify _llseek syscall decoder
X-Git-Tag: v4.16~151
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5477470e9c1c0d192ddd0e301c1b636d9b86d429;p=strace

lseek: simplify _llseek syscall decoder

After transition from long to kernel_ulong_t the implementation
could be made a bit simpler.

* lseek.c (SYS_FUNC(llseek)): Use direct cast to long long instead
of zero_extend_signed_to_ull.
---

diff --git a/lseek.c b/lseek.c
index 0dd43942..18d847b6 100644
--- a/lseek.c
+++ b/lseek.c
@@ -75,16 +75,15 @@ SYS_FUNC(lseek)
  * ((loff_t) hi << 32) | lo
  * Note that for architectures with kernel's long wider than userspace long
  * (such as x32), combining code will use *kernel's*, i.e. *wide* longs
- * for hi and lo. We would need to use tcp->ext_arg[N] on x32...
- * ...however, x32 (and x86_64) does not _have_ llseek syscall as such.
+ * for hi and lo.
  */
 SYS_FUNC(llseek)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprintf(", %lld, ",
-			(zero_extend_signed_to_ull(tcp->u_arg[1]) << 32)
-			| zero_extend_signed_to_ull(tcp->u_arg[2]));
+			  ((long long) tcp->u_arg[1] << 32)
+			| ((long long) tcp->u_arg[2]));
 	} else {
 		printnum_int64(tcp, tcp->u_arg[3], "%" PRIu64);
 		tprints(", ");