From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Mon, 29 Aug 2016 20:56:24 +0000 (+0300)
Subject: futex: fix FUTEX_WAKE_OP compare function mask
X-Git-Tag: v4.14~154
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=bfa22a596fc6ae7f706b0d1321210021af8bcbab;p=strace

futex: fix FUTEX_WAKE_OP compare function mask

According to the initial and current (v4.7) kernel implementations,
in FUTEX_WAKE_OP case the compare function does not have
FUTEX_OP_OPARG_SHIFT flag and occupies 4 bits starting with bit 24.

* futex.c (SYS_FUNC(futex)): Do not print FUTEX_OP_OPARG_SHIFT
for 27th bit of val3 in FUTEX_WAKE_OP case.
---

diff --git a/futex.c b/futex.c
index 7090c7d0..92682168 100644
--- a/futex.c
+++ b/futex.c
@@ -92,9 +92,7 @@ SYS_FUNC(futex)
 			tprints("FUTEX_OP_OPARG_SHIFT|");
 		printxval(futexwakeops, (val3 >> 28) & 0x7, "FUTEX_OP_???");
 		tprintf(", %u, ", (val3 >> 12) & 0xfff);
-		if ((val3 >> 24) & 8)
-			tprints("FUTEX_OP_OPARG_SHIFT|");
-		printxval(futexwakecmps, (val3 >> 24) & 0x7, "FUTEX_OP_CMP_???");
+		printxval(futexwakecmps, (val3 >> 24) & 0xf, "FUTEX_OP_CMP_???");
 		tprintf(", %u}", val3 & 0xfff);
 		break;
 	case FUTEX_WAIT_REQUEUE_PI: