From: Dmitry V. Levin <ldv@altlinux.org>
Date: Mon, 15 Feb 2016 18:30:02 +0000 (+0000)
Subject: Print offsets in lseek and _llseek syscalls as signed integers
X-Git-Tag: v4.12~541
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ddbede5d9c452c076a46e9096fe5ed1921d1d008;p=strace

Print offsets in lseek and _llseek syscalls as signed integers

* lseek.c (SYS_FUNC(lseek)): Print offset using %lld format.
(SYS_FUNC(llseek)): Likewise.  Treat high and low components of offset
as unsigned long integers.
* tests/llseek.c (main): Check that negative offset is printed properly.
* tests/lseek.c (main): Likewise.
---

diff --git a/lseek.c b/lseek.c
index fe4b695c..cfc6b586 100644
--- a/lseek.c
+++ b/lseek.c
@@ -7,7 +7,7 @@
  * Copyright (c) 2009 Andreas Schwab <schwab@redhat.com>
  * Copyright (c) 2012 H.J. Lu <hongjiu.lu@intel.com>
  * Copyright (c) 2013 Denys Vlasenko <vda.linux@googlemail.com>
- * Copyright (c) 2014-2015 Dmitry V. Levin <ldv@altlinux.org>
+ * Copyright (c) 2014-2016 Dmitry V. Levin <ldv@altlinux.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,10 +47,9 @@
 #if defined(LINUX_MIPSN32) || defined(X32)
 SYS_FUNC(lseek)
 {
-	long long offset;
-	int whence;
-
 	printfd(tcp, tcp->u_arg[0]);
+
+	long long offset;
 # ifdef X32
 	/* tcp->ext_arg is not initialized for i386 personality */
 	if (current_personality == 1)
@@ -58,11 +57,9 @@ SYS_FUNC(lseek)
 	else
 # endif
 	offset = tcp->ext_arg[1];
-	whence = tcp->u_arg[2];
-	if (whence == SEEK_SET)
-		tprintf(", %llu, ", offset);
-	else
-		tprintf(", %lld, ", offset);
+	int whence = tcp->u_arg[2];
+
+	tprintf(", %lld, ", offset);
 	printxval(whence_codes, whence, "SEEK_???");
 
 	return RVAL_DECODED | RVAL_LUDECIMAL;
@@ -70,16 +67,23 @@ SYS_FUNC(lseek)
 #else
 SYS_FUNC(lseek)
 {
-	long offset;
-	int whence;
-
 	printfd(tcp, tcp->u_arg[0]);
-	offset = tcp->u_arg[1];
-	whence = tcp->u_arg[2];
-	if (whence == SEEK_SET)
-		tprintf(", %lu, ", offset);
-	else
-		tprintf(", %ld, ", offset);
+
+	long offset =
+# if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
+#  ifdef X86_64
+		current_personality == 1 ?
+			(long)(int) tcp->u_arg[1] : tcp->u_arg[1];
+#  else
+		current_wordsize == 4 ?
+			(long)(int) tcp->u_arg[1] : tcp->u_arg[1];
+#  endif
+# else
+		tcp->u_arg[1];
+# endif
+	int whence = tcp->u_arg[2];
+
+	tprintf(", %ld, ", offset);
 	printxval(whence_codes, whence, "SEEK_???");
 
 	return RVAL_DECODED | RVAL_UDECIMAL;
@@ -103,14 +107,9 @@ SYS_FUNC(llseek)
 {
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
-		if (tcp->u_arg[4] == SEEK_SET)
-			tprintf(", %llu, ",
-				((long long) tcp->u_arg[1]) << 32 |
-				(unsigned long long) (unsigned) tcp->u_arg[2]);
-		else
-			tprintf(", %lld, ",
-				((long long) tcp->u_arg[1]) << 32 |
-				(unsigned long long) (unsigned) tcp->u_arg[2]);
+		tprintf(", %lld, ",
+			((unsigned long long) (unsigned long) tcp->u_arg[1]) << 32
+			| (unsigned long long) (unsigned long) tcp->u_arg[2]);
 	} else {
 		printnum_int64(tcp, tcp->u_arg[3], "%" PRIu64);
 		tprints(", ");
diff --git a/tests/llseek.c b/tests/llseek.c
index a9d1914a..2f691711 100644
--- a/tests/llseek.c
+++ b/tests/llseek.c
@@ -38,16 +38,16 @@
 int
 main(void)
 {
-	const unsigned long high = 0xdefaced;
+	const unsigned long high = 0xfacefeed;
 	const unsigned long low = 0xdeadbeef;
-	const unsigned long long offset = 0xdefaceddeadbeef;
+	const long long offset = 0xfacefeeddeadbeefLL;
 	unsigned long long result;
 
 	assert(syscall(__NR__llseek, -1, high, low, &result, SEEK_SET) == -1);
 	if (EBADF != errno)
 		perror_msg_and_skip("_llseek");
 
-	printf("_llseek(-1, %llu, %p, SEEK_SET) = -1 EBADF (%m)\n",
+	printf("_llseek(-1, %lld, %p, SEEK_SET) = -1 EBADF (%m)\n",
 	       offset, &result);
 
 	puts("+++ exited with 0 +++");
diff --git a/tests/lseek.c b/tests/lseek.c
index 9dcf0cad..227c4e30 100644
--- a/tests/lseek.c
+++ b/tests/lseek.c
@@ -39,7 +39,7 @@
 int
 main(void)
 {
-	const kernel_ulong_t offset = (kernel_ulong_t) 0xdefaced0badc0deULL;
+	const kernel_ulong_t offset = (kernel_ulong_t) 0xfacefeeddeadbeefULL;
 
 	if (sizeof(offset) > sizeof(long))
 		assert(lseek(-1, offset, SEEK_SET) == -1);
@@ -49,8 +49,12 @@ main(void)
 	if (EBADF != errno)
 		perror_msg_and_skip("lseek");
 
-	printf("lseek(-1, %llu, SEEK_SET) = -1 EBADF (%m)\n",
-	       (unsigned long long) offset);
+	if (sizeof(offset) > sizeof(long))
+		printf("lseek(-1, %lld, SEEK_SET) = -1 EBADF (%m)\n",
+		       (long long) offset);
+	else
+		printf("lseek(-1, %ld, SEEK_SET) = -1 EBADF (%m)\n",
+		       (long) offset);
 
 	puts("+++ exited with 0 +++");
 	return 0;