From: Dmitry V. Levin <ldv@altlinux.org>
Date: Mon, 16 May 2016 21:01:43 +0000 (+0000)
Subject: Fix decoding of fcntl/fcntl64 operation argument
X-Git-Tag: v4.12~155
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=77086594ce4ff74a6afa5d4570d2a1dfbc5ae3c5;p=strace

Fix decoding of fcntl/fcntl64 operation argument

Consistently treat operation argument of fcntl/fcntl64 syscalls as int
to match the kernel behaviour.

* fcntl.c (print_fcntl, SYS_FUNC(fcntl), SYS_FUNC(fcntl64)): Assign
2nd argument of syscall to a variable of type unsigned int
and use it in all subsequent checks and lookups.
* tests/struct_flock.c (invoke_test_syscall): New function.
(test_flock_einval, test_flock): Use it.
* tests/fcntl.c (test_flock64_einval): Use it.
* tests/fcntl64.c (test_flock64_einval, test_flock64): Use it.
---

diff --git a/fcntl.c b/fcntl.c
index e2a76f98..59eca9db 100644
--- a/fcntl.c
+++ b/fcntl.c
@@ -87,7 +87,9 @@ print_f_owner_ex(struct tcb *tcp, const long addr)
 static int
 print_fcntl(struct tcb *tcp)
 {
-	switch (tcp->u_arg[1]) {
+	const unsigned int cmd = tcp->u_arg[1];
+
+	switch (cmd) {
 	case F_SETFD:
 		tprints(", ");
 		printflags(fdflags, tcp->u_arg[2], "FD_???");
@@ -194,8 +196,8 @@ SYS_FUNC(fcntl)
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
-		const char *str =
-			xlookup(fcntlcmds, (unsigned long) tcp->u_arg[1]);
+		const unsigned int cmd = tcp->u_arg[1];
+		const char *str = xlookup(fcntlcmds, cmd);
 		if (str) {
 			tprints(str);
 		} else {
@@ -204,7 +206,7 @@ SYS_FUNC(fcntl)
 			 * constants, but we would like to show them
 			 * for better debugging experience.
 			 */
-			printxval(fcntl64cmds, tcp->u_arg[1], "F_???");
+			printxval(fcntl64cmds, cmd, "F_???");
 		}
 	}
 	return print_fcntl(tcp);
@@ -212,18 +214,18 @@ SYS_FUNC(fcntl)
 
 SYS_FUNC(fcntl64)
 {
+	const unsigned int cmd = tcp->u_arg[1];
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
-		const char *str =
-			xlookup(fcntl64cmds, (unsigned long) tcp->u_arg[1]);
+		const char *str = xlookup(fcntl64cmds, cmd);
 		if (str) {
 			tprints(str);
 		} else {
-			printxval(fcntlcmds, tcp->u_arg[1], "F_???");
+			printxval(fcntlcmds, cmd, "F_???");
 		}
 	}
-	switch (tcp->u_arg[1]) {
+	switch (cmd) {
 		case F_SETLK64:
 		case F_SETLKW64:
 			tprints(", ");
diff --git a/tests/fcntl.c b/tests/fcntl.c
index dfad530a..1ea83e14 100644
--- a/tests/fcntl.c
+++ b/tests/fcntl.c
@@ -44,7 +44,7 @@ test_flock64_einval(const int cmd, const char *name)
 		.l_start = 0xdefaced1facefeed,
 		.l_len = 0xdefaced2cafef00d
 	};
-	syscall(TEST_SYSCALL_NR, 0, cmd, &fl);
+	invoke_test_syscall(cmd, &fl);
 	printf("%s(0, %s, %p) = %s\n",
 	       TEST_SYSCALL_STR, name, &fl, EINVAL_STR);
 }
diff --git a/tests/fcntl64.c b/tests/fcntl64.c
index 726576e6..b83a098d 100644
--- a/tests/fcntl64.c
+++ b/tests/fcntl64.c
@@ -44,7 +44,7 @@ test_flock64_einval(const int cmd, const char *name)
 		.l_start = 0xdefaced1facefeed,
 		.l_len = 0xdefaced2cafef00d
 	};
-	syscall(TEST_SYSCALL_NR, 0, cmd, &fl);
+	invoke_test_syscall(cmd, &fl);
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl.l_start, (intmax_t) fl.l_len, EINVAL_STR);
@@ -64,7 +64,7 @@ test_flock64(void)
 		.l_type = F_RDLCK,
 		.l_len = FILE_LEN
 	};
-	int rc = syscall(TEST_SYSCALL_NR, 0, F_SETLK64, &fl);
+	long rc = invoke_test_syscall(F_SETLK64, &fl);
 	printf("%s(0, F_SETLK64, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, rc ? EINVAL_STR : "0");
@@ -72,12 +72,12 @@ test_flock64(void)
 	if (rc)
 		return;
 
-	syscall(TEST_SYSCALL_NR, 0, F_GETLK64, &fl);
+	invoke_test_syscall(F_GETLK64, &fl);
 	printf("%s(0, F_GETLK64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
-	syscall(TEST_SYSCALL_NR, 0, F_SETLK64, &fl);
+	invoke_test_syscall(F_SETLK64, &fl);
 	printf("%s(0, F_SETLK64, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
diff --git a/tests/struct_flock.c b/tests/struct_flock.c
index fd427501..aae71a03 100644
--- a/tests/struct_flock.c
+++ b/tests/struct_flock.c
@@ -42,6 +42,14 @@
 # define TYPEOF_FLOCK_OFF_T off_t
 #endif
 
+static long
+invoke_test_syscall(const unsigned int cmd, void *const p)
+{
+	const unsigned long op = (unsigned long) 0xffffffff00000000 | cmd;
+
+	return syscall(TEST_SYSCALL_NR, 0, op, (unsigned long) p);
+}
+
 static void
 test_flock_einval(const int cmd, const char *name)
 {
@@ -50,7 +58,7 @@ test_flock_einval(const int cmd, const char *name)
 		.l_start = (TYPEOF_FLOCK_OFF_T) 0xdefaced1facefeed,
 		.l_len = (TYPEOF_FLOCK_OFF_T) 0xdefaced2cafef00d
 	};
-	syscall(TEST_SYSCALL_NR, 0, cmd, &fl);
+	invoke_test_syscall(cmd, &fl);
 	printf("%s(0, %s, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=%jd, l_len=%jd}) = %s\n", TEST_SYSCALL_STR, name,
 	       (intmax_t) fl.l_start, (intmax_t) fl.l_len, EINVAL_STR);
@@ -66,19 +74,19 @@ test_flock(void)
 		.l_type = F_RDLCK,
 		.l_len = FILE_LEN
 	};
-	int rc = syscall(TEST_SYSCALL_NR, 0, F_SETLK, &fl);
+	long rc = invoke_test_syscall(F_SETLK, &fl);
 	printf("%s(0, F_SETLK, {l_type=F_RDLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = %s\n",
 	       TEST_SYSCALL_STR, FILE_LEN, rc ? EINVAL_STR : "0");
 	if (rc)
 		return;
 
-	syscall(TEST_SYSCALL_NR, 0, F_GETLK, &fl);
+	invoke_test_syscall(F_GETLK, &fl);
 	printf("%s(0, F_GETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d, l_pid=0}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);
 
-	syscall(TEST_SYSCALL_NR, 0, F_SETLK, &fl);
+	invoke_test_syscall(F_SETLK, &fl);
 	printf("%s(0, F_SETLK, {l_type=F_UNLCK, l_whence=SEEK_SET"
 	       ", l_start=0, l_len=%d}) = 0\n",
 	       TEST_SYSCALL_STR, FILE_LEN);