Implement decoding of fsmount syscall

... introduced by Linux kernel commits v5.2-rc1~141^2~2,
v5.2-rc1~20^2~1, and v5.2-rc1~20^2.

* fsmount.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* pathtrace.c (pathtrace_match_set): Add SEN_fsmount.
* xlat/fsmount_cmds.in: New file.
* xlat/mount_attr_atime.in: Likewise.
* xlat/mount_attr_flags.in: Likewise.
* linux/syscallent-common.h [BASE_NR + 432]: Wire up fsmount.
* NEWS: Mention this change.
* tests/fsmount.c: New file.
* tests/gen_tests.in (fsmount): New entry.
* tests/pure_executables.list: Add fsmount.
* tests/.gitignore: Likewise.

diff --git a/Makefile.am b/Makefile.am
index e22a1ced35255d2554e6a4a4820ef900591c7b8d..4f0eb642b785d7023a5c0dcac2f35f9bcf2a017d 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -133,6 +133,7 @@ strace_SOURCES =    \
        flock.h         \
        fs_x_ioctl.c    \
        fsconfig.c      \
+       fsmount.c       \
        fsopen.c        \
        futex.c         \
        gcc_compat.h    \

diff --git a/NEWS b/NEWS
index ef9da37b9f81e812bf61fc9b4bbf56349ab4f880..60d088489d06864b576bd6e74362fab15c594f6c 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -2,7 +2,7 @@ Noteworthy changes in release ?.? (????-??-??)
 ==============================================
 
 * Improvements
-  * Implemented decoding of open_tree, move_mount, fsopen, and fsconfig
+  * Implemented decoding of open_tree, move_mount, fsopen, fsconfig, and fsmount
     syscalls.
   * Enhanced decoding of clone syscall.
   * Updated lists of AT_*, AUDIT_*, CLONE_*, ETH_*, KEY_*, KVM_*, TIPC_*,

diff --git a/fsmount.c b/fsmount.c
new file mode 100644 (file)
index 0000000..c64e256
--- /dev/null
+++ b/fsmount.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2019 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+#include "defs.h"
+#ifdef HAVE_LINUX_MOUNT_H
+# include <linux/mount.h>
+#endif
+#include "xlat/fsmount_flags.h"
+#include "xlat/mount_attr_flags.h"
+
+SYS_FUNC(fsmount)
+{
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+
+       printflags(fsmount_flags, tcp->u_arg[1], "FSMOUNT_???");
+       tprints(", ");
+
+       printflags(mount_attr_flags, tcp->u_arg[2], "MOUNT_ATTR_???");
+
+       return RVAL_DECODED | RVAL_FD;
+}

diff --git a/linux/syscallent-common.h b/linux/syscallent-common.h
index c2e844eae7decfa8d9e54939089fce71daec148e..af96dc7a0527cae107012d7950f0ae81be4ce926 100644 (file)
--- a/linux/syscallent-common.h
+++ b/linux/syscallent-common.h
@@ -16,3 +16,4 @@
 [BASE_NR + 429] = { 5, TD|TF,          SEN(move_mount),                "move_mount"            },
 [BASE_NR + 430] = { 2, TD,             SEN(fsopen),                    "fsopen"                },
 [BASE_NR + 431] = { 5, TD|TF,          SEN(fsconfig),                  "fsconfig"              },
+[BASE_NR + 432] = { 3, TD,             SEN(fsmount),                   "fsmount"               },

diff --git a/pathtrace.c b/pathtrace.c
index 3c09bc3282d0f18a9d1e50c60c938b304293cbc9..a96b9ff68de1307d75b8abdd0a44752d97433a0a 100644 (file)
--- a/pathtrace.c
+++ b/pathtrace.c
@@ -341,6 +341,7 @@ pathtrace_match_set(struct tcb *tcp, struct path_set *set)
        case SEN_eventfd2:
        case SEN_eventfd:
        case SEN_fanotify_init:
+       case SEN_fsmount:
        case SEN_fsopen:
        case SEN_inotify_init:
        case SEN_inotify_init1:

diff --git a/tests/.gitignore b/tests/.gitignore
index 2b8e500acb76cc8fb9891febe79bb7020b9ffe1e..14f508029332d7a98846357b0696a6a7d4708ac6 100644 (file)
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -91,6 +91,7 @@ flock
 fork-f
 fsconfig
 fsconfig-P
+fsmount
 fsopen
 fstat
 fstat-Xabbrev

diff --git a/tests/fsmount.c b/tests/fsmount.c
new file mode 100644 (file)
index 0000000..5996173
--- /dev/null
+++ b/tests/fsmount.c
@@ -0,0 +1,98 @@
+/*
+ * Check decoding of fsmount syscall.
+ *
+ * Copyright (c) 2019 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "tests.h"
+#include <asm/unistd.h>
+#include "scno.h"
+
+#ifdef __NR_fsmount
+
+# include <fcntl.h>
+# include <stdio.h>
+# include <stdint.h>
+# include <unistd.h>
+
+static const char *errstr;
+
+static long
+k_fsmount(const unsigned int fs_fd,
+         const unsigned int flags,
+         const unsigned int attr_flags)
+{
+       const kernel_ulong_t fill = (kernel_ulong_t) 0xdefaced00000000ULL;
+       const kernel_ulong_t bad = (kernel_ulong_t) 0xbadc0dedbadc0dedULL;
+       const kernel_ulong_t arg1 = fill | fs_fd;
+       const kernel_ulong_t arg2 = fill | flags;
+       const kernel_ulong_t arg3 = fill | attr_flags;
+       const long rc = syscall(__NR_fsmount,
+                               arg1, arg2, arg3, bad, bad, bad);
+       errstr = sprintrc(rc);
+       return rc;
+}
+
+int
+main(void)
+{
+       skip_if_unavailable("/proc/self/fd/");
+
+       static const char path[] = "/dev/full";
+        int fd = open(path, O_WRONLY);
+        if (fd < 0)
+                perror_msg_and_fail("open: %s", path);
+
+       struct {
+               unsigned int val;
+               const char *str;
+       } flags[] = {
+               { ARG_STR(0) },
+               { 1, "FSMOUNT_CLOEXEC" },
+               { 2, "0x2 /* FSMOUNT_??? */" },
+               { 0xfffffffe, "0xfffffffe /* FSMOUNT_??? */" },
+               { -1, "FSMOUNT_CLOEXEC|0xfffffffe" }
+       },
+       attrs[] = {
+               { ARG_STR(0) },
+               { 1, "MOUNT_ATTR_RDONLY" },
+               { 0x10, "MOUNT_ATTR_NOATIME" },
+               { 0xbf, "MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV"
+                       "|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME"
+                       "|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME" },
+               { 0x40, "0x40 /* MOUNT_ATTR_??? */" },
+               { 0xffffff40, "0xffffff40 /* MOUNT_ATTR_??? */" },
+               { -1, "MOUNT_ATTR_RDONLY|MOUNT_ATTR_NOSUID|MOUNT_ATTR_NODEV"
+                       "|MOUNT_ATTR_NOEXEC|MOUNT_ATTR_NOATIME"
+                       "|MOUNT_ATTR_STRICTATIME|MOUNT_ATTR_NODIRATIME"
+                       "|0xffffff40" }
+       };
+
+       for (unsigned int i = 0; i < ARRAY_SIZE(flags); ++i) {
+               for (unsigned int j = 0; j < ARRAY_SIZE(attrs); ++j) {
+                       k_fsmount(-1, flags[i].val, attrs[j].val);
+                       printf("fsmount(-1, %s, %s) = %s\n",
+                              flags[i].str, attrs[j].str, errstr);
+
+                       k_fsmount(-100, flags[i].val, attrs[j].val);
+                       printf("fsmount(-100, %s, %s) = %s\n",
+                              flags[i].str, attrs[j].str, errstr);
+
+                       k_fsmount(fd, flags[i].val, attrs[j].val);
+                       printf("fsmount(%d<%s>, %s, %s) = %s\n",
+                              fd, path, flags[i].str, attrs[j].str, errstr);
+               }
+       }
+
+       puts("+++ exited with 0 +++");
+       return 0;
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_fsmount")
+
+#endif

diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 7cbfc417a1cfcf0c8565241e415b45338d84e69a..4e80b203c23c72d9824d529d8fb36ac7c384fc0d 100644 (file)
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -70,6 +70,7 @@ flock -a19
 fork-f -a26 -qq -f -e signal=none -e trace=chdir
 fsconfig       -s300 -y
 fsconfig-P     -s300 -y -P /dev/full -e trace=fsconfig
+fsmount        -a18 -y
 fsopen -a35
 fstat  -a15 -v -P stat.sample
 fstat-Xabbrev -a15 -v -Xabbrev -P stat.sample -e trace=fstat

diff --git a/tests/pure_executables.list b/tests/pure_executables.list
index 9fa551a8b3f32ce00ac74cbd3c8e4d01cf835d40..e58f2941799adeba042ac8e7c8cd5d0c2308acdf 100755 (executable)
--- a/tests/pure_executables.list
+++ b/tests/pure_executables.list
@@ -73,6 +73,7 @@ finit_module
 flock
 fsconfig
 fsconfig-P
+fsmount
 fsopen
 fstat
 fstat-Xabbrev

diff --git a/xlat/fsmount_flags.in b/xlat/fsmount_flags.in
new file mode 100644 (file)
index 0000000..8a3b95e
--- /dev/null
+++ b/xlat/fsmount_flags.in
@@ -0,0 +1 @@
+FSMOUNT_CLOEXEC        1

diff --git a/xlat/mount_attr_flags.in b/xlat/mount_attr_flags.in
new file mode 100644 (file)
index 0000000..f6356c1
--- /dev/null
+++ b/xlat/mount_attr_flags.in
@@ -0,0 +1,7 @@
+MOUNT_ATTR_RDONLY      0x01
+MOUNT_ATTR_NOSUID      0x02
+MOUNT_ATTR_NODEV       0x04
+MOUNT_ATTR_NOEXEC      0x08
+MOUNT_ATTR_NOATIME     0x10
+MOUNT_ATTR_STRICTATIME 0x20
+MOUNT_ATTR_NODIRATIME  0x80