strace/aio.c
Dmitry V. Levin d54388e1ce print_array: enhance printing of unfetchable object addresses
When umoven_func invocation fails to fetch data, it prints the faulty
address.  If this happens to a subsequent umoven_func invocation,
the printed address may be undistinguishable from a valid data printed
by print_func, e.g. when the data is printed in a numeric form like
[0x1, 0x2, 0x3, 0xdefaced].

Fix this source of confusion by moving the printing of the faulty
address from umoven_func to print_array itself.  This change renames
umoven_func to tfetch_mem_func and changes its semantics, so that
 - tfetch_mem_func never prints anything;
 - tfetch_mem_func returns true if the fetch succeeded,
   and false otherwise.

* defs.h (print_array): Replace umoven_func argument with
tfetch_mem_func.
* util.c (print_array): Replace umoven_func argument with
tfetch_mem_func, document expected tfetch_mem_func return value
semantics.  When tfetch_mem_func returns false, print either addr
or "... /* addr */" depending on the context (inside the array or not).
* bpf.c (print_ebpf_prog, print_bpf_prog_info,
BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Replace umoven_or_printaddr
argument of print_array with tfetch_mem.
* bpf_filter.c (print_bpf_fprog): Likewise.
* btrfs.c (btrfs_print_logical_ino_container,
btrfs_print_ino_path_container, btrfs_print_qgroup_inherit,
btrfs_ioctl): Likewise.
* dm.c (dm_decode_dm_target_deps): Likewise.
* epoll.c (epoll_wait_common): Likewise.
* file_ioctl.c (file_ioctl): Likewise.
* ipc_sem.c (tprint_sembuf_array): Likewise.
* kexec.c (print_kexec_segments): Likewise.
* mem.c (SYS_FUNC(subpage_prot)): Likewise.
* net.c (print_getsockopt): Likewise.
* netlink.c (decode_nlmsgerr_attr_cookie): Likewise.
* netlink_netlink_diag.c (decode_netlink_diag_groups): Likewise.
* netlink_packet_diag.c (decode_packet_diag_mclist): Likewise.
* netlink_unix_diag.c (decode_unix_diag_inode): Likewise.
* nlattr.c (decode_nla_meminfo): Likewise.
* numa.c (print_nodemask, SYS_FUNC(move_pages),
* perf_ioctl.c (perf_ioctl_query_bpf): Likewise.
* poll.c (decode_poll_entering): Likewise.
* printsiginfo.c (print_siginfo_array): Likewise.
* rtnl_tc.c (decode_tca_stab_data): Likewise.
* sock.c (decode_ifconf): Likewise.
* uid.c (print_groups): Likewise.
* io.c (SYS_FUNC(io_submit), SYS_FUNC(io_getevents)): Replace
umoven_or_printaddr argument of print_array with tfetch_mem.
(tprint_iov_upto): Replace umoven_or_printaddr_ignore_syserror
with tfetch_mem_ignore_syserror.
* v4l2.c (print_v4l2_format_fmt): Replace umoven_or_printaddr argument
of print_array with tfetch_mem.
(print_v4l2_ext_controls): Replace umoven_or_printaddr_ignore_syserror
with tfetch_mem_ignore_syserror.
* mmsghdr.c (fetch_struct_mmsghdr_or_printaddr): Rename
to fetch_struct_mmsghdr_for_print, do not print address, return bool.
(decode_mmsgvec): Replace fetch_struct_mmsghdr_or_printaddr
with fetch_struct_mmsghdr_for_print.
* tests/aio.c (main): Update expected output.
* tests/bpf.c (print_BPF_PROG_QUERY_attr5): Likewise.
* tests/ioctl_perf-success.c (main): Likewise.
* tests/ioctl_v4l2.c (main): Update expected output.
* tests/kexec_load.c (main): Likewise.
* tests/mmsg_name.c (test_mmsg_name): Update expected output.
* tests/move_pages.c (print_page_array, print_node_array): Likewise.
* tests/poll.c (print_pollfd_array_entering): Likewise.
* tests/preadv-pwritev.c (main): Likewise.
* tests/preadv2-pwritev2.c (dumpio): Likewise.
* tests/process_vm_readv_writev.c (print_iov): Likewise.
* tests/pwritev.c (print_iovec): Likewise.
* tests/readv.c (main): Likewise.
* tests/seccomp-filter-v.c
* tests/semop.c (main): Likewise.
* tests/set_mempolicy.c (print_nodes): Likewise.
* tests/setgroups.c (main): Likewise.
* tests/test_nlattr.h (print_nlattr) Likewise.

Co-Authored-by: Eugene Syromyatnikov <evgsyr@gmail.com>
2018-05-29 09:58:10 +00:00

264 lines
6.5 KiB
C

/*
* Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
* Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
* Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
* Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 1999-2017 The strace developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#include "print_fields.h"
#include <linux/aio_abi.h>
SYS_FUNC(io_setup)
{
if (entering(tcp))
tprintf("%u, ", (unsigned int) tcp->u_arg[0]);
else
printnum_ptr(tcp, tcp->u_arg[1]);
return 0;
}
SYS_FUNC(io_destroy)
{
printaddr(tcp->u_arg[0]);
return RVAL_DECODED;
}
enum iocb_sub {
SUB_NONE, SUB_COMMON, SUB_VECTOR
};
static enum iocb_sub
tprint_lio_opcode(unsigned int cmd)
{
static const struct {
const char *name;
enum iocb_sub sub;
} cmds[] = {
{ "IOCB_CMD_PREAD", SUB_COMMON },
{ "IOCB_CMD_PWRITE", SUB_COMMON },
{ "IOCB_CMD_FSYNC", SUB_NONE },
{ "IOCB_CMD_FDSYNC", SUB_NONE },
{ "IOCB_CMD_PREADX", SUB_NONE },
{ "IOCB_CMD_POLL", SUB_NONE },
{ "IOCB_CMD_NOOP", SUB_NONE },
{ "IOCB_CMD_PREADV", SUB_VECTOR },
{ "IOCB_CMD_PWRITEV", SUB_VECTOR },
};
if (cmd < ARRAY_SIZE(cmds)) {
tprints(cmds[cmd].name);
return cmds[cmd].sub;
}
tprintf("%u", cmd);
tprints_comment("IOCB_CMD_???");
return SUB_NONE;
}
static void
print_common_flags(struct tcb *tcp, const struct iocb *cb)
{
/* IOCB_FLAG_RESFD is available since v2.6.22-rc1~47 */
#ifdef IOCB_FLAG_RESFD
if (cb->aio_flags & IOCB_FLAG_RESFD)
PRINT_FIELD_FD(", ", *cb, aio_resfd, tcp);
if (cb->aio_flags & ~IOCB_FLAG_RESFD)
PRINT_FIELD_X(", ", *cb, aio_flags);
#endif
}
static bool
iocb_is_valid(const struct iocb *cb)
{
return cb->aio_buf == (unsigned long) cb->aio_buf &&
cb->aio_nbytes == (size_t) cb->aio_nbytes &&
(ssize_t) cb->aio_nbytes >= 0;
}
static enum iocb_sub
print_iocb_header(struct tcb *tcp, const struct iocb *cb)
{
enum iocb_sub sub;
if (cb->aio_data){
PRINT_FIELD_X("", *cb, aio_data);
tprints(", ");
}
if (cb->aio_key) {
PRINT_FIELD_U("", *cb, aio_key);
tprints(", ");
}
tprints("aio_lio_opcode=");
sub = tprint_lio_opcode(cb->aio_lio_opcode);
if (cb->aio_reqprio)
PRINT_FIELD_D(", ", *cb, aio_reqprio);
PRINT_FIELD_FD(", ", *cb, aio_fildes, tcp);
return sub;
}
static void
print_iocb(struct tcb *tcp, const struct iocb *cb)
{
enum iocb_sub sub = print_iocb_header(tcp, cb);
switch (sub) {
case SUB_COMMON:
if (cb->aio_lio_opcode == 1 && iocb_is_valid(cb)) {
PRINT_FIELD_STRN(", ", *cb, aio_buf,
cb->aio_nbytes, tcp);
} else {
PRINT_FIELD_X(", ", *cb, aio_buf);
}
PRINT_FIELD_U(", ", *cb, aio_nbytes);
PRINT_FIELD_D(", ", *cb, aio_offset);
print_common_flags(tcp, cb);
break;
case SUB_VECTOR:
if (iocb_is_valid(cb)) {
tprints(", aio_buf=");
tprint_iov(tcp, cb->aio_nbytes, cb->aio_buf,
cb->aio_lio_opcode == 8
? IOV_DECODE_STR
: IOV_DECODE_ADDR);
} else {
PRINT_FIELD_X(", ", *cb, aio_buf);
PRINT_FIELD_U(", ", *cb, aio_nbytes);
}
PRINT_FIELD_D(", ", *cb, aio_offset);
print_common_flags(tcp, cb);
break;
case SUB_NONE:
break;
}
}
static bool
print_iocbp(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
{
kernel_ulong_t addr;
struct iocb cb;
if (elem_size < sizeof(kernel_ulong_t)) {
addr = *(unsigned int *) elem_buf;
} else {
addr = *(kernel_ulong_t *) elem_buf;
}
tprints("{");
if (!umove_or_printaddr(tcp, addr, &cb))
print_iocb(tcp, &cb);
tprints("}");
return true;
}
SYS_FUNC(io_submit)
{
const kernel_long_t nr =
truncate_klong_to_current_wordsize(tcp->u_arg[1]);
const kernel_ulong_t addr = tcp->u_arg[2];
kernel_ulong_t iocbp;
printaddr(tcp->u_arg[0]);
tprintf(", %" PRI_kld ", ", nr);
if (nr < 0)
printaddr(addr);
else
print_array(tcp, addr, nr, &iocbp, current_wordsize,
tfetch_mem, print_iocbp, 0);
return RVAL_DECODED;
}
static bool
print_io_event(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
{
struct io_event *event = elem_buf;
PRINT_FIELD_X("{", *event, data);
PRINT_FIELD_X(", ", *event, obj);
PRINT_FIELD_D(", ", *event, res);
PRINT_FIELD_D(", ", *event, res2);
tprints("}");
return true;
}
SYS_FUNC(io_cancel)
{
if (entering(tcp)) {
printaddr(tcp->u_arg[0]);
tprints(", ");
struct iocb cb;
if (!umove_or_printaddr(tcp, tcp->u_arg[1], &cb)) {
tprints("{");
print_iocb_header(tcp, &cb);
tprints("}");
}
tprints(", ");
} else {
struct io_event event;
if (!umove_or_printaddr(tcp, tcp->u_arg[2], &event))
print_io_event(tcp, &event, sizeof(event), 0);
}
return 0;
}
SYS_FUNC(io_getevents)
{
if (entering(tcp)) {
printaddr(tcp->u_arg[0]);
tprintf(", %" PRI_kld ", %" PRI_kld ", ",
truncate_klong_to_current_wordsize(tcp->u_arg[1]),
truncate_klong_to_current_wordsize(tcp->u_arg[2]));
} else {
struct io_event buf;
print_array(tcp, tcp->u_arg[3], tcp->u_rval, &buf, sizeof(buf),
tfetch_mem, print_io_event, 0);
tprints(", ");
/*
* Since the timeout parameter is read by the kernel
* on entering syscall, it has to be decoded the same way
* whether the syscall has failed or not.
*/
temporarily_clear_syserror(tcp);
print_timespec(tcp, tcp->u_arg[4]);
restore_cleared_syserror(tcp);
}
return 0;
}