]> granicus.if.org Git - strace/blobdiff - io.c
Refactor tamper_with_syscall_exiting()
[strace] / io.c
diff --git a/io.c b/io.c
index 7f2f243fed0cb026f8a63b03a926346b62813179..cd803057b32131931eab75decbcb7ae9809f2a61 100644 (file)
--- a/io.c
+++ b/io.c
@@ -3,6 +3,7 @@
  * 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) 1999-2018 The strace developers.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * 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.
- *
- *     $Id$
  */
 
 #include "defs.h"
-
 #include <fcntl.h>
-#if HAVE_SYS_UIO_H
 #include <sys/uio.h>
-#endif
-
-#ifdef HAVE_LONG_LONG_OFF_T
-/*
- * Hacks for systems that have a long long off_t
- */
-
-#define sys_pread64    sys_pread
-#define sys_pwrite64   sys_pwrite
-#endif
 
-int
-sys_read(struct tcb *tcp)
+SYS_FUNC(read)
 {
        if (entering(tcp)) {
                printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
+               tprints(", ");
        } else {
                if (syserror(tcp))
-                       tprintf("%#lx", tcp->u_arg[1]);
+                       printaddr(tcp->u_arg[1]);
                else
-                       printstr(tcp, tcp->u_arg[1], tcp->u_rval);
-               tprintf(", %lu", tcp->u_arg[2]);
+                       printstrn(tcp, tcp->u_arg[1], tcp->u_rval);
+               tprintf(", %" PRI_klu, tcp->u_arg[2]);
        }
        return 0;
 }
 
-int
-sys_write(struct tcb *tcp)
+SYS_FUNC(write)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
-               tprintf(", %lu", tcp->u_arg[2]);
-       }
-       return 0;
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       printstrn(tcp, tcp->u_arg[1], tcp->u_arg[2]);
+       tprintf(", %" PRI_klu, tcp->u_arg[2]);
+
+       return RVAL_DECODED;
 }
 
-#if HAVE_SYS_UIO_H
-void
-tprint_iov(struct tcb *tcp, unsigned long len, unsigned long addr, int decode_iov)
-{
-#if defined(LINUX) && SUPPORTED_PERSONALITIES > 1
-       union {
-               struct { u_int32_t base; u_int32_t len; } iov32;
-               struct { u_int64_t base; u_int64_t len; } iov64;
-       } iov;
-#define sizeof_iov \
-  (personality_wordsize[current_personality] == 4 \
-   ? sizeof(iov.iov32) : sizeof(iov.iov64))
-#define iov_iov_base \
-  (personality_wordsize[current_personality] == 4 \
-   ? (u_int64_t) iov.iov32.base : iov.iov64.base)
-#define iov_iov_len \
-  (personality_wordsize[current_personality] == 4 \
-   ? (u_int64_t) iov.iov32.len : iov.iov64.len)
-#else
-       struct iovec iov;
-#define sizeof_iov sizeof(iov)
-#define iov_iov_base iov.iov_base
-#define iov_iov_len iov.iov_len
-#endif
-       unsigned long size, cur, end, abbrev_end;
-       int failed = 0;
+struct print_iovec_config {
+       enum iov_decode decode_iov;
+       kernel_ulong_t data_size;
+};
 
-       if (!len) {
-               tprintf("[]");
-               return;
-       }
-       size = len * sizeof_iov;
-       end = addr + size;
-       if (!verbose(tcp) || size / sizeof_iov != len || end < addr) {
-               tprintf("%#lx", addr);
-               return;
-       }
-       if (abbrev(tcp)) {
-               abbrev_end = addr + max_strlen * sizeof_iov;
-               if (abbrev_end < addr)
-                       abbrev_end = end;
+static bool
+print_iovec(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
+{
+       const kernel_ulong_t *iov;
+       kernel_ulong_t iov_buf[2], len;
+       struct print_iovec_config *c = data;
+
+       if (elem_size < sizeof(iov_buf)) {
+               iov_buf[0] = ((unsigned int *) elem_buf)[0];
+               iov_buf[1] = ((unsigned int *) elem_buf)[1];
+               iov = iov_buf;
        } else {
-               abbrev_end = end;
+               iov = elem_buf;
        }
-       tprintf("[");
-       for (cur = addr; cur < end; cur += sizeof_iov) {
-               if (cur > addr)
-                       tprintf(", ");
-               if (cur >= abbrev_end) {
-                       tprintf("...");
+
+       tprints("{iov_base=");
+
+       len = iov[1];
+
+       switch (c->decode_iov) {
+               case IOV_DECODE_STR:
+                       if (len > c->data_size)
+                               len = c->data_size;
+                       if (c->data_size != (kernel_ulong_t) -1)
+                               c->data_size -= len;
+                       printstrn(tcp, iov[0], len);
                        break;
-               }
-               if (umoven(tcp, cur, sizeof_iov, (char *) &iov) < 0) {
-                       tprintf("?");
-                       failed = 1;
+               case IOV_DECODE_NETLINK:
+                       if (len > c->data_size)
+                               len = c->data_size;
+                       if (c->data_size != (kernel_ulong_t) -1)
+                               c->data_size -= len;
+                       /* assume that the descriptor is 1st syscall argument */
+                       decode_netlink(tcp, tcp->u_arg[0], iov[0], len);
+                       break;
+               default:
+                       printaddr(iov[0]);
                        break;
-               }
-               tprintf("{");
-               if (decode_iov)
-                       printstr(tcp, (long) iov_iov_base, iov_iov_len);
-               else
-                       tprintf("%#lx", (long) iov_iov_base);
-               tprintf(", %lu}", (unsigned long)iov_iov_len);
        }
-       tprintf("]");
-       if (failed)
-               tprintf(" %#lx", addr);
-#undef sizeof_iov
-#undef iov_iov_base
-#undef iov_iov_len
+
+       tprintf(", iov_len=%" PRI_klu "}", iov[1]);
+
+       return true;
 }
 
-int
-sys_readv(struct tcb *tcp)
+/*
+ * data_size limits the cumulative size of printed data.
+ * Example: recvmsg returing a short read.
+ */
+void
+tprint_iov_upto(struct tcb *const tcp, const kernel_ulong_t len,
+               const kernel_ulong_t addr, const enum iov_decode decode_iov,
+               const kernel_ulong_t data_size)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-       } else {
-               if (syserror(tcp)) {
-                       tprintf("%#lx, %lu",
-                                       tcp->u_arg[1], tcp->u_arg[2]);
-                       return 0;
-               }
-               tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], 1);
-               tprintf(", %lu", tcp->u_arg[2]);
-       }
-       return 0;
+       kernel_ulong_t iov[2];
+       struct print_iovec_config config = {
+               .decode_iov = decode_iov, .data_size = data_size
+       };
+
+       print_array(tcp, addr, len, iov, current_wordsize * 2,
+                   tfetch_mem_ignore_syserror, print_iovec, &config);
 }
 
-int
-sys_writev(struct tcb *tcp)
+SYS_FUNC(readv)
 {
        if (entering(tcp)) {
                printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], 1);
-               tprintf(", %lu", tcp->u_arg[2]);
+               tprints(", ");
+       } else {
+               tprint_iov_upto(tcp, tcp->u_arg[2], tcp->u_arg[1],
+                               syserror(tcp) ? IOV_DECODE_ADDR :
+                               IOV_DECODE_STR, tcp->u_rval);
+               tprintf(", %" PRI_klu, tcp->u_arg[2]);
        }
        return 0;
 }
-#endif
 
-#if defined(SVR4)
+SYS_FUNC(writev)
+{
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], IOV_DECODE_STR);
+       tprintf(", %" PRI_klu, tcp->u_arg[2]);
 
-int
-sys_pread(struct tcb *tcp)
+       return RVAL_DECODED;
+}
+
+SYS_FUNC(pread)
 {
        if (entering(tcp)) {
                printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
+               tprints(", ");
        } else {
                if (syserror(tcp))
-                       tprintf("%#lx", tcp->u_arg[1]);
+                       printaddr(tcp->u_arg[1]);
                else
-                       printstr(tcp, tcp->u_arg[1], tcp->u_rval);
-#if UNIXWARE
-               /* off_t is signed int */
-               tprintf(", %lu, %ld", tcp->u_arg[2], tcp->u_arg[3]);
-#else
-               tprintf(", %lu, %llu", tcp->u_arg[2],
-                       LONG_LONG(tcp->u_arg[3], tcp->u_arg[4]));
-#endif
+                       printstrn(tcp, tcp->u_arg[1], tcp->u_rval);
+               tprintf(", %" PRI_klu ", ", tcp->u_arg[2]);
+               printllval(tcp, "%lld", 3);
        }
        return 0;
 }
 
-int
-sys_pwrite(struct tcb *tcp)
+SYS_FUNC(pwrite)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
-#if UNIXWARE
-               /* off_t is signed int */
-               tprintf(", %lu, %ld", tcp->u_arg[2], tcp->u_arg[3]);
-#else
-               tprintf(", %lu, %llu", tcp->u_arg[2],
-                       LONG_LONG(tcp->u_arg[3], tcp->u_arg[4]));
-#endif
-       }
-       return 0;
-}
-#endif /* SVR4 */
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       printstrn(tcp, tcp->u_arg[1], tcp->u_arg[2]);
+       tprintf(", %" PRI_klu ", ", tcp->u_arg[2]);
+       printllval(tcp, "%lld", 3);
 
-#ifdef FREEBSD
-#include <sys/types.h>
-#include <sys/socket.h>
+       return RVAL_DECODED;
+}
 
-int
-sys_sendfile(struct tcb *tcp)
+static void
+print_lld_from_low_high_val(struct tcb *tcp, int arg)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printfd(tcp, tcp->u_arg[1]);
-               tprintf(", %llu, %lu",
-                       LONG_LONG(tcp->u_arg[2], tcp->u_arg[3]),
-                       tcp->u_arg[4]);
-       } else {
-               off_t offset;
-
-               if (!tcp->u_arg[5])
-                       tprintf(", NULL");
-               else {
-                       struct sf_hdtr hdtr;
-
-                       if (umove(tcp, tcp->u_arg[5], &hdtr) < 0)
-                               tprintf(", %#lx", tcp->u_arg[5]);
-                       else {
-                               tprintf(", { ");
-                               tprint_iov(tcp, hdtr.hdr_cnt, hdtr.headers, 1);
-                               tprintf(", %u, ", hdtr.hdr_cnt);
-                               tprint_iov(tcp, hdtr.trl_cnt, hdtr.trailers, 1);
-                               tprintf(", %u }", hdtr.hdr_cnt);
-                       }
-               }
-               if (!tcp->u_arg[6])
-                       tprintf(", NULL");
-               else if (umove(tcp, tcp->u_arg[6], &offset) < 0)
-                       tprintf(", %#lx", tcp->u_arg[6]);
-               else
-                       tprintf(", [%llu]", offset);
-               tprintf(", %lu", tcp->u_arg[7]);
+#if SIZEOF_KERNEL_LONG_T > 4
+# ifndef current_klongsize
+       if (current_klongsize < SIZEOF_KERNEL_LONG_T) {
+               tprintf("%" PRI_kld, (tcp->u_arg[arg + 1] << 32)
+                              | tcp->u_arg[arg]);
+       } else
+# endif /* !current_klongsize */
+       {
+               tprintf("%" PRI_kld, tcp->u_arg[arg]);
        }
-       return 0;
+#else /* SIZEOF_KERNEL_LONG_T == 4 */
+       tprintf("%lld",
+                 ((long long) tcp->u_arg[arg + 1] << 32)
+               | ((long long) tcp->u_arg[arg]));
+#endif
 }
-#endif /* FREEBSD */
 
-#ifdef LINUX
-
-/* The SH4 ABI does allow long longs in odd-numbered registers, but
-   does not allow them to be split between registers and memory - and
-   there are only four argument registers for normal functions.  As a
-   result pread takes an extra padding argument before the offset.  This
-   was changed late in the 2.4 series (around 2.4.20).  */
-#if defined(SH)
-#define PREAD_OFFSET_ARG 4
-#else
-#define PREAD_OFFSET_ARG 3
-#endif
+#include "xlat/rwf_flags.h"
 
-int
-sys_pread(struct tcb *tcp)
+static int
+do_preadv(struct tcb *tcp, const int flags_arg)
 {
        if (entering(tcp)) {
                printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
+               tprints(", ");
        } else {
-               if (syserror(tcp))
-                       tprintf("%#lx", tcp->u_arg[1]);
-               else
-                       printstr(tcp, tcp->u_arg[1], tcp->u_rval);
-               tprintf(", %lu, ", tcp->u_arg[2]);
-               printllval(tcp, "%llu", PREAD_OFFSET_ARG);
+               kernel_ulong_t len =
+                       truncate_kulong_to_current_wordsize(tcp->u_arg[2]);
+
+               tprint_iov_upto(tcp, len, tcp->u_arg[1],
+                               syserror(tcp) ? IOV_DECODE_ADDR :
+                               IOV_DECODE_STR, tcp->u_rval);
+               tprintf(", %" PRI_klu ", ", len);
+               print_lld_from_low_high_val(tcp, 3);
+               if (flags_arg >= 0) {
+                       tprints(", ");
+                       printflags(rwf_flags, tcp->u_arg[flags_arg], "RWF_???");
+               }
        }
        return 0;
 }
 
-int
-sys_pwrite(struct tcb *tcp)
+SYS_FUNC(preadv)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
-               tprintf(", %lu, ", tcp->u_arg[2]);
-               printllval(tcp, "%llu", PREAD_OFFSET_ARG);
-       }
-       return 0;
+       return do_preadv(tcp, -1);
 }
 
-#if HAVE_SYS_UIO_H
-int
-sys_preadv(struct tcb *tcp)
+static int
+do_pwritev(struct tcb *tcp, const int flags_arg)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-       } else {
-               if (syserror(tcp)) {
-                       tprintf("%#lx, %lu", tcp->u_arg[1], tcp->u_arg[2]);
-                       return 0;
-               }
-               tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], 1);
-               tprintf(", %lu, ", tcp->u_arg[2]);
-               printllval(tcp, "%llu", PREAD_OFFSET_ARG);
+       kernel_ulong_t len =
+               truncate_kulong_to_current_wordsize(tcp->u_arg[2]);
+
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       tprint_iov(tcp, len, tcp->u_arg[1], IOV_DECODE_STR);
+       tprintf(", %" PRI_klu ", ", len);
+       print_lld_from_low_high_val(tcp, 3);
+       if (flags_arg >= 0) {
+               tprints(", ");
+               printflags(rwf_flags, tcp->u_arg[flags_arg], "RWF_???");
        }
-       return 0;
+
+       return RVAL_DECODED;
 }
 
-int
-sys_pwritev(struct tcb *tcp)
+SYS_FUNC(pwritev)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], 1);
-               tprintf(", %lu, ", tcp->u_arg[2]);
-               printllval(tcp, "%llu", PREAD_OFFSET_ARG);
-       }
-       return 0;
+       return do_pwritev(tcp, -1);
 }
-#endif /* HAVE_SYS_UIO_H */
 
-int
-sys_sendfile(struct tcb *tcp)
-{
-       if (entering(tcp)) {
-               off_t offset;
+/*
+ * x32 is the only architecture where preadv2 takes 5 arguments
+ * instead of 6, see preadv64v2 in kernel sources.
+ * Likewise, x32 is the only architecture where pwritev2 takes 5 arguments
+ * instead of 6, see pwritev64v2 in kernel sources.
+ */
 
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printfd(tcp, tcp->u_arg[1]);
-               tprintf(", ");
-               if (!tcp->u_arg[2])
-                       tprintf("NULL");
-               else if (umove(tcp, tcp->u_arg[2], &offset) < 0)
-                       tprintf("%#lx", tcp->u_arg[2]);
-               else
-                       tprintf("[%lu]", offset);
-               tprintf(", %lu", tcp->u_arg[3]);
-       }
-       return 0;
-}
+#if defined X86_64
+# define PREADV2_PWRITEV2_FLAGS_ARG_NO (current_personality == 2 ? 4 : 5)
+#elif defined X32
+# define PREADV2_PWRITEV2_FLAGS_ARG_NO (current_personality == 0 ? 4 : 5)
+#else
+# define PREADV2_PWRITEV2_FLAGS_ARG_NO 5
+#endif
 
-int
-sys_sendfile64(struct tcb *tcp)
+SYS_FUNC(preadv2)
 {
-       if (entering(tcp)) {
-               loff_t offset;
+       return do_preadv(tcp, PREADV2_PWRITEV2_FLAGS_ARG_NO);
+}
 
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printfd(tcp, tcp->u_arg[1]);
-               tprintf(", ");
-               if (!tcp->u_arg[2])
-                       tprintf("NULL");
-               else if (umove(tcp, tcp->u_arg[2], &offset) < 0)
-                       tprintf("%#lx", tcp->u_arg[2]);
-               else
-                       tprintf("[%llu]", (unsigned long long int) offset);
-               tprintf(", %lu", tcp->u_arg[3]);
-       }
-       return 0;
+SYS_FUNC(pwritev2)
+{
+       return do_pwritev(tcp, PREADV2_PWRITEV2_FLAGS_ARG_NO);
 }
 
-#endif /* LINUX */
+#include "xlat/splice_flags.h"
 
-#if _LFS64_LARGEFILE || HAVE_LONG_LONG_OFF_T
-int
-sys_pread64(struct tcb *tcp)
+SYS_FUNC(tee)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-       } else {
-               if (syserror(tcp))
-                       tprintf("%#lx", tcp->u_arg[1]);
-               else
-                       printstr(tcp, tcp->u_arg[1], tcp->u_rval);
-               tprintf(", %lu, ", tcp->u_arg[2]);
-               printllval(tcp, "%#llx", 3);
-       }
-       return 0;
+       /* int fd_in */
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       /* int fd_out */
+       printfd(tcp, tcp->u_arg[1]);
+       tprints(", ");
+       /* size_t len */
+       tprintf("%" PRI_klu ", ", tcp->u_arg[2]);
+       /* unsigned int flags */
+       printflags(splice_flags, tcp->u_arg[3], "SPLICE_F_???");
+
+       return RVAL_DECODED;
 }
 
-int
-sys_pwrite64(struct tcb *tcp)
+SYS_FUNC(splice)
 {
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
-               tprintf(", %lu, ", tcp->u_arg[2]);
-               printllval(tcp, "%#llx", 3);
-       }
-       return 0;
+       /* int fd_in */
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       /* loff_t *off_in */
+       printnum_int64(tcp, tcp->u_arg[1], "%" PRId64);
+       tprints(", ");
+       /* int fd_out */
+       printfd(tcp, tcp->u_arg[2]);
+       tprints(", ");
+       /* loff_t *off_out */
+       printnum_int64(tcp, tcp->u_arg[3], "%" PRId64);
+       tprints(", ");
+       /* size_t len */
+       tprintf("%" PRI_klu ", ", tcp->u_arg[4]);
+       /* unsigned int flags */
+       printflags(splice_flags, tcp->u_arg[5], "SPLICE_F_???");
+
+       return RVAL_DECODED;
 }
-#endif
 
-int
-sys_ioctl(struct tcb *tcp)
+SYS_FUNC(vmsplice)
 {
-       const struct ioctlent *iop;
-
-       if (entering(tcp)) {
-               printfd(tcp, tcp->u_arg[0]);
-               tprintf(", ");
-               iop = ioctl_lookup(tcp->u_arg[1]);
-               if (iop) {
-                       tprintf("%s", iop->symbol);
-                       while ((iop = ioctl_next_match(iop)))
-                               tprintf(" or %s", iop->symbol);
-               } else
-                       tprintf("%#lx", tcp->u_arg[1]);
-               ioctl_decode(tcp, tcp->u_arg[1], tcp->u_arg[2]);
-       }
-       else {
-               int ret;
-               if (!(ret = ioctl_decode(tcp, tcp->u_arg[1], tcp->u_arg[2])))
-                       tprintf(", %#lx", tcp->u_arg[2]);
-               else
-                       return ret - 1;
-       }
-       return 0;
+       /* int fd */
+       printfd(tcp, tcp->u_arg[0]);
+       tprints(", ");
+       /* const struct iovec *iov, unsigned long nr_segs */
+       tprint_iov(tcp, tcp->u_arg[2], tcp->u_arg[1], IOV_DECODE_STR);
+       tprintf(", %" PRI_klu ", ", tcp->u_arg[2]);
+       /* unsigned int flags */
+       printflags(splice_flags, tcp->u_arg[3], "SPLICE_F_???");
+
+       return RVAL_DECODED;
 }