Refactor tamper_with_syscall_exiting()

[strace] / io.c

diff --git a/io.c b/io.c
index dbef2e65b83eb2f9bb28ed6d789f032136c92070..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
@@ -69,7 +70,7 @@ print_iovec(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
        kernel_ulong_t iov_buf[2], len;
        struct print_iovec_config *c = data;
 
-        if (elem_size < sizeof(iov_buf)) {
+       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;
@@ -94,7 +95,8 @@ print_iovec(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
                                len = c->data_size;
                        if (c->data_size != (kernel_ulong_t) -1)
                                c->data_size -= len;
-                       decode_netlink(tcp, iov[0], iov[1]);
+                       /* assume that the descriptor is 1st syscall argument */
+                       decode_netlink(tcp, tcp->u_arg[0], iov[0], len);
                        break;
                default:
                        printaddr(iov[0]);
@@ -116,11 +118,12 @@ tprint_iov_upto(struct tcb *const tcp, const kernel_ulong_t len,
                const kernel_ulong_t data_size)
 {
        kernel_ulong_t iov[2];
-       struct print_iovec_config config =
-               { .decode_iov = decode_iov, .data_size = data_size };
+       struct print_iovec_config config = {
+               .decode_iov = decode_iov, .data_size = data_size
+       };
 
        print_array(tcp, addr, len, iov, current_wordsize * 2,
-                   umoven_or_printaddr_ignore_syserror, print_iovec, &config);
+                   tfetch_mem_ignore_syserror, print_iovec, &config);
 }
 
 SYS_FUNC(readv)
@@ -177,33 +180,20 @@ SYS_FUNC(pwrite)
 static void
 print_lld_from_low_high_val(struct tcb *tcp, int arg)
 {
-#if SIZEOF_LONG > 4 && SIZEOF_LONG == SIZEOF_LONG_LONG
+#if SIZEOF_KERNEL_LONG_T > 4
 # ifndef current_klongsize
-       if (current_klongsize < SIZEOF_LONG) {
-               tprintf("%" PRI_kld, (tcp->u_arg[arg + 1] << current_wordsize * 8)
+       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]);
        }
-#elif SIZEOF_LONG > 4
-# error Unsupported configuration: SIZEOF_LONG > 4 && SIZEOF_LONG_LONG > SIZEOF_LONG
-#elif SIZEOF_KERNEL_LONG_T > SIZEOF_LONG
-# ifndef current_klongsize
-       if (current_klongsize < SIZEOF_LONG_LONG) {
-               tprintf("%lld",
-                       (zero_extend_signed_to_ull(tcp->u_arg[arg + 1]) << sizeof(long) * 8)
-                       | zero_extend_signed_to_ull(tcp->u_arg[arg]));
-       } else
-# endif /* !current_klongsize */
-       {
-               tprintf("%" PRI_kld, tcp->u_arg[arg]);
-       }
-#else /* SIZEOF_LONG_LONG > SIZEOF_LONG && SIZEOF_KERNEL_LONG_T == SIZEOF_LONG */
+#else /* SIZEOF_KERNEL_LONG_T == 4 */
        tprintf("%lld",
-               (zero_extend_signed_to_ull(tcp->u_arg[arg + 1]) << sizeof(long) * 8)
-               | zero_extend_signed_to_ull(tcp->u_arg[arg]));
+                 ((long long) tcp->u_arg[arg + 1] << 32)
+               | ((long long) tcp->u_arg[arg]));
 #endif
 }
 
@@ -216,12 +206,13 @@ do_preadv(struct tcb *tcp, const int flags_arg)
                printfd(tcp, tcp->u_arg[0]);
                tprints(", ");
        } else {
-               unsigned long len = widen_to_ulong(tcp->u_arg[2]);
+               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(", %lu, ", len);
+               tprintf(", %" PRI_klu ", ", len);
                print_lld_from_low_high_val(tcp, 3);
                if (flags_arg >= 0) {
                        tprints(", ");
@@ -236,20 +227,16 @@ SYS_FUNC(preadv)
        return do_preadv(tcp, -1);
 }
 
-SYS_FUNC(preadv2)
-{
-       return do_preadv(tcp, 5);
-}
-
 static int
 do_pwritev(struct tcb *tcp, const int flags_arg)
 {
-       unsigned long len = widen_to_ulong(tcp->u_arg[2]);
+       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(", %lu, ", len);
+       tprintf(", %" PRI_klu ", ", len);
        print_lld_from_low_high_val(tcp, 3);
        if (flags_arg >= 0) {
                tprints(", ");
@@ -264,9 +251,29 @@ SYS_FUNC(pwritev)
        return do_pwritev(tcp, -1);
 }
 
+/*
+ * 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.
+ */
+
+#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
+
+SYS_FUNC(preadv2)
+{
+       return do_preadv(tcp, PREADV2_PWRITEV2_FLAGS_ARG_NO);
+}
+
 SYS_FUNC(pwritev2)
 {
-       return do_pwritev(tcp, 5);
+       return do_pwritev(tcp, PREADV2_PWRITEV2_FLAGS_ARG_NO);
 }
 
 #include "xlat/splice_flags.h"