Fix printing of unreadable struct iovec

* io.c (tprint_iov_upto): If the first element of iovec array is
unreadable, print its address without array markup.
* tests/readv.c (main): Check it.

diff --git a/io.c b/io.c
index 2075d201d33b8da1fc14b07c0e32187bbbd6b545..aac93eaecfa55bb6c50aa7075dc18321eb552256 100644 (file)
--- a/io.c
+++ b/io.c
@@ -86,17 +86,23 @@ tprint_iov_upto(struct tcb *tcp, unsigned long len, unsigned long addr, int deco
        } else {
                abbrev_end = end;
        }
-       tprints("[");
+       if (addr >= abbrev_end) {
+               tprints("[...]");
+               return;
+       }
        for (cur = addr; cur < end; cur += sizeof_iov) {
-               if (cur > addr)
+               if (cur > addr) {
                        tprints(", ");
-               if (cur >= abbrev_end) {
-                       tprints("...");
-                       break;
+                       if (cur >= abbrev_end) {
+                               tprints("...");
+                               break;
+                       }
                }
                if (umove_ulong_array_or_printaddr(tcp, cur, iov,
                                                   ARRAY_SIZE(iov)))
                        break;
+               if (cur <= addr)
+                       tprints("[");
                tprints("{");
                if (decode_iov) {
                        unsigned long len = iov[1];
@@ -108,7 +114,8 @@ tprint_iov_upto(struct tcb *tcp, unsigned long len, unsigned long addr, int deco
                        printaddr(iov[0]);
                tprintf(", %lu}", iov[1]);
        }
-       tprints("]");
+       if (cur > addr)
+               tprints("]");
 }
 
 void

diff --git a/tests/readv.c b/tests/readv.c
index ce765ec070083dc830b53db6b5d819590b5aada7..b0603c20063da8040d1bdef5d852e92073d2bab6 100644 (file)
--- a/tests/readv.c
+++ b/tests/readv.c
@@ -60,7 +60,7 @@ main(void)
        void *w2 = tail_memdup(w2_c, LENGTH_OF(w2_c));
 
        assert(writev(1, efault, 42) == -1);
-       tprintf("writev(1, [%p], 42) = -1 EFAULT (%m)\n", efault);
+       tprintf("writev(1, %p, 42) = -1 EFAULT (%m)\n", efault);
 
        assert(readv(0, efault, 42) == -1);
        tprintf("readv(0, %p, 42) = -1 EFAULT (%m)\n", efault);