It seems whoever wrote the preadv and pwritev system calls in the

kernel decided it would be fun to make them always take the low word
of the offset argument before the high word regardless of the
endianism of the system... Consistency - they've heard of it...

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10962

diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index b71e777546bff11d7d50534b1ab0c20e876cf2c1..c8c44aab64e3c0ec0353610d844275dd39b9d3c7 100644 (file)
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -379,6 +379,7 @@ SysRes ML_(do_fork_clone) ( ThreadId tid, UInt flags,
 #define POST(name)      DEFN_POST_TEMPLATE(linux, name)
 
 // Macros to support 64-bit syscall args split into two 32 bit values
+#define LOHI64(lo,hi)   ( ((ULong)(lo)) | (((ULong)(hi)) << 32) )
 #if defined(VG_LITTLEENDIAN)
 #define MERGE64(lo,hi)   ( ((ULong)(lo)) | (((ULong)(hi)) << 32) )
 #define MERGE64_FIRST(name) name##_low
@@ -3161,11 +3162,13 @@ PRE(sys_preadv)
    struct vki_iovec * vec;
    *flags |= SfMayBlock;
 #if VG_WORDSIZE == 4
-   PRINT("sys_preadv ( %ld, %#lx, %llu, %lld )",ARG1,ARG2,(ULong)ARG3,MERGE64(ARG4,ARG5));
+   /* Note that the offset argument here is in lo+hi order on both
+      big and little endian platforms... */
+   PRINT("sys_preadv ( %ld, %#lx, %llu, %lld )",ARG1,ARG2,(ULong)ARG3,LOHI64(ARG4,ARG5));
    PRE_REG_READ5(ssize_t, "preadv",
                  unsigned long, fd, const struct iovec *, vector,
-                 unsigned long, count, vki_u32, MERGE64_FIRST(offset),
-                 vki_u32, MERGE64_SECOND(offset));
+                 unsigned long, count, vki_u32, offset_low,
+                 vki_u32, offset_high);
 #elif VG_WORDSIZE == 8
    PRINT("sys_preadv ( %ld, %#lx, %llu, %lld )",ARG1,ARG2,(ULong)ARG3,(Long)ARG4);
    PRE_REG_READ4(ssize_t, "preadv",
@@ -3214,11 +3217,13 @@ PRE(sys_pwritev)
    struct vki_iovec * vec;
    *flags |= SfMayBlock;
 #if VG_WORDSIZE == 4
-   PRINT("sys_pwritev ( %ld, %#lx, %llu, %lld )",ARG1,ARG2,(ULong)ARG3,MERGE64(ARG4,ARG5));
+   /* Note that the offset argument here is in lo+hi order on both
+      big and little endian platforms... */
+   PRINT("sys_pwritev ( %ld, %#lx, %llu, %lld )",ARG1,ARG2,(ULong)ARG3,LOHI64(ARG4,ARG5));
    PRE_REG_READ5(ssize_t, "pwritev",
                  unsigned long, fd, const struct iovec *, vector,
-                 unsigned long, count, vki_u32, MERGE64_FIRST(offset),
-                 vki_u32, MERGE64_SECOND(offset));
+                 unsigned long, count, vki_u32, offset_low,
+                 vki_u32, offset_high);
 #elif VG_WORDSIZE == 8
    PRINT("sys_pwritev ( %ld, %#lx, %llu, %lld )",ARG1,ARG2,(ULong)ARG3,(Long)ARG4);
    PRE_REG_READ4(ssize_t, "pwritev",