Fix bug in _dl_pread when using pread64 syscall

In ARM_EABI mode, the pread64 syscall parameters are aligned on
64-bits. This syscall is used in rtld when processing FDPIC
relocations.

	* ldso/include/dl-syscall.h (__syscall_pread): Fix definition.
	(__dl_pread): Fix syscall invocation.
	* ldso/ldso/fdpic/dl-sysdep.h (__DL_PREAD): Handle __NR_pread64.

Signed-off-by: Mickaël Guêné <mickael.guene@st.com>
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>

ldso/include/dl-syscall.h

@@ -159,14 +159,25 @@ static __always_inline _syscall4(int, _dl_readlink, int, id, const char *, path,
 
 #ifdef __NR_pread64
 #define __NR___syscall_pread __NR_pread64
+#ifdef __UCLIBC_SYSCALL_ALIGN_64BIT__
+static __always_inline _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf, size_t, dummy,
+			size_t, count, off_t, offset_hi, off_t, offset_lo)
+
+static __always_inline ssize_t
+_dl_pread(int fd, void *buf, size_t count, off_t offset)
+{
+	return __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR((offset >> 32), (offset & 0xffffffff)));
+}
+#else
 static __always_inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,
 			size_t, count, off_t, offset_hi, off_t, offset_lo)
 
 static __always_inline ssize_t
 _dl_pread(int fd, void *buf, size_t count, off_t offset)
 {
-	return __syscall_pread(fd, buf, count, offset, offset >> 31);
+	return __syscall_pread(fd, buf, count, __LONG_LONG_PAIR(offset >> 31, offset));
 }
+#endif
 #elif defined __NR_pread
 #define __NR___syscall_pread __NR_pread
 static __always_inline _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,

ldso/ldso/fdpic/dl-sysdep.h

@@ -96,7 +96,7 @@ struct funcdesc_ht;
    elfinterp.c.  */
 #define DL_SKIP_BOOTSTRAP_RELOC(SYMTAB, INDEX, STRTAB) 0
 
-#ifdef __NR_pread
+#if defined(__NR_pread) || defined(__NR_pread64)
 #define _DL_PREAD(FD, BUF, SIZE, OFFSET) \
   (_dl_pread((FD), (BUF), (SIZE), (OFFSET)))
 #endif