linux: pread/write: fix 64bit handling

The syscall on 64bit ports takes 4 args as there is no need to split
up the value into two args.  Add support for that to the common code.

Once we fix that, the mips code can now leverage it for its 64bit and
32bit needs.  However, we can't just drop it entirely yet because its
n32 ABI needs special handling to treat it like a 64bit port.  This
does change the existing behavior which treats the n32 like a 32bit
port, but we want to do this.

In the future, we'll probably have to introduce a define for this as
it currently affects x86_64/x32 and mips/n32.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

libc/sysdeps/linux/common/pread_write.c

@@ -36,11 +36,16 @@ static _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf,
 		 size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo)
 #   define MY_PREAD(fd, buf, count, offset) __syscall_pread(fd, buf, count, 0, OFF_HI_LO(offset))
 #   define MY_PREAD64(fd, buf, count, offset) __syscall_pread(fd, buf, count, 0, OFF64_HI_LO(offset))
-#  else
+#  elif __WORDSIZE == 32
 static _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,
 		 size_t, count, off_t, offset_hi, off_t, offset_lo)
 #   define MY_PREAD(fd, buf, count, offset) __syscall_pread(fd, buf, count, OFF_HI_LO(offset))
 #   define MY_PREAD64(fd, buf, count, offset) __syscall_pread(fd, buf, count, OFF64_HI_LO(offset))
+#  else
+static _syscall4(ssize_t, __syscall_pread, int, fd, void *, buf,
+		 size_t, count, off_t, offset)
+#   define MY_PREAD(fd, buf, count, offset) __syscall_pread(fd, buf, count, offset)
+#   define MY_PREAD64(fd, buf, count, offset) __syscall_pread(fd, buf, count, offset)
 #  endif
 # endif
 #endif
@@ -53,11 +58,16 @@ static _syscall6(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
 		 size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo)
 #   define MY_PWRITE(fd, buf, count, offset) __syscall_pwrite(fd, buf, count, 0, OFF_HI_LO(offset))
 #   define MY_PWRITE64(fd, buf, count, offset) __syscall_pwrite(fd, buf, count, 0, OFF64_HI_LO(offset))
-#  else
+#  elif __WORDSIZE == 32
 static _syscall5(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
 		 size_t, count, off_t, offset_hi, off_t, offset_lo)
 #   define MY_PWRITE(fd, buf, count, offset) __syscall_pwrite(fd, buf, count, OFF_HI_LO(offset))
 #   define MY_PWRITE64(fd, buf, count, offset) __syscall_pwrite(fd, buf, count, OFF64_HI_LO(offset))
+#  else
+static _syscall4(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
+		 size_t, count, off_t, offset)
+#   define MY_PWRITE(fd, buf, count, offset) __syscall_pwrite(fd, buf, count, offset)
+#   define MY_PWRITE64(fd, buf, count, offset) __syscall_pwrite(fd, buf, count, offset)
 #  endif
 # endif
 #endif

libc/sysdeps/linux/mips/pread_write.c

@@ -10,56 +10,22 @@
 #include <endian.h>
 #include <sgidefs.h>
 
-#ifdef __NR_pread64
-# ifdef __NR_pread
-#  error "__NR_pread and __NR_pread64 both defined???"
-# endif
-# define __NR_pread __NR_pread64
-#endif
-
-#ifdef __NR_pread
-# if _MIPS_SIM == _MIPS_SIM_ABI64 /* glibc uses it for N32 as well */
-#  define __NR___syscall_pread __NR_pread
+/* We should generalize this for 32bit userlands w/64bit regs.  This applies
+ * to the x86_64 x32 and the mips n32 ABIs.  */
+#if _MIPS_SIM == _MIPS_SIM_NABI32
+# define __NR___syscall_pread __NR_pread
 static _syscall4(ssize_t, __syscall_pread, int, fd, void *, buf, size_t, count, off_t, offset)
-#  define MY_PREAD(fd, buf, count, offset) \
+# define MY_PREAD(fd, buf, count, offset) \
 	__syscall_pread(fd, buf, count, offset)
-#  define MY_PREAD64(fd, buf, count, offset) \
+# define MY_PREAD64(fd, buf, count, offset) \
 	__syscall_pread(fd, buf, count, offset)
-# else /* O32 || N32 */
-#  define __NR___syscall_pread __NR_pread
-static _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf,
-		 size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo)
-#  define MY_PREAD(fd, buf, count, offset) \
-	__syscall_pread(fd, buf, count, 0, OFF_HI_LO(offset))
-#  define MY_PREAD64(fd, buf, count, offset) \
-	__syscall_pread(fd, buf, count, 0, OFF64_HI_LO(offset))
-# endif
-#endif
-
-#ifdef __NR_pwrite64
-# ifdef __NR_pwrite
-#  error "__NR_pwrite and __NR_pwrite64 both defined???"
-# endif
-# define __NR_pwrite __NR_pwrite64
-#endif
 
-#ifdef __NR_pwrite
-# if _MIPS_SIM == _MIPS_SIM_ABI64 /* glibc uses it for N32 as well */
-#  define __NR___syscall_pwrite __NR_pwrite
+# define __NR___syscall_pwrite __NR_pwrite
 static _syscall4(ssize_t, __syscall_pwrite, int, fd, const void *, buf, size_t, count, off_t, offset)
-#  define MY_PWRITE(fd, buf, count, offset) \
+# define MY_PWRITE(fd, buf, count, offset) \
 	__syscall_pwrite(fd, buf, count, offset)
-#  define MY_PWRITE64(fd, buf, count, offset) \
+# define MY_PWRITE64(fd, buf, count, offset) \
 	__syscall_pwrite(fd, buf, count, offset)
-# else /* O32 || N32 */
-#  define __NR___syscall_pwrite __NR_pwrite
-static _syscall6(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
-		 size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo)
-#  define MY_PWRITE(fd, buf, count, offset) \
-	__syscall_pwrite(fd, buf, count, 0, OFF_HI_LO(offset))
-#  define MY_PWRITE64(fd, buf, count, offset) \
-	__syscall_pwrite(fd, buf, count, 0, OFF64_HI_LO(offset))
-# endif
 #endif
 
 #include "../common/pread_write.c"