[uClibc] pread/pwrite on mips

Atsushi Nemoto anemo at mba.ocn.ne.jp
Wed Aug 20 11:04:46 UTC 2003


I found that current pread/pwrite is broken on mips.

On mips, kernel needs 6 arguments for pread/pwrite system call.  (3
words for first 3 arguments + 1 padding word + 2 words for last 64bit
argument).  Also, mips64 kernel needs just 4 arguments so no wrapper
will be required.

This is a patch against 0.9.20.


diff -urN uClibc-0.9.20.org/libc/sysdeps/linux/mips/Makefile uClibc-0.9.20/libc/sysdeps/linux/mips/Makefile
--- uClibc-0.9.20.org/libc/sysdeps/linux/mips/Makefile	Fri Jan 31 08:46:32 2003
+++ uClibc-0.9.20/libc/sysdeps/linux/mips/Makefile	Wed Aug 20 18:54:43 2003
@@ -26,7 +26,7 @@
 SSRC=bsd-_setjmp.S bsd-setjmp.S setjmp.S clone.S fork.S syscall.S pipe.S
 SOBJS=$(patsubst %.S,%.o, $(SSRC))
 
-CSRC=__longjmp.c  brk.c vfork.c setjmp_aux.c _mmap.c __syscall_error.c cacheflush.c
+CSRC=__longjmp.c  brk.c vfork.c setjmp_aux.c _mmap.c __syscall_error.c cacheflush.c pread_write.c
 COBJS=$(patsubst %.c,%.o, $(CSRC))
 
 OBJS=$(SOBJS) $(MOBJ) $(COBJS)
diff -urN uClibc-0.9.20.org/libc/sysdeps/linux/mips/pread_write.c uClibc-0.9.20/libc/sysdeps/linux/mips/pread_write.c
--- uClibc-0.9.20.org/libc/sysdeps/linux/mips/pread_write.c	Thu Jan  1 09:00:00 1970
+++ uClibc-0.9.20/libc/sysdeps/linux/mips/pread_write.c	Wed Aug 20 19:05:08 2003
@@ -0,0 +1,94 @@
+/* vi: set sw=4 ts=4:
+ *
+ * Copyright (C) 2002 by Erik Andersen <andersen at uclibc.org>
+ * Based in part on the files
+ *		./sysdeps/unix/sysv/linux/pwrite.c,
+ *		./sysdeps/unix/sysv/linux/pread.c, 
+ *		sysdeps/posix/pread.c
+ *		sysdeps/posix/pwrite.c
+ * from GNU libc 2.2.5, but reworked considerably...
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#define _GNU_SOURCE
+#define _LARGEFILE64_SOURCE
+#include <features.h>
+#undef __OPTIMIZE__
+/* We absolutely do _NOT_ want interfaces silently
+ *  *  * renamed under us or very bad things will happen... */
+#ifdef __USE_FILE_OFFSET64
+# undef __USE_FILE_OFFSET64
+#endif
+
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#ifdef __NR_pread
+
+#ifdef __mips64
+_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, count, off_t, offset);
+#else /* !__mips64 */
+#define __NR___syscall_pread __NR_pread 
+static inline _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf, 
+		size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo);
+
+ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset)
+{ 
+	return(__syscall_pread(fd,buf,count,0,__LONG_LONG_PAIR((off_t)0,offset)));
+}
+weak_alias (__libc_pread, pread)
+
+#if defined __UCLIBC_HAS_LFS__ 
+ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
+{ 
+	return(__syscall_pread(fd, buf, count, 0,
+			__LONG_LONG_PAIR((off_t)(offset>>32),(off_t)(offset&0xffffffff))));
+}
+weak_alias (__libc_pread64, pread64)
+#endif /* __UCLIBC_HAS_LFS__  */
+#endif /* !__mips64 */
+
+#endif /* __NR_pread */
+
+
+#ifdef __NR_pwrite
+
+#ifdef __mips64
+_syscall4(ssize_t, pwrite, int, fd, const void *, buf, size_t, count, off_t, offset);
+#else /* !__mips64 */
+#define __NR___syscall_pwrite __NR_pwrite 
+static inline _syscall6(ssize_t, __syscall_pwrite, int, fd, const void *, buf, 
+		size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo);
+
+ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
+{ 
+	return(__syscall_pwrite(fd,buf,count,0,__LONG_LONG_PAIR((off_t)0,offset)));
+}
+weak_alias (__libc_pwrite, pwrite)
+
+#if defined __UCLIBC_HAS_LFS__ 
+ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
+{ 
+	return(__syscall_pwrite(fd, buf, count, 0,
+			__LONG_LONG_PAIR((off_t)(offset>>32),(off_t)(offset&0xffffffff))));
+}
+weak_alias (__libc_pwrite64, pwrite64)
+#endif /* __UCLIBC_HAS_LFS__  */
+#endif /* !__mips64 */
+#endif /* __NR_pwrite */
---
Atsushi Nemoto



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