[parisc-linux] pread/pwrite

[parisc-linux] pread/pwrite

[Matthew Wilcox]

Could those who're having problems with pread/pwrite try the following patch?

Index: fs/read_write.c
===================================================================
RCS file: /home/cvs/parisc/linux/fs/read_write.c,v
retrieving revision 1.6
diff -u -p -r1.6 read_write.c
--- fs/read_write.c	2000/11/10 21:43:50	1.6
+++ fs/read_write.c	2001/04/10 20:21:01
@@ -315,8 +315,8 @@ bad_file:
    lseek back to original location.  They fail just like lseek does on
    non-seekable files.  */
 
-asmlinkage ssize_t sys_pread(unsigned int fd, char * buf,
-			     size_t count, loff_t pos)
+static inline
+ssize_t do_pread(unsigned int fd, char * buf, size_t count, loff_t pos)
 {
 	ssize_t ret;
 	struct file * file;
@@ -346,8 +346,8 @@ bad_file:
 	return ret;
 }
 
-asmlinkage ssize_t sys_pwrite(unsigned int fd, const char * buf,
-			      size_t count, loff_t pos)
+static inline
+ssize_t do_pwrite(unsigned int fd, const char * buf, size_t count, loff_t pos)
 {
 	ssize_t ret;
 	struct file * file;
@@ -377,3 +377,35 @@ out:
 bad_file:
 	return ret;
 }
+
+#if BITS_PER_LONG == 32
+#ifdef __BIG_ENDIAN
+#define LOFF_T(high, low) unsigned int high, unsigned int low
+#else
+#define LOFF_T(high, low) unsigned int low, unsigned int high
+#endif
+
+asmlinkage
+ssize_t sys_pread(unsigned int fd, char *buf, size_t count, LOFF_T(high, low))
+{
+	return do_pread(fd, buf, count, (loff_t)high << 32 | low);
+}
+
+ssize_t sys_pwrite(unsigned int fd, char *buf, size_t count, LOFF_T(high, low))
+{
+	return do_pwrite(fd, buf, count, (loff_t)high << 32 | low);
+}
+
+
+#else /* BITS_PER_LONG != 32 */
+asmlinkage
+ssize_t sys_pread(unsigned int fd, char *buf, size_t count, loff_t pos)
+{
+	return do_pread(fd, buf, count, pos);
+}
+
+ssize_t sys_pwrite(unsigned int fd, char *buf, size_t count, loff_t pos)
+{
+	return do_pwrite(fd, buf, count, pos);
+}
+#endif

-- 
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Re: [parisc-linux] pread/pwrite

[Richard Hirst]

Hi Willy,

> Could those who're having problems with pread/pwrite try the following patch?

  I don't see how this is supposed to work with a 32 bit userspace and 64
bit kernel.  Do we also need syscall wrappers for pread/pwrite, something
like this:

Index: arch/parisc/kernel/sys_parisc32.c
===================================================================
RCS file: /home/cvs/parisc/linux/arch/parisc/kernel/sys_parisc32.c,v
retrieving revision 1.4
diff -u -r1.4 sys_parisc32.c
--- sys_parisc32.c	2001/04/10 20:05:24	1.4
+++ sys_parisc32.c	2001/04/11 10:18:17
@@ -2727,3 +2727,19 @@
 	}
 	sys_fcntl(fd, cmd, arg);
 }
+
+
+asmlinkage int sys32_pread(int fd, void *buf, size_t count, unsigned int high, unsigned int low)
+{
+	extern asmlinkage ssize_t sys_pread(unsigned int, char *, size_t, loff_t);
+
+	return sys_pread(fd, buf, count, (loff_t)high << 32 | low);
+}
+
+asmlinkage int sys32_pwrite(int fd, void *buf, size_t count, unsigned int high, unsigned int low)
+{
+	extern asmlinkage ssize_t sys_pwrite(unsigned int, char *, size_t, loff_t);
+
+	return sys_pwrite(fd, buf, count, (loff_t)high << 32 | low);
+}
+
Index: arch/parisc/kernel/syscall.S
===================================================================
RCS file: /home/cvs/parisc/linux/arch/parisc/kernel/syscall.S,v
retrieving revision 1.60
diff -u -r1.60 syscall.S
--- syscall.S	2001/04/10 20:05:24	1.60
+++ syscall.S	2001/04/11 10:18:18
@@ -441,8 +441,8 @@
 	ENTRY_SAME(getitimer)	/* 105 */
 	ENTRY_SAME(capget)
 	ENTRY_SAME(capset)
-	ENTRY_SAME(pread)
-	ENTRY_SAME(pwrite)
+	ENTRY_DIFF(pread)
+	ENTRY_DIFF(pwrite)
 	ENTRY_SAME(getcwd)		/* 110 */
 	ENTRY_SAME(vhangup)
 	ENTRY_SAME(fstat64)