evie/android_kernel_oneplus_msm8998
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staging: comedi: serial2002: fix different address space sparse warnings

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The struct file_operations (*read) and (*write) operations expect the
buffer to be a __user space pointer.

Currently the (*write) operations in this driver cause this warning:
warning: incorrect type in argument 2 (different address spaces)
  expected char const [noderef] <asn:1>*<noident>
  got unsigned char [usertype] *buf

And the (*read) operations cause this warning:
warning: incorrect type in argument 2 (different address spaces)
  expected char [noderef] <asn:1>*<noident>
  got unsigned char *<noident>

Use __force to cast the buffer to a __user pointer to suppress the
warnings.

Consolidate the (*read) calls into a helper function, __tty_readb().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten 2013-04-05 16:07:49 -07:00 • committed by Greg Kroah-Hartman
parent 4445d254cd
commit 32ef0e3e30
1 changed files with 14 additions and 11 deletions
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25
drivers/staging/comedi/drivers/serial2002.c
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@ -82,17 +82,26 @@ static long tty_ioctl(struct file *f, unsigned op, unsigned long param)
static int tty_write(struct file *f, unsigned char *buf, int count)
{
const char __user *p = (__force const char __user *)buf;
int result;
mm_segment_t oldfs;
oldfs = get_fs();
set_fs(KERNEL_DS);
f->f_pos = 0;
result = f->f_op->write(f, buf, count, &f->f_pos);
result = f->f_op->write(f, p, count, &f->f_pos);
set_fs(oldfs);
return result;
}
static int __tty_readb(struct file *f, unsigned char *buf)
{
char __user *p = (__force char __user *)buf;
f->f_pos = 0;
return f->f_op->read(f, p, 1, &f->f_pos);
}
#if 0
/*
* On 2.6.26.3 this occaisonally gave me page faults, worked around by
@ -113,6 +122,7 @@ static int tty_available(struct file *f)
static int tty_read(struct file *f, int timeout)
{
unsigned char ch;
int result;
result = -1;
@ -147,25 +157,18 @@ static int tty_read(struct file *f, int timeout)
elapsed) * HZ) / 10000);
}
poll_freewait(&table);
{
unsigned char ch;
f->f_pos = 0;
if (f->f_op->read(f, &ch, 1, &f->f_pos) == 1)
result = ch;
}
if (__tty_readb(f, &ch) == 1)
result = ch;
} else {
/* Device does not support poll, busy wait */
int retries = 0;
while (1) {
unsigned char ch;
retries++;
if (retries >= timeout)
break;
f->f_pos = 0;
if (f->f_op->read(f, &ch, 1, &f->f_pos) == 1) {
if (__tty_readb(f, &ch) == 1) {
result = ch;
break;
}