Thank you for looking at my bug report and proposed patch with such
careful scrutiny! I think the mem leak fix you propose is fine, but I
had an ulterior motive for writing the user/kernel fix as I did.
The user/kernel bug was discovered by our automatic bug-finding tool,
cqual, and my patch allowed i2c-dev.c to pass through cqual with no
warnings. The new patch does not, because rdwr_pa[i].buf is sometimes a
a user pointer and sometimes a kernel pointer, e.g. on i2c-dev.c, line
248:
data_ptrs[i] = rdwr_pa[i].buf; // rdwr_pa[i].buf is user pointer
rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); // now it's kernel
Cqual is not just a bug finder, it can verify the _absence_ of bugs. I
think this is pretty cool. Imagine a kernel that can be automatically
verified to have no user/kernel bugs. You'd never have to worry about
user/kernel bugs again!
But like all automatic code verification tools, cqual imposes certain
limits on the types of code you can write. For example, cqual doesn't
allow a variable to sometimes hold a user pointer and sometimes hold a
kernel pointer, like rdwr_pa[i].buf now does. The original patch avoids
this, but the new patch doesn't for performance reasons. FWIW, I think
Linus' checker will also fail to check the new patch.
So there's a trade-off here between performance and automatic code
auditing. Considering that
1. The performance cost of the original patch is minor.
2. i2c-dev.c has had user/kernel bugs in the past.
3. This user/kernel bug was tricky and time consuming to understand.
I propose that having code which can be automatically verified may be
more important than squeezing out every last cycle. In other words,
user/kernel bugs have proven so tricky to detect and fix that it's worth
writing _slightly_ less efficient code in order to have code which can
be automatically verified.
After looking at your rewritten patch, I thought of a possibly cleaner
way to make i2c-dev.c pass cqual without warnings. I've included it
below. I'd like to work with the i2c developers to find a solution
which can be automatically audited and that you like.
Thanks for giving this so much thought.
Best,
Rob
This patch is against i2c cvs. The basic idea is this:
- move all the fields, except buf, of i2c_msg into a substructure, md
(i.e. metadata).
- lots of 1 line changes based on this
- Now the i2cdev_ioctl I2C_RDWR works as follows:
copy all the i2_msg structures from userspace onto tmp_pa
for i = 1 to number of messages
rdwr_pa[i].md = tmp_pa[i].md;
rdwr_pa[i].buf = kmalloc(...);
copy_from_user (rdwr_pa[i].buf, tmp_pa[i].buf);
instead of
copy all the i2_msg structures from userspace onto rdwr_pa
for i = 1 to number of messages
data_ptr[i] = rdwr_pa[i].buf;
rdwr_pa[i].buf = kmalloc(...);
copy_from_user (rdwr_pa[i].buf, data_ptr[i]);
The overhead versus the current version of the ioctl is
- the extra memory consumed by tmp_pa (versus data_ptr)
- the copy of the md field (versus the copy of rdwr_pa[i].buf).
The benefit is
- never have to worry about user/kernel bugs again.
diff -urN --exclude=CVS i2c.orig/kernel/i2c-algo-bit.c i2c.md/kernel/i2c-algo-bit.c
--- i2c.orig/kernel/i2c-algo-bit.c Fri Jul 25 00:56:42 2003
+++ i2c.md/kernel/i2c-algo-bit.c Wed Aug 13 16:02:16 2003
@@ -336,8 +336,8 @@
struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
char c;
const char *temp = msg->buf;
- int count = msg->len;
- unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK;
+ int count = msg->md.len;
+ unsigned short nak_ok = msg->md.flags & I2C_M_IGNORE_NAK;
int retval;
int wrcount=0;
@@ -371,7 +371,7 @@
int rdcount=0; /* counts bytes read */
struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
char *temp = msg->buf;
- int count = msg->len;
+ int count = msg->md.len;
while (count > 0) {
inval = i2c_inb(i2c_adap);
@@ -414,8 +414,8 @@
*/
static inline int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
{
- unsigned short flags = msg->flags;
- unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK;
+ unsigned short flags = msg->md.flags;
+ unsigned short nak_ok = msg->md.flags & I2C_M_IGNORE_NAK;
struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
unsigned char addr;
@@ -425,7 +425,7 @@
if ( (flags & I2C_M_TEN) ) {
/* a ten bit address */
- addr = 0xf0 | (( msg->addr >> 7) & 0x03);
+ addr = 0xf0 | (( msg->md.addr >> 7) & 0x03);
DEB2(printk(KERN_DEBUG "addr0: %d\n",addr));
/* try extended address code...*/
ret = try_address(i2c_adap, addr, retries);
@@ -434,7 +434,7 @@
return -EREMOTEIO;
}
/* the remaining 8 bit address */
- ret = i2c_outb(i2c_adap,msg->addr & 0x7f);
+ ret = i2c_outb(i2c_adap,msg->md.addr & 0x7f);
if ((ret != 1) && !nak_ok) {
/* the chip did not ack / xmission error occurred */
printk(KERN_ERR "died at 2nd address code.\n");
@@ -451,7 +451,7 @@
}
}
} else { /* normal 7bit address */
- addr = ( msg->addr << 1 );
+ addr = ( msg->md.addr << 1 );
if (flags & I2C_M_RD )
addr |= 1;
if (flags & I2C_M_REV_DIR_ADDR )
@@ -476,30 +476,30 @@
i2c_start(adap);
for (i=0;i<num;i++) {
pmsg = &msgs[i];
- nak_ok = pmsg->flags & I2C_M_IGNORE_NAK;
- if (!(pmsg->flags & I2C_M_NOSTART)) {
+ nak_ok = pmsg->md.flags & I2C_M_IGNORE_NAK;
+ if (!(pmsg->md.flags & I2C_M_NOSTART)) {
if (i) {
i2c_repstart(adap);
}
ret = bit_doAddress(i2c_adap, pmsg);
if ((ret != 0) && !nak_ok) {
DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: NAK from device addr %2.2x msg #%d\n"
- ,msgs[i].addr,i));
+ ,msgs[i].md.addr,i));
return (ret<0) ? ret : -EREMOTEIO;
}
}
- if (pmsg->flags & I2C_M_RD ) {
+ if (pmsg->md.flags & I2C_M_RD ) {
/* read bytes into buffer*/
ret = readbytes(i2c_adap, pmsg);
DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: read %d bytes.\n",ret));
- if (ret < pmsg->len ) {
+ if (ret < pmsg->md.len ) {
return (ret<0)? ret : -EREMOTEIO;
}
} else {
/* write bytes from buffer */
ret = sendbytes(i2c_adap, pmsg);
DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: wrote %d bytes.\n",ret));
- if (ret < pmsg->len ) {
+ if (ret < pmsg->md.len ) {
return (ret<0) ? ret : -EREMOTEIO;
}
}
diff -urN --exclude=CVS i2c.orig/kernel/i2c-algo-biths.c i2c.md/kernel/i2c-algo-biths.c
--- i2c.orig/kernel/i2c-algo-biths.c Fri Jul 25 00:56:42 2003
+++ i2c.md/kernel/i2c-algo-biths.c Wed Aug 13 16:04:36 2003
@@ -440,31 +440,31 @@
unsigned char addr[2];
int count;
- if ( msg->flags & I2C_M_TEN ) {
+ if ( msg->md.flags & I2C_M_TEN ) {
/* a ten bit address */
count = 2;
- addr[0] = 0xf0 | (( msg->addr >> 7) & 0x03);
- addr[1] = msg->addr & 0x7f;
+ addr[0] = 0xf0 | (( msg->md.addr >> 7) & 0x03);
+ addr[1] = msg->md.addr & 0x7f;
/* try extended address code ... and the remaining 8 bit address */
- TRY(i2c_outb(adap, msg->flags, addr, &count));
+ TRY(i2c_outb(adap, msg->md.flags, addr, &count));
- if ( msg->flags & I2C_M_RD ) {
+ if ( msg->md.flags & I2C_M_RD ) {
TRY(i2c_start(adap));
/* okay, now switch into reading mode */
count = 1;
addr[0] |= 0x01;
- TRY(i2c_outb(adap, msg->flags, addr, &count));
+ TRY(i2c_outb(adap, msg->md.flags, addr, &count));
}
} else { /* normal 7bit address */
count = 1;
- addr[0] = ( msg->addr << 1 );
- if (msg->flags & I2C_M_RD )
+ addr[0] = ( msg->md.addr << 1 );
+ if (msg->md.flags & I2C_M_RD )
addr[0] |= 1;
- if (msg->flags & I2C_M_REV_DIR_ADDR )
+ if (msg->md.flags & I2C_M_REV_DIR_ADDR )
addr[0] ^= 1;
- TRY(i2c_outb(adap, msg->flags, addr, &count));
+ TRY(i2c_outb(adap, msg->md.flags, addr, &count));
}
}
@@ -498,13 +498,13 @@
}
}
- for (j=0; j<num; j++) msgs[j].err = 0; // unprocessed
+ for (j=0; j<num; j++) msgs[j].md.err = 0; // unprocessed
do switch (state) {
case MSG_INIT:
msg = &msgs[mn];
- if ((msg->flags & I2C_M_NOSTART) && (mn)) {
+ if ((msg->md.flags & I2C_M_NOSTART) && (mn)) {
state = MSG_DATA;
break;
}
@@ -524,13 +524,13 @@
}
case MSG_DATA:
- j = msg->len;
- if ( msg->flags & I2C_M_RD ) {
- i2c_inb(adap, msg->flags, msg->buf, &j);
+ j = msg->md.len;
+ if ( msg->md.flags & I2C_M_RD ) {
+ i2c_inb(adap, msg->md.flags, msg->buf, &j);
} else {
- i2c_outb(adap, msg->flags, msg->buf, &j);
+ i2c_outb(adap, msg->md.flags, msg->buf, &j);
}
- msg->done = msg->len - j;
+ msg->md.done = msg->md.len - j;
if (adap->errors) {
state = MSG_STOP;
break;
@@ -539,30 +539,30 @@
case MSG_READY:
mn++;
if (mn<num) {
- msg->err = errflag(adap->errors);
- debug_protocol(adap, msg->err);
+ msg->md.err = errflag(adap->errors);
+ debug_protocol(adap, msg->md.err);
state = MSG_INIT;
break;
}
case MSG_STOP:
- msg->err = errflag(adap->errors);
+ msg->md.err = errflag(adap->errors);
i2c_stop(adap);
j = 0;
while (adap->errors) {
if ( ++j > 10) {
- msg->err = -ENODEV;
+ msg->md.err = -ENODEV;
break;
}
i2c_stop(adap);
}
- debug_protocol(adap, msg->err);
+ debug_protocol(adap, msg->md.err);
state = MSG_EXIT;
break;
default: /* not reached */
state = MSG_EXIT;
- msg->err = -EINVAL;
+ msg->md.err = -EINVAL;
break;
} while (state != MSG_EXIT);
@@ -570,9 +570,9 @@
if (adap->dstr) kfree(adap->dstr);
for (j=0; j<num; j++)
- debug_printout(i2c_adap, j, msgs[j].err);
+ debug_printout(i2c_adap, j, msgs[j].md.err);
- return (msg->err < 0) ? msg->err : mn;
+ return (msg->md.err < 0) ? msg->md.err : mn;
}
static u32 bit_func(struct i2c_adapter *i2c_adap)
diff -urN --exclude=CVS i2c.orig/kernel/i2c-algo-pcf.c i2c.md/kernel/i2c-algo-pcf.c
--- i2c.orig/kernel/i2c-algo-pcf.c Fri Jul 25 00:56:42 2003
+++ i2c.md/kernel/i2c-algo-pcf.c Wed Aug 13 16:05:59 2003
@@ -299,12 +299,12 @@
static inline int pcf_doAddress(struct i2c_algo_pcf_data *adap,
struct i2c_msg *msg, int retries)
{
- unsigned short flags = msg->flags;
+ unsigned short flags = msg->md.flags;
unsigned char addr;
int ret;
if ( (flags & I2C_M_TEN) ) {
/* a ten bit address */
- addr = 0xf0 | (( msg->addr >> 7) & 0x03);
+ addr = 0xf0 | (( msg->md.addr >> 7) & 0x03);
DEB2(printk(KERN_DEBUG "addr0: %d\n",addr));
/* try extended address code...*/
ret = try_address(adap, addr, retries);
@@ -313,7 +313,7 @@
return -EREMOTEIO;
}
/* the remaining 8 bit address */
- i2c_outb(adap,msg->addr & 0x7f);
+ i2c_outb(adap,msg->md.addr & 0x7f);
/* Status check comes here */
if (ret != 1) {
printk(KERN_ERR "died at 2nd address code.\n");
@@ -330,7 +330,7 @@
}
}
} else { /* normal 7bit address */
- addr = ( msg->addr << 1 );
+ addr = ( msg->md.addr << 1 );
if (flags & I2C_M_RD )
addr |= 1;
if (flags & I2C_M_REV_DIR_ADDR )
@@ -362,8 +362,8 @@
pmsg = &msgs[i];
DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
- pmsg->flags & I2C_M_RD ? "read" : "write",
- pmsg->len, pmsg->addr, i + 1, num);)
+ pmsg->md.flags & I2C_M_RD ? "read" : "write",
+ pmsg->md.len, pmsg->md.addr, i + 1, num);)
ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
@@ -391,25 +391,25 @@
#endif
DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
- i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
+ i, msgs[i].md.addr, msgs[i].md.flags, msgs[i].md.len);)
/* Read */
- if (pmsg->flags & I2C_M_RD) {
+ if (pmsg->md.flags & I2C_M_RD) {
/* read bytes into buffer*/
- ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
+ ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->md.len,
(i + 1 == num));
- if (ret != pmsg->len) {
+ if (ret != pmsg->md.len) {
DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
"only read %d bytes.\n",ret));
} else {
DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
}
} else { /* Write */
- ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
+ ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->md.len,
(i + 1 == num));
- if (ret != pmsg->len) {
+ if (ret != pmsg->md.len) {
DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
"only wrote %d bytes.\n",ret));
} else {
diff -urN --exclude=CVS i2c.orig/kernel/i2c-core.c i2c.md/kernel/i2c-core.c
--- i2c.orig/kernel/i2c-core.c Fri Jul 25 00:56:42 2003
+++ i2c.md/kernel/i2c-core.c Wed Aug 13 15:59:06 2003
@@ -702,9 +702,9 @@
struct i2c_msg msg;
if (client->adapter->algo->master_xfer) {
- msg.addr = client->addr;
- msg.flags = client->flags & I2C_M_TEN;
- msg.len = count;
+ msg.md.addr = client->addr;
+ msg.md.flags = client->flags & I2C_M_TEN;
+ msg.md.len = count;
(const char *)msg.buf = buf;
DEB2(printk(KERN_DEBUG "i2c-core.o: master_send: writing %d bytes on %s.\n",
@@ -731,10 +731,10 @@
struct i2c_msg msg;
int ret;
if (client->adapter->algo->master_xfer) {
- msg.addr = client->addr;
- msg.flags = client->flags & I2C_M_TEN;
- msg.flags |= I2C_M_RD;
- msg.len = count;
+ msg.md.addr = client->addr;
+ msg.md.flags = client->flags & I2C_M_TEN;
+ msg.md.flags |= I2C_M_RD;
+ msg.md.len = count;
msg.buf = buf;
DEB2(printk(KERN_DEBUG "i2c-core.o: master_recv: reading %d bytes on %s.\n",
@@ -1211,39 +1211,39 @@
unsigned char msgbuf0[34];
unsigned char msgbuf1[34];
int num = read_write == I2C_SMBUS_READ?2:1;
- struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
- { addr, flags | I2C_M_RD, 0, msgbuf1 }
+ struct i2c_msg msg[2] = { { { addr, flags, 1 }, msgbuf0 },
+ { { addr, flags | I2C_M_RD, 0 } , msgbuf1 }
};
int i;
msgbuf0[0] = command;
switch(size) {
case I2C_SMBUS_QUICK:
- msg[0].len = 0;
+ msg[0].md.len = 0;
/* Special case: The read/write field is used as data */
- msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
+ msg[0].md.flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
num = 1;
break;
case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_READ) {
/* Special case: only a read! */
- msg[0].flags = I2C_M_RD | flags;
+ msg[0].md.flags = I2C_M_RD | flags;
num = 1;
}
break;
case I2C_SMBUS_BYTE_DATA:
if (read_write == I2C_SMBUS_READ)
- msg[1].len = 1;
+ msg[1].md.len = 1;
else {
- msg[0].len = 2;
+ msg[0].md.len = 2;
msgbuf0[1] = data->byte;
}
break;
case I2C_SMBUS_WORD_DATA:
if (read_write == I2C_SMBUS_READ)
- msg[1].len = 2;
+ msg[1].md.len = 2;
else {
- msg[0].len=3;
+ msg[0].md.len=3;
msgbuf0[1] = data->word & 0xff;
msgbuf0[2] = (data->word >> 8) & 0xff;
}
@@ -1251,8 +1251,8 @@
case I2C_SMBUS_PROC_CALL:
num = 2; /* Special case */
read_write = I2C_SMBUS_READ;
- msg[0].len = 3;
- msg[1].len = 2;
+ msg[0].md.len = 3;
+ msg[1].md.len = 2;
msgbuf0[1] = data->word & 0xff;
msgbuf0[2] = (data->word >> 8) & 0xff;
break;
@@ -1263,16 +1263,16 @@
"under I2C emulation!\n");
return -1;
} else {
- msg[0].len = data->block[0] + 2;
- if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
+ msg[0].md.len = data->block[0] + 2;
+ if (msg[0].md.len > I2C_SMBUS_BLOCK_MAX + 2) {
printk(KERN_ERR "i2c-core.o: smbus_access called with "
"invalid block write size (%d)\n",
data->block[0]);
return -1;
}
if(size == I2C_SMBUS_BLOCK_DATA_PEC)
- (msg[0].len)++;
- for (i = 1; i <= msg[0].len; i++)
+ (msg[0].md.len)++;
+ for (i = 1; i <= msg[0].md.len; i++)
msgbuf0[i] = data->block[i-1];
}
break;
@@ -1283,10 +1283,10 @@
return -1;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (read_write == I2C_SMBUS_READ) {
- msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX;
+ msg[1].md.len = I2C_SMBUS_I2C_BLOCK_MAX;
} else {
- msg[0].len = data->block[0] + 1;
- if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
+ msg[0].md.len = data->block[0] + 1;
+ if (msg[0].md.len > I2C_SMBUS_I2C_BLOCK_MAX + 1) {
printk("i2c-core.o: i2c_smbus_xfer_emulated called with "
"invalid block write size (%d)\n",
data->block[0]);
diff -urN --exclude=CVS i2c.orig/kernel/i2c-dev.c i2c.md/kernel/i2c-dev.c
--- i2c.orig/kernel/i2c-dev.c Sat Aug 9 11:59:43 2003
+++ i2c.md/kernel/i2c-dev.c Thu Aug 14 10:51:49 2003
@@ -170,8 +170,8 @@
struct i2c_rdwr_ioctl_data rdwr_arg;
struct i2c_smbus_ioctl_data data_arg;
union i2c_smbus_data temp;
+ struct i2c_msg *tmp_pa;
struct i2c_msg *rdwr_pa;
- u8 **data_ptrs;
int i,datasize,res;
unsigned long funcs;
@@ -218,43 +218,46 @@
if (rdwr_arg.nmsgs > 42)
return -EINVAL;
- rdwr_pa = (struct i2c_msg *)
+ tmp_pa = (struct i2c_msg *)
kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
GFP_KERNEL);
- if (rdwr_pa == NULL) return -ENOMEM;
+ if (tmp_pa == NULL) return -ENOMEM;
- if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
+ if (copy_from_user(tmp_pa, rdwr_arg.msgs,
rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
- kfree(rdwr_pa);
+ kfree(tmp_pa);
return -EFAULT;
}
- data_ptrs = (u8 **) kmalloc(rdwr_arg.nmsgs * sizeof(u8 *),
- GFP_KERNEL);
- if (data_ptrs == NULL) {
- kfree(rdwr_pa);
+ rdwr_pa = (struct i2c_msg *)
+ kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
+ GFP_KERNEL);
+
+ if (rdwr_pa == NULL) {
+ kfree(tmp_pa);
return -ENOMEM;
}
res = 0;
for( i=0; i<rdwr_arg.nmsgs; i++ )
{
+ rdwr_pa[i].md = tmp_pa[i].md;
+
/* Limit the size of the message to a sane amount */
- if (rdwr_pa[i].len > 8192) {
+ if (rdwr_pa[i].md.len > 8192) {
res = -EINVAL;
break;
}
- data_ptrs[i] = rdwr_pa[i].buf;
- rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
+ rdwr_pa[i].buf = kmalloc(rdwr_pa[i].md.len, GFP_KERNEL);
if(rdwr_pa[i].buf == NULL)
{
res = -ENOMEM;
break;
}
if(copy_from_user(rdwr_pa[i].buf,
- data_ptrs[i],
- rdwr_pa[i].len))
+ tmp_pa[i].buf,
+ rdwr_pa[i].md.len))
{
++i; /* Needs to be kfreed too */
res = -EFAULT;
@@ -265,8 +268,8 @@
int j;
for (j = 0; j < i; ++j)
kfree(rdwr_pa[j].buf);
- kfree(data_ptrs);
kfree(rdwr_pa);
+ kfree(tmp_pa);
return res;
}
@@ -275,20 +278,20 @@
rdwr_arg.nmsgs);
while(i-- > 0)
{
- if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD))
+ if( res>=0 && (rdwr_pa[i].md.flags & I2C_M_RD))
{
if(copy_to_user(
- data_ptrs[i],
+ tmp_pa[i].buf,
rdwr_pa[i].buf,
- rdwr_pa[i].len))
+ rdwr_pa[i].md.len))
{
res = -EFAULT;
}
}
kfree(rdwr_pa[i].buf);
}
- kfree(data_ptrs);
kfree(rdwr_pa);
+ kfree(tmp_pa);
return res;
case I2C_SMBUS:
diff -urN --exclude=CVS i2c.orig/kernel/i2c.h i2c.md/kernel/i2c.h
--- i2c.orig/kernel/i2c.h Sat Aug 2 22:07:09 2003
+++ i2c.md/kernel/i2c.h Wed Aug 13 15:54:49 2003
@@ -355,18 +355,20 @@
* I2C Message - used for pure i2c transaction, also from /dev interface
*/
struct i2c_msg {
- __u16 addr; /* slave address */
- __u16 flags;
+ struct {
+ __u16 addr; /* slave address */
+ __u16 flags;
#define I2C_M_TEN 0x10 /* we have a ten bit chip address */
#define I2C_M_RD 0x01
#define I2C_M_NOSTART 0x4000
#define I2C_M_REV_DIR_ADDR 0x2000
#define I2C_M_IGNORE_NAK 0x1000
#define I2C_M_NO_RD_ACK 0x0800
- __u16 len; /* msg length */
+ __u16 len; /* msg length */
+ int err;
+ short done;
+ } md;
__u8 *buf; /* pointer to msg data */
- int err;
- short done;
};
/* To determine what functionality is present */
