[PATCH] s390 (8/8): console driver fixes.

From: Martin Schwidefsky
Date: Tue Oct 21 2003 - 10:17:05 EST

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Move copy_from_user out of locked code in the 3215 and sclp driver.

diffstat:
drivers/s390/char/con3215.c | 88 ++++++++++++++++++-------------------------
drivers/s390/char/sclp_con.c | 4 -
drivers/s390/char/sclp_rw.c | 16 +------
drivers/s390/char/sclp_rw.h | 2
drivers/s390/char/sclp_tty.c | 38 ++++++++++++++----
5 files changed, 73 insertions(+), 75 deletions(-)

diff -urN linux-2.6/drivers/s390/char/con3215.c linux-2.6-s390/drivers/s390/char/con3215.c
--- linux-2.6/drivers/s390/char/con3215.c Fri Oct 17 23:43:20 2003
+++ linux-2.6-s390/drivers/s390/char/con3215.c Tue Oct 21 16:37:39 2003
@@ -96,6 +96,7 @@
int msg_dstat; /* dstat for pending message */
int msg_cstat; /* cstat for pending message */
int line_pos; /* position on the line (for tabs) */
+ char ubuffer[80]; /* copy_from_user buffer */
};

/* array of 3215 devices structures */
@@ -532,15 +533,12 @@
/*
* String write routine for 3215 devices
*/
-static int
-raw3215_write(struct raw3215_info *raw, const char *str,
- int from_user, unsigned int length)
+static void
+raw3215_write(struct raw3215_info *raw, const char *str, unsigned int length)
{
unsigned long flags;
- int ret, c;
- int count;
+ int c, count;

- ret = 0;
while (length > 0) {
spin_lock_irqsave(raw->lock, flags);
count = (length > RAW3215_BUFFER_SIZE) ?
@@ -550,46 +548,19 @@
raw3215_make_room(raw, count);

/* copy string to output buffer and convert it to EBCDIC */
- if (from_user) {
- while (1) {
- c = min_t(int, count,
- min(RAW3215_BUFFER_SIZE - raw->count,
- RAW3215_BUFFER_SIZE - raw->head));
- if (c <= 0)
- break;
- c -= copy_from_user(raw->buffer + raw->head,
- str, c);
- if (c == 0) {
- if (!ret)
- ret = -EFAULT;
- break;
- }
- ASCEBC(raw->buffer + raw->head, c);
- raw->head = (raw->head + c) &
- (RAW3215_BUFFER_SIZE - 1);
- raw->count += c;
- raw->line_pos += c;
- str += c;
- count -= c;
- ret += c;
- }
- } else {
- while (1) {
- c = min_t(int, count,
- min(RAW3215_BUFFER_SIZE - raw->count,
- RAW3215_BUFFER_SIZE - raw->head));
- if (c <= 0)
- break;
- memcpy(raw->buffer + raw->head, str, c);
- ASCEBC(raw->buffer + raw->head, c);
- raw->head = (raw->head + c) &
- (RAW3215_BUFFER_SIZE - 1);
- raw->count += c;
- raw->line_pos += c;
- str += c;
- count -= c;
- ret += c;
- }
+ while (1) {
+ c = min_t(int, count,
+ min(RAW3215_BUFFER_SIZE - raw->count,
+ RAW3215_BUFFER_SIZE - raw->head));
+ if (c <= 0)
+ break;
+ memcpy(raw->buffer + raw->head, str, c);
+ ASCEBC(raw->buffer + raw->head, c);
+ raw->head = (raw->head + c) & (RAW3215_BUFFER_SIZE - 1);
+ raw->count += c;
+ raw->line_pos += c;
+ str += c;
+ count -= c;
}
if (!(raw->flags & RAW3215_WORKING)) {
raw3215_mk_write_req(raw);
@@ -598,8 +569,6 @@
}
spin_unlock_irqrestore(raw->lock, flags);
}
-
- return ret;
}

/*
@@ -825,7 +794,7 @@
for (i = 0; i < count; i++)
if (str[i] == '\t' || str[i] == '\n')
break;
- raw3215_write(raw, str, 0, i);
+ raw3215_write(raw, str, i);
count -= i;
str += i;
if (count > 0) {
@@ -1021,12 +990,29 @@
const unsigned char *buf, int count)
{
struct raw3215_info *raw;
- int ret = 0;
+ int length, ret;

if (!tty)
return 0;
raw = (struct raw3215_info *) tty->driver_data;
- ret = raw3215_write(raw, buf, from_user, count);
+ if (!from_user) {
+ raw3215_write(raw, buf, count);
+ return count;
+ }
+ ret = 0;
+ while (count > 0) {
+ length = count < 80 ? count : 80;
+ length -= copy_from_user(raw->ubuffer, buf, length);
+ if (length == 0) {
+ if (!ret)
+ ret = -EFAULT;
+ break;
+ }
+ raw3215_write(raw, raw->ubuffer, count);
+ buf += length;
+ count -= length;
+ ret += length;
+ }
return ret;
}

diff -urN linux-2.6/drivers/s390/char/sclp_con.c linux-2.6-s390/drivers/s390/char/sclp_con.c
--- linux-2.6/drivers/s390/char/sclp_con.c Fri Oct 17 23:43:12 2003
+++ linux-2.6-s390/drivers/s390/char/sclp_con.c Tue Oct 21 16:37:39 2003
@@ -134,8 +134,8 @@
}
/* try to write the string to the current output buffer */
written = sclp_write(sclp_conbuf, (const unsigned char *)
- message, count, 0);
- if (written == -EFAULT || written == count)
+ message, count);
+ if (written == count)
break;
/*
* Not all characters could be written to the current
diff -urN linux-2.6/drivers/s390/char/sclp_rw.c linux-2.6-s390/drivers/s390/char/sclp_rw.c
--- linux-2.6/drivers/s390/char/sclp_rw.c Fri Oct 17 23:43:10 2003
+++ linux-2.6-s390/drivers/s390/char/sclp_rw.c Tue Oct 21 16:37:39 2003
@@ -175,11 +175,9 @@
* is not busy)
*/
int
-sclp_write(struct sclp_buffer *buffer,
- const unsigned char *msg, int count, int from_user)
+sclp_write(struct sclp_buffer *buffer, const unsigned char *msg, int count)
{
int spaces, i_msg;
- char ch;
int rc;

/*
@@ -206,13 +204,7 @@
* This is in order to a slim and quick implementation.
*/
for (i_msg = 0; i_msg < count; i_msg++) {
- if (from_user) {
- if (get_user(ch, msg + i_msg) != 0)
- return -EFAULT;
- } else
- ch = msg[i_msg];
-
- switch (ch) {
+ switch (msg[i_msg]) {
case '\n': /* new line, line feed (ASCII) */
/* check if new mto needs to be created */
if (buffer->current_line == NULL) {
@@ -286,7 +278,7 @@
break;
default: /* no escape character */
/* do not output unprintable characters */
- if (!isprint(ch))
+ if (!isprint(msg[i_msg]))
break;
/* check if new mto needs to be created */
if (buffer->current_line == NULL) {
@@ -295,7 +287,7 @@
if (rc)
return i_msg;
}
- *buffer->current_line++ = sclp_ascebc(ch);
+ *buffer->current_line++ = sclp_ascebc(msg[i_msg]);
buffer->current_length++;
break;
}
diff -urN linux-2.6/drivers/s390/char/sclp_rw.h linux-2.6-s390/drivers/s390/char/sclp_rw.h
--- linux-2.6/drivers/s390/char/sclp_rw.h Fri Oct 17 23:43:16 2003
+++ linux-2.6-s390/drivers/s390/char/sclp_rw.h Tue Oct 21 16:37:39 2003
@@ -89,7 +89,7 @@
struct sclp_buffer *sclp_make_buffer(void *, unsigned short, unsigned short);
void *sclp_unmake_buffer(struct sclp_buffer *);
int sclp_buffer_space(struct sclp_buffer *);
-int sclp_write(struct sclp_buffer *buffer, const unsigned char *, int, int);
+int sclp_write(struct sclp_buffer *buffer, const unsigned char *, int);
void sclp_emit_buffer(struct sclp_buffer *,void (*)(struct sclp_buffer *,int));
void sclp_set_columns(struct sclp_buffer *, unsigned short);
void sclp_set_htab(struct sclp_buffer *, unsigned short);
diff -urN linux-2.6/drivers/s390/char/sclp_tty.c linux-2.6-s390/drivers/s390/char/sclp_tty.c
--- linux-2.6/drivers/s390/char/sclp_tty.c Fri Oct 17 23:42:55 2003
+++ linux-2.6-s390/drivers/s390/char/sclp_tty.c Tue Oct 21 16:37:39 2003
@@ -322,7 +322,7 @@
* Write a string to the sclp tty.
*/
static void
-sclp_tty_write_string(const unsigned char *str, int count, int from_user)
+sclp_tty_write_string(const unsigned char *str, int count)
{
unsigned long flags;
void *page;
@@ -348,8 +348,8 @@
sclp_ioctls.htab);
}
/* try to write the string to the current output buffer */
- written = sclp_write(sclp_ttybuf, str, count, from_user);
- if (written == -EFAULT || written == count)
+ written = sclp_write(sclp_ttybuf, str, count);
+ if (written == count)
break;
/*
* Not all characters could be written to the current
@@ -389,12 +389,32 @@
sclp_tty_write(struct tty_struct *tty, int from_user,
const unsigned char *buf, int count)
{
+ int length, ret;
+
if (sclp_tty_chars_count > 0) {
- sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
+ sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
sclp_tty_chars_count = 0;
}
- sclp_tty_write_string(buf, count, from_user);
- return count;
+ if (!from_user) {
+ sclp_tty_write_string(buf, count);
+ return count;
+ }
+ ret = 0;
+ while (count > 0) {
+ length = count < SCLP_TTY_BUF_SIZE ?
+ count : SCLP_TTY_BUF_SIZE;
+ length -= copy_from_user(sclp_tty_chars, buf, length);
+ if (length == 0) {
+ if (!ret)
+ ret = -EFAULT;
+ break;
+ }
+ sclp_tty_write_string(sclp_tty_chars, length);
+ buf += length;
+ count -= length;
+ ret += length;
+ }
+ return ret;
}

/*
@@ -412,7 +432,7 @@
{
sclp_tty_chars[sclp_tty_chars_count++] = ch;
if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
- sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
+ sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
sclp_tty_chars_count = 0;
}
}
@@ -425,7 +445,7 @@
sclp_tty_flush_chars(struct tty_struct *tty)
{
if (sclp_tty_chars_count > 0) {
- sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
+ sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
sclp_tty_chars_count = 0;
}
}
@@ -464,7 +484,7 @@
sclp_tty_flush_buffer(struct tty_struct *tty)
{
if (sclp_tty_chars_count > 0) {
- sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
+ sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
sclp_tty_chars_count = 0;
}
}
-
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Next message: James Finnie: "RE: VIA IDE performance under 2.6.0-test7/8?"
Previous message: Martin Schwidefsky: "[PATCH] s390 (7/8): static root object fix."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]