diff options
author | Alan Cox <alan@lxorguk.ukuu.org.uk> | 2006-02-14 12:50:54 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-14 13:01:39 -0500 |
commit | 5552c28f6937d2a2b873d06c6d09b96204722dd0 (patch) | |
tree | 041a8ba94166d9c75c34dc385d5298ae4d59d9fe | |
parent | 303794400992b907b7cac0d91788603636c7e0fe (diff) |
[PATCH] Fix locking error in esp
Noted by Al Viro.
Also remove unused tmp_buf
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | drivers/char/esp.c | 22 |
1 files changed, 2 insertions, 20 deletions
diff --git a/drivers/char/esp.c b/drivers/char/esp.c index 57539d8f9f7c..09dc4b01232c 100644 --- a/drivers/char/esp.c +++ b/drivers/char/esp.c | |||
@@ -150,17 +150,6 @@ static void rs_wait_until_sent(struct tty_struct *, int); | |||
150 | /* Standard COM flags (except for COM4, because of the 8514 problem) */ | 150 | /* Standard COM flags (except for COM4, because of the 8514 problem) */ |
151 | #define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST) | 151 | #define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST) |
152 | 152 | ||
153 | /* | ||
154 | * tmp_buf is used as a temporary buffer by serial_write. We need to | ||
155 | * lock it in case the memcpy_fromfs blocks while swapping in a page, | ||
156 | * and some other program tries to do a serial write at the same time. | ||
157 | * Since the lock will only come under contention when the system is | ||
158 | * swapping and available memory is low, it makes sense to share one | ||
159 | * buffer across all the serial ports, since it significantly saves | ||
160 | * memory if large numbers of serial ports are open. | ||
161 | */ | ||
162 | static unsigned char *tmp_buf; | ||
163 | |||
164 | static inline int serial_paranoia_check(struct esp_struct *info, | 153 | static inline int serial_paranoia_check(struct esp_struct *info, |
165 | char *name, const char *routine) | 154 | char *name, const char *routine) |
166 | { | 155 | { |
@@ -1267,7 +1256,7 @@ static int rs_write(struct tty_struct * tty, | |||
1267 | if (serial_paranoia_check(info, tty->name, "rs_write")) | 1256 | if (serial_paranoia_check(info, tty->name, "rs_write")) |
1268 | return 0; | 1257 | return 0; |
1269 | 1258 | ||
1270 | if (!tty || !info->xmit_buf || !tmp_buf) | 1259 | if (!tty || !info->xmit_buf) |
1271 | return 0; | 1260 | return 0; |
1272 | 1261 | ||
1273 | while (1) { | 1262 | while (1) { |
@@ -2291,11 +2280,7 @@ static int esp_open(struct tty_struct *tty, struct file * filp) | |||
2291 | tty->driver_data = info; | 2280 | tty->driver_data = info; |
2292 | info->tty = tty; | 2281 | info->tty = tty; |
2293 | 2282 | ||
2294 | if (!tmp_buf) { | 2283 | spin_unlock_irqrestore(&info->lock, flags); |
2295 | tmp_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL); | ||
2296 | if (!tmp_buf) | ||
2297 | return -ENOMEM; | ||
2298 | } | ||
2299 | 2284 | ||
2300 | /* | 2285 | /* |
2301 | * Start up serial port | 2286 | * Start up serial port |
@@ -2602,9 +2587,6 @@ static void __exit espserial_exit(void) | |||
2602 | free_pages((unsigned long)dma_buffer, | 2587 | free_pages((unsigned long)dma_buffer, |
2603 | get_order(DMA_BUFFER_SZ)); | 2588 | get_order(DMA_BUFFER_SZ)); |
2604 | 2589 | ||
2605 | if (tmp_buf) | ||
2606 | free_page((unsigned long)tmp_buf); | ||
2607 | |||
2608 | while (free_pio_buf) { | 2590 | while (free_pio_buf) { |
2609 | pio_buf = free_pio_buf->next; | 2591 | pio_buf = free_pio_buf->next; |
2610 | kfree(free_pio_buf); | 2592 | kfree(free_pio_buf); |