[PATCH] drivers/tty/synclink: let receive buffer size match max framesize
From: Chen Gang
Date: Wed Dec 19 2012 - 23:15:46 EST
By Paul Fulghum:
Fix call to line discipline receive_buf by synclink drivers.
Dummy flag buffer argument is ignored by N_HDLC line discipline but might
be of insufficient size if accessed by a different line discipline
selected by mistake. flag buffer allocation now matches max size of data
buffer. Unused char_buf buffers are removed.
By Chen Gang:
Give a comment for rx_get_buf
the receive buffer size is DMABUFSIZE limited, which alloc in alloc_bufs
it is always less than max_frame_size
so do not need check the length whether larger than max_frame_size.
Extern the limitation.
the maxframe parameter (which input from outside) has value limitition
so define macro in include/linux/synclink.h to extern the limitation
and use macro instead of hard code numbers in all relative c source files
Beautify source code:
for function mgslpc_probe in drivers/char/pcmcia/synclink_cs.c
use tab instead of 4 spaces for each line header.
Unit test:
for "Give a comment for rx_get_buf":
only a comment, not need test.
also can reference free_buf, so can confirm our conclusion.
for "Extern the limitation":
modify source code, call the relative function when insmod module.
pass maxframe=6000, for synclink_gt, synclink_cs, synclink, synclinkmp.
pass maxframe=3000, for synclink_gt, synclink_cs, synclink, synclinkmp.
pass maxframe=70000, for synclink_gt, synclink_cs, synclink, synclinkmp.
for "Beautify source code":
vimdiff the new file and the original file.
restore the new file to the original file, word by word.
make sure that we only use tab instead of 4 spaces for each line header.
Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
Signed-off-by: Paul Fulghum <paulkf@xxxxxxxxxxxxx>
---
drivers/char/pcmcia/synclink_cs.c | 102 ++++++++++++++++++++-----------------
drivers/tty/synclink.c | 23 ++++++---
drivers/tty/synclink_gt.c | 29 ++++++++---
drivers/tty/synclinkmp.c | 22 +++++---
include/linux/synclink.h | 3 ++
5 files changed, 111 insertions(+), 68 deletions(-)
diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index b66eaa0..4f78e30 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -210,7 +210,7 @@ typedef struct _mgslpc_info {
char testing_irq;
unsigned int init_error; /* startup error (DIAGS) */
- char flag_buf[MAX_ASYNC_BUFFER_SIZE];
+ char *flag_buf;
bool drop_rts_on_tx_done;
struct _input_signal_events input_signal_events;
@@ -514,49 +514,49 @@ static const struct tty_port_operations mgslpc_port_ops = {
static int mgslpc_probe(struct pcmcia_device *link)
{
- MGSLPC_INFO *info;
- int ret;
+ MGSLPC_INFO *info;
+ int ret;
- if (debug_level >= DEBUG_LEVEL_INFO)
- printk("mgslpc_attach\n");
-
- info = kzalloc(sizeof(MGSLPC_INFO), GFP_KERNEL);
- if (!info) {
- printk("Error can't allocate device instance data\n");
- return -ENOMEM;
- }
-
- info->magic = MGSLPC_MAGIC;
- tty_port_init(&info->port);
- info->port.ops = &mgslpc_port_ops;
- INIT_WORK(&info->task, bh_handler);
- info->max_frame_size = 4096;
- info->port.close_delay = 5*HZ/10;
- info->port.closing_wait = 30*HZ;
- init_waitqueue_head(&info->status_event_wait_q);
- init_waitqueue_head(&info->event_wait_q);
- spin_lock_init(&info->lock);
- spin_lock_init(&info->netlock);
- memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
- info->idle_mode = HDLC_TXIDLE_FLAGS;
- info->imra_value = 0xffff;
- info->imrb_value = 0xffff;
- info->pim_value = 0xff;
-
- info->p_dev = link;
- link->priv = info;
-
- /* Initialize the struct pcmcia_device structure */
-
- ret = mgslpc_config(link);
- if (ret) {
- tty_port_destroy(&info->port);
- return ret;
- }
-
- mgslpc_add_device(info);
+ if (debug_level >= DEBUG_LEVEL_INFO)
+ printk("mgslpc_attach\n");
- return 0;
+ info = kzalloc(sizeof(MGSLPC_INFO), GFP_KERNEL);
+ if (!info) {
+ printk("Error can't allocate device instance data\n");
+ return -ENOMEM;
+ }
+
+ info->magic = MGSLPC_MAGIC;
+ tty_port_init(&info->port);
+ info->port.ops = &mgslpc_port_ops;
+ INIT_WORK(&info->task, bh_handler);
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
+ info->port.close_delay = 5*HZ/10;
+ info->port.closing_wait = 30*HZ;
+ init_waitqueue_head(&info->status_event_wait_q);
+ init_waitqueue_head(&info->event_wait_q);
+ spin_lock_init(&info->lock);
+ spin_lock_init(&info->netlock);
+ memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
+ info->idle_mode = HDLC_TXIDLE_FLAGS;
+ info->imra_value = 0xffff;
+ info->imrb_value = 0xffff;
+ info->pim_value = 0xff;
+
+ info->p_dev = link;
+ link->priv = info;
+
+ /* Initialize the struct pcmcia_device structure */
+
+ ret = mgslpc_config(link);
+ if (ret) {
+ tty_port_destroy(&info->port);
+ return ret;
+ }
+
+ mgslpc_add_device(info);
+
+ return 0;
}
/* Card has been inserted.
@@ -2674,6 +2674,14 @@ static int rx_alloc_buffers(MGSLPC_INFO *info)
if (info->rx_buf == NULL)
return -ENOMEM;
+ /* unused flag buffer to satisfy receive_buf calling interface */
+ info->flag_buf = kzalloc(info->max_frame_size, GFP_KERNEL);
+ if (!info->flag_buf) {
+ kfree(info->rx_buf);
+ info->rx_buf = NULL;
+ return -ENOMEM;
+ }
+
rx_reset_buffers(info);
return 0;
}
@@ -2682,6 +2690,8 @@ static void rx_free_buffers(MGSLPC_INFO *info)
{
kfree(info->rx_buf);
info->rx_buf = NULL;
+ kfree(info->flag_buf);
+ info->flag_buf = NULL;
}
static int claim_resources(MGSLPC_INFO *info)
@@ -2728,10 +2738,10 @@ static void mgslpc_add_device(MGSLPC_INFO *info)
current_dev->next_device = info;
}
- if (info->max_frame_size < 4096)
- info->max_frame_size = 4096;
- else if (info->max_frame_size > 65535)
- info->max_frame_size = 65535;
+ if (info->max_frame_size < SYNCLINK_MIN_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
+ else if (info->max_frame_size > SYNCLINK_MAX_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MAX_FRAME_SIZE;
printk( "SyncLink PC Card %s:IO=%04X IRQ=%d\n",
info->device_name, info->io_base, info->irq_level);
diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c
index 9e071f6..94ce422 100644
--- a/drivers/tty/synclink.c
+++ b/drivers/tty/synclink.c
@@ -291,8 +291,7 @@ struct mgsl_struct {
bool lcr_mem_requested;
u32 misc_ctrl_value;
- char flag_buf[MAX_ASYNC_BUFFER_SIZE];
- char char_buf[MAX_ASYNC_BUFFER_SIZE];
+ char *flag_buf;
bool drop_rts_on_tx_done;
bool loopmode_insert_requested;
@@ -3898,7 +3897,13 @@ static int mgsl_alloc_intermediate_rxbuffer_memory(struct mgsl_struct *info)
info->intermediate_rxbuffer = kmalloc(info->max_frame_size, GFP_KERNEL | GFP_DMA);
if ( info->intermediate_rxbuffer == NULL )
return -ENOMEM;
-
+ /* unused flag buffer to satisfy receive_buf calling interface */
+ info->flag_buf = kzalloc(info->max_frame_size, GFP_KERNEL);
+ if (!info->flag_buf) {
+ kfree(info->intermediate_rxbuffer);
+ info->intermediate_rxbuffer = NULL;
+ return -ENOMEM;
+ }
return 0;
} /* end of mgsl_alloc_intermediate_rxbuffer_memory() */
@@ -3917,6 +3922,8 @@ static void mgsl_free_intermediate_rxbuffer_memory(struct mgsl_struct *info)
{
kfree(info->intermediate_rxbuffer);
info->intermediate_rxbuffer = NULL;
+ kfree(info->flag_buf);
+ info->flag_buf = NULL;
} /* end of mgsl_free_intermediate_rxbuffer_memory() */
@@ -4237,10 +4244,10 @@ static void mgsl_add_device( struct mgsl_struct *info )
current_dev->next_device = info;
}
- if ( info->max_frame_size < 4096 )
- info->max_frame_size = 4096;
- else if ( info->max_frame_size > 65535 )
- info->max_frame_size = 65535;
+ if (info->max_frame_size < SYNCLINK_MIN_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
+ else if (info->max_frame_size > SYNCLINK_MAX_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MAX_FRAME_SIZE;
if ( info->bus_type == MGSL_BUS_TYPE_PCI ) {
printk( "SyncLink PCI v%d %s: IO=%04X IRQ=%d Mem=%08X,%08X MaxFrameSize=%u\n",
@@ -4286,7 +4293,7 @@ static struct mgsl_struct* mgsl_allocate_device(void)
info->port.ops = &mgsl_port_ops;
info->magic = MGSL_MAGIC;
INIT_WORK(&info->task, mgsl_bh_handler);
- info->max_frame_size = 4096;
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
info->port.close_delay = 5*HZ/10;
info->port.closing_wait = 30*HZ;
init_waitqueue_head(&info->status_event_wait_q);
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index aba1e59..4dda746 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -317,8 +317,7 @@ struct slgt_info {
unsigned char *tx_buf;
int tx_count;
- char flag_buf[MAX_ASYNC_BUFFER_SIZE];
- char char_buf[MAX_ASYNC_BUFFER_SIZE];
+ char *flag_buf;
bool drop_rts_on_tx_done;
struct _input_signal_events input_signal_events;
@@ -3355,11 +3354,24 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
return retval;
}
+/*
+ * allocate buffers used for calling line discipline receive_buf
+ * directly in synchronous mode
+ * note: add 5 bytes to max frame size to allow appending
+ * 32-bit CRC and status byte when configured to do so
+ */
static int alloc_tmp_rbuf(struct slgt_info *info)
{
info->tmp_rbuf = kmalloc(info->max_frame_size + 5, GFP_KERNEL);
if (info->tmp_rbuf == NULL)
return -ENOMEM;
+ /* unused flag buffer to satisfy receive_buf calling interface */
+ info->flag_buf = kzalloc(info->max_frame_size + 5, GFP_KERNEL);
+ if (!info->flag_buf) {
+ kfree(info->tmp_rbuf);
+ info->tmp_rbuf = NULL;
+ return -ENOMEM;
+ }
return 0;
}
@@ -3367,6 +3379,8 @@ static void free_tmp_rbuf(struct slgt_info *info)
{
kfree(info->tmp_rbuf);
info->tmp_rbuf = NULL;
+ kfree(info->flag_buf);
+ info->flag_buf = NULL;
}
/*
@@ -3547,10 +3561,10 @@ static void add_device(struct slgt_info *info)
current_dev->next_device = info;
}
- if (info->max_frame_size < 4096)
- info->max_frame_size = 4096;
- else if (info->max_frame_size > 65535)
- info->max_frame_size = 65535;
+ if (info->max_frame_size < SYNCLINK_MIN_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
+ else if (info->max_frame_size > SYNCLINK_MAX_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MAX_FRAME_SIZE;
switch(info->pdev->device) {
case SYNCLINK_GT_DEVICE_ID:
@@ -3600,7 +3614,7 @@ static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev
info->port.ops = &slgt_port_ops;
info->magic = MGSL_MAGIC;
INIT_WORK(&info->task, bh_handler);
- info->max_frame_size = 4096;
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
info->base_clock = 14745600;
info->rbuf_fill_level = DMABUFSIZE;
info->port.close_delay = 5*HZ/10;
@@ -4778,6 +4792,7 @@ cleanup:
/*
* pass receive buffer (RAW synchronous mode) to tty layer
+ * the receive buffer size is DMABUFSIZE limited
* return true if buffer available, otherwise false
*/
static bool rx_get_buf(struct slgt_info *info)
diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
index fd43fb6..621c562 100644
--- a/drivers/tty/synclinkmp.c
+++ b/drivers/tty/synclinkmp.c
@@ -262,8 +262,7 @@ typedef struct _synclinkmp_info {
bool sca_statctrl_requested;
u32 misc_ctrl_value;
- char flag_buf[MAX_ASYNC_BUFFER_SIZE];
- char char_buf[MAX_ASYNC_BUFFER_SIZE];
+ char *flag_buf;
bool drop_rts_on_tx_done;
struct _input_signal_events input_signal_events;
@@ -3553,6 +3552,13 @@ static int alloc_tmp_rx_buf(SLMP_INFO *info)
info->tmp_rx_buf = kmalloc(info->max_frame_size, GFP_KERNEL);
if (info->tmp_rx_buf == NULL)
return -ENOMEM;
+ /* unused flag buffer to satisfy receive_buf calling interface */
+ info->flag_buf = kzalloc(info->max_frame_size, GFP_KERNEL);
+ if (!info->flag_buf) {
+ kfree(info->tmp_rx_buf);
+ info->tmp_rx_buf = NULL;
+ return -ENOMEM;
+ }
return 0;
}
@@ -3560,6 +3566,8 @@ static void free_tmp_rx_buf(SLMP_INFO *info)
{
kfree(info->tmp_rx_buf);
info->tmp_rx_buf = NULL;
+ kfree(info->flag_buf);
+ info->flag_buf = NULL;
}
static int claim_resources(SLMP_INFO *info)
@@ -3729,10 +3737,10 @@ static void add_device(SLMP_INFO *info)
current_dev->next_device = info;
}
- if ( info->max_frame_size < 4096 )
- info->max_frame_size = 4096;
- else if ( info->max_frame_size > 65535 )
- info->max_frame_size = 65535;
+ if (info->max_frame_size < SYNCLINK_MIN_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
+ else if (info->max_frame_size > SYNCLINK_MAX_FRAME_SIZE)
+ info->max_frame_size = SYNCLINK_MAX_FRAME_SIZE;
printk( "SyncLink MultiPort %s: "
"Mem=(%08x %08X %08x %08X) IRQ=%d MaxFrameSize=%u\n",
@@ -3773,7 +3781,7 @@ static SLMP_INFO *alloc_dev(int adapter_num, int port_num, struct pci_dev *pdev)
info->port.ops = &port_ops;
info->magic = MGSL_MAGIC;
INIT_WORK(&info->task, bh_handler);
- info->max_frame_size = 4096;
+ info->max_frame_size = SYNCLINK_MIN_FRAME_SIZE;
info->port.close_delay = 5*HZ/10;
info->port.closing_wait = 30*HZ;
init_waitqueue_head(&info->status_event_wait_q);
diff --git a/include/linux/synclink.h b/include/linux/synclink.h
index f1405b1..61ac4b2 100644
--- a/include/linux/synclink.h
+++ b/include/linux/synclink.h
@@ -13,6 +13,9 @@
#include <uapi/linux/synclink.h>
+#define SYNCLINK_MIN_FRAME_SIZE 4096
+#define SYNCLINK_MAX_FRAME_SIZE 65535
+
/* provide 32 bit ioctl compatibility on 64 bit systems */
#ifdef CONFIG_COMPAT
#include <linux/compat.h>
--
1.7.10.4
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