Re: [PATCH] cdrom_sysctl_info fix

From: Dave Young
Date: Mon Jun 18 2007 - 00:57:28 EST

Hi jens,
Thanks for rework this patch.But it has some bugs, results kernel oops.

On Fri, Jun 15, 2007 at 03:26:57PM +0200, Jens Axboe wrote:
> On Thu, Jun 14 2007, Dave Young wrote:
> > Hi,
> >
> > Fix the cdrom_sysctl_info possible buffer overwrite bug. Somd
> > codingstyle fixes are included as well.
>
> How about something like this? The current code is actually racy,
> because there's no protection against adding/removing a cdrom while it
> runs. This patch is largely based on yours, just abstracted the printing
> and looping into a function and bail when we run out of room (and print
> a message to that effect).
You are right
>
> If you could test it and verify that it does the right thing (eg prints
> the same as before), that would be great!
>
> diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
> index 3625a05..ae5a475 100644
> --- a/drivers/cdrom/cdrom.c
> +++ b/drivers/cdrom/cdrom.c
> @@ -302,7 +302,7 @@ module_param(lockdoor, bool, 0);
> module_param(check_media_type, bool, 0);
> module_param(mrw_format_restart, bool, 0);
>
> -static DEFINE_SPINLOCK(cdrom_lock);
> +static DEFINE_MUTEX(cdrom_mutex);
>
> static const char *mrw_format_status[] = {
> "not mrw",
> @@ -438,10 +438,10 @@ int register_cdrom(struct cdrom_device_info *cdi)
> cdo->generic_packet = cdrom_dummy_generic_packet;
>
> cdinfo(CD_REG_UNREG, "drive \"/dev/%s\" registered\n", cdi->name);
> - spin_lock(&cdrom_lock);
> + mutex_lock(&cdrom_mutex);
> cdi->next = topCdromPtr;
> topCdromPtr = cdi;
> - spin_unlock(&cdrom_lock);
> + mutex_unlock(&cdrom_mutex);
> return 0;
> }
> #undef ENSURE
> @@ -452,7 +452,7 @@ int unregister_cdrom(struct cdrom_device_info *unreg)
> cdinfo(CD_OPEN, "entering unregister_cdrom\n");
>
> prev = NULL;
> - spin_lock(&cdrom_lock);
> + mutex_lock(&cdrom_mutex);
> cdi = topCdromPtr;
> while (cdi && cdi != unreg) {
> prev = cdi;
> @@ -460,7 +460,7 @@ int unregister_cdrom(struct cdrom_device_info *unreg)
> }
>
> if (cdi == NULL) {
> - spin_unlock(&cdrom_lock);
> + mutex_unlock(&cdrom_mutex);
> return -2;
> }
> if (prev)
> @@ -468,7 +468,7 @@ int unregister_cdrom(struct cdrom_device_info *unreg)
> else
> topCdromPtr = cdi->next;
>
> - spin_unlock(&cdrom_lock);
> + mutex_unlock(&cdrom_mutex);
>
> if (cdi->exit)
> cdi->exit(cdi);
> @@ -3289,103 +3289,112 @@ static struct cdrom_sysctl_settings {
> int check; /* check media type */
> } cdrom_sysctl_settings;
>
> +static int cdrom_print_int(const char *header, int val, char *info, int *pos)
> +{
The val is diffrent for every devices, isn't it?
> + const int max_size = sizeof(cdrom_sysctl_settings.info);
> + struct cdrom_device_info *cdi;
> + int ret;
> +
> + ret = scnprintf(info + *pos, max_size, header);
> + if (!ret)
> + return 1;
> +
> + *pos += ret;
> +
> + for (cdi = topCdromPtr; cdi; cdi = cdi->next) {
> + ret = scnprintf(info + *pos, max_size, "\t%d", val);
The max_size should be max_size - *pos
> + if (!ret)
> + return 1;
> + *pos += ret;
> + }
> +
> + return 0;
> +}
> +
> static int cdrom_sysctl_info(ctl_table *ctl, int write, struct file * filp,
> void __user *buffer, size_t *lenp, loff_t *ppos)
> {
> - int pos;
> + int pos;
> struct cdrom_device_info *cdi;
> char *info = cdrom_sysctl_settings.info;
> + const int max_size = sizeof(cdrom_sysctl_settings.info);
>
> if (!*lenp || (*ppos && !write)) {
> *lenp = 0;
> return 0;
> }
>
> + mutex_lock(&cdrom_mutex);
> +
> pos = sprintf(info, "CD-ROM information, " VERSION "\n");
>
> - pos += sprintf(info+pos, "\ndrive name:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%s", cdi->name);
> -
> - pos += sprintf(info+pos, "\ndrive speed:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", cdi->speed);
> -
> - pos += sprintf(info+pos, "\ndrive # of slots:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", cdi->capacity);
> -
> - pos += sprintf(info+pos, "\nCan close tray:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_CLOSE_TRAY) != 0);
> -
> - pos += sprintf(info+pos, "\nCan open tray:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_OPEN_TRAY) != 0);
> -
> - pos += sprintf(info+pos, "\nCan lock tray:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_LOCK) != 0);
> -
> - pos += sprintf(info+pos, "\nCan change speed:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_SELECT_SPEED) != 0);
> -
> - pos += sprintf(info+pos, "\nCan select disk:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_SELECT_DISC) != 0);
> -
> - pos += sprintf(info+pos, "\nCan read multisession:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MULTI_SESSION) != 0);
> -
> - pos += sprintf(info+pos, "\nCan read MCN:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MCN) != 0);
> -
> - pos += sprintf(info+pos, "\nReports media changed:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MEDIA_CHANGED) != 0);
> -
> - pos += sprintf(info+pos, "\nCan play audio:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_PLAY_AUDIO) != 0);
> -
> - pos += sprintf(info+pos, "\nCan write CD-R:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_CD_R) != 0);
> -
> - pos += sprintf(info+pos, "\nCan write CD-RW:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_CD_RW) != 0);
> -
> - pos += sprintf(info+pos, "\nCan read DVD:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD) != 0);
> -
> - pos += sprintf(info+pos, "\nCan write DVD-R:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD_R) != 0);
> -
> - pos += sprintf(info+pos, "\nCan write DVD-RAM:");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD_RAM) != 0);
> -
> - pos += sprintf(info+pos, "\nCan read MRW:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MRW) != 0);
> -
> - pos += sprintf(info+pos, "\nCan write MRW:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MRW_W) != 0);
> -
> - pos += sprintf(info+pos, "\nCan write RAM:\t");
> - for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
> - pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_RAM) != 0);
> -
> - strcpy(info+pos,"\n\n");
> -
> - return proc_dostring(ctl, write, filp, buffer, lenp, ppos);
> + pos += scnprintf(info + pos, max_size - pos, "\ndrive name:\t");
> + for (cdi = topCdromPtr; cdi != NULL; cdi = cdi->next)
> + pos += scnprintf(info + pos, max_size - pos, "\t%s", cdi->name);
> +
> + if (cdrom_print_int("\ndrive speed:\t", cdi->speed, info, &pos))
Now the cdi is NULL
> + goto done;
> + if (cdrom_print_int("\ndrive # of slots:", cdi->capacity, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan close tray:\t",
> + CDROM_CAN(CDC_CLOSE_TRAY) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan open tray:\t",
> + CDROM_CAN(CDC_OPEN_TRAY) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan lock tray:\t",
> + CDROM_CAN(CDC_LOCK) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan change speed:\t",
> + CDROM_CAN(CDC_SELECT_SPEED) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan select disk:\t",
> + CDROM_CAN(CDC_SELECT_DISC) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan read multisession:",
> + CDROM_CAN(CDC_MULTI_SESSION) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan read MCN:",
> + CDROM_CAN(CDC_MCN) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nReports media changed:",
> + CDROM_CAN(CDC_MEDIA_CHANGED) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan play audio:",
> + CDROM_CAN(CDC_PLAY_AUDIO) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan write CD-R:\t",
> + CDROM_CAN(CDC_CD_R) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan write CD-RW:\t",
> + CDROM_CAN(CDC_CD_RW) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan read DVD:\t",
> + CDROM_CAN(CDC_DVD) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan write DVD-R:\t",
> + CDROM_CAN(CDC_DVD_R) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan write DVD-RAM:\t",
> + CDROM_CAN(CDC_DVD_RAM) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan read MRW:\t",
> + CDROM_CAN(CDC_MRW) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan write MRW:\t",
> + CDROM_CAN(CDC_MRW_W) != 0, info, &pos))
> + goto done;
> + if (cdrom_print_int("\nCan write RAM:\t",
> + CDROM_CAN(CDC_RAM) != 0, info, &pos))
> + goto done;
> + if (!scnprintf(info + pos, max_size - pos, "\n\n"))
> + goto done;
> +doit:
> + mutex_unlock(&cdrom_mutex);
> + return proc_dostring(ctl, write, filp, buffer, lenp, ppos);
> +done:
> + printk(KERN_INFO "cdrom: info buffer too small\n");
> + goto doit;
> }
>
> /* Unfortunately, per device settings are not implemented through
>
> --
> Jens Axboe
And there's several more '\t' in the printed strings. so the result not aligned right.

I rewite the patch according to yours, please help to check. Pass the cdrom_print_info function one more argument for diffrent type printing, do you have better solutions for this? thanks for replying :)


Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx>
---
diff -upr linux/drivers/cdrom/cdrom.c linux.new/drivers/cdrom/cdrom.c
--- linux/drivers/cdrom/cdrom.c 2007-06-18 12:36:40.000000000 +0000
+++ linux.new/drivers/cdrom/cdrom.c 2007-06-18 12:38:51.000000000 +0000
@@ -302,7 +302,7 @@ module_param(lockdoor, bool, 0);
module_param(check_media_type, bool, 0);
module_param(mrw_format_restart, bool, 0);

-static DEFINE_SPINLOCK(cdrom_lock);
+static DEFINE_MUTEX(cdrom_mutex);

static const char *mrw_format_status[] = {
"not mrw",
@@ -438,10 +438,10 @@ int register_cdrom(struct cdrom_device_i
cdo->generic_packet = cdrom_dummy_generic_packet;

cdinfo(CD_REG_UNREG, "drive \"/dev/%s\" registered\n", cdi->name);
- spin_lock(&cdrom_lock);
+ mutex_lock(&cdrom_mutex);
cdi->next = topCdromPtr;
topCdromPtr = cdi;
- spin_unlock(&cdrom_lock);
+ mutex_unlock(&cdrom_mutex);
return 0;
}
#undef ENSURE
@@ -452,7 +452,7 @@ int unregister_cdrom(struct cdrom_device
cdinfo(CD_OPEN, "entering unregister_cdrom\n");

prev = NULL;
- spin_lock(&cdrom_lock);
+ mutex_lock(&cdrom_mutex);
cdi = topCdromPtr;
while (cdi && cdi != unreg) {
prev = cdi;
@@ -460,7 +460,7 @@ int unregister_cdrom(struct cdrom_device
}

if (cdi == NULL) {
- spin_unlock(&cdrom_lock);
+ mutex_unlock(&cdrom_mutex);
return -2;
}
if (prev)
@@ -468,7 +468,7 @@ int unregister_cdrom(struct cdrom_device
else
topCdromPtr = cdi->next;

- spin_unlock(&cdrom_lock);
+ mutex_unlock(&cdrom_mutex);

if (cdi->exit)
cdi->exit(cdi);
@@ -3289,103 +3289,137 @@ static struct cdrom_sysctl_settings {
int check; /* check media type */
} cdrom_sysctl_settings;

+enum cdrom_print_option {
+ CTL_NAME,
+ CTL_SPEED,
+ CTL_SLOTS,
+ CTL_CAPABILITY
+};
+
+static int cdrom_print_info(const char *header, int val, char *info,
+ int *pos, enum cdrom_print_option option)
+{
+ const int max_size = sizeof(cdrom_sysctl_settings.info);
+ struct cdrom_device_info *cdi;
+ int ret;
+
+ ret = scnprintf(info + *pos, max_size - *pos, header);
+ if (!ret)
+ return 1;
+
+ *pos += ret;
+
+ for (cdi = topCdromPtr; cdi; cdi = cdi->next) {
+ switch (option) {
+ case CTL_NAME:
+ ret = scnprintf(info + *pos, max_size - *pos,
+ "\t%s", cdi->name);
+ break;
+ case CTL_SPEED:
+ ret = scnprintf(info + *pos, max_size - *pos,
+ "\t%d", cdi->speed);
+ break;
+ case CTL_SLOTS:
+ ret = scnprintf(info + *pos, max_size - *pos,
+ "\t%d", cdi->capacity);
+ break;
+ case CTL_CAPABILITY:
+ ret = scnprintf(info + *pos, max_size - *pos,
+ "\t%d", CDROM_CAN(val) != 0);
+ break;
+ default:
+ printk(KERN_INFO "cdrom: invalid option%d\n", option);
+ return 1;
+ }
+ if (!ret)
+ return 1;
+ *pos += ret;
+ }
+
+ return 0;
+}
+
static int cdrom_sysctl_info(ctl_table *ctl, int write, struct file * filp,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
- int pos;
- struct cdrom_device_info *cdi;
+ int pos;
char *info = cdrom_sysctl_settings.info;
+ const int max_size = sizeof(cdrom_sysctl_settings.info);

if (!*lenp || (*ppos && !write)) {
*lenp = 0;
return 0;
}

+ mutex_lock(&cdrom_mutex);
+
pos = sprintf(info, "CD-ROM information, " VERSION "\n");

- pos += sprintf(info+pos, "\ndrive name:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%s", cdi->name);
-
- pos += sprintf(info+pos, "\ndrive speed:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", cdi->speed);
-
- pos += sprintf(info+pos, "\ndrive # of slots:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", cdi->capacity);
-
- pos += sprintf(info+pos, "\nCan close tray:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_CLOSE_TRAY) != 0);
-
- pos += sprintf(info+pos, "\nCan open tray:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_OPEN_TRAY) != 0);
-
- pos += sprintf(info+pos, "\nCan lock tray:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_LOCK) != 0);
-
- pos += sprintf(info+pos, "\nCan change speed:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_SELECT_SPEED) != 0);
-
- pos += sprintf(info+pos, "\nCan select disk:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_SELECT_DISC) != 0);
-
- pos += sprintf(info+pos, "\nCan read multisession:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MULTI_SESSION) != 0);
-
- pos += sprintf(info+pos, "\nCan read MCN:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MCN) != 0);
-
- pos += sprintf(info+pos, "\nReports media changed:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MEDIA_CHANGED) != 0);
-
- pos += sprintf(info+pos, "\nCan play audio:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_PLAY_AUDIO) != 0);
-
- pos += sprintf(info+pos, "\nCan write CD-R:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_CD_R) != 0);
-
- pos += sprintf(info+pos, "\nCan write CD-RW:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_CD_RW) != 0);
-
- pos += sprintf(info+pos, "\nCan read DVD:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD) != 0);
-
- pos += sprintf(info+pos, "\nCan write DVD-R:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD_R) != 0);
-
- pos += sprintf(info+pos, "\nCan write DVD-RAM:");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_DVD_RAM) != 0);
-
- pos += sprintf(info+pos, "\nCan read MRW:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MRW) != 0);
-
- pos += sprintf(info+pos, "\nCan write MRW:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_MRW_W) != 0);
-
- pos += sprintf(info+pos, "\nCan write RAM:\t");
- for (cdi=topCdromPtr;cdi!=NULL;cdi=cdi->next)
- pos += sprintf(info+pos, "\t%d", CDROM_CAN(CDC_RAM) != 0);
-
- strcpy(info+pos,"\n\n");
-
- return proc_dostring(ctl, write, filp, buffer, lenp, ppos);
+ if (cdrom_print_info("\ndrive name:\t", 0, info, &pos, CTL_NAME))
+ goto done;
+ if (cdrom_print_info("\ndrive speed:\t", 0, info, &pos, CTL_SPEED))
+ goto done;
+ if (cdrom_print_info("\ndrive # of slots:", 0, info, &pos, CTL_SLOTS))
+ goto done;
+ if (cdrom_print_info("\nCan close tray:\t",
+ CDC_CLOSE_TRAY, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan open tray:\t",
+ CDC_OPEN_TRAY, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan lock tray:\t",
+ CDC_LOCK, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan change speed:",
+ CDC_SELECT_SPEED, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan select disk:",
+ CDC_SELECT_DISC, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan read multisession:",
+ CDC_MULTI_SESSION, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan read MCN:\t",
+ CDC_MCN, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nReports media changed:",
+ CDC_MEDIA_CHANGED, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan play audio:\t",
+ CDC_PLAY_AUDIO, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan write CD-R:\t",
+ CDC_CD_R, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan write CD-RW:",
+ CDC_CD_RW, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan read DVD:\t",
+ CDC_DVD, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan write DVD-R:",
+ CDC_DVD_R, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan write DVD-RAM:",
+ CDC_DVD_RAM, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan read MRW:\t",
+ CDC_MRW, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan write MRW:\t",
+ CDC_MRW_W, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (cdrom_print_info("\nCan write RAM:\t",
+ CDC_RAM, info, &pos, CTL_CAPABILITY))
+ goto done;
+ if (!scnprintf(info + pos, max_size - pos, "\n\n"))
+ goto done;
+doit:
+ mutex_unlock(&cdrom_mutex);
+ return proc_dostring(ctl, write, filp, buffer, lenp, ppos);
+done:
+ printk(KERN_INFO "cdrom: info buffer too small\n");
+ goto doit;
}

/* Unfortunately, per device settings are not implemented through
Only in linux/drivers/cdrom: cdrom.old


--
Regards
dave
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/