[alsa-devel] [PATCH 1/2] ALSA: usb-audio: Refactor clock finder helpers
There are lots of open-coded functions to find a clock source, selector and multiplier. Now there are both v2 and v3, so six variants.
This patch refactors the code to use a common helper for the main loop, and define each validator function for each target. There is no functional change.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support") Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/clock.c | 127 +++++++++++++++++++++++------------------------------- 1 file changed, 53 insertions(+), 74 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index ab39ccb974c6..c5f0cf532c0c 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -35,105 +35,84 @@ #include "clock.h" #include "quirks.h"
-static struct uac_clock_source_descriptor * - snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface, - int clock_id) +static void *find_descriptor(struct usb_host_interface *iface, int id, + bool (*validator)(void *, int), u8 type) { - struct uac_clock_source_descriptor *cs = NULL; + void *cs = NULL;
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, - ctrl_iface->extralen, - cs, UAC2_CLOCK_SOURCE))) { - if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) + while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen, + cs, type))) { + if (validator(cs, id)) return cs; }
return NULL; }
-static struct uac3_clock_source_descriptor * - snd_usb_find_clock_source_v3(struct usb_host_interface *ctrl_iface, - int clock_id) +static bool validate_clock_source_v2(void *p, int id) { - struct uac3_clock_source_descriptor *cs = NULL; - - while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, - ctrl_iface->extralen, - cs, UAC3_CLOCK_SOURCE))) { - if (cs->bClockID == clock_id) - return cs; - } - - return NULL; + struct uac_clock_source_descriptor *cs = p; + return cs->bLength >= sizeof(*cs) && cs->bClockID == id; }
-static struct uac_clock_selector_descriptor * - snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface, - int clock_id) +static bool validate_clock_source_v3(void *p, int id) { - struct uac_clock_selector_descriptor *cs = NULL; - - while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, - ctrl_iface->extralen, - cs, UAC2_CLOCK_SELECTOR))) { - if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) { - if (cs->bLength < 5 + cs->bNrInPins) - return NULL; - return cs; - } - } - - return NULL; + struct uac3_clock_source_descriptor *cs = p; + return cs->bClockID == id; }
-static struct uac3_clock_selector_descriptor * - snd_usb_find_clock_selector_v3(struct usb_host_interface *ctrl_iface, - int clock_id) +static bool validate_clock_selector_v2(void *p, int id) { - struct uac3_clock_selector_descriptor *cs = NULL; - - while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, - ctrl_iface->extralen, - cs, UAC3_CLOCK_SELECTOR))) { - if (cs->bClockID == clock_id) - return cs; - } - - return NULL; + struct uac_clock_selector_descriptor *cs = p; + return cs->bLength >= sizeof(*cs) && cs->bClockID == id && + cs->bLength >= 5 + cs->bNrInPins; }
-static struct uac_clock_multiplier_descriptor * - snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface, - int clock_id) +static bool validate_clock_selector_v3(void *p, int id) { - struct uac_clock_multiplier_descriptor *cs = NULL; - - while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, - ctrl_iface->extralen, - cs, UAC2_CLOCK_MULTIPLIER))) { - if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) - return cs; - } - - return NULL; + struct uac3_clock_selector_descriptor *cs = p; + return cs->bClockID == id; }
-static struct uac3_clock_multiplier_descriptor * - snd_usb_find_clock_multiplier_v3(struct usb_host_interface *ctrl_iface, - int clock_id) +static bool validate_clock_multiplier_v2(void *p, int id) { - struct uac3_clock_multiplier_descriptor *cs = NULL; + struct uac_clock_multiplier_descriptor *cs = p; + return cs->bLength >= sizeof(*cs) && cs->bClockID == id; +}
- while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra, - ctrl_iface->extralen, - cs, UAC3_CLOCK_MULTIPLIER))) { - if (cs->bClockID == clock_id) - return cs; - } +static bool validate_clock_multiplier_v3(void *p, int id) +{ + struct uac3_clock_multiplier_descriptor *cs = p; + return cs->bClockID == id; +}
- return NULL; +#define DEFINE_FIND_HELPER(name, obj, validator, type) \ +static obj *name(struct usb_host_interface *iface, int id) \ +{ \ + return find_descriptor(iface, id, validator, type); \ }
+DEFINE_FIND_HELPER(snd_usb_find_clock_source, + struct uac_clock_source_descriptor, + validate_clock_source_v2, UAC2_CLOCK_SOURCE); +DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3, + struct uac3_clock_source_descriptor, + validate_clock_source_v3, UAC3_CLOCK_SOURCE); + +DEFINE_FIND_HELPER(snd_usb_find_clock_selector, + struct uac_clock_selector_descriptor, + validate_clock_selector_v2, UAC2_CLOCK_SELECTOR); +DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3, + struct uac3_clock_selector_descriptor, + validate_clock_selector_v3, UAC3_CLOCK_SELECTOR); + +DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier, + struct uac_clock_multiplier_descriptor, + validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER); +DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3, + struct uac3_clock_multiplier_descriptor, + validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER); + static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id) { unsigned char buf;
The UAC3 clock parser codes lack of the sanity checks for malformed descriptors like UAC2 parser does. Without it, the driver may lead to a potential crash.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support") Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/clock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index c5f0cf532c0c..169fb3ac3715 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -58,7 +58,7 @@ static bool validate_clock_source_v2(void *p, int id) static bool validate_clock_source_v3(void *p, int id) { struct uac3_clock_source_descriptor *cs = p; - return cs->bClockID == id; + return cs->bLength >= sizeof(*cs) && cs->bClockID == id; }
static bool validate_clock_selector_v2(void *p, int id) @@ -71,7 +71,8 @@ static bool validate_clock_selector_v2(void *p, int id) static bool validate_clock_selector_v3(void *p, int id) { struct uac3_clock_selector_descriptor *cs = p; - return cs->bClockID == id; + return cs->bLength >= sizeof(*cs) && cs->bClockID == id && + cs->bLength >= 5 + cs->bNrInPins; }
static bool validate_clock_multiplier_v2(void *p, int id) @@ -83,7 +84,7 @@ static bool validate_clock_multiplier_v2(void *p, int id) static bool validate_clock_multiplier_v3(void *p, int id) { struct uac3_clock_multiplier_descriptor *cs = p; - return cs->bClockID == id; + return cs->bLength >= sizeof(*cs) && cs->bClockID == id; }
#define DEFINE_FIND_HELPER(name, obj, validator, type) \
On Tue, Apr 3, 2018 at 8:48 AM, Takashi Iwai tiwai@suse.de wrote:
The UAC3 clock parser codes lack of the sanity checks for malformed descriptors like UAC2 parser does. Without it, the driver may lead to a potential crash.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support") Signed-off-by: Takashi Iwai tiwai@suse.de
sound/usb/clock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index c5f0cf532c0c..169fb3ac3715 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -58,7 +58,7 @@ static bool validate_clock_source_v2(void *p, int id) static bool validate_clock_source_v3(void *p, int id) { struct uac3_clock_source_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id;}
static bool validate_clock_selector_v2(void *p, int id) @@ -71,7 +71,8 @@ static bool validate_clock_selector_v2(void *p, int id) static bool validate_clock_selector_v3(void *p, int id) { struct uac3_clock_selector_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&cs->bLength >= 5 + cs->bNrInPins;}
static bool validate_clock_multiplier_v2(void *p, int id) @@ -83,7 +84,7 @@ static bool validate_clock_multiplier_v2(void *p, int id) static bool validate_clock_multiplier_v3(void *p, int id) { struct uac3_clock_multiplier_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id;}
#define DEFINE_FIND_HELPER(name, obj, validator, type) \
2.16.2
Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
These address all the comments I had on patch 1. sorry for the noise.
On Tue, Apr 3, 2018 at 6:48 PM, Takashi Iwai tiwai@suse.de wrote:
The UAC3 clock parser codes lack of the sanity checks for malformed descriptors like UAC2 parser does. Without it, the driver may lead to a potential crash.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support") Signed-off-by: Takashi Iwai tiwai@suse.de
sound/usb/clock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index c5f0cf532c0c..169fb3ac3715 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -58,7 +58,7 @@ static bool validate_clock_source_v2(void *p, int id) static bool validate_clock_source_v3(void *p, int id) { struct uac3_clock_source_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
I'm not sure why UAC2 checks are relaxed, but we can be more strict here since bLength of uac3_clock_source_descriptor is defined by standard and should be 12, so we can check for exact match in this place.
}
static bool validate_clock_selector_v2(void *p, int id) @@ -71,7 +71,8 @@ static bool validate_clock_selector_v2(void *p, int id) static bool validate_clock_selector_v3(void *p, int id) { struct uac3_clock_selector_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&cs->bLength >= 5 + cs->bNrInPins;}
Same here, bLength is defined by spec, can be easily calculated and must be "11+bNrInPins"
static bool validate_clock_multiplier_v2(void *p, int id) @@ -83,7 +84,7 @@ static bool validate_clock_multiplier_v2(void *p, int id) static bool validate_clock_multiplier_v3(void *p, int id) { struct uac3_clock_multiplier_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
Also here, bLength should be 11 as per spec
By the way, we can make UAC2 bLength checks more strict as well, assuming there is no any hw bug we try to workaroud
Thanks, Ruslan
On Wed, 04 Apr 2018 01:15:05 +0200, Ruslan Bilovol wrote:
On Tue, Apr 3, 2018 at 6:48 PM, Takashi Iwai tiwai@suse.de wrote:
The UAC3 clock parser codes lack of the sanity checks for malformed descriptors like UAC2 parser does. Without it, the driver may lead to a potential crash.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support") Signed-off-by: Takashi Iwai tiwai@suse.de
sound/usb/clock.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index c5f0cf532c0c..169fb3ac3715 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -58,7 +58,7 @@ static bool validate_clock_source_v2(void *p, int id) static bool validate_clock_source_v3(void *p, int id) { struct uac3_clock_source_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id;I'm not sure why UAC2 checks are relaxed, but we can be more strict here since bLength of uac3_clock_source_descriptor is defined by standard and should be 12, so we can check for exact match in this place.
}
static bool validate_clock_selector_v2(void *p, int id) @@ -71,7 +71,8 @@ static bool validate_clock_selector_v2(void *p, int id) static bool validate_clock_selector_v3(void *p, int id) { struct uac3_clock_selector_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&cs->bLength >= 5 + cs->bNrInPins;}
Same here, bLength is defined by spec, can be easily calculated and must be "11+bNrInPins"
static bool validate_clock_multiplier_v2(void *p, int id) @@ -83,7 +84,7 @@ static bool validate_clock_multiplier_v2(void *p, int id) static bool validate_clock_multiplier_v3(void *p, int id) { struct uac3_clock_multiplier_descriptor *cs = p;
return cs->bClockID == id;
return cs->bLength >= sizeof(*cs) && cs->bClockID == id;Also here, bLength should be 11 as per spec
By the way, we can make UAC2 bLength checks more strict as well, assuming there is no any hw bug we try to workaroud
OK, let's make the check more strict altogether.
thanks,
Takashi
On Tue, Apr 3, 2018 at 8:48 AM, Takashi Iwai tiwai@suse.de wrote:
There are lots of open-coded functions to find a clock source, selector and multiplier. Now there are both v2 and v3, so six variants.
This patch refactors the code to use a common helper for the main loop, and define each validator function for each target. There is no functional change.
Fixes: 9a2fe9b801f5 ("ALSA: usb: initial USB Audio Device Class 3.0 support") Signed-off-by: Takashi Iwai tiwai@suse.de
sound/usb/clock.c | 127 +++++++++++++++++++++++------------------------------- 1 file changed, 53 insertions(+), 74 deletions(-)
diff --git a/sound/usb/clock.c b/sound/usb/clock.c index ab39ccb974c6..c5f0cf532c0c 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -35,105 +35,84 @@ #include "clock.h" #include "quirks.h"
-static struct uac_clock_source_descriptor *
snd_usb_find_clock_source(struct usb_host_interface *ctrl_iface,int clock_id)+static void *find_descriptor(struct usb_host_interface *iface, int id,
bool (*validator)(void *, int), u8 type)
this comment isn't very important, and might be wrong: find_descriptor is a very generic name, it might make grepping a little confusing. Could you use find_clock_descriptor? find_uac_clock_descriptor?
{
struct uac_clock_source_descriptor *cs = NULL;
void *cs = NULL;
while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,ctrl_iface->extralen,cs, UAC2_CLOCK_SOURCE))) {if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)
while ((cs = snd_usb_find_csint_desc(iface->extra, iface->extralen,cs, type))) {if (validator(cs, id)) return cs; } return NULL;}
-static struct uac3_clock_source_descriptor *
snd_usb_find_clock_source_v3(struct usb_host_interface *ctrl_iface,int clock_id)+static bool validate_clock_source_v2(void *p, int id) {
struct uac3_clock_source_descriptor *cs = NULL;while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,ctrl_iface->extralen,cs, UAC3_CLOCK_SOURCE))) {if (cs->bClockID == clock_id)return cs;}return NULL;
struct uac_clock_source_descriptor *cs = p;return cs->bLength >= sizeof(*cs) && cs->bClockID == id;}
-static struct uac_clock_selector_descriptor *
snd_usb_find_clock_selector(struct usb_host_interface *ctrl_iface,int clock_id)+static bool validate_clock_source_v3(void *p, int id) {
struct uac_clock_selector_descriptor *cs = NULL;while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,ctrl_iface->extralen,cs, UAC2_CLOCK_SELECTOR))) {if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id) {if (cs->bLength < 5 + cs->bNrInPins)return NULL;return cs;}}return NULL;
struct uac3_clock_source_descriptor *cs = p;return cs->bClockID == id;
uac3_clock_source_descriptor has a fixed size (12). Consider a sizeof() check here to be consistent?
}
-static struct uac3_clock_selector_descriptor *
snd_usb_find_clock_selector_v3(struct usb_host_interface *ctrl_iface,int clock_id)+static bool validate_clock_selector_v2(void *p, int id) {
struct uac3_clock_selector_descriptor *cs = NULL;while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,ctrl_iface->extralen,cs, UAC3_CLOCK_SELECTOR))) {if (cs->bClockID == clock_id)return cs;}return NULL;
struct uac_clock_selector_descriptor *cs = p;return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&cs->bLength >= 5 + cs->bNrInPins;}
-static struct uac_clock_multiplier_descriptor *
snd_usb_find_clock_multiplier(struct usb_host_interface *ctrl_iface,int clock_id)+static bool validate_clock_selector_v3(void *p, int id) {
struct uac_clock_multiplier_descriptor *cs = NULL;while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,ctrl_iface->extralen,cs, UAC2_CLOCK_MULTIPLIER))) {if (cs->bLength >= sizeof(*cs) && cs->bClockID == clock_id)return cs;}return NULL;
struct uac3_clock_selector_descriptor *cs = p;return cs->bClockID == id;
clock cs->bLength should be 11+ bytes for a v3 clock selector descriptor. consider an >= size check. (I don't know how sizeof works with []-terminated structs)
}
-static struct uac3_clock_multiplier_descriptor *
snd_usb_find_clock_multiplier_v3(struct usb_host_interface *ctrl_iface,int clock_id)+static bool validate_clock_multiplier_v2(void *p, int id) {
struct uac3_clock_multiplier_descriptor *cs = NULL;
struct uac_clock_multiplier_descriptor *cs = p;return cs->bLength >= sizeof(*cs) && cs->bClockID == id;+}
while ((cs = snd_usb_find_csint_desc(ctrl_iface->extra,ctrl_iface->extralen,cs, UAC3_CLOCK_MULTIPLIER))) {if (cs->bClockID == clock_id)return cs;}+static bool validate_clock_multiplier_v3(void *p, int id) +{
struct uac3_clock_multiplier_descriptor *cs = p;return cs->bClockID == id;
uac3_clock_multiplier_descriptor has fixed size (11)
+}
return NULL;+#define DEFINE_FIND_HELPER(name, obj, validator, type) \ +static obj *name(struct usb_host_interface *iface, int id) \ +{ \
return find_descriptor(iface, id, validator, type); \}
+DEFINE_FIND_HELPER(snd_usb_find_clock_source,
struct uac_clock_source_descriptor,validate_clock_source_v2, UAC2_CLOCK_SOURCE);+DEFINE_FIND_HELPER(snd_usb_find_clock_source_v3,
struct uac3_clock_source_descriptor,validate_clock_source_v3, UAC3_CLOCK_SOURCE);+DEFINE_FIND_HELPER(snd_usb_find_clock_selector,
struct uac_clock_selector_descriptor,validate_clock_selector_v2, UAC2_CLOCK_SELECTOR);+DEFINE_FIND_HELPER(snd_usb_find_clock_selector_v3,
struct uac3_clock_selector_descriptor,validate_clock_selector_v3, UAC3_CLOCK_SELECTOR);+DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier,
struct uac_clock_multiplier_descriptor,validate_clock_multiplier_v2, UAC2_CLOCK_MULTIPLIER);+DEFINE_FIND_HELPER(snd_usb_find_clock_multiplier_v3,
struct uac3_clock_multiplier_descriptor,validate_clock_multiplier_v3, UAC3_CLOCK_MULTIPLIER);static int uac_clock_selector_get_val(struct snd_usb_audio *chip, int selector_id) { unsigned char buf; -- 2.16.2
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participants (3)
-
Andrew Chant -
Ruslan Bilovol -
Takashi Iwai