[ALSA] emu10k1 - Fix ABI for older ld10k1

Fix ABI for older ld10k1.  When no EMU10K1_PVERSION ioctl is issued,
the driver accepts ioctls with the old struct size without TLV information.
Also, changed the struct field to make the conversion easier from the
old to the new structs.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 79 insertions, 21 deletions

diff --git a/sound/pci/emu10k1/emufx.c b/sound/pci/emu10k1/emufx.c
index d8e8db89535f..7b173c496953 100644
--- a/sound/pci/emu10k1/emufx.c
+++ b/sound/pci/emu10k1/emufx.c
@@ -655,13 +655,66 @@ snd_emu10k1_look_for_ctl(struct snd_emu10k1 *emu, struct snd_ctl_elem_id *id)
         return NULL;
 }
 
+#define MAX_TLV_SIZE    256
+
+static unsigned int *copy_tlv(unsigned int __user *_tlv)
+{
+        unsigned int data[2];
+        unsigned int *tlv;
+
+        if (!_tlv)
+                return NULL;
+        if (copy_from_user(data, _tlv, sizeof(data)))
+                return NULL;
+        if (data[1] >= MAX_TLV_SIZE)
+                return NULL;
+        tlv = kmalloc(data[1] * 4 + sizeof(data), GFP_KERNEL);
+        if (!tlv)
+                return NULL;
+        memcpy(tlv, data, sizeof(data));
+        if (copy_from_user(tlv + 2, _tlv + 2, data[1])) {
+                kfree(tlv);
+                return NULL;
+        }
+        return tlv;
+}
+
+static int copy_gctl(struct snd_emu10k1 *emu,
+                     struct snd_emu10k1_fx8010_control_gpr *gctl,
+                     struct snd_emu10k1_fx8010_control_gpr __user *_gctl,
+                     int idx)
+{
+        struct snd_emu10k1_fx8010_control_old_gpr __user *octl;
+
+        if (emu->support_tlv)
+                return copy_from_user(gctl, &_gctl[idx], sizeof(*gctl));
+        octl = (struct snd_emu10k1_fx8010_control_old_gpr __user *)_gctl;
+        if (copy_from_user(gctl, &octl[idx], sizeof(*octl)))
+                return -EFAULT;
+        gctl->tlv = NULL;
+        return 0;
+}
+
+static int copy_gctl_to_user(struct snd_emu10k1 *emu,
+                     struct snd_emu10k1_fx8010_control_gpr __user *_gctl,
+                     struct snd_emu10k1_fx8010_control_gpr *gctl,
+                     int idx)
+{
+        struct snd_emu10k1_fx8010_control_old_gpr __user *octl;
+
+        if (emu->support_tlv)
+                return copy_to_user(&_gctl[idx], gctl, sizeof(*gctl));
+        
+        octl = (struct snd_emu10k1_fx8010_control_old_gpr __user *)_gctl;
+        return copy_to_user(&octl[idx], gctl, sizeof(*octl));
+}
+
 static int snd_emu10k1_verify_controls(struct snd_emu10k1 *emu,
                                        struct snd_emu10k1_fx8010_code *icode)
 {
         unsigned int i;
         struct snd_ctl_elem_id __user *_id;
         struct snd_ctl_elem_id id;
-        struct snd_emu10k1_fx8010_control_gpr __user *_gctl;
         struct snd_emu10k1_fx8010_control_gpr *gctl;
         int err;
         
@@ -676,9 +729,8 @@ static int snd_emu10k1_verify_controls(struct snd_emu10k1 *emu,
         if (! gctl)
                 return -ENOMEM;
         err = 0;
-        for (i = 0, _gctl = icode->gpr_add_controls;
-             i < icode->gpr_add_control_count; i++, _gctl++) {
-                if (copy_from_user(gctl, _gctl, sizeof(*gctl))) {
+        for (i = 0; i < icode->gpr_add_control_count; i++) {
+                if (copy_gctl(emu, gctl, icode->gpr_add_controls, i)) {
                         err = -EFAULT;
                         goto __error;
                 }
@@ -697,10 +749,9 @@ static int snd_emu10k1_verify_controls(struct snd_emu10k1 *emu,
                         goto __error;
                 }
         }
-        for (i = 0, _gctl = icode->gpr_list_controls;
-             i < icode->gpr_list_control_count; i++, _gctl++) {
+        for (i = 0; i < icode->gpr_list_control_count; i++) {
                 /* FIXME: we need to check the WRITE access */
-                if (copy_from_user(gctl, _gctl, sizeof(*gctl))) {
+                if (copy_gctl(emu, gctl, icode->gpr_list_controls, i)) {
                         err = -EFAULT;
                         goto __error;
                 }
@@ -718,13 +769,14 @@ static void snd_emu10k1_ctl_private_free(struct snd_kcontrol *kctl)
         kctl->private_value = 0;
         list_del(&ctl->list);
         kfree(ctl);
+        if (kctl->tlv.p)
+                kfree(kctl->tlv.p);
 }
 
 static int snd_emu10k1_add_controls(struct snd_emu10k1 *emu,
                                     struct snd_emu10k1_fx8010_code *icode)
 {
         unsigned int i, j;
-        struct snd_emu10k1_fx8010_control_gpr __user *_gctl;
         struct snd_emu10k1_fx8010_control_gpr *gctl;
         struct snd_emu10k1_fx8010_ctl *ctl, *nctl;
         struct snd_kcontrol_new knew;
@@ -740,9 +792,8 @@ static int snd_emu10k1_add_controls(struct snd_emu10k1 *emu,
                 goto __error;
         }
 
-        for (i = 0, _gctl = icode->gpr_add_controls;
-             i < icode->gpr_add_control_count; i++, _gctl++) {
-                if (copy_from_user(gctl, _gctl, sizeof(*gctl))) {
+        for (i = 0; i < icode->gpr_add_control_count; i++) {
+                if (copy_gctl(emu, gctl, icode->gpr_add_controls, i)) {
                         err = -EFAULT;
                         goto __error;
                 }
@@ -763,11 +814,10 @@ static int snd_emu10k1_add_controls(struct snd_emu10k1 *emu,
                 knew.device = gctl->id.device;
                 knew.subdevice = gctl->id.subdevice;
                 knew.info = snd_emu10k1_gpr_ctl_info;
-                if (gctl->tlv.p) {
-                        knew.tlv.p = gctl->tlv.p;
+                knew.tlv.p = copy_tlv(gctl->tlv);
+                if (knew.tlv.p)
                         knew.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
                                 SNDRV_CTL_ELEM_ACCESS_TLV_READ;
-                } 
                 knew.get = snd_emu10k1_gpr_ctl_get;
                 knew.put = snd_emu10k1_gpr_ctl_put;
                 memset(nctl, 0, sizeof(*nctl));
@@ -785,12 +835,14 @@ static int snd_emu10k1_add_controls(struct snd_emu10k1 *emu,
                         ctl = kmalloc(sizeof(*ctl), GFP_KERNEL);
                         if (ctl == NULL) {
                                 err = -ENOMEM;
+                                kfree(knew.tlv.p);
                                 goto __error;
                         }
                         knew.private_value = (unsigned long)ctl;
                         *ctl = *nctl;
                         if ((err = snd_ctl_add(emu->card, kctl = snd_ctl_new1(&knew, emu))) < 0) {
                                 kfree(ctl);
+                                kfree(knew.tlv.p);
                                 goto __error;
                         }
                         kctl->private_free = snd_emu10k1_ctl_private_free;
@@ -841,7 +893,6 @@ static int snd_emu10k1_list_controls(struct snd_emu10k1 *emu,
         unsigned int i = 0, j;
         unsigned int total = 0;
         struct snd_emu10k1_fx8010_control_gpr *gctl;
-        struct snd_emu10k1_fx8010_control_gpr __user *_gctl;
         struct snd_emu10k1_fx8010_ctl *ctl;
         struct snd_ctl_elem_id *id;
         struct list_head *list;
@@ -850,11 +901,11 @@ static int snd_emu10k1_list_controls(struct snd_emu10k1 *emu,
         if (! gctl)
                 return -ENOMEM;
 
-        _gctl = icode->gpr_list_controls;       
         list_for_each(list, &emu->fx8010.gpr_ctl) {
                 ctl = emu10k1_gpr_ctl(list);
                 total++;
-                if (_gctl && i < icode->gpr_list_control_count) {
+                if (icode->gpr_list_controls &&
+                    i < icode->gpr_list_control_count) {
                         memset(gctl, 0, sizeof(*gctl));
                         id = &ctl->kcontrol->id;
                         gctl->id.iface = id->iface;
@@ -871,11 +922,11 @@ static int snd_emu10k1_list_controls(struct snd_emu10k1 *emu,
                         gctl->min = ctl->min;
                         gctl->max = ctl->max;
                         gctl->translation = ctl->translation;
-                        if (copy_to_user(_gctl, gctl, sizeof(*gctl))) {
+                        if (copy_gctl_to_user(emu, icode->gpr_list_controls,
+                                              gctl, i)) {
                                 kfree(gctl);
                                 return -EFAULT;
                         }
-                        _gctl++;
                         i++;
                 }
         }
@@ -1026,7 +1077,7 @@ snd_emu10k1_init_mono_control(struct snd_emu10k1_fx8010_control_gpr *ctl,
         ctl->gpr[0] = gpr + 0; ctl->value[0] = defval;
         ctl->min = 0;
         ctl->max = 100;
-        ctl->tlv.p = snd_emu10k1_db_scale1;
+        ctl->tlv = snd_emu10k1_db_scale1;
         ctl->translation = EMU10K1_GPR_TRANSLATION_TABLE100;    
 }
 
@@ -1041,7 +1092,7 @@ snd_emu10k1_init_stereo_control(struct snd_emu10k1_fx8010_control_gpr *ctl,
         ctl->gpr[1] = gpr + 1; ctl->value[1] = defval;
         ctl->min = 0;
         ctl->max = 100;
-        ctl->tlv.p = snd_emu10k1_db_scale1;
+        ctl->tlv = snd_emu10k1_db_scale1;
         ctl->translation = EMU10K1_GPR_TRANSLATION_TABLE100;
 }
 
@@ -1566,7 +1617,9 @@ A_OP(icode, &ptr, iMAC0, A_GPR(var), A_GPR(var), A_GPR(vol), A_EXTIN(input))
         seg = snd_enter_user();
         icode->gpr_add_control_count = nctl;
         icode->gpr_add_controls = (struct snd_emu10k1_fx8010_control_gpr __user *)controls;
+        emu->support_tlv = 1; /* support TLV */
         err = snd_emu10k1_icode_poke(emu, icode);
+        emu->support_tlv = 0; /* clear again */
         snd_leave_user(seg);
 
  __err:
@@ -2183,7 +2236,9 @@ static int __devinit _snd_emu10k1_init_efx(struct snd_emu10k1 *emu)
         seg = snd_enter_user();
         icode->gpr_add_control_count = i;
         icode->gpr_add_controls = (struct snd_emu10k1_fx8010_control_gpr __user *)controls;
+        emu->support_tlv = 1; /* support TLV */
         err = snd_emu10k1_icode_poke(emu, icode);
+        emu->support_tlv = 0; /* clear again */
         snd_leave_user(seg);
         if (err >= 0)
                 err = snd_emu10k1_ipcm_poke(emu, ipcm);
@@ -2327,6 +2382,9 @@ static int snd_emu10k1_fx8010_ioctl(struct snd_hwdep * hw, struct file *file, un
         int res;
         
         switch (cmd) {
+        case SNDRV_EMU10K1_IOCTL_PVERSION:
+                emu->support_tlv = 1;
+                return put_user(SNDRV_EMU10K1_VERSION, (int __user *)argp);
         case SNDRV_EMU10K1_IOCTL_INFO:
                 info = kmalloc(sizeof(*info), GFP_KERNEL);
                 if (!info)