From 09cf03b80c593b08e8b630a145e14f485200b5af Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Sat, 19 May 2012 17:21:25 +0200 Subject: [PATCH] ALSA: hda - Fix possible races of accesses to connection list array Like the previous fixes for cache hash accesses, a protection over accesses to the widget connection list array must be provided. Together with this action, remove snd_hda_get_conn_list() which can be always race, and replace it with either snd_hda_get_num_conns() or snd_hda_get_connections() calls. Signed-off-by: Takashi Iwai --- sound/pci/hda/hda_codec.c | 82 +++++++++++++++++++------------------------ sound/pci/hda/hda_codec.h | 7 ++-- sound/pci/hda/patch_realtek.c | 17 ++++----- sound/pci/hda/patch_via.c | 2 +- 4 files changed, 52 insertions(+), 56 deletions(-) diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index c556fe1..eb09a33 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -334,78 +334,67 @@ static hda_nid_t *lookup_conn_list(struct snd_array *array, hda_nid_t nid) return NULL; } +/* read the connection and add to the cache */ +static int read_and_add_raw_conns(struct hda_codec *codec, hda_nid_t nid) +{ + hda_nid_t list[HDA_MAX_CONNECTIONS]; + int len; + + len = snd_hda_get_raw_connections(codec, nid, list, ARRAY_SIZE(list)); + if (len < 0) + return len; + return snd_hda_override_conn_list(codec, nid, len, list); +} + /** - * snd_hda_get_conn_list - get connection list + * snd_hda_get_connections - copy connection list * @codec: the HDA codec * @nid: NID to parse - * @listp: the pointer to store NID list + * @conn_list: connection list array; when NULL, checks only the size + * @max_conns: max. number of connections to store * * Parses the connection list of the given widget and stores the list * of NIDs. * * Returns the number of connections, or a negative error code. */ -int snd_hda_get_conn_list(struct hda_codec *codec, hda_nid_t nid, - const hda_nid_t **listp) +int snd_hda_get_connections(struct hda_codec *codec, hda_nid_t nid, + hda_nid_t *conn_list, int max_conns) { struct snd_array *array = &codec->conn_lists; - int len, err; - hda_nid_t list[HDA_MAX_CONNECTIONS]; + int len; hda_nid_t *p; bool added = false; again: + mutex_lock(&codec->hash_mutex); + len = -1; /* if the connection-list is already cached, read it */ p = lookup_conn_list(array, nid); if (p) { - if (listp) - *listp = p + 2; - return p[1]; + len = p[1]; + if (conn_list && len > max_conns) { + snd_printk(KERN_ERR "hda_codec: " + "Too many connections %d for NID 0x%x\n", + len, nid); + mutex_unlock(&codec->hash_mutex); + return -EINVAL; + } + if (conn_list && len) + memcpy(conn_list, p + 2, len * sizeof(hda_nid_t)); } + mutex_unlock(&codec->hash_mutex); + if (len >= 0) + return len; if (snd_BUG_ON(added)) return -EINVAL; - /* read the connection and add to the cache */ - len = snd_hda_get_raw_connections(codec, nid, list, HDA_MAX_CONNECTIONS); + len = read_and_add_raw_conns(codec, nid); if (len < 0) return len; - err = snd_hda_override_conn_list(codec, nid, len, list); - if (err < 0) - return err; added = true; goto again; } -EXPORT_SYMBOL_HDA(snd_hda_get_conn_list); - -/** - * snd_hda_get_connections - copy connection list - * @codec: the HDA codec - * @nid: NID to parse - * @conn_list: connection list array - * @max_conns: max. number of connections to store - * - * Parses the connection list of the given widget and stores the list - * of NIDs. - * - * Returns the number of connections, or a negative error code. - */ -int snd_hda_get_connections(struct hda_codec *codec, hda_nid_t nid, - hda_nid_t *conn_list, int max_conns) -{ - const hda_nid_t *list; - int len = snd_hda_get_conn_list(codec, nid, &list); - - if (len <= 0) - return len; - if (len > max_conns) { - snd_printk(KERN_ERR "hda_codec: " - "Too many connections %d for NID 0x%x\n", - len, nid); - return -EINVAL; - } - memcpy(conn_list, list, len * sizeof(hda_nid_t)); - return len; -} EXPORT_SYMBOL_HDA(snd_hda_get_connections); /** @@ -543,6 +532,7 @@ int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int len, hda_nid_t *p; int i, old_used; + mutex_lock(&codec->hash_mutex); p = lookup_conn_list(array, nid); if (p) *p = -1; /* invalidate the old entry */ @@ -553,10 +543,12 @@ int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int len, for (i = 0; i < len; i++) if (!add_conn_list(array, list[i])) goto error_add; + mutex_unlock(&codec->hash_mutex); return 0; error_add: array->used = old_used; + mutex_unlock(&codec->hash_mutex); return -ENOMEM; } EXPORT_SYMBOL_HDA(snd_hda_override_conn_list); diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h index 29a311b..54b5281 100644 --- a/sound/pci/hda/hda_codec.h +++ b/sound/pci/hda/hda_codec.h @@ -911,10 +911,13 @@ int snd_hda_get_sub_nodes(struct hda_codec *codec, hda_nid_t nid, hda_nid_t *start_id); int snd_hda_get_connections(struct hda_codec *codec, hda_nid_t nid, hda_nid_t *conn_list, int max_conns); +static inline int +snd_hda_get_num_conns(struct hda_codec *codec, hda_nid_t nid) +{ + return snd_hda_get_connections(codec, nid, NULL, 0); +} int snd_hda_get_raw_connections(struct hda_codec *codec, hda_nid_t nid, hda_nid_t *conn_list, int max_conns); -int snd_hda_get_conn_list(struct hda_codec *codec, hda_nid_t nid, - const hda_nid_t **listp); int snd_hda_override_conn_list(struct hda_codec *codec, hda_nid_t nid, int nums, const hda_nid_t *list); int snd_hda_get_conn_index(struct hda_codec *codec, hda_nid_t mux, diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c index 152f458..0d68bb0 100644 --- a/sound/pci/hda/patch_realtek.c +++ b/sound/pci/hda/patch_realtek.c @@ -349,7 +349,7 @@ static int alc_mux_select(struct hda_codec *codec, unsigned int adc_idx, nid = get_capsrc(spec, adc_idx); /* no selection? */ - num_conns = snd_hda_get_conn_list(codec, nid, NULL); + num_conns = snd_hda_get_num_conns(codec, nid); if (num_conns <= 1) return 1; @@ -2543,7 +2543,6 @@ static int alc_auto_fill_adc_caps(struct hda_codec *codec) nid = codec->start_nid; for (i = 0; i < codec->num_nodes; i++, nid++) { hda_nid_t src; - const hda_nid_t *list; unsigned int caps = get_wcaps(codec, nid); int type = get_wcaps_type(caps); @@ -2554,6 +2553,7 @@ static int alc_auto_fill_adc_caps(struct hda_codec *codec) src = nid; for (;;) { int n; + hda_nid_t conn_nid; type = get_wcaps_type(get_wcaps(codec, src)); if (type == AC_WID_PIN) break; @@ -2561,13 +2561,14 @@ static int alc_auto_fill_adc_caps(struct hda_codec *codec) cap_nids[nums] = src; break; } - n = snd_hda_get_conn_list(codec, src, &list); + n = snd_hda_get_num_conns(codec, src); if (n > 1) { cap_nids[nums] = src; break; } else if (n != 1) break; - src = *list; + if (snd_hda_get_connections(codec, src, &src, 1) != 1) + break; } if (++nums >= max_nums) break; @@ -2708,7 +2709,7 @@ static void alc_auto_init_analog_input(struct hda_codec *codec) /* mute all loopback inputs */ if (spec->mixer_nid) { - int nums = snd_hda_get_conn_list(codec, spec->mixer_nid, NULL); + int nums = snd_hda_get_num_conns(codec, spec->mixer_nid); for (i = 0; i < nums; i++) snd_hda_codec_write(codec, spec->mixer_nid, 0, AC_VERB_SET_AMP_GAIN_MUTE, @@ -3338,7 +3339,7 @@ static int alc_auto_add_sw_ctl(struct hda_codec *codec, if (wid_type == AC_WID_PIN || wid_type == AC_WID_AUD_OUT) { type = ALC_CTL_WIDGET_MUTE; val = HDA_COMPOSE_AMP_VAL(nid, chs, 0, HDA_OUTPUT); - } else if (snd_hda_get_conn_list(codec, nid, NULL) == 1) { + } else if (snd_hda_get_num_conns(codec, nid) == 1) { type = ALC_CTL_WIDGET_MUTE; val = HDA_COMPOSE_AMP_VAL(nid, chs, 0, HDA_INPUT); } else { @@ -3898,7 +3899,7 @@ static void alc_remove_invalid_adc_nids(struct hda_codec *codec) nums = 0; for (n = 0; n < spec->num_adc_nids; n++) { hda_nid_t cap = spec->private_capsrc_nids[n]; - int num_conns = snd_hda_get_conn_list(codec, cap, NULL); + int num_conns = snd_hda_get_num_conns(codec, cap); for (i = 0; i < imux->num_items; i++) { hda_nid_t pin = spec->imux_pins[i]; if (pin) { @@ -4027,7 +4028,7 @@ static void select_or_unmute_capsrc(struct hda_codec *codec, hda_nid_t cap, if (get_wcaps_type(get_wcaps(codec, cap)) == AC_WID_AUD_MIX) { snd_hda_codec_amp_stereo(codec, cap, HDA_INPUT, idx, HDA_AMP_MUTE, 0); - } else if (snd_hda_get_conn_list(codec, cap, NULL) > 1) { + } else if (snd_hda_get_num_conns(codec, cap) > 1) { snd_hda_codec_write_cache(codec, cap, 0, AC_VERB_SET_CONNECT_SEL, idx); } diff --git a/sound/pci/hda/patch_via.c b/sound/pci/hda/patch_via.c index db272fb..82b3680 100644 --- a/sound/pci/hda/patch_via.c +++ b/sound/pci/hda/patch_via.c @@ -485,7 +485,7 @@ static void activate_output_mix(struct hda_codec *codec, struct nid_path *path, if (!path) return; - num = snd_hda_get_conn_list(codec, mix_nid, NULL); + num = snd_hda_get_num_conns(codec, mix_nid); for (i = 0; i < num; i++) { if (i == idx) val = AMP_IN_UNMUTE(i); -- 2.7.4