From 1cb8ecf1b8579752b51929c4b375d15dfcb5a3eb Mon Sep 17 00:00:00 2001 From: Chen Liangjun Date: Mon, 12 Nov 2012 13:41:13 +0800 Subject: [PATCH] ENGR00233780 ASRC: limit output buffer size to avoid kernel dump For ASRC memory to memory transfer, user would send driver input buffer and driver would copy converted output buffer into user's buffer. However, ASRC can't promise the ratio of output buffer size/input buffer size being equal to output sample rate/input sample rate.e.g, for convert from 8k to 48k and 1000 bytes input buffer size, ASRC may pop out 5999 bytes or 6001 bytes. If driver copy all 6001 bytes into user's buffer, kernel dump may happens cause of accessing unexisted buffer. In this patch, if ASRC output buffer size is larger than user's buffer size, discard exact part. Signed-off-by: Chen Liangjun --- drivers/mxc/asrc/mxc_asrc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/mxc/asrc/mxc_asrc.c b/drivers/mxc/asrc/mxc_asrc.c index 77f88f36e696..4a17f5856d45 100644 --- a/drivers/mxc/asrc/mxc_asrc.c +++ b/drivers/mxc/asrc/mxc_asrc.c @@ -961,6 +961,8 @@ static void asrc_read_output_FIFO_S16(struct asrc_pair_params *params) size = asrc_get_output_FIFO_size(params->index); } + if (t_size > ASRC_OUTPUT_LAST_SAMPLE) + t_size = ASRC_OUTPUT_LAST_SAMPLE; params->output_last_period.length = t_size * params->channel_nums * 2; } @@ -985,6 +987,8 @@ static void asrc_read_output_FIFO_S24(struct asrc_pair_params *params) size = asrc_get_output_FIFO_size(params->index); } + if (t_size > ASRC_OUTPUT_LAST_SAMPLE) + t_size = ASRC_OUTPUT_LAST_SAMPLE; params->output_last_period.length = t_size * params->channel_nums * 4; } @@ -1288,9 +1292,6 @@ static int mxc_asrc_prepare_output_buffer(struct asrc_pair_params *params, { u32 word_size; - pbuf->output_buffer_length = asrc_get_output_buffer_size( - pbuf->input_buffer_length, - params->input_sample_rate, params->output_sample_rate); switch (params->output_word_width) { case ASRC_WIDTH_24_BIT: word_size = 4; -- 2.39.5