Re: [PATCH 1/3] soc: qcom: mdt_loader: Allow hash at any phdr

[Bjorn Andersson]

On Wed 06 Jan 15:23 CST 2021, Siddharth Gupta wrote:

> The assumption that the elf program header will always have the hash
> segment program header at index 1 may not hold true in all cases. This
> change updates the read metadata function to find the hash program header
> dynamically.
> 

Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

Regards,
Bjorn

> Signed-off-by: Siddharth Gupta <sidgup@xxxxxxxxxxxxxx>
> ---
>  drivers/soc/qcom/mdt_loader.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
> index 24cd193..813216d 100644
> --- a/drivers/soc/qcom/mdt_loader.c
> +++ b/drivers/soc/qcom/mdt_loader.c
> @@ -4,7 +4,7 @@
>   *
>   * Copyright (C) 2016 Linaro Ltd
>   * Copyright (C) 2015 Sony Mobile Communications Inc
> - * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
> + * Copyright (c) 2012-2013, 2020 The Linux Foundation. All rights reserved.
>   */
>  
>  #include <linux/device.h>
> @@ -88,6 +88,7 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
>  	const struct elf32_phdr *phdrs;
>  	const struct elf32_hdr *ehdr;
>  	size_t hash_offset;
> +	size_t hash_index;
>  	size_t hash_size;
>  	size_t ehdr_size;
>  	void *data;
> @@ -98,14 +99,19 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
>  	if (ehdr->e_phnum < 2)
>  		return ERR_PTR(-EINVAL);
>  
> -	if (phdrs[0].p_type == PT_LOAD || phdrs[1].p_type == PT_LOAD)
> +	if (phdrs[0].p_type == PT_LOAD)
>  		return ERR_PTR(-EINVAL);
>  
> -	if ((phdrs[1].p_flags & QCOM_MDT_TYPE_MASK) != QCOM_MDT_TYPE_HASH)
> +	for (hash_index = 1; hash_index < ehdr->e_phnum; hash_index++) {
> +		if (phdrs[hash_index].p_type != PT_LOAD &&
> +		   (phdrs[hash_index].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH)
> +			break;
> +	}
> +	if (hash_index >= ehdr->e_phnum)
>  		return ERR_PTR(-EINVAL);
>  
>  	ehdr_size = phdrs[0].p_filesz;
> -	hash_size = phdrs[1].p_filesz;
> +	hash_size = phdrs[hash_index].p_filesz;
>  
>  	data = kmalloc(ehdr_size + hash_size, GFP_KERNEL);
>  	if (!data)
> @@ -115,7 +121,7 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len)
>  	if (ehdr_size + hash_size == fw->size)
>  		hash_offset = phdrs[0].p_filesz;
>  	else
> -		hash_offset = phdrs[1].p_offset;
> +		hash_offset = phdrs[hash_index].p_offset;
>  
>  	memcpy(data, fw->data, ehdr_size);
>  	memcpy(data + ehdr_size, fw->data + hash_offset, hash_size);
> -- 
> Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>