2021-01-06 21:26:31

by Siddharth Gupta

[permalink] [raw]
Subject: [PATCH 1/3] soc: qcom: mdt_loader: Allow hash at any phdr

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.

Signed-off-by: Siddharth Gupta <[email protected]>
---
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


2021-01-08 00:05:38

by Bjorn Andersson

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

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 <[email protected]>

Regards,
Bjorn

> Signed-off-by: Siddharth Gupta <[email protected]>
> ---
> 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
>