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

[Siddharth Gupta <sidgup@codeaurora.org>]

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 <sidgup@codeaurora.org>
---
 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);
-- 
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a Linux Foundation Collaborative Project