From 7668bc8b07dec7eeb8f2682e50ae5c740c25c704 Mon Sep 17 00:00:00 2001
From: Michael Forney <mforney@mforney.org>
Date: Thu, 30 Jan 2020 11:38:23 -0800
Subject: [PATCH] Avoid pointer arithmetic with `void *`
Upstream: https://github.com/plougher/squashfs-tools/pull/86

`void *` is a pointer to an incomplete type, so cannot be used in
pointer arithmetic.
---
 squashfs-tools/action.c     |  2 +-
 squashfs-tools/mksquashfs.c | 10 +++++-----
 squashfs-tools/unsquashfs.c |  6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/squashfs-tools/action.c b/squashfs-tools/action.c
index 4b06ccb..b107470 100644
--- a/squashfs-tools/action.c
+++ b/squashfs-tools/action.c
@@ -950,7 +950,7 @@ void *get_frag_action(void *fragment)
 	if (fragment == &def_fragment)
 		action = &fragment_spec[0] - 1;
 	else 
-		action = fragment - offsetof(struct action, data);
+		action = (struct action *)((char *)fragment - offsetof(struct action, data));
 
 	if (++action == spec_list_end)
 		return NULL;
diff --git a/squashfs-tools/mksquashfs.c b/squashfs-tools/mksquashfs.c
index a45b77f..d9e7b01 100644
--- a/squashfs-tools/mksquashfs.c
+++ b/squashfs-tools/mksquashfs.c
@@ -516,7 +516,7 @@ int read_bytes(int fd, void *buff, int bytes)
 	int res, count;
 
 	for(count = 0; count < bytes; count += res) {
-		res = read(fd, buff + count, bytes - count);
+		res = read(fd, (char *)buff + count, bytes - count);
 		if(res < 1) {
 			if(res == 0)
 				goto bytes_read;
@@ -563,7 +563,7 @@ int write_bytes(int fd, void *buff, int bytes)
 	int res, count;
 
 	for(count = 0; count < bytes; count += res) {
-		res = write(fd, buff + count, bytes - count);
+		res = write(fd, (char *)buff + count, bytes - count);
 		if(res == -1) {
 			if(errno != EINTR) {
 				ERROR("Write failed because %s\n",
@@ -889,7 +889,7 @@ int create_inode(squashfs_inode *i_no, struct dir_info *dir_info,
 	struct stat *buf = &dir_ent->inode->buf;
 	union squashfs_inode_header inode_header;
 	struct squashfs_base_inode_header *base = &inode_header.base;
-	void *inode;
+	char *inode;
 	char *filename = pathname(dir_ent);
 	int nlink = dir_ent->inode->nlink;
 	int xattr = read_xattrs(dir_ent);
@@ -982,7 +982,7 @@ int create_inode(squashfs_inode *i_no, struct dir_info *dir_info,
 	}
 	else if(type == SQUASHFS_LDIR_TYPE) {
 		int i;
-		unsigned char *p;
+		char *p;
 		struct squashfs_ldir_inode_header *dir = &inode_header.ldir;
 		struct cached_dir_index *index = dir_in->index;
 		unsigned int i_count = dir_in->i_count;
@@ -1680,7 +1680,7 @@ long long generic_write_table(int length, void *buffer, int length2,
 	for(i = 0; i < meta_blocks; i++) {
 		int avail_bytes = length > SQUASHFS_METADATA_SIZE ?
 			SQUASHFS_METADATA_SIZE : length;
-		c_byte = mangle(cbuffer + BLOCK_OFFSET, buffer + i *
+		c_byte = mangle(cbuffer + BLOCK_OFFSET, (char *)buffer + i *
 			SQUASHFS_METADATA_SIZE , avail_bytes,
 			SQUASHFS_METADATA_SIZE, uncompressed, 0);
 		SQUASHFS_SWAP_SHORTS(&c_byte, cbuffer, 1);
diff --git a/squashfs-tools/unsquashfs.c b/squashfs-tools/unsquashfs.c
index 727f1d5..5e8b2cb 100644
--- a/squashfs-tools/unsquashfs.c
+++ b/squashfs-tools/unsquashfs.c
@@ -640,7 +640,7 @@ int read_fs_bytes(int fd, long long byte, int bytes, void *buff)
 	}
 
 	for(count = 0; count < bytes; count += res) {
-		res = read(fd, buff + count, bytes - count);
+		res = read(fd, (char *)buff + count, bytes - count);
 		if(res < 1) {
 			if(res == 0) {
 				ERROR("Read on filesystem failed because "
@@ -748,7 +748,7 @@ void *read_inode_table(long long start, long long end)
 	int res;
 	long long size = 0;
 	long long bytes = 0;
-	void *inode_table = NULL;
+	char *inode_table = NULL;
 
 	TRACE("read_inode_table: start %lld, end %lld\n", start, end);
 
@@ -1226,7 +1226,7 @@ void *read_directory_table(long long start, long long end)
 	int res;
 	long long bytes = 0;
 	long long size = 0;
-	void *directory_table = malloc(1);
+	char *directory_table = malloc(1);
 
 	TRACE("read_directory_table: start %lld, end %lld\n", start, end);
 
-- 
2.25.0