[PATCH 0/2] platform/x86: dell_rbu: Packet data fixes

[PATCH 0/2] platform/x86: dell_rbu: Packet data fixes

[Stuart Hayes]

Two fixes related to packet data.

Stuart Hayes (2):
  platform/x86: dell_rbu: Fix list usage
  platform/x86: dell_rbu: Stop overwriting data buffer

 drivers/platform/x86/dell/dell_rbu.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

-- 
2.47.1

[PATCH 1/2] platform/x86: dell_rbu: Fix list usage

[Stuart Hayes]

Stop using an entire struct packet_data just for the embedded list_head,
and fix usage of that list_head.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
---
 drivers/platform/x86/dell/dell_rbu.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/platform/x86/dell/dell_rbu.c b/drivers/platform/x86/dell/dell_rbu.c
index e30ca325938c..6a602a80160a 100644
--- a/drivers/platform/x86/dell/dell_rbu.c
+++ b/drivers/platform/x86/dell/dell_rbu.c
@@ -77,14 +77,14 @@ struct packet_data {
 	int ordernum;
 };
 
-static struct packet_data packet_data_head;
+struct list_head packet_data_list;
 
 static struct platform_device *rbu_device;
 static int context;
 
 static void init_packet_head(void)
 {
-	INIT_LIST_HEAD(&packet_data_head.list);
+	INIT_LIST_HEAD(&packet_data_list);
 	rbu_data.packet_read_count = 0;
 	rbu_data.num_packets = 0;
 	rbu_data.packetsize = 0;
@@ -183,7 +183,7 @@ static int create_packet(void *data, size_t length)
 
 	/* initialize the newly created packet headers */
 	INIT_LIST_HEAD(&newpacket->list);
-	list_add_tail(&newpacket->list, &packet_data_head.list);
+	list_add_tail(&newpacket->list, &packet_data_list);
 
 	memcpy(newpacket->data, data, length);
 
@@ -292,7 +292,7 @@ static int packet_read_list(char *data, size_t * pread_length)
 	remaining_bytes = *pread_length;
 	bytes_read = rbu_data.packet_read_count;
 
-	list_for_each_entry(newpacket, (&packet_data_head.list)->next, list) {
+	list_for_each_entry(newpacket, &packet_data_list, list) {
 		bytes_copied = do_packet_read(pdest, newpacket,
 			remaining_bytes, bytes_read, &temp_count);
 		remaining_bytes -= bytes_copied;
@@ -315,7 +315,7 @@ static void packet_empty_list(void)
 {
 	struct packet_data *newpacket, *tmp;
 
-	list_for_each_entry_safe(newpacket, tmp, (&packet_data_head.list)->next, list) {
+	list_for_each_entry_safe(newpacket, tmp, &packet_data_list, list) {
 		list_del(&newpacket->list);
 
 		/*
-- 
2.47.1

Re: [PATCH 1/2] platform/x86: dell_rbu: Fix list usage

[kernel test robot]

Hi Stuart,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.15-rc7 next-20250522]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Stuart-Hayes/platform-x86-dell_rbu-Fix-list-usage/20250522-002119
base:   linus/master
patch link:    https://lore.kernel.org/r/20250521161639.47357-2-stuart.w.hayes%40gmail.com
patch subject: [PATCH 1/2] platform/x86: dell_rbu: Fix list usage
config: x86_64-randconfig-r113-20250522 (https://download.01.org/0day-ci/archive/20250522/202505222012.YMyWZkiR-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250522/202505222012.YMyWZkiR-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505222012.YMyWZkiR-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/platform/x86/dell/dell_rbu.c:80:18: sparse: sparse: symbol 'packet_data_list' was not declared. Should it be static?
   drivers/platform/x86/dell/dell_rbu.c:112:20: sparse: sparse: context imbalance in 'create_packet' - unexpected unlock

vim +/packet_data_list +80 drivers/platform/x86/dell/dell_rbu.c

    79	
  > 80	struct list_head packet_data_list;
    81	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH 2/2] platform/x86: dell_rbu: Stop overwriting data buffer

[Stuart Hayes]

The dell_rbu driver will use memset to clear the data held by each packet
when it is no longer needed (when the driver is unloaded, the packet size
is changed, etc).

The amount of memory that is cleared is (currently) the normal packet
size.  However, the last packet in the list may be smaller.  Fix this to
only clear the memory actually used by each packet, to prevent it from
writing past the end of data buffer.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
---
 drivers/platform/x86/dell/dell_rbu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/dell/dell_rbu.c b/drivers/platform/x86/dell/dell_rbu.c
index 6a602a80160a..bedf03fa4f41 100644
--- a/drivers/platform/x86/dell/dell_rbu.c
+++ b/drivers/platform/x86/dell/dell_rbu.c
@@ -322,7 +322,7 @@ static void packet_empty_list(void)
 		 * zero out the RBU packet memory before freeing
 		 * to make sure there are no stale RBU packets left in memory
 		 */
-		memset(newpacket->data, 0, rbu_data.packetsize);
+		memset(newpacket->data, 0, newpacket->length);
 		set_memory_wb((unsigned long)newpacket->data,
 			1 << newpacket->ordernum);
 		free_pages((unsigned long) newpacket->data,
-- 
2.47.1