From e01a00ff62adca8ec464f3c8d82cfa0e8d8728dd Mon Sep 17 00:00:00 2001 From: Sergei Trofimovich Date: Tue, 30 Mar 2021 08:19:58 +0100 Subject: [PATCH] scsi: hpsa: Add an assert to prevent __packed reintroduction Link: https://lore.kernel.org/r/20210330071958.3788214-3-slyfox@gentoo.org Fixes: f749d8b7a989 ("scsi: hpsa: Correct dev cmds outstanding for retried cmds") CC: linux-ia64@vger.kernel.org CC: storagedev@microchip.com CC: linux-scsi@vger.kernel.org CC: Joe Szczypek CC: Scott Benesh CC: Scott Teel CC: Tomas Henzl CC: "Martin K. Petersen" CC: Don Brace Reported-by: John Paul Adrian Glaubitz Suggested-by: Don Brace Reviewed-by: Arnd Bergmann Signed-off-by: Sergei Trofimovich Signed-off-by: Martin K. Petersen --- drivers/scsi/hpsa_cmd.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/scsi/hpsa_cmd.h b/drivers/scsi/hpsa_cmd.h index 885b1f1fb20a..ba6a3aa8d954 100644 --- a/drivers/scsi/hpsa_cmd.h +++ b/drivers/scsi/hpsa_cmd.h @@ -22,6 +22,9 @@ #include +#include /* static_assert */ +#include /* offsetof */ + /* general boundary defintions */ #define SENSEINFOBYTES 32 /* may vary between hbas */ #define SG_ENTRIES_IN_CMD 32 /* Max SG entries excluding chain blocks */ @@ -454,6 +457,15 @@ struct CommandList { atomic_t refcount; /* Must be last to avoid memset in hpsa_cmd_init() */ } __aligned(COMMANDLIST_ALIGNMENT); +/* + * Make sure our embedded atomic variable is aligned. Otherwise we break atomic + * operations on architectures that don't support unaligned atomics like IA64. + * + * The assert guards against reintroductin against unwanted __packed to + * the struct CommandList. + */ +static_assert(offsetof(struct CommandList, refcount) % __alignof__(atomic_t) == 0); + /* Max S/G elements in I/O accelerator command */ #define IOACCEL1_MAXSGENTRIES 24 #define IOACCEL2_MAXSGENTRIES 28