[PATCH v2 3/3] hpsa: add an assert to prevent from __packed reintroduction
From: Sergei Trofimovich <hidden>
Date: 2021-03-30 07:21:44
Also in:
lkml
Subsystem:
hewlett-packard smart array raid driver (hpsa), scsi subsystem, the rest · Maintainers:
Don Brace, "James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
CC: linux-ia64@vger.kernel.org CC: storagedev@microchip.com CC: linux-scsi@vger.kernel.org CC: Joe Szczypek <redacted> CC: Scott Benesh <redacted> CC: Scott Teel <redacted> CC: Tomas Henzl <redacted> CC: "Martin K. Petersen" <martin.petersen@oracle.com> CC: Don Brace <don.brace@microchip.com> Reported-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Suggested-by: Don Brace <don.brace@microchip.com> Fixes: f749d8b7a "scsi: hpsa: Correct dev cmds outstanding for retried cmds" Signed-off-by: Sergei Trofimovich <redacted> --- 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 <linux/compiler.h> +#include <linux/build_bug.h> /* static_assert */ +#include <linux/stddef.h> /* 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
--
2.31.1