Messages in this thread Patch in this message | | | Date | Tue, 10 Aug 2021 16:07:41 -0500 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH][next] scsi: smartpqi: Replace one-element array with flexible-array member |
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There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2].
Refactor the code a bit according to the use of a flexible-array member in struct pqi_event_config instead of a one-element array, and use the struct_size() helper.
This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy().
This issue was found with the help of Coccinelle and audited and fixed, manually.
[1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- drivers/scsi/smartpqi/smartpqi.h | 2 +- drivers/scsi/smartpqi/smartpqi_init.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index f340afc011b5..70eca203d72f 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -415,7 +415,7 @@ struct pqi_event_config { u8 reserved[2]; u8 num_event_descriptors; u8 reserved1; - struct pqi_event_descriptor descriptors[1]; + struct pqi_event_descriptor descriptors[]; }; #define PQI_MAX_EVENT_DESCRIPTORS 255 diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index c1f0f8da9fe2..f9107127bd6e 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -4740,8 +4740,7 @@ static int pqi_create_queues(struct pqi_ctrl_info *ctrl_info) } #define PQI_REPORT_EVENT_CONFIG_BUFFER_LENGTH \ - (offsetof(struct pqi_event_config, descriptors) + \ - (PQI_MAX_EVENT_DESCRIPTORS * sizeof(struct pqi_event_descriptor))) + struct_size((struct pqi_event_config *)0, descriptors, PQI_MAX_EVENT_DESCRIPTORS) static int pqi_configure_events(struct pqi_ctrl_info *ctrl_info, bool enable_events) -- 2.27.0
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