drivers/scsi/mvumi.c | 4 ++-- drivers/scsi/mvumi.h | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-)
One-element arrays (and multi-element arrays being treated as
dynamically sized) are deprecated[1] and are being replaced with
flexible array members in support of the ongoing efforts to tighten the
FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing
with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.
Replace one-element arrays with flexible-array member in struct
mvumi_msg_frame, struct mvumi_rsp_frame, and struct mvumi_hs_header,
adjusting the explicit sizing calculations at the same time.
This results in no functional differences in binary output. An explicit
add is now folded into the size calculation:
│ mov 0x1070(%r14),%eax
│ - add $0x4,%eax
│ - movabs $0xfffffffdc,%rbx
│ + movabs $0xfffffffe0,%rbx
│ add %rax,%rbx
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/scsi/mvumi.c | 4 ++--
drivers/scsi/mvumi.h | 6 +++---
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c
index b3dcb8918618..60c65586f30e 100644
--- a/drivers/scsi/mvumi.c
+++ b/drivers/scsi/mvumi.c
@@ -1841,7 +1841,7 @@ static enum mvumi_qc_result mvumi_send_command(struct mvumi_hba *mhba,
cmd->frame->request_id = mhba->io_seq++;
cmd->request_id = cmd->frame->request_id;
mhba->tag_cmd[cmd->frame->tag] = cmd;
- frame_len = sizeof(*ib_frame) - 4 +
+ frame_len = sizeof(*ib_frame) +
ib_frame->sg_counts * sizeof(struct mvumi_sgl);
if (mhba->hba_capability & HS_CAPABILITY_SUPPORT_DYN_SRC) {
struct mvumi_dyn_list_entry *dle;
@@ -2387,7 +2387,7 @@ static int mvumi_io_attach(struct mvumi_hba *mhba)
struct Scsi_Host *host = mhba->shost;
struct scsi_device *sdev = NULL;
int ret;
- unsigned int max_sg = (mhba->ib_max_size + 4 -
+ unsigned int max_sg = (mhba->ib_max_size -
sizeof(struct mvumi_msg_frame)) / sizeof(struct mvumi_sgl);
host->irq = mhba->pdev->irq;
diff --git a/drivers/scsi/mvumi.h b/drivers/scsi/mvumi.h
index a88c58787b68..1306a4abf19a 100644
--- a/drivers/scsi/mvumi.h
+++ b/drivers/scsi/mvumi.h
@@ -279,7 +279,7 @@ struct mvumi_msg_frame {
u16 request_id;
u16 reserved1;
u8 cdb[MAX_COMMAND_SIZE];
- u32 payload[1];
+ u32 payload[];
};
/*
@@ -294,7 +294,7 @@ struct mvumi_rsp_frame {
u8 req_status;
u8 rsp_flag; /* Indicates the type of Data_Payload.*/
u16 request_id;
- u32 payload[1];
+ u32 payload[];
};
struct mvumi_ob_data {
@@ -380,7 +380,7 @@ struct mvumi_hs_header {
u8 page_code;
u8 checksum;
u16 frame_length;
- u32 frame_content[1];
+ u32 frame_content[];
};
/*
--
2.34.1
On Wed, 04 Jan 2023 17:11:50 -0800, Kees Cook wrote:
> One-element arrays (and multi-element arrays being treated as
> dynamically sized) are deprecated[1] and are being replaced with
> flexible array members in support of the ongoing efforts to tighten the
> FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing
> with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.
>
> Replace one-element arrays with flexible-array member in struct
> mvumi_msg_frame, struct mvumi_rsp_frame, and struct mvumi_hs_header,
> adjusting the explicit sizing calculations at the same time.
>
> [...]
Applied to 6.3/scsi-queue, thanks!
[1/1] scsi: mvumi: Replace 1-element arrays with flexible array members
https://git.kernel.org/mkp/scsi/c/201e0a7c7f36
--
Martin K. Petersen Oracle Linux Engineering
Kees, > One-element arrays (and multi-element arrays being treated as > dynamically sized) are deprecated[1] and are being replaced with > flexible array members in support of the ongoing efforts to tighten > the FORTIFY_SOURCE routines on memcpy(), correctly instrument array > indexing with UBSAN_BOUNDS, and to globally enable > -fstrict-flex-arrays=3. > > Replace one-element arrays with flexible-array member in struct > mvumi_msg_frame, struct mvumi_rsp_frame, and struct mvumi_hs_header, > adjusting the explicit sizing calculations at the same time. Applied to 6.3/scsi-staging, thanks! -- Martin K. Petersen Oracle Linux Engineering
On Wed, Jan 04, 2023 at 05:11:50PM -0800, Kees Cook wrote:
> One-element arrays (and multi-element arrays being treated as
> dynamically sized) are deprecated[1] and are being replaced with
> flexible array members in support of the ongoing efforts to tighten the
> FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing
> with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.
>
> Replace one-element arrays with flexible-array member in struct
> mvumi_msg_frame, struct mvumi_rsp_frame, and struct mvumi_hs_header,
> adjusting the explicit sizing calculations at the same time.
>
> This results in no functional differences in binary output. An explicit
> add is now folded into the size calculation:
>
> │ mov 0x1070(%r14),%eax
> │ - add $0x4,%eax
> │ - movabs $0xfffffffdc,%rbx
> │ + movabs $0xfffffffe0,%rbx
> │ add %rax,%rbx
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: linux-scsi@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
Wow, those "magical" 4s seem quite elusive. It's more common to see people
using sizeof applied to the element type, like sizeof(u32).
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks!
--
Gustavo
> ---
> drivers/scsi/mvumi.c | 4 ++--
> drivers/scsi/mvumi.h | 6 +++---
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/mvumi.c b/drivers/scsi/mvumi.c
> index b3dcb8918618..60c65586f30e 100644
> --- a/drivers/scsi/mvumi.c
> +++ b/drivers/scsi/mvumi.c
> @@ -1841,7 +1841,7 @@ static enum mvumi_qc_result mvumi_send_command(struct mvumi_hba *mhba,
> cmd->frame->request_id = mhba->io_seq++;
> cmd->request_id = cmd->frame->request_id;
> mhba->tag_cmd[cmd->frame->tag] = cmd;
> - frame_len = sizeof(*ib_frame) - 4 +
> + frame_len = sizeof(*ib_frame) +
> ib_frame->sg_counts * sizeof(struct mvumi_sgl);
> if (mhba->hba_capability & HS_CAPABILITY_SUPPORT_DYN_SRC) {
> struct mvumi_dyn_list_entry *dle;
> @@ -2387,7 +2387,7 @@ static int mvumi_io_attach(struct mvumi_hba *mhba)
> struct Scsi_Host *host = mhba->shost;
> struct scsi_device *sdev = NULL;
> int ret;
> - unsigned int max_sg = (mhba->ib_max_size + 4 -
> + unsigned int max_sg = (mhba->ib_max_size -
> sizeof(struct mvumi_msg_frame)) / sizeof(struct mvumi_sgl);
>
> host->irq = mhba->pdev->irq;
> diff --git a/drivers/scsi/mvumi.h b/drivers/scsi/mvumi.h
> index a88c58787b68..1306a4abf19a 100644
> --- a/drivers/scsi/mvumi.h
> +++ b/drivers/scsi/mvumi.h
> @@ -279,7 +279,7 @@ struct mvumi_msg_frame {
> u16 request_id;
> u16 reserved1;
> u8 cdb[MAX_COMMAND_SIZE];
> - u32 payload[1];
> + u32 payload[];
> };
>
> /*
> @@ -294,7 +294,7 @@ struct mvumi_rsp_frame {
> u8 req_status;
> u8 rsp_flag; /* Indicates the type of Data_Payload.*/
> u16 request_id;
> - u32 payload[1];
> + u32 payload[];
> };
>
> struct mvumi_ob_data {
> @@ -380,7 +380,7 @@ struct mvumi_hs_header {
> u8 page_code;
> u8 checksum;
> u16 frame_length;
> - u32 frame_content[1];
> + u32 frame_content[];
> };
>
> /*
> --
> 2.34.1
>
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