On 8/13/25 22:07, Bryan Gurney wrote:
From: "Gustavo A. R. Silva" <[email protected]>
purex_item.iocb is defined as a 64-element u8 array, but 64 is the
minimum size and it can be allocated larger. This makes it a standard
empty flex array.
This was motivated by field-spanning write warnings during FPIN testing.
https://lore.kernel.org/linux-nvme/[email protected]/
> kernel: memcpy: detected field-spanning write (size 60) of single field
> "((uint8_t *)fpin_pkt + buffer_copy_offset)"
> at drivers/scsi/qla2xxx/qla_isr.c:1221 (size 44)
I removed the outer wrapper from the iocb flex array, so that it can be
linked to `purex_item.size` with `__counted_by`.
These changes remove the default minimum 64-byte allocation, requiring
further changes.
In `struct scsi_qla_host` the embedded `default_item` is now followed
by `__default_item_iocb[QLA_DEFAULT_PAYLOAD_SIZE]` to reserve space
that will be used as `default_item.iocb`. This is wrapped using the
`TRAILING_OVERLAP()` macro helper, which effectively creates a union
between flexible-array member `default_item.iocb` and `__default_item_iocb`.
Since `struct pure_item` now contains a flexible-array member, the
helper must be placed at the end of `struct scsi_qla_host` to prevent
a `-Wflex-array-member-not-at-end` warning.
`qla24xx_alloc_purex_item()` is adjusted to no longer expect the
default minimum size to be part of `sizeof(struct purex_item)`,
the entire flexible array size is added to the structure size for
allocation.
This also slightly changes the layout of the purex_item struct, as
2-bytes of padding are added between `size` and `iocb`. The resulting
size is the same, but iocb is shifted 2-bytes (the original `purex_item`
structure was padded at the end, after the 64-byte defined array size).
I don't think this is a problem.
Tested-by: Bryan Gurney <[email protected]>
Co-developed-by: Chris Leech <[email protected]>
Signed-off-by: Chris Leech <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/scsi/qla2xxx/qla_def.h | 10 ++++++----
drivers/scsi/qla2xxx/qla_isr.c | 17 ++++++++---------
drivers/scsi/qla2xxx/qla_nvme.c | 2 +-
drivers/scsi/qla2xxx/qla_os.c | 5 +++--
4 files changed, 18 insertions(+), 16 deletions(-)
Not sure if this shouldn't be a stand-alone patch, but anyway:
Reviewed-by: Hannes Reinecke <[email protected]>
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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