Messages in this thread | | | Date | Thu, 17 Jun 2021 13:48:49 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [char-misc-next 2/2] mei: revamp mei extension header structure layout. |
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On Wed, Jun 16, 2021 at 12:15:57AM +0300, Tomas Winkler wrote: > The mei extension header was build as array of flexible structures > which will not work if actually more headers are added
Why not? What is wrong with what you currently have?
And did you forget a '.' here?
> Use basic type u8 for the variable sized extension. > Define explicitly mei_ext_hdr_vtag structure. > Fix also mei_ext_next() function to point correctly to the > end of the header. > > Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> > --- > drivers/misc/mei/client.c | 16 +++++++++------- > drivers/misc/mei/hw.h | 28 ++++++++++++++++++++-------- > drivers/misc/mei/interrupt.c | 23 ++++++++++------------- > 3 files changed, 39 insertions(+), 28 deletions(-) > > diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c > index 18e49479d8b0..96f4e59c32a5 100644 > --- a/drivers/misc/mei/client.c > +++ b/drivers/misc/mei/client.c > @@ -1726,12 +1726,15 @@ int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp) > return rets; > } > > -static inline u8 mei_ext_hdr_set_vtag(struct mei_ext_hdr *ext, u8 vtag) > +static inline u8 mei_ext_hdr_set_vtag(void *ext, u8 vtag) > { > - ext->type = MEI_EXT_HDR_VTAG; > - ext->ext_payload[0] = vtag; > - ext->length = mei_data2slots(sizeof(*ext)); > - return ext->length; > + struct mei_ext_hdr_vtag *vtag_hdr = ext; > + > + vtag_hdr->hdr.type = MEI_EXT_HDR_VTAG; > + vtag_hdr->hdr.length = mei_data2slots(sizeof(*vtag_hdr)); > + vtag_hdr->vtag = vtag; > + vtag_hdr->reserved = 0; > + return vtag_hdr->hdr.length; > } > > /** > @@ -1745,7 +1748,6 @@ static struct mei_msg_hdr *mei_msg_hdr_init(const struct mei_cl_cb *cb) > { > size_t hdr_len; > struct mei_ext_meta_hdr *meta; > - struct mei_ext_hdr *ext; > struct mei_msg_hdr *mei_hdr; > bool is_ext, is_vtag; > > @@ -1764,7 +1766,7 @@ static struct mei_msg_hdr *mei_msg_hdr_init(const struct mei_cl_cb *cb) > > hdr_len += sizeof(*meta); > if (is_vtag) > - hdr_len += sizeof(*ext); > + hdr_len += sizeof(struct mei_ext_hdr_vtag); > > setup_hdr: > mei_hdr = kzalloc(hdr_len, GFP_KERNEL); > diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h > index b10606550613..dfd60c916da0 100644 > --- a/drivers/misc/mei/hw.h > +++ b/drivers/misc/mei/hw.h > @@ -235,9 +235,8 @@ enum mei_ext_hdr_type { > struct mei_ext_hdr { > u8 type; > u8 length; > - u8 ext_payload[2]; > - u8 hdr[]; > -}; > + u8 data[]; > +} __packed;
why packed?
> > /** > * struct mei_ext_meta_hdr - extend header meta data > @@ -250,8 +249,21 @@ struct mei_ext_meta_hdr { > u8 count; > u8 size; > u8 reserved[2]; > - struct mei_ext_hdr hdrs[]; > -}; > + u8 hdrs[]; > +} __packed;
Why packed?
> + > +/** > + * struct mei_ext_hdr_vtag - extend header for vtag > + * > + * @hdr: standard extend header > + * @vtag: virtual tag > + * @reserved: reserved > + */ > +struct mei_ext_hdr_vtag { > + struct mei_ext_hdr hdr; > + u8 vtag; > + u8 reserved; > +} __packed;
Why packed?
These are not being read directly from hardware are they?
thanks,
greg k-h
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