Re: [PATCHv3 5/5] scsi_devinfo: fixup string compare
On 08/16/2017 01:03 AM, Bart Van Assche wrote: > On Fri, 2017-08-11 at 16:23 +0200, Hannes Reinecke wrote: >> When checking the model and vendor string we need to use the >> minimum value of either string, otherwise we'll miss out on >> wildcard matches. >> And we should take card when matching with zero size strings; > > "card"? Did you perhaps mean "care"? > Yes, indeed. >> results might be unpredictable. >> With this patch the rules for matching devinfo strings are >> as follows: >> - Vendor strings must match exactly >> - Empty Model strings will only match if the devinfo model >> is also empty >> - Model strings shorter than the devinfo model string will >> not match > > The above sentence contradicts the first sentence. > Ah. Will be rewriting this. >> +/* >> + * @model specifies the full string, and >> + * must be larger or equal to devinfo->model >> + */ > > What does "larger than or equal to" mean for strings? Did you perhaps mean > that > devinfo->model must be a prefix of @model? > Yes. >> if (!memcmp(devinfo->vendor, vendor, >> - sizeof(devinfo->vendor)) && >> - !memcmp(devinfo->model, model, >> - sizeof(devinfo->model))) >> +sizeof(devinfo->vendor)) && >> +!memcmp(devinfo->model, model, >> +sizeof(devinfo->model))) >> return devinfo; > > Is this a whitespace-only change? If so, please fold it in the previous patch. > Ok. Cheers, Hannes -- Dr. Hannes ReineckeTeamlead Storage & Networking h...@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)
Re: [PATCHv3 5/5] scsi_devinfo: fixup string compare
On Fri, 2017-08-11 at 16:23 +0200, Hannes Reinecke wrote: > When checking the model and vendor string we need to use the > minimum value of either string, otherwise we'll miss out on > wildcard matches. > And we should take card when matching with zero size strings; "card"? Did you perhaps mean "care"? > results might be unpredictable. > With this patch the rules for matching devinfo strings are > as follows: > - Vendor strings must match exactly > - Empty Model strings will only match if the devinfo model > is also empty > - Model strings shorter than the devinfo model string will > not match The above sentence contradicts the first sentence. > + /* > + * @model specifies the full string, and > + * must be larger or equal to devinfo->model > + */ What does "larger than or equal to" mean for strings? Did you perhaps mean that devinfo->model must be a prefix of @model? > if (!memcmp(devinfo->vendor, vendor, > - sizeof(devinfo->vendor)) && > - !memcmp(devinfo->model, model, > - sizeof(devinfo->model))) > + sizeof(devinfo->vendor)) && > + !memcmp(devinfo->model, model, > + sizeof(devinfo->model))) > return devinfo; Is this a whitespace-only change? If so, please fold it in the previous patch. Thanks, Bart.
Re: [PATCHv3 5/5] scsi_devinfo: fixup string compare
On Fri, 11 Aug 2017, Hannes Reinecke wrote:
> When checking the model and vendor string we need to use the
> minimum value of either string, otherwise we'll miss out on
> wildcard matches.
You really should fix this sentence.
> And we should take card when matching with zero size strings;
> results might be unpredictable.
> With this patch the rules for matching devinfo strings are
> as follows:
> - Vendor strings must match exactly
> - Empty Model strings will only match if the devinfo model
> is also empty
> - Model strings shorter than the devinfo model string will
> not match
>
> Fixes: 5e7ff2c ("SCSI: fix new bug in scsi_dev_info_list string matching")
> Signed-off-by: Hannes Reinecke
> ---
Aside from the patch description,
Reviewed-by: Alan Stern
> drivers/scsi/scsi_devinfo.c | 29 -
> 1 file changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
> index 776c701..d39b27c 100644
> --- a/drivers/scsi/scsi_devinfo.c
> +++ b/drivers/scsi/scsi_devinfo.c
> @@ -399,8 +399,8 @@ int scsi_dev_info_list_add_keyed(int compatible, char
> *vendor, char *model,
>
> /**
> * scsi_dev_info_list_find - find a matching dev_info list entry.
> - * @vendor: vendor string
> - * @model: model (product) string
> + * @vendor: full vendor string
> + * @model: full model (product) string
> * @key: specify list to use
> *
> * Description:
> @@ -415,7 +415,7 @@ static struct scsi_dev_info_list
> *scsi_dev_info_list_find(const char *vendor,
> struct scsi_dev_info_list *devinfo;
> struct scsi_dev_info_list_table *devinfo_table =
> scsi_devinfo_lookup_by_key(key);
> - size_t vmax, mmax;
> + size_t vmax, mmax, mlen;
> const char *vskip, *mskip;
>
> if (IS_ERR(devinfo_table))
> @@ -454,22 +454,25 @@ static struct scsi_dev_info_list
> *scsi_dev_info_list_find(const char *vendor,
> dev_info_list) {
> if (devinfo->compatible) {
> /*
> - * Behave like the older version of get_device_flags.
> + * vendor strings must be an exact match
>*/
> - if (memcmp(devinfo->vendor, vskip, vmax) ||
> - (vmax < sizeof(devinfo->vendor) &&
> - devinfo->vendor[vmax]))
> + if (vmax != strlen(devinfo->vendor) ||
> + memcmp(devinfo->vendor, vskip, vmax))
> continue;
> - if (memcmp(devinfo->model, mskip, mmax) ||
> - (mmax < sizeof(devinfo->model) &&
> - devinfo->model[mmax]))
> +
> + /*
> + * @model specifies the full string, and
> + * must be larger or equal to devinfo->model
> + */
> + mlen = strlen(devinfo->model);
> + if (mmax < mlen || memcmp(devinfo->model, mskip, mlen))
> continue;
> return devinfo;
> } else {
> if (!memcmp(devinfo->vendor, vendor,
> - sizeof(devinfo->vendor)) &&
> - !memcmp(devinfo->model, model,
> - sizeof(devinfo->model)))
> + sizeof(devinfo->vendor)) &&
> + !memcmp(devinfo->model, model,
> + sizeof(devinfo->model)))
> return devinfo;
> }
> }
>
[PATCHv3 5/5] scsi_devinfo: fixup string compare
When checking the model and vendor string we need to use the
minimum value of either string, otherwise we'll miss out on
wildcard matches.
And we should take card when matching with zero size strings;
results might be unpredictable.
With this patch the rules for matching devinfo strings are
as follows:
- Vendor strings must match exactly
- Empty Model strings will only match if the devinfo model
is also empty
- Model strings shorter than the devinfo model string will
not match
Fixes: 5e7ff2c ("SCSI: fix new bug in scsi_dev_info_list string matching")
Signed-off-by: Hannes Reinecke
---
drivers/scsi/scsi_devinfo.c | 29 -
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index 776c701..d39b27c 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -399,8 +399,8 @@ int scsi_dev_info_list_add_keyed(int compatible, char
*vendor, char *model,
/**
* scsi_dev_info_list_find - find a matching dev_info list entry.
- * @vendor:vendor string
- * @model: model (product) string
+ * @vendor:full vendor string
+ * @model: full model (product) string
* @key: specify list to use
*
* Description:
@@ -415,7 +415,7 @@ static struct scsi_dev_info_list
*scsi_dev_info_list_find(const char *vendor,
struct scsi_dev_info_list *devinfo;
struct scsi_dev_info_list_table *devinfo_table =
scsi_devinfo_lookup_by_key(key);
- size_t vmax, mmax;
+ size_t vmax, mmax, mlen;
const char *vskip, *mskip;
if (IS_ERR(devinfo_table))
@@ -454,22 +454,25 @@ static struct scsi_dev_info_list
*scsi_dev_info_list_find(const char *vendor,
dev_info_list) {
if (devinfo->compatible) {
/*
-* Behave like the older version of get_device_flags.
+* vendor strings must be an exact match
*/
- if (memcmp(devinfo->vendor, vskip, vmax) ||
- (vmax < sizeof(devinfo->vendor) &&
- devinfo->vendor[vmax]))
+ if (vmax != strlen(devinfo->vendor) ||
+ memcmp(devinfo->vendor, vskip, vmax))
continue;
- if (memcmp(devinfo->model, mskip, mmax) ||
- (mmax < sizeof(devinfo->model) &&
- devinfo->model[mmax]))
+
+ /*
+* @model specifies the full string, and
+* must be larger or equal to devinfo->model
+*/
+ mlen = strlen(devinfo->model);
+ if (mmax < mlen || memcmp(devinfo->model, mskip, mlen))
continue;
return devinfo;
} else {
if (!memcmp(devinfo->vendor, vendor,
-sizeof(devinfo->vendor)) &&
-!memcmp(devinfo->model, model,
- sizeof(devinfo->model)))
+ sizeof(devinfo->vendor)) &&
+ !memcmp(devinfo->model, model,
+ sizeof(devinfo->model)))
return devinfo;
}
}
--
1.8.5.6
