On Thu, 2020-08-27 at 23:36 +0200, Julia Lawall wrote: > On Fri, 28 Aug 2020, Denis Efremov wrote: [] > Regarding current device_attr_show.cocci implementation, it detects the functions > > by declaration: > > ssize_t any_name(struct device *dev, struct device_attribute *attr, char *buf) > > > > and I limited the check to: > > "return snprintf" > > pattern because there are already too many warnings. > > > > Actually, it looks more correct to check for: > > ssize_t show(struct device *dev, struct device_attribute *attr, char *buf) > > { > > <... > > * snprintf@p(...); > > ...> > > } > > > > This pattern should also highlight the snprintf calls there we save returned > > value in a var, e.g.: > > > > ret += snprintf(...); > > ... > > ret += snprintf(...); > > ... > > ret += snprintf(...); > > > > return ret; > > > > > Something like > > > > > > identifier f; > > > fresh identifier = "sysfs" ## f; > > > > > > may be useful. Let me know if further help is needed. > > > > Initially, I wrote the rule to search for DEVICE_ATTR(..., ..., func_name, ...) > > This is what I would have expected. > > > functions. However, it looks like matching function prototype is enough. At least, > > I failed to find false positives. I rejected the initial DEVICE_ATTR() searching > > because I thought that it's impossible to handle DEVICE_ATTR_RO()/DEVICE_ATTR_RW() > > macroses with coccinelle as they "generate" function names internally with > > "##". "fresh identifier" should really help here, but now I doubt it's required in > > device_attr_show.cocci, function prototype is enough. > > It's true that it is probably unique enough. I tried: @@ identifier f_show =~ "^.*_show$"; identifier dev, attr, buf; const char *chr; @@ ssize_t f_show(struct device *dev, struct device_attribute *attr, char *buf) { <... ( - sprintf + sysfs_sprintf (...); | - snprintf(buf, PAGE_SIZE, + sysfs_sprintf(buf, ...); | - scnprintf(buf, PAGE_SIZE, + sysfs_sprintf(buf, ...); | strcpy(buf, chr); sysfs_strcpy(buf, chr); ) ...> } which finds direct statements without an assign but that doesn't find arch/arm/common/dmabounce.c:static ssize_t dmabounce_show(struct device *dev, struct device_attribute *attr, char *buf) arch/arm/common/dmabounce.c-{ arch/arm/common/dmabounce.c- struct dmabounce_device_info *device_info = dev->archdata.dmabounce; arch/arm/common/dmabounce.c- return sprintf(buf, "%lu %lu %lu %lu %lu %lu\n", arch/arm/common/dmabounce.c- device_info->small.allocs, arch/arm/common/dmabounce.c- device_info->large.allocs, arch/arm/common/dmabounce.c- device_info->total_allocs - device_info->small.allocs - arch/arm/common/dmabounce.c- device_info->large.allocs, arch/arm/common/dmabounce.c- device_info->total_allocs, arch/arm/common/dmabounce.c- device_info->map_op_count, arch/arm/common/dmabounce.c- device_info->bounce_count); arch/arm/common/dmabounce.c-}