| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <ZifEQ42hMPazjiWd@yilunxu-OptiPlex-7050>
Date: Tue, 23 Apr 2024 22:22:59 +0800
From: Xu Yilun <yilun.xu@...ux.intel.com>
To: "Colberg, Peter" <peter.colberg@...el.com>
Cc: "Wu, Hao" <hao.wu@...el.com>, "mdf@...nel.org" <mdf@...nel.org>,
"linux-fpga@...r.kernel.org" <linux-fpga@...r.kernel.org>,
"Xu, Yilun" <yilun.xu@...el.com>, "Rix, Tom" <trix@...hat.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"russ.weight@...ux.dev" <russ.weight@...ux.dev>,
"Pagani, Marco" <marpagan@...hat.com>,
"matthew.gerlach@...ux.intel.com" <matthew.gerlach@...ux.intel.com>
Subject: Re: [RFC PATCH v2 3/9] fpga: dfl: migrate AFU MMIO region management
driver to dfl_feature_dev_data
On Tue, Apr 09, 2024 at 11:56:19PM +0000, Colberg, Peter wrote:
> On Tue, 2024-04-09 at 19:39 -0400, Peter Colberg wrote:
> > This change separates out most of the symbol name changes required by this
> > patch series for the file: drivers/fpga/dfl-afu-region.c. This is done to
> > split a single monolithic change into multiple, smaller patches at the
> > request of the maintainer.
> >
> > Signed-off-by: Peter Colberg <peter.colberg@...el.com>
> > ---
> > v2:
> > - Split monolithic patch into series at request of maintainer
> > ---
> > drivers/fpga/dfl-afu-region.c | 51 ++++++++++++++++++-----------------
> > 1 file changed, 26 insertions(+), 25 deletions(-)
> >
> > diff --git a/drivers/fpga/dfl-afu-region.c b/drivers/fpga/dfl-afu-region.c
> > index 2e7b41629406..b11a5b21e666 100644
> > --- a/drivers/fpga/dfl-afu-region.c
> > +++ b/drivers/fpga/dfl-afu-region.c
> > @@ -12,11 +12,11 @@
> >
> > /**
> > * afu_mmio_region_init - init function for afu mmio region support
> > - * @pdata: afu platform device's pdata.
> > + * @fdata: afu feature dev data
> > */
> > -void afu_mmio_region_init(struct dfl_feature_platform_data *pdata)
> > +void afu_mmio_region_init(struct dfl_feature_dev_data *fdata)
> > {
> > - struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata);
> > + struct dfl_afu *afu = dfl_fpga_fdata_get_private(fdata);
> >
> > INIT_LIST_HEAD(&afu->regions);
> > }
> > @@ -39,7 +39,7 @@ static struct dfl_afu_mmio_region *get_region_by_index(struct dfl_afu *afu,
> > /**
> > * afu_mmio_region_add - add a mmio region to given feature dev.
> > *
> > - * @pdata: afu platform device's pdata.
> > + * @fdata: afu feature dev data
> > * @region_index: region index.
> > * @region_size: region size.
> > * @phys: region's physical address of this region.
> > @@ -47,14 +47,15 @@ static struct dfl_afu_mmio_region *get_region_by_index(struct dfl_afu *afu,
> > *
> > * Return: 0 on success, negative error code otherwise.
> > */
> > -int afu_mmio_region_add(struct dfl_feature_platform_data *pdata,
> > +int afu_mmio_region_add(struct dfl_feature_dev_data *fdata,
> > u32 region_index, u64 region_size, u64 phys, u32 flags)
> > {
> > + struct device *dev = &fdata->dev->dev;
> > struct dfl_afu_mmio_region *region;
> > struct dfl_afu *afu;
> > int ret = 0;
> >
> > - region = devm_kzalloc(&pdata->dev->dev, sizeof(*region), GFP_KERNEL);
> > + region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL);
> > if (!region)
> > return -ENOMEM;
> >
> > @@ -63,13 +64,13 @@ int afu_mmio_region_add(struct dfl_feature_platform_data *pdata,
> > region->phys = phys;
> > region->flags = flags;
> >
> > - mutex_lock(&pdata->lock);
> > + mutex_lock(&fdata->lock);
> >
> > - afu = dfl_fpga_pdata_get_private(pdata);
> > + afu = dfl_fpga_fdata_get_private(fdata);
> >
> > /* check if @index already exists */
> > if (get_region_by_index(afu, region_index)) {
> > - mutex_unlock(&pdata->lock);
> > + mutex_unlock(&fdata->lock);
> > ret = -EEXIST;
> > goto exit;
> > }
> > @@ -80,37 +81,37 @@ int afu_mmio_region_add(struct dfl_feature_platform_data *pdata,
> >
> > afu->region_cur_offset += region_size;
> > afu->num_regions++;
> > - mutex_unlock(&pdata->lock);
> > + mutex_unlock(&fdata->lock);
> >
> > return 0;
> >
> > exit:
> > - devm_kfree(&pdata->dev->dev, region);
> > + devm_kfree(dev, region);
>
> An internal reviewer commented that calling devm_kfree() in almost all
> cases shows a misunderstanding of object lifetime and may unveil bugs.
> They suggested to either drop the explicit devm_kfree(), or move from
> devm_*() to plain allocation.
>
> I could not find specific documentation on the recommended use cases
> for devm_kfree() to immediately free a resource on error, but the
> description of devres groups advises that explicit freeing using
> devres_release_group() is usually useful in midlayer drivers where
> interface functions should not have side effects [1].
>
> Which implementation would you prefer and why? Dropping devm_kfree(),
> moving to plain allocation, or leaving everything as is?
Using devm_*() usually means the lifecycle of the allocated object
should be the same as the device. Otherwise use the plain allocation.
Please check which case fits for you.
Thanks,
Yilun
>
> [1] https://docs.kernel.org/driver-api/driver-model/devres.html#devres-group
>
> Thanks,
> Peter
>
> > return ret;
> > }
> >
> > /**
> > * afu_mmio_region_destroy - destroy all mmio regions under given feature dev.
> > - * @pdata: afu platform device's pdata.
> > + * @fdata: afu feature dev data
> > */
> > -void afu_mmio_region_destroy(struct dfl_feature_platform_data *pdata)
> > +void afu_mmio_region_destroy(struct dfl_feature_dev_data *fdata)
> > {
> > - struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata);
> > + struct dfl_afu *afu = dfl_fpga_fdata_get_private(fdata);
> > struct dfl_afu_mmio_region *tmp, *region;
> >
> > list_for_each_entry_safe(region, tmp, &afu->regions, node)
> > - devm_kfree(&pdata->dev->dev, region);
> > + devm_kfree(&fdata->dev->dev, region);
> > }
> >
> > /**
> > * afu_mmio_region_get_by_index - find an afu region by index.
> > - * @pdata: afu platform device's pdata.
> > + * @fdata: afu feature dev data
> > * @region_index: region index.
> > * @pregion: ptr to region for result.
> > *
> > * Return: 0 on success, negative error code otherwise.
> > */
> > -int afu_mmio_region_get_by_index(struct dfl_feature_platform_data *pdata,
> > +int afu_mmio_region_get_by_index(struct dfl_feature_dev_data *fdata,
> > u32 region_index,
> > struct dfl_afu_mmio_region *pregion)
> > {
> > @@ -118,8 +119,8 @@ int afu_mmio_region_get_by_index(struct dfl_feature_platform_data *pdata,
> > struct dfl_afu *afu;
> > int ret = 0;
> >
> > - mutex_lock(&pdata->lock);
> > - afu = dfl_fpga_pdata_get_private(pdata);
> > + mutex_lock(&fdata->lock);
> > + afu = dfl_fpga_fdata_get_private(fdata);
> > region = get_region_by_index(afu, region_index);
> > if (!region) {
> > ret = -EINVAL;
> > @@ -127,14 +128,14 @@ int afu_mmio_region_get_by_index(struct dfl_feature_platform_data *pdata,
> > }
> > *pregion = *region;
> > exit:
> > - mutex_unlock(&pdata->lock);
> > + mutex_unlock(&fdata->lock);
> > return ret;
> > }
> >
> > /**
> > * afu_mmio_region_get_by_offset - find an afu mmio region by offset and size
> > *
> > - * @pdata: afu platform device's pdata.
> > + * @fdata: afu feature dev data
> > * @offset: region offset from start of the device fd.
> > * @size: region size.
> > * @pregion: ptr to region for result.
> > @@ -144,7 +145,7 @@ int afu_mmio_region_get_by_index(struct dfl_feature_platform_data *pdata,
> > *
> > * Return: 0 on success, negative error code otherwise.
> > */
> > -int afu_mmio_region_get_by_offset(struct dfl_feature_platform_data *pdata,
> > +int afu_mmio_region_get_by_offset(struct dfl_feature_dev_data *fdata,
> > u64 offset, u64 size,
> > struct dfl_afu_mmio_region *pregion)
> > {
> > @@ -152,8 +153,8 @@ int afu_mmio_region_get_by_offset(struct dfl_feature_platform_data *pdata,
> > struct dfl_afu *afu;
> > int ret = 0;
> >
> > - mutex_lock(&pdata->lock);
> > - afu = dfl_fpga_pdata_get_private(pdata);
> > + mutex_lock(&fdata->lock);
> > + afu = dfl_fpga_fdata_get_private(fdata);
> > for_each_region(region, afu)
> > if (region->offset <= offset &&
> > region->offset + region->size >= offset + size) {
> > @@ -162,6 +163,6 @@ int afu_mmio_region_get_by_offset(struct dfl_feature_platform_data *pdata,
> > }
> > ret = -EINVAL;
> > exit:
> > - mutex_unlock(&pdata->lock);
> > + mutex_unlock(&fdata->lock);
> > return ret;
> > }
>
Powered by blists - more mailing lists