[PATCH] kernel/memremap: Remove stale devres_free() call

[PATCH] kernel/memremap: Remove stale devres_free() call

[Oliver O'Halloran]

devm_memremap_pages() was re-worked in e8d513483300 to take a caller
allocated struct dev_pagemap as a function parameter. A call to
devres_free() was left in the error cleanup path which results in
a kernel panic if the remap fails for some reason. Remove it
to fix the panic and let devm_memremap_pages() fail gracefully.

Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface to use struct dev_pagemap")
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
---
Both in-tree users of devm_memremap_pages() embed dev_pagemap into other
structures so this shouldn't cause any leaks. Logan's p2p series does
add one usage that assumes pgmap will be freed on error so that'll
need fixing.
---
 kernel/memremap.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 4dd4274cabe2..895e6b76b25e 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -427,7 +427,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
  err_pfn_remap:
  err_radix:
 	pgmap_radix_release(res, pgoff);
-	devres_free(pgmap);
 	return ERR_PTR(error);
 }
 EXPORT_SYMBOL(devm_memremap_pages);
-- 
2.9.5

Re: [PATCH] kernel/memremap: Remove stale devres_free() call

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH] kernel/memremap: Remove stale devres_free() call

[Logan Gunthorpe]

On 05/03/18 09:56 PM, Oliver O'Halloran wrote:
> devm_memremap_pages() was re-worked in e8d513483300 to take a caller
> allocated struct dev_pagemap as a function parameter. A call to
> devres_free() was left in the error cleanup path which results in
> a kernel panic if the remap fails for some reason. Remove it
> to fix the panic and let devm_memremap_pages() fail gracefully.
> 
> Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface to use struct dev_pagemap")
> Cc: Logan Gunthorpe <logang@deltatee.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

> ---
> Both in-tree users of devm_memremap_pages() embed dev_pagemap into other
> structures so this shouldn't cause any leaks. Logan's p2p series does
> add one usage that assumes pgmap will be freed on error so that'll
> need fixing.

Yup, nice catch! I'll fix that for the next series.

Thanks,

Logan

Re: [PATCH] kernel/memremap: Remove stale devres_free() call

[Dan Williams]

On Tue, Mar 6, 2018 at 8:55 AM, Logan Gunthorpe <logang@deltatee.com> wrote:
>
>
> On 05/03/18 09:56 PM, Oliver O'Halloran wrote:
>>
>> devm_memremap_pages() was re-worked in e8d513483300 to take a caller
>> allocated struct dev_pagemap as a function parameter. A call to
>> devres_free() was left in the error cleanup path which results in
>> a kernel panic if the remap fails for some reason. Remove it
>> to fix the panic and let devm_memremap_pages() fail gracefully.
>>
>> Fixes: e8d513483300 ("memremap: change devm_memremap_pages interface to
>> use struct dev_pagemap")
>> Cc: Logan Gunthorpe <logang@deltatee.com>
>> Cc: Christoph Hellwig <hch@lst.de>
>> Cc: Dan Williams <dan.j.williams@intel.com>
>> Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
>
>
> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

Thanks, applied.