Re: [PATCH] highmem: Make __kunmap_{local,atomic}() take "const void *"

From: kernel test robot
Date: Wed Jun 15 2022 - 13:34:04 EST


Hi "Fabio,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v5.19-rc2 next-20220615]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/intel-lab-lkp/linux/commits/Fabio-M-De-Francesco/highmem-Make-__kunmap_-local-atomic-take-const-void/20220614-222749
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
config: parisc-allyesconfig (https://download.01.org/0day-ci/archive/20220616/202206160154.0Asirpka-lkp@xxxxxxxxx/config)
compiler: hppa-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/558ba1aeb12cc7940165f07160e51afb0bc1a64b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Fabio-M-De-Francesco/highmem-Make-__kunmap_-local-atomic-take-const-void/20220614-222749
git checkout 558ba1aeb12cc7940165f07160e51afb0bc1a64b
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=parisc SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

In file included from include/linux/highmem.h:13,
from include/linux/bvec.h:10,
from include/linux/skbuff.h:17,
from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
from drivers/net/wwan/t7xx/t7xx_pci.c:39:
include/linux/highmem-internal.h: In function '__kunmap_local':
>> include/linux/highmem-internal.h:203:31: error: passing argument 1 of 'kunmap_flush_on_unmap' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
203 | kunmap_flush_on_unmap(addr);
| ^~~~
In file included from include/linux/cacheflush.h:5,
from include/linux/highmem.h:8,
from include/linux/bvec.h:10,
from include/linux/skbuff.h:17,
from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
from drivers/net/wwan/t7xx/t7xx_pci.c:39:
arch/parisc/include/asm/cacheflush.h:78:48: note: expected 'void *' but argument is of type 'const void *'
78 | static inline void kunmap_flush_on_unmap(void *addr)
| ~~~~~~^~~~
In file included from include/linux/highmem.h:13,
from include/linux/bvec.h:10,
from include/linux/skbuff.h:17,
from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
from drivers/net/wwan/t7xx/t7xx_pci.c:39:
include/linux/highmem-internal.h: In function '__kunmap_atomic':
include/linux/highmem-internal.h:230:31: error: passing argument 1 of 'kunmap_flush_on_unmap' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
230 | kunmap_flush_on_unmap(addr);
| ^~~~
In file included from include/linux/cacheflush.h:5,
from include/linux/highmem.h:8,
from include/linux/bvec.h:10,
from include/linux/skbuff.h:17,
from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
from drivers/net/wwan/t7xx/t7xx_pci.c:39:
arch/parisc/include/asm/cacheflush.h:78:48: note: expected 'void *' but argument is of type 'const void *'
78 | static inline void kunmap_flush_on_unmap(void *addr)
| ~~~~~~^~~~
cc1: all warnings being treated as errors


vim +203 include/linux/highmem-internal.h

f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 199
558ba1aeb12cc7 Fabio M. De Francesco 2022-06-14 200 static inline void __kunmap_local(const void *addr)
f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 201 {
f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 202 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 @203 kunmap_flush_on_unmap(addr);
f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 204 #endif
f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 205 }
f3ba3c710ac5a3 Thomas Gleixner 2020-11-18 206

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