[PATCH 5/6] fbdev: Move CFB read and write code into helper functions
Thomas Zimmermann
tzimmermann at suse.de
Wed Apr 26 14:24:06 UTC 2023
Hi
Am 26.04.23 um 07:16 schrieb kernel test robot:
> Hi Thomas,
>
> kernel test robot noticed the following build warnings:
FYI these errors come from systems that use volatile __iomem pointers
with plain memcpy(). See my patchset at [1] for an improvement.
Best regards
Thomas
[1] https://patchwork.freedesktop.org/series/116985/
>
> [auto build test WARNING on drm-misc/drm-misc-next]
> [also build test WARNING on linus/master next-20230425]
> [cannot apply to v6.3]
> [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#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Thomas-Zimmermann/fbdev-Return-number-of-bytes-read-or-written/20230425-223011
> base: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
> patch link: https://lore.kernel.org/r/20230425142846.730-6-tzimmermann%40suse.de
> patch subject: [PATCH 5/6] fbdev: Move CFB read and write code into helper functions
> config: riscv-randconfig-s033-20230423 (https://download.01.org/0day-ci/archive/20230426/202304261317.QAEwArcB-lkp@intel.com/config)
> compiler: riscv64-linux-gcc (GCC) 12.1.0
> reproduce:
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # apt-get install sparse
> # sparse version: v0.6.4-39-gce1a6720-dirty
> # https://github.com/intel-lab-lkp/linux/commit/d4a150f3dfa8e73f2e92f1c7efc9271e17632cc2
> git remote add linux-review https://github.com/intel-lab-lkp/linux
> git fetch --no-tags linux-review Thomas-Zimmermann/fbdev-Return-number-of-bytes-read-or-written/20230425-223011
> git checkout d4a150f3dfa8e73f2e92f1c7efc9271e17632cc2
> # save the config file
> mkdir build_dir && cp config build_dir/.config
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=riscv olddefconfig
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=riscv SHELL=/bin/bash drivers/video/fbdev/core/
>
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp at intel.com>
> | Link: https://lore.kernel.org/oe-kbuild-all/202304261317.QAEwArcB-lkp@intel.com/
>
> sparse warnings: (new ones prefixed by >>)
> WARNING: invalid argument to '-march': '_zihintpause'
>>> drivers/video/fbdev/core/fb_cfb_fops.c:44:39: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected void const * @@ got unsigned char [noderef] [usertype] __iomem *[assigned] src @@
> drivers/video/fbdev/core/fb_cfb_fops.c:44:39: sparse: expected void const *
> drivers/video/fbdev/core/fb_cfb_fops.c:44:39: sparse: got unsigned char [noderef] [usertype] __iomem *[assigned] src
>>> drivers/video/fbdev/core/fb_cfb_fops.c:113:32: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void * @@ got unsigned char [noderef] [usertype] __iomem *[assigned] dst @@
> drivers/video/fbdev/core/fb_cfb_fops.c:113:32: sparse: expected void *
> drivers/video/fbdev/core/fb_cfb_fops.c:113:32: sparse: got unsigned char [noderef] [usertype] __iomem *[assigned] dst
>
> vim +44 drivers/video/fbdev/core/fb_cfb_fops.c
>
> 6
> 7 ssize_t fb_cfb_read(struct fb_info *info, char __user *buf, size_t count, loff_t *ppos)
> 8 {
> 9 unsigned long p = *ppos;
> 10 u8 *buffer, *dst;
> 11 u8 __iomem *src;
> 12 int c, cnt = 0, err = 0;
> 13 unsigned long total_size;
> 14
> 15 if (!info->screen_base)
> 16 return -ENODEV;
> 17
> 18 total_size = info->screen_size;
> 19
> 20 if (total_size == 0)
> 21 total_size = info->fix.smem_len;
> 22
> 23 if (p >= total_size)
> 24 return 0;
> 25
> 26 if (count >= total_size)
> 27 count = total_size;
> 28
> 29 if (count + p > total_size)
> 30 count = total_size - p;
> 31
> 32 buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL);
> 33 if (!buffer)
> 34 return -ENOMEM;
> 35
> 36 src = (u8 __iomem *)(info->screen_base + p);
> 37
> 38 if (info->fbops->fb_sync)
> 39 info->fbops->fb_sync(info);
> 40
> 41 while (count) {
> 42 c = (count > PAGE_SIZE) ? PAGE_SIZE : count;
> 43 dst = buffer;
> > 44 fb_memcpy_fromfb(dst, src, c);
> 45 dst += c;
> 46 src += c;
> 47
> 48 if (copy_to_user(buf, buffer, c)) {
> 49 err = -EFAULT;
> 50 break;
> 51 }
> 52 *ppos += c;
> 53 buf += c;
> 54 cnt += c;
> 55 count -= c;
> 56 }
> 57
> 58 kfree(buffer);
> 59
> 60 return cnt ? cnt : err;
> 61 }
> 62 EXPORT_SYMBOL(fb_cfb_read);
> 63
> 64 ssize_t fb_cfb_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos)
> 65 {
> 66 unsigned long p = *ppos;
> 67 u8 *buffer, *src;
> 68 u8 __iomem *dst;
> 69 int c, cnt = 0, err = 0;
> 70 unsigned long total_size;
> 71
> 72 if (!info->screen_base)
> 73 return -ENODEV;
> 74
> 75 total_size = info->screen_size;
> 76
> 77 if (total_size == 0)
> 78 total_size = info->fix.smem_len;
> 79
> 80 if (p > total_size)
> 81 return -EFBIG;
> 82
> 83 if (count > total_size) {
> 84 err = -EFBIG;
> 85 count = total_size;
> 86 }
> 87
> 88 if (count + p > total_size) {
> 89 if (!err)
> 90 err = -ENOSPC;
> 91
> 92 count = total_size - p;
> 93 }
> 94
> 95 buffer = kmalloc((count > PAGE_SIZE) ? PAGE_SIZE : count, GFP_KERNEL);
> 96 if (!buffer)
> 97 return -ENOMEM;
> 98
> 99 dst = (u8 __iomem *)(info->screen_base + p);
> 100
> 101 if (info->fbops->fb_sync)
> 102 info->fbops->fb_sync(info);
> 103
> 104 while (count) {
> 105 c = (count > PAGE_SIZE) ? PAGE_SIZE : count;
> 106 src = buffer;
> 107
> 108 if (copy_from_user(src, buf, c)) {
> 109 err = -EFAULT;
> 110 break;
> 111 }
> 112
> > 113 fb_memcpy_tofb(dst, src, c);
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 840 bytes
Desc: OpenPGP digital signature
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20230426/fdb88f5e/attachment-0001.sig>
More information about the dri-devel
mailing list