linux.git/drivers/video/fbdev/core/fbmem.c, branch v5.13

Revert "fb_defio: Remove custom address_space_operations"

2021-06-01T15:38:40+00:00

Commit ccf953d8f3d6 makes framebuffers which use deferred I/O stop
displaying updates after the first one.  This is because the pages
handled by fb_defio no longer have a page_mapping().  That prevents
page_mkclean() from marking the PTEs as clean, and so writes are only
noticed the first time.

Reported-by: Andy Shevchenko 
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/YLZEhv0cpZp8uVE3@casper.infradead.org

fbmem: fix horribly incorrect placement of __maybe_unused

2021-05-09T21:03:33+00:00

Commit b9d79e4ca4ff ("fbmem: Mark proc_fb_seq_ops as __maybe_unused")
places the '__maybe_unused' in an entirely incorrect location between
the "struct" keyword and the structure name.

It's a wonder that gcc accepts that silently, but clang quite reasonably
warns about it:

    drivers/video/fbdev/core/fbmem.c:736:21: warning: attribute declaration must precede definition [-Wignored-attributes]
    static const struct __maybe_unused seq_operations proc_fb_seq_ops = {
                        ^

Fix it.

Cc: Guenter Roeck 
Cc: Daniel Vetter 
Signed-off-by: Linus Torvalds

fbmem: Mark proc_fb_seq_ops as __maybe_unused

2021-05-04T15:12:37+00:00

With CONFIG_PROC_FS=n and -Werror, 0-day reports:

drivers/video/fbdev/core/fbmem.c:736:36: error:
	'proc_fb_seq_ops' defined but not used

Mark it as __maybe_unused.

Reported-by: kernel test robot 
Signed-off-by: Guenter Roeck 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20210504142910.2084722-1-linux@roeck-us.net

fb_defio: Remove custom address_space_operations

2021-03-12T14:10:03+00:00

There's no need to give the page an address_space.  Leaving the
page->mapping as NULL will cause the VM to handle set_page_dirty()
the same way that it's handled now, and that was the only reason to
set the address_space in the first place.

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: William Kucharski 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/20210310185530.1053320-1-willy@infradead.org

drm: remove pgprot_decrypted() before calls to io_remap_pfn_range()

2020-11-10T16:19:14+00:00

commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set
pgprot_decrypted()") moves the pgprot_decrypted() into
io_remap_pfn_range(). Delete any, now confusing, open coded calls that
directly precede io_remap_pfn_range():

- drm_io_prot() is only in drm_mmap_locked() to call io_remap_pfn_range()

- fb_mmap() immediately calls vm_iomap_memory() which is a convenience
  wrapper for io_remap_pfn_range()

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/0-v1-2e6a0db57868+166-drm_sme_clean_jgg@nvidia.com

fbdev: simplify fb_getput_cmap()

2020-09-25T14:34:50+00:00

This function is one of the remaining users of compat_alloc_user_space()
and copy_in_user().

Clean it up by copying to a local data structure copy instead,
which also leads to more readable code.

Signed-off-by: Arnd Bergmann 
Acked-by: Daniel Vetter 
Signed-off-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20200918100926.1447563-1-arnd@arndb.de

fbmem: add margin check to fb_check_caps()

2020-09-08T11:33:01+00:00

A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting
or yres setting in struct fb_var_screeninfo will result in a
KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as
the margins are being cleared. The margins are cleared in
chunks and if the xres setting or yres setting is a value of
zero upto the chunk size, the failure will occur.

Add a margin check to validate xres and yres settings.

Signed-off-by: George Kennedy 
Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com
Reviewed-by: Dan Carpenter 
Cc: Dhaval Giani 
Signed-off-by: Bartlomiej Zolnierkiewicz 
Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com

Merge drm/drm-next into drm-misc-next

2020-08-12T18:42:08+00:00

Backmerging drm-next into drm-misc-next for nouveau and panel updates.
Resolves a conflict between ttm and nouveau, where struct ttm_mem_res got
renamed to struct ttm_resource.

Signed-off-by: Thomas Zimmermann

fbmem: pull fbcon_update_vcs() out of fb_set_var()

2020-08-04T05:37:23+00:00

syzbot is reporting OOB read bug in vc_do_resize() [1] caused by memcpy()
based on outdated old_{rows,row_size} values, for resize_screen() can
recurse into vc_do_resize() which changes vc->vc_{cols,rows} that outdates
old_{rows,row_size} values which were saved before calling resize_screen().

Daniel Vetter explained that resize_screen() should not recurse into
fbcon_update_vcs() path due to FBINFO_MISC_USEREVENT being still set
when calling resize_screen().

Instead of masking FBINFO_MISC_USEREVENT before calling fbcon_update_vcs(),
we can remove FBINFO_MISC_USEREVENT by calling fbcon_update_vcs() only if
fb_set_var() returned 0. This change assumes that it is harmless to call
fbcon_update_vcs() when fb_set_var() returned 0 without reaching
fb_notifier_call_chain().

[1] https://syzkaller.appspot.com/bug?id=c70c88cfd16dcf6e1d3c7f0ab8648b3144b5b25e

Reported-and-tested-by: syzbot 
Suggested-by: Daniel Vetter 
Signed-off-by: Tetsuo Handa 
Reported-by: kernel test robot  for missing #include
Signed-off-by: Daniel Vetter 
Link: https://patchwork.freedesktop.org/patch/msgid/075b7e37-3278-cd7d-31ab-c5073cfa8e92@i-love.sakura.ne.jp

fbdev: Use fallthrough pseudo-keyword

2020-08-03T19:38:37+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Sam Ravnborg 
Link: https://patchwork.freedesktop.org/patch/msgid/20200707210539.GA12530@embeddedor