The driver may sleep in a interrupt handler.
The function call paths (from bottom to top) in Linux-4.16 are:
[FUNC] kzalloc(GFP_KERNEL)
drivers/media/pci/ivtv/ivtv-yuv.c, 938:
kzalloc in ivtv_yuv_init
drivers/media/pci/ivtv/ivtv-yuv.c, 960:
ivtv_yuv_init in ivtv_yuv_next_free
drivers/media/pci/ivtv/ivtv-yuv.c, 1126:
ivtv_yuv_next_free in ivtv_yuv_setup_stream_frame
drivers/media/pci/ivtv/ivtv-irq.c, 827:
ivtv_yuv_setup_stream_frame in ivtv_irq_dec_data_req
drivers/media/pci/ivtv/ivtv-irq.c, 1013:
ivtv_irq_dec_data_req in ivtv_irq_handler
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Due to the 80-cols restrictions, and latter due to checkpatch
warnings, several strings were broken into multiple lines. This
is not considered a good practice anymore, as it makes harder
to grep for strings at the source code.
As we're right now fixing other drivers due to KERN_CONT, we need
to be able to identify what printk strings don't end with a "\n".
It is a way easier to detect those if we don't break long lines.
So, join those continuation lines.
The patch was generated via the script below, and manually
adjusted if needed.
</script>
use Text::Tabs;
while (<>) {
if ($next ne "") {
$c=$_;
if ($c =~ /^\s+\"(.*)/) {
$c2=$1;
$next =~ s/\"\n$//;
$n = expand($next);
$funpos = index($n, '(');
$pos = index($c2, '",');
if ($funpos && $pos > 0) {
$s1 = substr $c2, 0, $pos + 2;
$s2 = ' ' x ($funpos + 1) . substr $c2, $pos + 2;
$s2 =~ s/^\s+//;
$s2 = ' ' x ($funpos + 1) . $s2 if ($s2 ne "");
print unexpand("$next$s1\n");
print unexpand("$s2\n") if ($s2 ne "");
} else {
print "$next$c2\n";
}
$next="";
next;
} else {
print $next;
}
$next="";
} else {
if (m/\"$/) {
if (!m/\\n\"$/) {
$next=$_;
next;
}
}
}
print $_;
}
</script>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This removes the 'write' and 'force' use from get_user_pages_unlocked()
and replaces them with 'gup_flags' to make the use of FOLL_FORCE
explicit in callers as use of this flag can result in surprising
behaviour (and hence bugs) within the mm subsystem.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We will soon modify the vanilla get_user_pages() so it can no
longer be used on mm/tasks other than 'current/current->mm',
which is by far the most common way it is called. For now,
we allow the old-style calls, but warn when they are used.
(implemented in previous patch)
This patch switches all callers of:
get_user_pages()
get_user_pages_unlocked()
get_user_pages_locked()
to stop passing tsk/mm so they will no longer see the warnings.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: jack@suse.cz
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210156.113E9407@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Convert ivtv_yuv_prep_user_dma() to use get_user_pages_unlocked() so
that we don't unnecessarily leak knowledge about mm locking into drivers
code.
CC: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Rename all PCI drivers with their own directory under
drivers/media/video into drivers/media/pci and update the
building system.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Jia-Ju Bai