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path: root/drivers/media/dvb-core/dvb_ringbuffer.c
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2017-10-25locking/atomics, media/dvb_ringbuffer: Convert ACCESS_ONCE() to ↵Mark Rutland
READ_ONCE()/WRITE_ONCE() For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the DVB ringbuffer code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-6-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-27[media] media: Drop FSF's postal address from the source code filesSakari Ailus
Drop the FSF's postal address from the source code files that typically contain mostly the license text. Of the 628 removed instances, 578 are outdated. The patch has been created with the following command without manual edits: git grep -l "675 Mass Ave\|59 Temple Place\|51 Franklin St" -- \ drivers/media/ include/media|while read i; do i=$i perl -e ' open(F,"< $ENV{i}"); $a=join("", <F>); $a =~ s/[ \t]*\*\n.*You should.*\n.*along with.*\n.*(\n.*USA.*$)?\n//m && $a =~ s/(^.*)Or, (point your browser to) /$1To obtain the license, $2\n$1/m; close(F); open(F, "> $ENV{i}"); print F $a; close(F);'; done Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-09[media] media: dvb_ringbuffer: Add memory barriersSoeren Moch
Implement memory barriers according to Documentation/circular-buffers.txt: - use smp_store_release() to update ringbuffer read/write pointers - use smp_load_acquire() to load write pointer on reader side - use ACCESS_ONCE() to load read pointer on writer side This fixes data stream corruptions observed e.g. on an ARM Cortex-A9 quad core system with different types (PCI, USB) of DVB tuners. Signed-off-by: Soeren Moch <smoch@web.de> Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2014-09-08[media] ngene: properly handle __user ptrMauro Carvalho Chehab
Sparse is complaining about ngene's bad usage of a __user ptr: >> drivers/media/pci/ngene/ngene-dvb.c:62:48: sparse: incorrect type in argument 2 (different address spaces) drivers/media/pci/ngene/ngene-dvb.c:62:48: expected unsigned char const [usertype] *buf drivers/media/pci/ngene/ngene-dvb.c:62:48: got char const [noderef] <asn:1>*buf As this is intercepting a .write() file ops, we can't just memcpy. We need to use copy_from_user. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2012-08-13[media] dvb: move the dvb core one level upMauro Carvalho Chehab
just like the V4L2 core, move the DVB core to drivers/media, as the intention is to get rid of both "video" and "dvb" directories. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>