android_kernel_xiaomi_sm8350/kernel
Ira W. Snyder 399f1e30ac kfifo: fix scatterlist usage
The kfifo_dma family of functions use sg_mark_end() on the last element in
their scatterlist.  This forces use of a fresh scatterlist for each DMA
operation, which makes recycling a single scatterlist impossible.

Change the behavior of the kfifo_dma functions to match the usage of the
dma_map_sg function.  This means that users must respect the returned
nents value.  The sample code is updated to reflect the change.

This bug is trivial to cause: call kfifo_dma_in_prepare() such that it
prepares a scatterlist with a single entry comprising the whole fifo.
This is the case when you map the entirety of a newly created empty fifo.
This causes the setup_sgl() function to mark the first scatterlist entry
as the end of the chain, no matter what comes after it.

Afterwards, add and remove some data from the fifo such that another call
to kfifo_dma_in_prepare() will create two scatterlist entries.  It returns
nents=2.  However, due to the previous sg_mark_end() call, sg_is_last()
will now return true for the first scatterlist element.  This causes the
sample code to print a single scatterlist element when it should print
two.

By removing the call to sg_mark_end(), we make the API as similar as
possible to the DMA mapping API.  All users are required to respect the
returned nents.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-01 10:50:58 -07:00
..
debug Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-09-08 11:13:42 -07:00
gcov gcov: fix null-pointer dereference for certain module types 2010-09-09 18:57:23 -07:00
irq irq: Add new IRQ flag IRQF_NO_SUSPEND 2010-07-29 13:24:57 +02:00
power Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 2010-09-11 15:50:53 -07:00
time time: Workaround gcc loop optimization that causes 64bit div errors 2010-08-13 12:03:24 -07:00
trace Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-09-10 07:31:24 -07:00
.gitignore
acct.c pass a struct path to vfs_statfs 2010-08-09 16:48:42 -04:00
async.c async: use workqueue for worker pool 2010-07-14 11:29:46 +02:00
audit_tree.c fanotify: use both marks when possible 2010-07-28 10:18:55 -04:00
audit_watch.c Revert "fsnotify: store struct file not struct path" 2010-08-12 14:23:04 -07:00
audit.c Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-08-10 11:39:13 -07:00
audit.h Audit: split audit watch Kconfig 2010-07-28 09:58:19 -04:00
auditfilter.c audit: do not get and put just to free a watch 2010-07-28 09:58:17 -04:00
auditsc.c vfs: add helpers to get root and pwd 2010-08-11 00:28:20 -04:00
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c
cgroup.c cgroups: fix API thinko 2010-09-09 18:57:23 -07:00
compat.c compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
configs.c
cpu.c sched: adjust when cpu_active and cpuset configurations are updated during cpu on/offlining 2010-06-08 21:40:36 +02:00
cpuset.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-06 09:39:22 -07:00
cred.c Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
delayacct.c
dma.c
early_res.c kmemleak: Add support for NO_BOOTMEM configurations 2010-07-19 11:54:15 +01:00
elfcore.c
exec_domain.c sys_personality: remove the bogus checks in sys_personality()->__set_personality() path 2010-08-09 20:45:05 -07:00
exit.c Fix unprotected access to task credentials in waitid() 2010-08-17 18:07:43 -07:00
extable.c
fork.c rmap: fix walk during fork 2010-09-22 17:22:39 -07:00
freezer.c
futex_compat.c
futex.c futex: futex_find_get_task remove credentails check 2010-06-30 15:43:44 -07:00
groups.c kernel/groups.c: fix integer overflow in groups_search 2010-09-09 18:57:24 -07:00
hrtimer.c gcc-4.6: kernel/*: Fix unused but set warnings 2010-09-05 14:36:58 +02:00
hung_task.c
hw_breakpoint.c hw breakpoints: Fix pid namespace bug 2010-09-17 04:42:59 +02:00
itimer.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kexec: return -EFAULT on copy_to_user() failures 2010-08-11 08:59:22 -07:00
kfifo.c kfifo: fix scatterlist usage 2010-10-01 10:50:58 -07:00
kmod.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
kprobes.c
ksysfs.c
kthread.c kthread: implement kthread_data() 2010-06-29 10:07:09 +02:00
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c sched_clock: Add local_clock() API and improve documentation 2010-06-09 10:34:49 +02:00
Makefile Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-08-10 11:39:13 -07:00
module.c module: cleanup comments, remove noinline 2010-08-05 12:59:13 +09:30
mutex-debug.c
mutex-debug.h
mutex.c mutex: Fix annotations to include it in kernel-locking docbook 2010-09-03 08:19:51 +02:00
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
padata.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2010-08-04 15:23:14 -07:00
panic.c lib/bug.c: add oops end marker to WARN implementation 2010-08-11 08:59:22 -07:00
params.c param: locking for kernel parameters 2010-08-11 23:04:20 +09:30
perf_event.c perf: Fix CPU hotplug 2010-09-09 20:38:52 +02:00
pid_namespace.c
pid.c pids: alloc_pidmap: remove the unnecessary boundary checks 2010-08-11 08:59:20 -07:00
pm_qos_params.c PM QoS: Correct pr_debug() misuse and improve parameter checks 2010-09-11 00:53:05 +02:00
posix-cpu-timers.c Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux 2010-08-10 12:07:51 -07:00
posix-timers.c posix_timer: Move copy_to_user(created_timer_id) down in timer_create() 2010-07-23 15:08:12 +02:00
printk.c gcc-4.6: printk: use stable variable to dump kmsg buffer 2010-08-09 20:45:06 -07:00
profile.c
ptrace.c ptrace: optimize exit_ptrace() for the likely case 2010-08-11 08:59:19 -07:00
range.c kernel/range: remove unused definition of ARRAY_SIZE() 2010-08-09 20:45:06 -07:00
rcupdate.c tree/tiny rcu: Add debug RCU head objects 2010-06-14 16:37:26 -07:00
rcutiny_plugin.h
rcutiny.c tree/tiny rcu: Add debug RCU head objects 2010-06-14 16:37:26 -07:00
rcutorture.c sched_clock: Add local_clock() API and improve documentation 2010-06-09 10:34:49 +02:00
rcutree_plugin.h
rcutree_trace.c
rcutree.c tree/tiny rcu: Add debug RCU head objects 2010-06-14 16:37:26 -07:00
rcutree.h
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c sched_clock: Add local_clock() API and improve documentation 2010-06-09 10:34:49 +02:00
sched_cpupri.c sched: No need for bootmem special cases 2010-07-17 12:06:22 +02:00
sched_cpupri.h sched: No need for bootmem special cases 2010-07-17 12:06:22 +02:00
sched_debug.c sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug 2010-07-21 21:46:12 +02:00
sched_fair.c sched: Fix nohz balance kick 2010-09-21 13:50:50 +02:00
sched_features.h
sched_idletask.c
sched_rt.c sched: task_tick_rt: Remove the obsolete ->signal != NULL check 2010-06-18 10:46:56 +02:00
sched_stats.h sched: Remove the obsolete exit_state/signal hacks 2010-06-18 10:46:56 +02:00
sched.c sched: Fix user time incorrectly accounted as system time on 32-bit 2010-09-15 10:41:36 +02:00
seccomp.c
semaphore.c
signal.c CRED: Fix RCU warning due to previous patch fixing __task_cred()'s checks 2010-08-04 11:17:10 -07:00
smp.c
softirq.c kernel/: fix BUG_ON checks for cpu notifier callbacks direct call 2010-06-04 15:21:45 -07:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c stop_machine: struct cpu_stopper, remove alignment padding on 64 bits 2010-08-09 20:45:06 -07:00
sys_ni.c fanotify: sys_fanotify_mark declartion 2010-07-28 09:58:55 -04:00
sys.c pid: make setpgid() system call use RCU read-side critical section 2010-08-31 17:00:18 -07:00
sysctl_binary.c
sysctl_check.c
sysctl.c gcc-4.6: kernel/*: Fix unused but set warnings 2010-09-05 14:36:58 +02:00
taskstats.c
test_kprobes.c
time.c time: Kill off CONFIG_GENERIC_TIME 2010-07-27 12:40:54 +02:00
timeconst.pl
timer.c kernel/timer.c: fix kernel-doc function parameter warning 2010-08-10 15:33:09 -07:00
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c user_ns: Introduce user_nsmap_uid and user_ns_map_gid. 2010-06-16 14:55:34 -07:00
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c lockup_detector: Sync touch_*_watchdog back to old semantics 2010-09-01 10:02:28 +02:00
workqueue_sched.h workqueue: implement concurrency managed dynamic worker pool 2010-06-29 10:07:14 +02:00
workqueue.c workqueue: add documentation 2010-09-13 10:26:52 +02:00