Dan Williams
90a545e981
restrict /dev/mem to idle io memory ranges
...
This effectively promotes IORESOURCE_BUSY to IORESOURCE_EXCLUSIVE
semantics by default. If userspace really believes it is safe to access
the memory region it can also perform the extra step of disabling an
active driver. This protects device address ranges with read side
effects and otherwise directs userspace to use the driver.
Persistent memory presents a large "mistake surface" to /dev/mem as now
accidental writes can corrupt a filesystem.
In general if a device driver is busily using a memory region it already
informs other parts of the kernel to not touch it via
request_mem_region(). /dev/mem should honor the same safety restriction
by default. Debugging a device driver from userspace becomes more
difficult with this enabled. Any application using /dev/mem or mmap of
sysfs pci resources will now need to perform the extra step of either:
1/ Disabling the driver, for example:
echo <device id> > /dev/bus/<parent bus>/drivers/<driver name>/unbind
2/ Rebooting with "iomem=relaxed" on the command line
3/ Recompiling with CONFIG_IO_STRICT_DEVMEM=n
Traditional users of /dev/mem like dosemu are unaffected because the
first 1MB of memory is not subject to the IO_STRICT_DEVMEM restriction.
Legacy X configurations use /dev/mem to talk to graphics hardware, but
that functionality has since moved to kernel graphics drivers.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:30:49 -08:00
..
bpf
bpf: fix allocation warnings in bpf maps and integer overflow
2015-12-02 23:36:00 -05:00
configs
debug
events
Merge branch 'for-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2015-12-08 13:35:52 -08:00
gcov
irq
Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-15 09:30:48 -08:00
livepatch
livepatch: x86: fix relocation computation with kASLR
2015-11-11 17:36:04 +01:00
locking
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
power
mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM
2015-11-06 17:50:42 -08:00
printk
printk: prevent userland from spoofing kernel messages
2015-11-06 17:50:42 -08:00
rcu
Merge branches 'doc.2015.10.06a', 'percpu-rwsem.2015.10.06a' and 'torture.2015.10.06a' into HEAD
2015-10-07 16:06:25 -07:00
sched
sched/wait: Fix the signal handling fix
2015-12-13 14:30:59 -08:00
time
Merge branches 'irq-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-15 09:30:48 -08:00
trace
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-12-08 13:01:23 -08:00
.gitignore
certs: add .gitignore to stop git nagging about x509_certificate_list
2015-10-21 15:18:35 +01:00
acct.c
async.c
audit.c
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
audit.h
audit: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
audit_fsnotify.c
audit_tree.c
audit: audit_tree_match can be boolean
2015-11-04 08:23:51 -05:00
audit_watch.c
Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
2015-09-08 13:34:59 -07:00
auditfilter.c
audit: fix comment block whitespace
2015-11-04 08:23:51 -05:00
auditsc.c
Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
2015-09-08 13:34:59 -07:00
backtracetest.c
bounds.c
capability.c
cgroup.c
cgroup: fix handling of multi-destination migration from subtree_control enabling
2015-12-03 10:18:21 -05:00
cgroup_freezer.c
cgroup: fix handling of multi-destination migration from subtree_control enabling
2015-12-03 10:18:21 -05:00
cgroup_pids.c
cgroup_pids: don't account for the root cgroup
2015-12-03 10:18:21 -05:00
compat.c
configs.c
context_tracking.c
context_tracking: avoid irq_save/irq_restore on guest entry and exit
2015-11-10 12:06:23 +01:00
cpu.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-03 18:03:50 -08:00
cpu_pm.c
kernel/cpu_pm: fix cpu_cluster_pm_exit comment
2015-09-03 02:42:20 +02:00
cpuset.c
cgroup: fix handling of multi-destination migration from subtree_control enabling
2015-12-03 10:18:21 -05:00
crash_dump.c
cred.c
kernel/cred.c: remove unnecessary kdebug atomic reads
2015-09-10 13:29:01 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-11-03 18:03:50 -08:00
extable.c
kernel/extable.c: remove duplicated include
2015-09-10 13:29:01 -07:00
fork.c
cgroup: pids: fix race between cgroup_post_fork() and cgroup_migrate()
2015-11-30 09:48:18 -05:00
freezer.c
futex.c
driver core update for 4.4-rc1
2015-11-04 21:50:37 -08:00
futex_compat.c
groups.c
hung_task.c
irq_work.c
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
jump_label.c
treewide: Remove old email address
2015-11-23 09:44:58 +01:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec_core.c
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec_file.c
kexec: use file name as the output message prefix
2015-11-06 17:50:42 -08:00
kexec_internal.h
kexec: split kexec_file syscall code to kexec_file.c
2015-09-10 13:29:01 -07:00
kmod.c
kmod: don't run async usermode helper as a child of kworker thread
2015-10-23 17:55:10 +09:00
kprobes.c
ksysfs.c
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
kthread.c
kernel/kthread.c:kthread_create_on_node(): clarify documentation
2015-09-04 16:54:41 -07:00
latencytop.c
Makefile
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
membarrier.c
sys_membarrier(): system-wide memory barrier (generic, x86)
2015-09-11 15:21:34 -07:00
memremap.c
libnvdimm for 4.4:
2015-11-10 12:07:22 -08:00
module-internal.h
module.c
module: Fix locking in symbol_put_addr()
2015-08-24 10:37:01 +09:30
module_signing.c
KEYS: Merge the type-specific data with the payload data
2015-10-21 15:18:36 +01:00
notifier.c
Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2015-09-01 08:40:25 -07:00
nsproxy.c
padata.c
panic.c
kernel/panic.c: turn off locks debug before releasing console lock
2015-11-20 16:17:32 -08:00
params.c
Nothing exciting, minor tweaks and cleanups.
2015-11-09 15:53:39 -08:00
pid.c
pidns: fix NULL dereference in __task_pid_nr_ns()
2015-11-24 12:03:55 -08:00
pid_namespace.c
profile.c
mm: rename alloc_pages_exact_node() to __alloc_pages_node()
2015-09-08 15:35:28 -07:00
ptrace.c
seccomp, ptrace: add support for dumping seccomp filters
2015-10-27 19:55:13 -07:00
range.c
reboot.c
kexec: split kexec_load syscall from kexec core code
2015-09-10 13:29:01 -07:00
relay.c
resource.c
restrict /dev/mem to idle io memory ranges
2016-01-09 06:30:49 -08:00
seccomp.c
seccomp, ptrace: add support for dumping seccomp filters
2015-10-27 19:55:13 -07:00
signal.c
kernel/signal.c: unexport sigsuspend()
2015-11-20 16:17:32 -08:00
smp.c
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
2015-11-06 17:50:42 -08:00
smpboot.c
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c
kernel: remove stop_machine() Kconfig dependency
2015-12-12 10:15:34 -08:00
sys.c
pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
2015-11-06 17:50:42 -08:00
sys_ni.c
mm: mlock: add new mlock system call
2015-11-05 19:34:48 -08:00
sysctl.c
kernel/watchdog.c: add sysctl knob hardlockup_panic
2015-11-05 19:34:48 -08:00
sysctl_binary.c
task_work.c
task_work: remove fifo ordering guarantee
2015-09-05 13:46:58 -07:00
taskstats.c
test_kprobes.c
torture.c
torture: Consolidate cond_resched_rcu_qs() into stutter_wait()
2015-10-06 11:25:01 -07:00
tracepoint.c
tracepoint: Give priority to probes of tracepoints
2015-10-25 21:33:54 -04:00
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c
capabilities: ambient capabilities
2015-09-04 16:54:41 -07:00
utsname.c
utsname_sysctl.c
watchdog.c
kernel/watchdog.c: fix race between proc_watchdog_thresh() and watchdog_timer_fn()
2015-11-05 19:34:48 -08:00
workqueue.c
Merge branch 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2015-11-05 14:16:27 -08:00
workqueue_internal.h