The naming is meant to discourage random use: the helper functions are
not really any more "unsafe" than the traditional double-underscore
functions (which need the address range checking), but they do need even
more infrastructure around them, and should not be used willy-nilly.
In addition to checking the access range, these user access functions
require that you wrap the user access with a "user_acess_{begin,end}()"
around it.
That allows architectures that implement kernel user access control
(x86: SMAP, arm64: PAN) to do the user access control in the wrapping
user_access_begin/end part, and then batch up the actual user space
accesses using the new interfaces.
The main (and hopefully only) use for these are for core generic access
helpers, initially just the generic user string functions
(strnlen_user() and strncpy_from_user()).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ic64efea41f97171bdbdabe3e531489aebd9b6fac
(cherry picked from commit 5b24a7a2aa)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
(cherry picked from commit bb1fceca22)
When tcp_sendmsg() allocates a fresh and empty skb, it puts it at the
tail of the write queue using tcp_add_write_queue_tail()
Then it attempts to copy user data into this fresh skb.
If the copy fails, we undo the work and remove the fresh skb.
Unfortunately, this undo lacks the change done to tp->highest_sack and
we can leave a dangling pointer (to a freed skb)
Later, tcp_xmit_retransmit_queue() can dereference this pointer and
access freed memory. For regular kernels where memory is not unmapped,
this might cause SACK bugs because tcp_highest_sack_seq() is buggy,
returning garbage instead of tp->snd_nxt, but with various debug
features like CONFIG_DEBUG_PAGEALLOC, this can crash the kernel.
This bug was found by Marco Grassi thanks to syzkaller.
Fixes: 6859d49475 ("[TCP]: Abstract tp->highest_sack accessing & point to next skb")
Reported-by: Marco Grassi <marco.gra@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change-Id: I58bb02d6e4e399612e8580b9e02d11e661df82f5
Bug: 31183296
The current percpu-rwsem read side is entirely free of serializing insns
at the cost of having a synchronize_sched() in the write path.
The latency of the synchronize_sched() is too high for cgroups. The
commit 1ed1328792 talks about the write path being a fairly cold path
but this is not the case for Android which moves task to the foreground
cgroup and back around binder IPC calls from foreground processes to
background processes, so it is significantly hotter than human initiated
operations.
Switch cgroup_threadgroup_rwsem into the slow mode for now to avoid the
problem, hopefully it should not be that slow after another commit
80127a3968 ("locking/percpu-rwsem: Optimize readers and reduce global
impact").
We could just add rcu_sync_enter() into cgroup_init() but we do not want
another synchronize_sched() at boot time, so this patch adds the new helper
which doesn't block but currently can only be called before the first use.
Cc: Tejun Heo <tj@kernel.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Reported-by: John Stultz <john.stultz@linaro.org>
Reported-by: Dmitry Shmidt <dimitrysh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
[jstultz: backported to 4.4]
Change-Id: I34aa9c394d3052779b56976693e96d861bd255f2
Mailing-list-URL: https://lkml.org/lkml/2016/8/11/557
Signed-off-by: John Stultz <john.stultz@linaro.org>
Currently the percpu-rwsem switches to (global) atomic ops while a
writer is waiting; which could be quite a while and slows down
releasing the readers.
This patch cures this problem by ordering the reader-state vs
reader-count (see the comments in __percpu_down_read() and
percpu_down_write()). This changes a global atomic op into a full
memory barrier, which doesn't have the global cacheline contention.
This also enables using the percpu-rwsem with rcu_sync disabled in order
to bias the implementation differently, reducing the writer latency by
adding some cost to readers.
Mailing-list-URL: https://lkml.org/lkml/2016/8/9/181
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[jstultz: Backported to 4.4]
Change-Id: I8ea04b4dca2ec36f1c2469eccafde1423490572f
Signed-off-by: John Stultz <john.stultz@linaro.org>
This patch adds a new sysfs node (latency_hist) and reports IO
(svc time) latency histograms. Disabled by default, can be enabled
by echoing 0 into latency_hist, stats can be cleared by writing 2
into latency_hist.
Bug: 30677035
Change-Id: I625938135ea33e6e87cf6af1fc7edc136d8b4b32
Signed-off-by: Mohan Srinivasan <srmohan@google.com>
Fix RTA_UID enum to match it with the Android userspace code which
assumes RTA_UID=18.
With this patch all Android kernel networking unit tests mentioned here
https://source.android.com/devices/tech/config/kernel_network_tests.html
are success.
Without this patch multinetwork_test.py unit test fails.
Change-Id: I3ff36670f7d4e5bf5f01dce584ae9d53deabb3ed
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
This is a wrap-up of three patches pending upstream approval.
I'm bundling them because they are interdependent, and it'll be
easier to drop it on rebase later.
1. dm: allow a dm-fs-style device to be shared via dm-ioctl
Integrates feedback from Alisdair, Mike, and Kiyoshi.
Two main changes occur here:
- One function is added which allows for a programmatically created
mapped device to be inserted into the dm-ioctl hash table. This binds
the device to a name and, optional, uuid which is needed by udev and
allows for userspace management of the mapped device.
- dm_table_complete() was extended to handle all of the final
functional changes required for the table to be operational once
called.
2. init: boot to device-mapper targets without an initr*
Add a dm= kernel parameter modeled after the md= parameter from
do_mounts_md. It allows for device-mapper targets to be configured at
boot time for use early in the boot process (as the root device or
otherwise). It also replaces /dev/XXX calls with major:minor opportunistically.
The format is dm="name uuid ro,table line 1,table line 2,...". The
parser expects the comma to be safe to use as a newline substitute but,
otherwise, uses the normal separator of space. Some attempt has been
made to make it forgiving of additional spaces (using skip_spaces()).
A mapped device created during boot will be assigned a minor of 0 and
may be access via /dev/dm-0.
An example dm-linear root with no uuid may look like:
root=/dev/dm-0 dm="lroot none ro, 0 4096 linear /dev/ubdb 0, 4096 4096 linear /dv/ubdc 0"
Once udev is started, /dev/dm-0 will become /dev/mapper/lroot.
Older upstream threads:
http://marc.info/?l=dm-devel&m=127429492521964&w=2http://marc.info/?l=dm-devel&m=127429499422096&w=2http://marc.info/?l=dm-devel&m=127429493922000&w=2
Latest upstream threads:
https://patchwork.kernel.org/patch/104859/https://patchwork.kernel.org/patch/104860/https://patchwork.kernel.org/patch/104861/
Bug: 27175947
Signed-off-by: Will Drewry <wad@chromium.org>
Review URL: http://codereview.chromium.org/2020011
Change-Id: I92bd53432a11241228d2e5ac89a3b20d19b05a31
New driver memory_state_time tracks time spent in different DDR
frequency and bandwidth states.
Memory drivers such as qcom,cpubw can post updated state to the driver
after registering a callback. Processed by a workqueue
Bandwidth buckets are read in from device tree in the relevant qualcomm
section, can be defined in any quantity and spacing.
The data is exposed at /sys/kernel/memory_state_time, able to be read by
the Android framework.
Functionality is behind a config option CONFIG_MEMORY_STATE_TIME
Change-Id: I4fee165571cb975fb9eacbc9aada5e6d7dd748f0
Signed-off-by: James Carr <carrja@google.com>
This reverts commit 4e09c51018.
I checked for the usage of this debug helper in AOSP common kernels as
well as vendor kernels (e.g exynos, msm, mediatek, omap, tegra, x86,
x86_64) hosted at https://android.googlesource.com/kernel/ and I found
out that other than few fairly obsolete Omap trees (for tuna & Glass)
and Exynos tree (for Manta), there is no active user of this debug
helper. So we can safely remove this helper code.
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
This patch backports 969624b (which backports caaee6234d upstream),
from the v4.4-stable branch to the common/android-4.4 branch.
This patch is needed to provide the PTRACE_MODE_ATTACH_FSCREDS definition
which was used by the backported version of proc/<tid>/timerslack_ns
in change-id: Ie5799b9a3402a31f88cd46437dcda4a0e46415a7
commit caaee6234d upstream.
By checking the effective credentials instead of the real UID / permitted
capabilities, ensure that the calling process actually intended to use its
credentials.
To ensure that all ptrace checks use the correct caller credentials (e.g.
in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
flag), use two new flags and require one of them to be set.
The problem was that when a privileged task had temporarily dropped its
privileges, e.g. by calling setreuid(0, user_uid), with the intent to
perform following syscalls with the credentials of a user, it still passed
ptrace access checks that the user would not be able to pass.
While an attacker should not be able to convince the privileged task to
perform a ptrace() syscall, this is a problem because the ptrace access
check is reused for things in procfs.
In particular, the following somewhat interesting procfs entries only rely
on ptrace access checks:
/proc/$pid/stat - uses the check for determining whether pointers
should be visible, useful for bypassing ASLR
/proc/$pid/maps - also useful for bypassing ASLR
/proc/$pid/cwd - useful for gaining access to restricted
directories that contain files with lax permissions, e.g. in
this scenario:
lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
drwx------ root root /root
drwxr-xr-x root root /root/foobar
-rw-r--r-- root root /root/foobar/secret
Therefore, on a system where a root-owned mode 6755 binary changes its
effective credentials as described and then dumps a user-specified file,
this could be used by an attacker to reveal the memory layout of root's
processes or reveal the contents of files he is not allowed to access
(through /proc/$pid/cwd).
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[jstultz: Cherry-picked for common/android-4.4]
Signed-off-by: John Stultz <john.stultz@linaro.org>
This backports da8b44d5a9 from upstream.
This patchset introduces a /proc/<pid>/timerslack_ns interface which
would allow controlling processes to be able to set the timerslack value
on other processes in order to save power by avoiding wakeups (Something
Android currently does via out-of-tree patches).
The first patch tries to fix the internal timer_slack_ns usage which was
defined as a long, which limits the slack range to ~4 seconds on 32bit
systems. It converts it to a u64, which provides the same basically
unlimited slack (500 years) on both 32bit and 64bit machines.
The second patch introduces the /proc/<pid>/timerslack_ns interface
which allows the full 64bit slack range for a task to be read or set on
both 32bit and 64bit machines.
With these two patches, on a 32bit machine, after setting the slack on
bash to 10 seconds:
$ time sleep 1
real 0m10.747s
user 0m0.001s
sys 0m0.005s
The first patch is a little ugly, since I had to chase the slack delta
arguments through a number of functions converting them to u64s. Let me
know if it makes sense to break that up more or not.
Other than that things are fairly straightforward.
This patch (of 2):
The timer_slack_ns value in the task struct is currently a unsigned
long. This means that on 32bit applications, the maximum slack is just
over 4 seconds. However, on 64bit machines, its much much larger (~500
years).
This disparity could make application development a little (as well as
the default_slack) to a u64. This means both 32bit and 64bit systems
have the same effective internal slack range.
Now the existing ABI via PR_GET_TIMERSLACK and PR_SET_TIMERSLACK specify
the interface as a unsigned long, so we preserve that limitation on
32bit systems, where SET_TIMERSLACK can only set the slack to a unsigned
long value, and GET_TIMERSLACK will return ULONG_MAX if the slack is
actually larger then what can be stored by an unsigned long.
This patch also modifies hrtimer functions which specified the slack
delta as a unsigned long.
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oren Laadan <orenl@cellrox.com>
Cc: Ruchi Kandoi <kandoiruchi@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Backport notes: This resolves clk warnings in the designware i2c
driver on HiKey seen during suspend/resume.
Cherrypicked from: aa8e54b559
If a suitable prepare callback cannot be found for a given device and
its driver has no PM callbacks at all, assume that it can go direct to
complete when the system goes to sleep.
The reason for this is that there's lots of devices in a system that do
no PM at all and there's no reason for them to prevent their ancestors
to do direct_complete if they can support it.
Change-Id: Ia773afb4b266f012336b99fc8cf87453839e078b
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[jstultz: Backported to 4.4]
Signed-off-by: John Stultz <john.stultz@linaro.org>
When kernel.perf_event_open is set to 3 (or greater), disallow all
access to performance events by users without CAP_SYS_ADMIN.
Add a Kconfig symbol CONFIG_SECURITY_PERF_EVENTS_RESTRICT that
makes this value the default.
This is based on a similar feature in grsecurity
(CONFIG_GRKERNSEC_PERF_HARDEN). This version doesn't include making
the variable read-only. It also allows enabling further restriction
at run-time regardless of whether the default is changed.
https://lkml.org/lkml/2016/1/11/587
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Bug: 29054680
Change-Id: Iff5bff4fc1042e85866df9faa01bce8d04335ab8
If CONFIG_DUAL_ROLE_USB_INTF is disabled but the exported functions
are referenced, the build will result in warnings such as:
In file included from include/linux/usb/class-dual-role.h:112:13:
warning: ‘dual_role_instance_changed’ defined but not used
[-Wunused-function]
These stub functions should be static inline.
Change-Id: I5a9ef58dca32306fac5a4c7f28cdaa36fa8ae078
Signed-off-by: Jack Pham <jackp@codeaurora.org>
(cherry picked from commit 2d152dbb0743526b21d6bbefe097f874c027f860)
(cherry picked from commit 8ad66cafaa10e6ba94ff79a8dbc2cc437c6bfe93)
This reverts commit 91fa97e1e5.
This patch is no longer valid. There are no users for this status irq and
callback in android-4.x. The Qcom platform (mach-msm/qsd8x50, HTC Dream..)
and SDCC controller (msm_sdcc) using this status IRQ and callback are
dropped from mainline sometime back.
27842bb18b00 (mmc: Remove msm_sdcc driver)
c0c89fafa2 (ARM: Remove mach-msm and associated ARM architecture code)
Change-Id: Ia38e42a06dc184395f79c1ec1d306bf9775704d5
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Allows FUSE to report to inotify that it is acting
as a layered filesystem. The userspace component
returns a string representing the location of the
underlying file. If the string cannot be resolved
into a path, the top level path is returned instead.
bug: 23904372
Change-Id: Iabdca0bbedfbff59e9c820c58636a68ef9683d9f
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Drivers should use extcon moving forward.
Documentation/extcon/porting-android-switch-class describes
how to port existing switch class drivers to extcon.
This reverts commit e4b8e66e0a.
Change-Id: I5b622c7ab4c0cb9670f8903f259a99888f503c1a
CONFIG_SDCARD_FS_CI_SEARCH only guards a define for
LOOKUP_CASE_INSENSITIVE, which is never used in the
kernel. Remove both, along with the option matching
that supports it.
Change-Id: I363a8f31de8ee7a7a934d75300cc9ba8176e2edf
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Attempts to build sdcardfs as module fail with
fs/sdcardfs/lookup.c: In function '__sdcardfs_lookup':
fs/sdcardfs/lookup.c:243:5: error: 'LOOKUP_CASE_INSENSITIVE' undeclared
This occurs because the define is enclosed with #ifdef
CONFIG_SDCARD_FS_CI_SEARCH. If SDCARD_FS_CI_SEARCH is configured to be
built as module, this does not work. Alternatives would be to use #if
IS_ENABLED(CONFIG_SDCARD_FS_CI_SEARCH), or to declare SDCARD_FS_CI_SEARCH
as bool, but that does not work because the define is used unconditionally
in the source.
Note that LOOKUP_CASE_INSENSITIVE is only set but not evaluated in the
current source code, so setting the flag has no real effect.
Fixes: 84a1b7d3d3 ("Included sdcardfs source code for kernel 3.0")
Cc: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Inotify does not currently know when a filesystem
is acting as a wrapper around another fs. This means
that inotify watchers will miss any modifications to
the base file, as well as any made in a separate
stacked fs that points to the same file.
d_canonical_path solves this problem by allowing the fs
to map a dentry to a path in the lower fs. Inotify
can use it to find the appropriate place to watch to
be informed of all changes to a file.
Change-Id: I09563baffad1711a045e45c1bd0bd8713c2cc0b6
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Only included the source code as is for kernel 3.0. Following patches
take care of porting this file system to version 3.10.
Change-Id: I09e76db77cd98a059053ba5b6fd88572a4b75b5b
Signed-off-by: Daniel Campello <campello@google.com>
(cherry picked from commit https://lkml.org/lkml/2016/2/4/831)
d07e22597d ("mm: mmap: add new /proc tunable for mmap_base ASLR")
added the ability to choose from a range of values to use for entropy
count in generating the random offset to the mmap_base address. The
maximum value on this range was set to 32 bits for 64-bit x86 systems, but
this value could be increased further, requiring more than the 32 bits of
randomness provided by get_random_int(), as is already possible for arm64.
Add a new function: get_random_long() which more naturally fits with the
mmap usage of get_random_int() but operates exactly the same as
get_random_int().
Also, fix the shifting constant in mmap_rnd() to be an unsigned long so
that values greater than 31 bits generate an appropriate mask without
overflow. This is especially important on x86, as its shift instruction
uses a 5-bit mask for the shift operand, which meant that any value for
mmap_rnd_bits over 31 acts as a no-op and effectively disables mmap_base
randomization.
Finally, replace calls to get_random_int() with get_random_long() where
appropriate.
Bug: 26963541
Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>
Change-Id: I5b45621088666d5d1dfbf43952f25ea0798b10ba
The API to log the suspend reason was introduced with commit 57caa2ad5c
("power: Adds functionality to log the last suspend abort reason.").
It is called from functions enabled with PM_SLEEP and from functions
enabled with SUSPEND, but only available if SUSPEND is enabled.
This can result in build failures such as the following if PM_SLEEP
is enabled, but SUSPEND is not.
kernel/built-in.o: In function `try_to_freeze_tasks':
process.c:(.text+0x30928): undefined reference to `log_suspend_abort_reason'
drivers/built-in.o: In function `syscore_suspend':
(.text+0x6e250): undefined reference to `log_suspend_abort_reason'
drivers/built-in.o: In function `__device_suspend':
main.c:(.text+0x7a528): undefined reference to `log_suspend_abort_reason'
Fixes: 57caa2ad5c ("power: Adds functionality to log the last suspend abort reason.")
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Commit 1af89c1ef3 ("Hack: net: PPPoPNS and PPPoLAC build fixes for 4.1")
fixed the build for PPPoPNS and PPPoLAC by re-introducing a field in
struct msghdr which was removed upstream. Re-introducing the field doesn't
get it used, so it is quite likely that the code never worked. Fix it up for
good.
Fixes: 1af89c1ef3 ("Hack: net: PPPoPNS and PPPoLAC build fixes for 4.1")
Signed-off-by: Guenter Roeck <groeck@chromium.org>
This implements SOCK_DESTROY for TCP sockets. It causes all
blocking calls on the socket to fail fast with ECONNABORTED and
causes a protocol close of the socket. It informs the other end
of the connection by sending a RST, i.e., initiating a TCP ABORT
as per RFC 793. ECONNABORTED was chosen for consistency with
FreeBSD.
[cherry-pick of net-next c1e64e298b]
Change-Id: I728a01ef03f2ccfb9016a3f3051ef00975980e49
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This passes the SOCK_DESTROY operation to the underlying protocol
diag handler, or returns -EOPNOTSUPP if that handler does not
define a destroy operation.
Most of this patch is just renaming functions. This is not
strictly necessary, but it would be fairly counterintuitive to
have the code to destroy inet sockets be in a function whose name
starts with inet_diag_get.
[backport of net-next 6eb5d2e08f]
Change-Id: Idc13a7def20f492a5323ad2f8de105426293bd37
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a SOCK_DESTROY operation, a destroy function
pointer to sock_diag_handler, and a diag_destroy function
pointer. It does not include any implementation code.
[backport of net-next 64be0aed59]
Change-Id: Ic5327ff14b39dd268083ee4c1dc2c934b2820df5
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, inet_diag_dump_one_icsk finds a socket and then dumps
its information to userspace. Split it into a part that finds the
socket and a part that dumps the information.
[cherry-pick of net-next b613f56ec9]
Change-Id: I144765afb6ff1cd66eb4757c9418112fb0b08a6f
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* What
This provides an interface for issuing an FITRIM which uses the
secure discard instead of just a discard.
Only the eMMC command is "secure", and not how the FS uses it:
due to the fact that the FS might reassign a region somewhere else,
the original deleted data will not be affected by the "trim" which only
handles un-used regions.
So we'll just call it "deep discard", and note that this is a
"best effort" cleanup.
* Why
Once in a while, We want to be able to cleanup most of the unused blocks
after erasing a bunch of files.
We don't want to constantly secure-discard via a mount option.
From an eMMC spec perspective, it tells the device to really get rid of
all the data for the specified blocks and not just put them back into the
pool of free ones (unlike the normal TRIM). The eMMC spec says the
secure trim handling must make sure the data (and metadata) is not available
anymore. A simple TRIM doesn't clear the data, it just puts blocks in the
free pool.
JEDEC Standard No. 84-A441
7.6.9 Secure Erase
7.6.10 Secure Trim
From an FS perspective, it is acceptable to leave some data behind.
- directory entries related to deleted files
- databases entries related to deleted files
- small-file data stored in inode extents
- blocks held by the FS waiting to be re-used (mitigated by sync).
- blocks reassigned by the FS prior to FIDTRIM.
Change-Id: I676a1404a80130d93930c84898360f2e6fb2f81e
Signed-off-by: Geremy Condra <gcondra@google.com>
Signed-off-by: JP Abgrall <jpa@google.com>
Emulate NMIs on systems where they are not available by using timer
interrupts on other cpus. Each cpu will use its softlockup hrtimer
to check that the next cpu is processing hrtimer interrupts by
verifying that a counter is increasing.
This patch is useful on systems where the hardlockup detector is not
available due to a lack of NMIs, for example most ARM SoCs.
Without this patch any cpu stuck with interrupts disabled can
cause a hardware watchdog reset with no debugging information,
but with this patch the kernel can detect the lockup and panic,
which can result in useful debugging info.
Change-Id: Ia5faf50243e19c1755201212e04c8892d929785a
Signed-off-by: Colin Cross <ccross@android.com>
Place SLPZ pin in sleep state at system suspend time if a GPIO is
provided by board platform data.
Change-Id: I93c61fa0ae474e968e0f909209c9bfcaafe3dd2c
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Add wake_peer which is called before starting UART TX. The idea here
is to provide a mechanism where we can wakeup our peer before sending
data.
Change-Id: I42e0779b635f64ca99184b45d5b028de80197491
Signed-off-by: San Mehat <san@google.com>
(cherry picked from commit https://lkml.org/lkml/2015/12/21/337)
ASLR only uses as few as 8 bits to generate the random offset for the
mmap base address on 32 bit architectures. This value was chosen to
prevent a poorly chosen value from dividing the address space in such
a way as to prevent large allocations. This may not be an issue on all
platforms. Allow the specification of a minimum number of bits so that
platforms desiring greater ASLR protection may determine where to place
the trade-off.
Bug: 24047224
Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>
Change-Id: Ibf9ed3d4390e9686f5cc34f605d509a20d40e6c2
Userspace processes often have multiple allocators that each do
anonymous mmaps to get memory. When examining memory usage of
individual processes or systems as a whole, it is useful to be
able to break down the various heaps that were allocated by
each layer and examine their size, RSS, and physical memory
usage.
This patch adds a user pointer to the shared union in
vm_area_struct that points to a null terminated string inside
the user process containing a name for the vma. vmas that
point to the same address will be merged, but vmas that
point to equivalent strings at different addresses will
not be merged.
Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name);
Setting the name to NULL clears it.
The names of named anonymous vmas are shown in /proc/pid/maps
as [anon:<name>] and in /proc/pid/smaps in a new "Name" field
that is only present for named vmas. If the userspace pointer
is no longer valid all or part of the name will be replaced
with "<fault>".
The idea to store a userspace pointer to reduce the complexity
within mm (at the expense of the complexity of reading
/proc/pid/mem) came from Dave Hansen. This results in no
runtime overhead in the mm subsystem other than comparing
the anon_name pointers when considering vma merging. The pointer
is stored in a union with fieds that are only used on file-backed
mappings, so it does not increase memory usage.
Includes fix from Jed Davis <jld@mozilla.com> for typo in
prctl_set_vma_anon_name, which could attempt to set the name
across two vmas at the same time due to a typo, which might
corrupt the vma list. Fix it to use tmp instead of end to limit
the name setting to a single vma at a time.
Change-Id: I9aa7b6b5ef536cd780599ba4e2fba8ceebe8b59f
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Add a skip_initramfs option to allow choosing whether to boot using
the initramfs or not at runtime.
Change-Id: If30428fa748c1d4d3d7b9d97c1f781de5e4558c3
Signed-off-by: Rom Lemarchand <romlem@google.com>
The old logic assumes CMDLINE_FROM_BOOTLOADER vs. CMDLINE_FORCE and
ignores CMDLINE_EXTEND. Here's the old logic:
- CONFIG_CMDLINE_FORCE=true
CONFIG_CMDLINE
- dt bootargs=non-empty:
dt bootargs
- dt bootargs=empty, @data is non-empty string
@data is left unchanged
- dt bootargs=empty, @data is empty string
CONFIG_CMDLINE (or "" if that's not defined)
The new logic is now documented in of_fdt.h and is copied here for
reference:
- CONFIG_CMDLINE_FORCE=true
CONFIG_CMDLINE
- CONFIG_CMDLINE_EXTEND=true, @data is non-empty string
@data + dt bootargs (even if dt bootargs are empty)
- CONFIG_CMDLINE_EXTEND=true, @data is empty string
CONFIG_CMDLINE + dt bootargs (even if dt bootargs are empty)
- CMDLINE_FROM_BOOTLOADER=true, dt bootargs=non-empty:
dt bootargs
- CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is non-empty string
@data is left unchanged
- CMDLINE_FROM_BOOTLOADER=true, dt bootargs=empty, @data is empty string
CONFIG_CMDLINE (or "" if that's not defined)
Signed-off-by: Doug Anderson <dianders@chromium.org>
CC: devicetree-discuss@lists.ozlabs.org
CC: Grant Likely <grant.likely@secretlab.ca>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Rob Herring <rob.herring@calxeda.com>
Change-Id: I40ace250847f813358125dfcaa8998fd32cf7ea3
Signed-off-by: Colin Cross <ccross@android.com>
At times, it is necessary for boards to provide some additional information
as part of panic logs. Provide information on the board hardware as part
of panic logs.
It is safer to print this information at the very end in case something
bad happens as part of the information retrieval itself.
To use this, set global mach_panic_string to an appropriate string in the
board file.
Change-Id: Id12cdda87b0cd2940dd01d52db97e6162f671b4d
Signed-off-by: Nishanth Menon <nm@ti.com>
PR_SET_TIMERSLACK_PID value keep colliding with that of
newer prctls in mainline (e.g. first with PR_SET_THP_DISABLE,
and again with PR_MPX_ENABLE_MANAGEMENT).
So reset PR_SET_TIMERSLACK_PID to a large number so as to
avoid conflict in the near term while it is out of mainline
tree.
Corresponding Change-Id up for review in platform/system/core
is Icd8c658c8eb62136dc26c2c4c94f7782e9827cdb
Change-Id: I061b25473acc020c13ee22ecfb32336bc358e76a
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Second argument is similar to PR_SET_TIMERSLACK, if non-zero then the
slack is set to that value otherwise sets it to the default for the thread.
Takes PID of the thread as the third argument.
This allows power/performance management software to set timer slack for
other threads according to its policy for the thread (such as when the
thread is designated foreground vs. background activity)
Change-Id: I744d451ff4e60dae69f38f53948ff36c51c14a3f
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Refactor *allow_attach() handler to align it with the changes
from mainline commit 1f7dd3e5a6 "cgroup: fix handling of
multi-destination migration from subtree_control enabling".
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
