mte_supported() lets code efficiently detect the presence of MTE, and
ScopedDisableMTE lets code disable MTE RAII-style in a particular region
of code.
Bug: 135772972
Change-Id: I628a054b50d79f67f39f35d44232b7a2ae166afb
Fixes includes in heap tagging to ensure that bionic under MTE builds
successfully.
Thanks Kevin for finding this!
Test: TARGET_EXPERIMENTAL_MTE=true mmma bionic
Bug: N/A
Change-Id: Idd1b9ed3737e48a35f8d8628d13e85f1d58f5c93
This patch introduces tagged pointers to bionic. We add a static tag to
all pointers on arm64 compatible platforms (needs requisite
top-byte-ignore hardware feature and relevant kernel patches).
We dynamically detect TBI-compatible devices (a device with the TBI feature and
kernel support) at process start time, and insert an implementation-dependent
tag into the top byte of the pointer for all heap allocations. We then check
that the tag has not been truncated when deallocating the memory.
If an application incorrectly writes to the top byte of the pointer, we
terminate the process at time of detection. This will allow MTE-incompatible
applications to be caught early.
Bug: 135754954
Bug: 147147490
Test: cd bionic && atest .
Change-Id: Ie424325ba1e3c4443040ac265aeaa28d9e405d28
setprogname() does a basename, but we were initializing __progname
directly. Stop doing that, and add some tests.
Test: treehugger
Change-Id: I06f306ade4161b2f0c7e314a3b1b30c9420117b7
Updates getifaddrs() to behave as if RTM_GETLINK requests are not
allowed for non-system apps that have their target SDK set to R.
This change will be reverted when kernel changes enforcing this behavior
are merged, and is purely meant to check for potential appcompat issues
beforehand.
Bug: 141455849
Test: atest bionic-unit-tests-static
Test: atest NetworkInterfaceTest
Test: Connect to Wi-Fi network
Test: Set up hotspot
Test: Cast from device
Test: Pair Bluetooth device
Test: Call getifaddrs() directly from within an app.
Test: Call NetworkInterface#getNetworkInterfaces() from within an app.
Test: Repeat above tests with an app that targets Android R.
Change-Id: I472891d3e8a18c86ae478be1bab1048636aa95b4
The previous implementation of getifaddrs() depended on RTM_GETLINK requests being allowed, returning an error otherwise. This change makes getifaddrs() attempt to get all necessary information from RTM_NEWADDR messages when RTM_NEWLINK messages are not available.
The code is functionally the same when RTM_GETLINK requests are allowed. When RTM_GETLINK requests are denied, only interfaces that have a network address are returned, and physical addresses for these interfaces remain unset.
In addition, this change updates the copyright notice because repohooks asked nicely.
Bug: 141455849
Test: atest bionic-unit-tests-static
Test: atest NetworkInterfaceTest
Test: Connect to Wi-Fi network
Test: Set up hotspot
Test: Cast from device
Test: Pair Bluetooth device
Test: Call getifaddrs() directly from within an app.
Test: Call NetworkInterface#getNetworkInterfaces() from within an app.
Change-Id: Ia47e037d181ca5df6d9fdae19b405cabfafc6b0f
Use O_PATH like musl to let the kernel do the hard work, rather than the
traditional BSD manual scheme.
Also add the most obvious missing tests from reading the man page, plus
a non-obvious test for deleted files.
Bug: http://b/131435126
Test: treehugger
Change-Id: Ie8a8986fea55f045952a81afee377ce8288a49d5
The BSD "Not a typewriter" translation of ENOTTY looks very weird in
2020. The glibc "Inappropriate ioctl for device" is more generic, and
so much less likely to be inappropriate.
Test: strace on a failed fs ioctl
Change-Id: Iad374d6b91ca9f2e4fa1079986fd698feef8359f
This reverts commit 43d5f9d4dd.
Bug: 135754954
Bug: 147147490
Exempt-From-Owner-Approval: clean revert
Reason for revert: Breaks ART gtest, see:
https://ci.chromium.org/p/art/builders/ci/angler-armv8-non-gen-cc/561
The crash happens on mprotect of a page, the test crashes with ENOMEM.
Change-Id: I52eea1abbfaf8d8e2226f92d30aa55aba3810528
This patch introduces tagged pointers to bionic. We add a static tag to
all pointers on arm64 compatible platforms (needs requisite
top-byte-ignore hardware feature and relevant kernel patches).
We dynamically detect TBI-compatible devices (a device with the TBI feature and
kernel support) at process start time, and insert an implementation-dependent
tag into the top byte of the pointer for all heap allocations. We then check
that the tag has not been truncated when deallocating the memory.
If an application incorrectly writes to the top byte of the pointer, we
terminate the process at time of detection. This will allow MTE-incompatible
applications to be caught early.
Bug: 135754954
Bug: 147147490
Test: cd bionic && atest .
Change-Id: I6e5b809fc81f55dd517f845eaf20f3c0ebd4d86e
This patch adds a case for the profiling signal handler (previously just
for native heapprofd profiling) when si_value == 1, corresponding to
traced_perf being the requesting party.
The handler opens /proc/self/{maps,mem}, connects to (init-created)
/dev/socket/traced_perf, and then sends the fds over the socket.
Everything happens synchronously within the signal handler. Socket is
made non-blocking, and we do not retry.
Bug: 144281346
Change-Id: Iea904694caeefe317ed8818e5b150e8819af91c2
This patch refactors heapprofd_malloc to make it easier to reuse the
reserved signal for multiple purposes. We define a new generic signal
handler for profilers, which dispatches to more specific logic based on
the signal's payload (si_value).
The profiler signal handler is installed during libc preinit, after
malloc initialization (so races against synchronous heapprofd
initialization need not be considered). In terms of code organization, I
copied the existing approach with a loosely referenced function in
bionic_globals.h. Do tell if you'd rather a different approach here.
The profileability of a process is quite tied to the malloc
files/interfaces in bionic - in particular, it's set through
android_mallopt. I do not change that, but instead introduce a new
android_mallopt option to be able to query profileability of the
process (which is now used by the new profiler signal handler). As part
of that, gZygoteChildProfileable is moved from heapprofd_malloc to
common (alongside gZygoteChild).
I've removed the masking and reraising of the heapprofd signal when
racing against malloc_limit init. We're ok with taking a simpler
approach and dropping the heapprofd signal in such an unlikely race.
Note: this requires a corresponding change in heapprofd to use sigqueue()
instead of kill(), as the latter leaves the si_value uninitialized(?) on
the receiving side.
Bug: 144281346
Change-Id: I93bb2e82cff5870e5ca499cf86439860aca9dfa5
This is attempt number two, all known failures and issues have
been fixed.
Bug: 137795072
Test: Built both svelte and non-svelte versions. Ran enormous numbers
Test: of performance testing.
Test: Ran scudo unit tests.
Test: Ran bionic unit tests.
Test: Ran libmemunreachable tests.
Test: Ran atest CtsRsBlasTestCases on cuttlefish instance.
Change-Id: Ib0c6ef38b63b7a1f39f4431ed8414afe3a92f9b5
This doesn't add any functionality for now, but there are
a couple of changes in flight that will want to add enumerators
to the mallopt, so let's give them a place to add them.
Bug: 135772972
Bug: 135754954
Change-Id: I6e810020f66070e844500c6fa99b703963365659
Historically we've made a few mistakes where they haven't matched the
right number. And most non-Googlers are much more familiar with the
numbers, so it seems to make sense to rely more on them. Especially in
header files, which we actually expect real people to have to read from
time to time.
Test: treehugger
Change-Id: I0d4a97454ee108de1d32f21df285315c5488d886
This reverts commit 6ffbe97859.
Reason for revert: Droidcop-triggered revert due to breakage b/146543543
Change-Id: Ie9a5b2f6ca5dbc8d3c6cafe70e34838d74e45c56
Bug: 146543543
Bug: 137795072
Test: Built both svelte and non-svelte versions. Ran enormous numbers
Test: of performance testing.
Test: Ran scudo unit tests.
Test: Ran bionic unit tests.
Change-Id: Iec6c98f2bdf6e0d5a6d18dff0c0883fac391c6d5
This is a no-op (kernel returns -EINVAL) if the kernel doesn't understand
the prctl.
Bug: 144799191
Change-Id: I8708e92e31d7a60b2847ae2bc242e46dafb77680
For reasons explained in the code comment, go back to roughly our old
code. The "new" tests are just the old tests resurrected.
This also passes the current toybox xargs tests, which were the
motivation for going back on our earlier decision.
Test: bionic and toybox tests
Change-Id: I33cbcc04107efe81fdbc8166dc9ae844e471173e
Currently, scudo doesn't call libc's malloc initialisers. This causes
problems with any functionality that relies on an initialised__libc_globals
inside of bionic malloc's stubs (e.g. malloc()).
This manifests in two ways (that I can think of):
1. Dispatch tables don't work with scudo, so malloc_debug has never
worked in an executable linked against scudo.
2. Allocators that require initialisation and are called from bionic
malloc's stubs (GWP-ASan) never get initialised.
Bug: 135634846
Test: atest bionic-unit-tests-scudo
Change-Id: I3e3344d7d510ce4e8d3709cd69c8cb0fe5adedda
pthread_atfork may call malloc() during its once-init. This causes
problems with allocators (GWP-ASan) that require explicit initialisation
before calls to malloc().
Bug: 135634846
Test: atest bionic
Change-Id: I1810a00465db99d5aa34fa6f74dea5908a628d3a
Right now, when we read a system property, we first (assuming we've
already looked up the property's prop_info) read the property's serial
number; if we find that the low bit (the dirty bit) in the serial
number is set, we futex-wait for that serial number to become
non-dirty. By doing so, we spare readers from seeing partially-updated
property values if they race with the property service's non-atomic
memcpy to the property value slot. (The futex-wait here isn't
essential to the algorithm: spinning while dirty would suffice,
although it'd be somewhat less efficient.)
The problem with this approach is that readers can wait on the
property service process, potentially causing delays due to scheduling
variance. Property reads are not guaranteed to complete in finite time
right now.
This change makes property reads wait-free and ensures that they
complete in finite time in all cases. In the new approach, we prevent
value tearing by backing up each property we're about to modify and
directing readers to the backup copy if they try to read a property
with the dirty bit set.
(The wait freedom is limited to the case of readers racing against
*one* property update. A writer can still delay readers by rapidly
updating a property --- but after this change, readers can't hang due
to PID 1 scheduling delays.)
I considered adding explicit atomic access to short property values,
but between binary compatibility with the existing property database
and the need to carefully handle transitions of property values
between "short" (compatible with atomics) and "long" (incompatible
with atomics) length domains, I figured the complexity wasn't worth it
and that making property reads wait-free would be adequate.
Test: boots
Bug: 143561649
Change-Id: Ifd3108aedba5a4b157b66af6ca0a4ed084bd5982
I have no idea why I used the iterate name internally which is
completely unlike every other function name. Change this to match
everyone else so that it's now malloc_iterate everywhere.
This is probably the last chance to change this before mainline
modules begin, so make everything consistent.
Test: Compiles, unit tests passes.
Change-Id: I56d293377fa0fe1a3dc3dd85d6432f877cc2003c
