Commit graph

13 commits

Author SHA1 Message Date
Josh Gao
97271920bf Add a tool to track down fd leaks.
Add a hook that's called upon file descriptor creation to libc, and a
library that uses it to capture backtraces for file descriptor creation,
to make it easier to hunt down file descriptor leaks.

Currently, this doesn't capture all of the ways of creating a file
descriptor, but completeness isn't required for this to be useful as
long as leaked file descriptors are created with a function that is
tracked. The primary unhandled case is binder, which receives file
descriptors as a payload in a not-trivially-parsable byte blob, but
there's a chance that the leak we're currently trying to track down
isn't of a file descriptor received over binder, so leave that for
later.

Bug: http://b/140703823
Test: manual
Change-Id: I308a14c2e234cdba4207157b634ab6b8bc539dd9
(cherry picked from commit b7eccd4b15)
2020-01-30 13:55:10 -08:00
Mitch Phillips
3b21ada5f1 Add tagged pointers to bionic.
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
2020-01-23 10:37:24 -08:00
Ryan Savitski
e95316330b platform profiler signal: add traced_perf codepath
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
2020-01-15 22:55:04 +00:00
Ryan Savitski
175c8867b0 allow for heapprofd's signal to be multiplexed
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
2020-01-15 22:55:03 +00:00
Peter Collingbourne
6dfde988e3 Merge "Add an android_mallopt for controlling the heap tagging level." 2020-01-10 15:22:24 +00:00
Peter Collingbourne
1e110fb717 Add an android_mallopt for controlling the heap tagging level.
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
2020-01-09 16:39:10 -08:00
Josh Gao
5074e7d28f Move sigrtmin.h into platform headers.
Test: mma
Change-Id: Ibc97ef96fe9e32b948c245b06039b95fe4342f39
2020-01-02 14:14:15 -08:00
Josh Gao
4956c372cf Move bionic_macros.h from private to platform.
Test: treehugger
Change-Id: Ie473914f4c8924c7240b3ac22093a9daf42fc948
2020-01-02 14:09:50 -08:00
Peter Collingbourne
e5e7395c9f Update bionic to use the MTE API proposed on LKML.
Patch set available here:
https://lore.kernel.org/linux-arm-kernel/20191211184027.20130-1-catalin.marinas@arm.com/
and in my android-experimental-mte branch.

Bug: 135772972
Change-Id: Ib46fd508330b330ef3afc713a9a4e26675ddb857
2019-12-13 12:13:29 -08:00
Elliott Hughes
cdb52fc147 Make private/bionic_page.h available as platform/bionic/page.h.
Bug: http://b/145825270
Test: treehugger
Change-Id: I52958f370c0df2c02cb8250e2cf0705d4e93e908
2019-12-12 15:26:14 -08:00
Peter Collingbourne
900d07d6a1 Add arm64 string.h function implementations for use with hardware supporting MTE.
As it turns out, our "generic" arm64 implementations of certain string.h
functions are not actually generic, since they will eagerly read memory
possibly outside of the bounds of an MTE granule, which may lead to a segfault
on MTE-enabled hardware. Therefore, move the implementations into a "default"
directory and use ifuncs to select between them and a new set of "mte"
implementations, conditional on whether the hardware and kernel support MTE.

The MTE implementations are currently naive implementations written in C
but will later be replaced with a set of optimized assembly implementations.

Bug: 135772972
Change-Id: Ife37c4e0e6fd60ff20a34594cc09c541af4d1dd7
2019-10-29 16:18:31 -07:00
Christopher Ferris
c5d3a4348a Make tls related header files platform accessible.
There are places in frameworks and art code that directly included
private bionic header files. Move these files to the new platform
include files.

This change also moves the __get_tls.h header file to tls.h and includes
the tls defines header so that there is a single header that platform
code can use to get __get_tls and the defines.

Also, simplify the visibility rules for platform includes.

Bug: 141560639

Test: Builds and bionic unit tests pass.
Change-Id: I9e5e9c33fe8a85260f69823468bc9d340ab7a1f9
Merged-In: I9e5e9c33fe8a85260f69823468bc9d340ab7a1f9
(cherry picked from commit 44631c919a)
2019-09-27 12:14:24 -07:00
Christopher Ferris
2b0638ef29 Make bionic_malloc.h a platform header.
Instead of having platform directories directly include the
private header, create a platform header directory and export it.

Bug: 130763340

Test: Builds.
Change-Id: Ie0f092b3fe077a3de8b90266c0b28bfbc20d0dfa
Merged-In: Ie0f092b3fe077a3de8b90266c0b28bfbc20d0dfa
(cherry picked from commit 8f582ef2f8)
2019-09-16 12:27:33 -07:00