Commit Graph

9 Commits

Author SHA1 Message Date
Peter Collingbourne affb132ab8 hwasan: Move stack ring buffer initialization before InitStackAndTls.
D104248 moved the call to GetThreadStackAndTls to before the
initialization of the ring buffer TLS slot. As a result, if libc
is instrumented we crash in pthread_getattr_np which is called from
__sanitizer::GetThreadStackTopAndBottom.

Fix the problem by moving the stack ring buffer initialization before
the call to InitStackAndTls.

Differential Revision: https://reviews.llvm.org/D108184
2021-08-17 10:18:07 -07:00
Leonard Chan 966386514b [compiler-rt][hwasan] Setup hwasan thread handling on Fuchsia
This patch splits up hwasan thread creation between `__sanitizer_before_thread_create_hook`,
`__sanitizer_thread_create_hook`, and `__sanitizer_thread_start_hook`.
The linux implementation creates the hwasan thread object inside the
new thread. On Fuchsia, we know the stack bounds before thread creation,
so we can initialize part of the thread object in `__sanitizer_before_thread_create_hook`,
then initialize the stack ring buffer in `__sanitizer_thread_start_hook`
once we enter the thread.

Differential Revision: https://reviews.llvm.org/D104085
2021-07-07 15:05:28 -07:00
Leonard Chan b06fbdeae7 [compiler-rt][hwasan] Add InitState options to thread initialization
Similar to InitOptions in asan, we can use this optional struct for
initializing some members thread objects before they are created. On
linux, this is unused and can remain undefined. On fuchsia, this will
just be the stack bounds.

Differential Revision: https://reviews.llvm.org/D104553
2021-06-23 11:42:14 -07:00
Leonard Chan 88d93923e6 [compiler-rt][hwasan] Move Thread::Init into hwasan_linux.cpp
This allows for other implementations to define their own version of `Thread::Init`.
This will be the case for Fuchsia where much of the thread initialization can be
broken up between different thread hooks (`__sanitizer_before_thread_create_hook`,
`__sanitizer_thread_create_hook`, `__sanitizer_thread_start_hook`). Namely, setting
up the heap ring buffer and stack info and can be setup before thread creation.
The stack ring buffer can also be setup before thread creation, but storing it into
`__hwasan_tls` can only be done on the thread start hook since it's only then we
can access `__hwasan_tls` for that thread correctly.

Differential Revision: https://reviews.llvm.org/D104248
2021-06-18 10:32:41 -07:00
Evgenii Stepanov 18959a6a09 [hwasan] Fix missing synchronization in AllocThread.
The problem was introduced in D100348.

It's really hard to trigger the bug in a stress test - the race is just too
narrow - but the new checks in Thread::Init should at least provide usable
diagnostic if the problem ever returns.

Differential Revision: https://reviews.llvm.org/D101881
2021-05-05 11:57:18 -07:00
Matt Morehouse fe5f66d925 [HWASan][NFC] Introduce constants for tag bits and masks.
x86_64 aliasing mode will use fewer than 8 bits for tags, so refactor
existing code to remove hard-coded 0xff and 8 values.

Reviewed By: vitalybuka, eugenis

Differential Revision: https://reviews.llvm.org/D98072
2021-03-22 12:32:29 -07:00
Evgenii Stepanov eaea9ed835 [hwasan] Reset current thread pointer on thread exit.
Summary:
This is necessary to handle calls to free() after __hwasan_thread_exit,
which is possible in glibc.

Also, add a null check to GetCurrentThread, otherwise the logic in
GetThreadByBufferAddress turns it into a non-null value. This means that
all of the checks for GetCurrentThread() != nullptr do not have any
effect at all right now!

Reviewers: pcc, hctim

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D79608
2020-05-08 10:31:25 -07:00
Peter Collingbourne d57f7cc15e hwasan: Use bits [3..11) of the ring buffer entry address as the base stack tag.
This saves roughly 32 bytes of instructions per function with stack objects
and causes us to preserve enough information that we can recover the original
tags of all stack variables.

Now that stack tags are deterministic, we no longer need to pass
-hwasan-generate-tags-with-calls during check-hwasan. This also means that
the new stack tag generation mechanism is exercised by check-hwasan.

Differential Revision: https://reviews.llvm.org/D63360

llvm-svn: 363636
2019-06-17 23:39:51 +00:00
Nico Weber e3b6d11038 hwasan: Rename source files from cc to cpp
As discussed elsewhere: LLVM uses cpp as its C++ source extension; the
sanitizers should too. This updates files in hwasan.

Patch generated by

    for f in lib/hwasan/*.cc ; do svn mv $f ${f%.cc}.cpp; done

followed by

    for f in lib/hwasan/*.cpp ; do sed -i '' -e '1s/\.cc -/.cpp /' $f; done

CMakeLists.txt updated manually.

Differential Revision: https://reviews.llvm.org/D58620

llvm-svn: 354989
2019-02-27 15:44:03 +00:00