With memtag_stack, each function is responsible for cleaning up
allocation tags for its stack frame. Allocation tags for anything below
SP must match the address tag in SP.
Both vfork and longjmp implement non-local control transfer which
abandons part of the stack without proper cleanup. Update allocation
tags:
* For longjmp, we know both source and destination values of SP.
* For vfork, save the value of SP before exit() or exec*() - the only
valid ways of ending the child process according to POSIX - and reset
tags from there to SP-in-parent.
This is not 100% solid and can be confused by a number of hopefully
uncommon conditions:
* Segmented stacks.
* Longjmp from sigaltstack into the main stack.
* Some kind of userspace thread implementation using longjmp (that's UB,
longjmp can only return to the caller on the current stack).
* and other strange things.
This change adds a sanity limit on the size of the tag cleanup. Also,
this logic is only activated in the binaries that carry the
NT_MEMTAG_STACK note (set by -fsanitize=memtag-stack) which is meant as
a debugging configuration, is not compatible with pre-armv9 CPUs, and
should not be set on production code.
Bug: b/174878242
Test: fvp_mini with ToT LLVM (more test in a separate change)
Change-Id: Ibef8b2fc5a6ce85c8e562dead1019964d9f6b80b
The toolchain is new enough that should be able to use the actual
instructions now...
Test: treehugger
Change-Id: I30aafcdc5386268344c40dc6cc9a22caf591915a
The most notable change is in sigsetjmp/siglongjmp. The former
stores LR signed with the current SP into jmp_buf. Calling siglongjmp
reads a signed LR and the corresponding SP from jmp_buf. This way not
only the checksum provides some means of integrity protection but
Pointer Authentication too.
Test: Tested on FVP with BTI enabled.
Change-Id: I9d720239775f8d2829a677901f546c4b14b5cbe5
Our various fd debugging facilities get extremely confused by a vforked
process closing file descriptors in preparation to exec: fdsan can
abort, and fdtrack will delete backtraces for any file descriptors that
get closed. Keep track of whether we're in a vforked child in order to
be able to detect this.
Bug: http://b/153926671
Test: 32/64-bit bionic-unit-tests on blueline, x86_64 emulator
Change-Id: I8a082fd06bfdfef0e2a88dbce350b6f667f7df9f
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)
Call a hwasan hook in the parent return path for vfork() to let hwasan
update its shadow. See https://github.com/google/sanitizers/issues/925
for more details.
Bug: 112438058
Test: bionic-unit-tests
Change-Id: I9a06800962913e822bd66e072012d0a2c5be453d
To make it easier for Native Bridge implementations
to override these symbols.
Bug: http://b/67993967
Test: make
Change-Id: I4c53e53af494bca365dd2b3305ab0ccc2b23ba44
The use of the .hidden directive to avoid going via the PLT for
__set_errno had the side-effect of actually making __set_errno
hidden (which is odd because assembler directives don't usually
affect symbols defined in a different file --- you can't even
create a weak reference to a symbol that's defined in a different
file).
This change switches the system call stubs over to a new always-hidden
__set_errno_internal and has a visible __set_errno on LP32 just for
binary compatibility with old NDK apps.
(cherry-pick of 7efad83d430f4d824f2aaa75edea5106f6ff8aae.)
Bug: 17423135
Change-Id: I6b6d7a05dda85f923d22e5ffd169a91e23499b7b
vfork() was removed from POSIX 2008, so this replaces its implementation
with a call to fork().
Bug: 13935372
Change-Id: I6d99ac9e52a2efc5ee9bda1cab908774b830cedc
Fix syscall generator to add cfi directives and add the directives
for all arm64 assembler.
Bug: 15138290
Change-Id: I7f0e4a16c141ac624e5276917a3a1ed45778e057
