This is important as with exceptions enabled, non-POD allocas often have
two lifetime ends: the exception handler, and the normal one.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D108365
In that case it is very likely that there will be a tag mismatch anyway.
We handle the case that the pointer belongs to neither of the allocators
by getting a nullptr from allocator.GetBlockBegin.
Reviewed By: hctim, eugenis
Differential Revision: https://reviews.llvm.org/D108383
Fixes a regression when the allocator is disabled, and a dirty
allocation is re-used. This only occurs when the allocator is disabled,
so a test-only fix, but still necessary.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D108650
The shadow for a short granule is stored in the last byte of the
granule. Currently, if there's a tail-overwrite report (a
buffer-overflow-write in uninstrumented code), we report the shadow byte
as a mismatch against the magic.
Fix this bug by slapping the shadow into the expected value. This also
makes sure that if the uninstrumented WRITE does clobber the shadow
byte, it reports the shadow was actually clobbered as well.
Reviewed By: eugenis, fmayer
Differential Revision: https://reviews.llvm.org/D107938
Before this change we were locking the StackDepot in the fork()
interceptor. This results in a deadlock when allocator functions are
used in a pthread_atfork() callback.
Instead, set up a pthread_atfork() callback at init that locks/unlocks
both StackDepot and the allocator. Since our callback is set up very
early, the pre-fork callback is executed late, and both post-fork ones
are executed early, which works perfect for us.
Differential Revision: https://reviews.llvm.org/D108063
Since d564cfb53c71dbbbd46b6719f5fe53d70313de45 moved
__hwasan_tag_mismatch4 this test has been reporting
a frame 0 of __hwasan_tag_mismatch_v2.
This failure can be seen on our bots:
https://lab.llvm.org/buildbot/#/builders/185/builds/170
Before the change:
#0 0xaaaaba100e40 in main <...>/register-dump-read.c:21:10
After the change:
#0 0xaaaab8494bec in __hwasan_tag_mismatch_v2 <...>/hwasan/hwasan_tag_mismatch_aarch64.S:147
#1 0xaaaab84b4df8 in main <..>/register-dump-read.c:14:10
Update the test to check for a main frame as either frame
0 or frame 1.
The existing one actually failed on the int* p, not on int z (as can be
seen by the fault being 8 bytes rather than 4).
This is also needed to make sure the stack safety analysis does not
classify the alloca as safe.
Reviewed By: hctim
Differential Revision: https://reviews.llvm.org/D105705
We would find an address with matching tag, only to discover in
ShowCandidate that it's very far away from [stack].
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105197
If the fault address is at the boundary of memory regions, this could
cause us to segfault otherwise.
Ran test with old compiler_rt to make sure it fails.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105032
A heap or global buffer that is far away from the faulting address is
unlikely to be the cause, especially if there is a potential
use-after-free as well, so we want to show it after the other
causes.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104781
Explain what the given stack trace means before showing it, rather than
only in the paragraph at the end.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104523
The default callback instrumentation in x86 LAM mode uses ASLR bits
to randomly choose a tag, and thus has a 1/64 chance of choosing a
stack tag of 0, causing stack tests to fail intermittently. By using
__hwasan_generate_tag to pick tags, we guarantee non-zero tags and
eliminate the test flakiness.
aarch64 doesn't seem to have this problem using thread-local addresses
to pick tags, so perhaps we can remove this workaround once we implement
a similar mechanism for LAM.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D104470
Before: ADDR is located -320 bytes to the right of 1072-byte region
After: ADDR is located 752 bytes inside 1072-byte region
Reviewed By: eugenis, walli99
Differential Revision: https://reviews.llvm.org/D104412
Adds the basic instrumentation needed for stack tagging.
Currently does not support stack short granules or TLS stack histories,
since a different code path is followed for the callback instrumentation
we use.
We may simply wait to support these two features until we switch to
a custom calling convention.
Patch By: xiangzhangllvm, morehouse
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D102901
-fsanitize-hwaddress-experimental-aliasing is intended to distinguish
aliasing mode from LAM mode on x86_64. check-hwasan is configured
to use aliasing mode while check-hwasan-lam is configured to use LAM
mode.
The current patch doesn't actually do anything differently in the two
modes. A subsequent patch will actually build the separate runtimes
and use them in each mode.
Currently LAM mode tests must be run in an emulator that
has LAM support. To ensure LAM mode isn't broken by future patches, I
will next set up a QEMU buildbot to run the HWASan tests in LAM.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D102288
This test has two modes - testing reused threads with multiple loops of
batch create/join, and testing new threads with a single loop of
create/join per fork.
The non-reuse variant catches the problem that was fixed in D101881 with
a high probability.
Differential Revision: https://reviews.llvm.org/D101936
Now that page aliasing for x64 has landed, we don't need to worry about
passing tagged pointers to libc, and thus D98875 removed it.
Unfortunately, we still test on aarch64 devices that don't have the
kernel tagged address ABI (https://reviews.llvm.org/D98875#2649269).
All the memory that we pass to the kernel in these tests is from global
variables. Instead of having architecture-specific untagging mechanisms
for this memory, let's just not tag the globals.
Reviewed By: eugenis, morehouse
Differential Revision: https://reviews.llvm.org/D101121
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses. This should enable
easier experimentation with HWASan on x86_64 platforms.
Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.
Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes. This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98875
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses. This should enable
easier experimentation with HWASan on x86_64 platforms.
Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.
Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes. This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98875
Subsequent patches will implement page-aliasing mode for x86_64, which
will initially only work for the primary heap allocator. We force
callback instrumentation to simplify the initial aliasing
implementation.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98069
When adding this function in https://reviews.llvm.org/D68794 I did not
notice that internal_prctl has the API of the syscall to prctl rather
than the API of the glibc (posix) wrapper.
This means that the error return value is not necessarily -1 and that
errno is not set by the call.
For InitPrctl this means that the checks do not catch running on a
kernel *without* the required ABI (not caught since I only tested this
function correctly enables the ABI when it exists).
This commit updates the two calls which check for an error condition to
use internal_iserror. That function sets a provided integer to an
equivalent errno value and returns a boolean to indicate success or not.
Tested by running on a kernel that has this ABI and on one that does
not. Verified that running on the kernel without this ABI the current
code prints the provided error message and does not attempt to run the
program. Verified that running on the kernel with this ABI the current
code does not print an error message and turns on the ABI.
This done on an x86 kernel (where the ABI does not exist), an AArch64
kernel without this ABI, and an AArch64 kernel with this ABI.
In order to keep running the testsuite on kernels that do not provide
this new ABI we add another option to the HWASAN_OPTIONS environment
variable, this option determines whether the library kills the process
if it fails to enable the relaxed syscall ABI or not.
This new flag is `fail_without_syscall_abi`.
The check-hwasan testsuite results do not change with this patch on
either x86, AArch64 without a kernel supporting this ABI, and AArch64
with a kernel supporting this ABI.
Differential Revision: https://reviews.llvm.org/D96964
D90422 changed this test to write a fixed value into register x23
instead of x20, but it did not update the list of reserved registers.
This meant that x23 may have been live across the register write,
although this happens to not be the case with the current compiler.
Fix the problem by updating the reserved register list.
Remove an invalid check from sizes.cpp that only passes when overcommit is disabled.
Fixes PR48274.
Differential Revision: https://reviews.llvm.org/D91999
Similar to __asan_set_error_report_callback, pass the entire report to a
user provided callback function.
Differential Revision: https://reviews.llvm.org/D91825
