AddressableBits is in the Utility module of LLDB. It currently directly
refers to Process, which is from the Target LLDB module. This is a
layering violation which concretely means that it is impossible to link
anything that uses Utility without it also using Target as well. This is
generally not an issue for LLDB (since everything is built together) but
it may make it difficult to write unit tests for AddressableBits later
on.
[lldb] Add SBProcess methods for get/set/use address masks (#83095)
I'm reviving a patch from phabracator, https://reviews.llvm.org/D155905
which was approved but I wasn't thrilled with all the API I was adding
to SBProcess for all of the address mask types / memory regions. In this
update, I added enums to control type address mask type (code, data,
any) and address space specifiers (low, high, all) with defaulted
arguments for the most common case. I originally landed this via
https://github.com/llvm/llvm-project/pull/83095 but it failed on CIs
outside of arm64 Darwin so I had to debug it on more environments
and update the patch.
This patch is also fixing a bug in the "addressable bits to address
mask" calculation I added in AddressableBits::SetProcessMasks. If lldb
were told that 64 bits are valid for addressing, this method would
overflow the calculation and set an invalid mask. Added tests to check
this specific bug while I was adding these APIs.
This patch changes the value of "no mask set" from 0 to
LLDB_INVALID_ADDRESS_MASK, which is UINT64_MAX. A mask of all 1's
means "no bits are used for addressing" which is an impossible mask,
whereas a mask of 0 means "all bits are used for addressing" which
is possible.
I added a base class implementation of ABI::FixCodeAddress and
ABI::FixDataAddress that will apply the Process mask values if they
are set to a value other than LLDB_INVALID_ADDRESS_MASK.
I updated all the callers/users of the Mask methods which were
handling a value of 0 to mean invalid mask to use
LLDB_INVALID_ADDRESS_MASK.
I added code to the all AArch64 ABI Fix* methods to apply the
Highmem masks if they have been set. These will not be set on a
Linux environment, but in TestAddressMasks.py I test the highmem
masks feature for any AArch64 target, so all AArch64 ABI plugins
must handle it.
rdar://123530562
This reverts commit 9a12b0a60084b2b92f728e1bddec884a47458459.
TestAddressMasks fails its first test on lldb-x86_64-debian,
lldb-arm-ubuntu, lldb-aarch64-ubuntu bots. Reverting while
investigating.
I'm reviving a patch from phabracator, https://reviews.llvm.org/D155905
which was approved but I wasn't thrilled with all the API I was adding
to SBProcess for all of the address mask types / memory regions. In this
update, I added enums to control type address mask type (code, data,
any) and address space specifiers (low, high, all) with defaulted
arguments for the most common case.
This patch is also fixing a bug in the "addressable bits to address
mask" calculation I added in AddressableBits::SetProcessMasks. If lldb
were told that 64 bits are valid for addressing, this method would
overflow the calculation and set an invalid mask. Added tests to check
this specific bug while I was adding these APIs.
rdar://123530562
I wrote some complicated conditionals for how to handle a partially
specified AddressableBits object in https://reviews.llvm.org/D158041 ,
and how to reuse existing masks if they were set and we had an
unspecified value.
I don't think this logic is the right thing to start
with. Simplify back to the most straightforward
setting, where only the bits that have been specified
are set in the Process.
Add support for the `low_mem_addressing_bits` and
`high_mem_addressing_bits` keys in the stop reply packet,
in addition to the existing `addressing_bits`. Same
behavior as in the qHostInfo packet.
Clean up AddressableBits so we don't need to check if
any values have been set in the object before using it
to potentially update the Process address masks.
Differential Revision: https://reviews.llvm.org/D158041
On AArch64 systems, we may have different page table setups for
low memory and high memory, and therefore a different number of
bits used for addressing depending on which half of memory the
address is in.
This patch extends the qHostInfo and LC_NOTE "addrable bits" so
that it can specify the number of addressing bits in high memory
and in low memory separately. It builds on the patch I added in
https://reviews.llvm.org/D151292 where Process tracks the separate
address masks, and there is a user setting to set them manually.
Differential Revision: https://reviews.llvm.org/D157667
rdar://113225907
