The ARM Guarded Control Stack extension (GCS) is similar to existing
shadow stack extensions for other architectures.
The core note will include which features of GCS are enabled, which have
been locked in their current state, and the stack pointer of the shadow
stack.
Note that 0x40f is NT_ARM_POE, FPMR is supported by LLDB and GCS will be
soon, POE is not at this time. So NT_ARM_POE will be added when that
work starts.
See
https://github.com/torvalds/linux/blob/master/include/uapi/linux/elf.h.
This patch introduces a new generic target, `gfx9-4-generic`. Since it doesn’t support FP8 and XF32-related instructions, the patch includes several code reorganizations to accommodate these changes.
For llvm_linux platform, define the following meaning for bits 9, 10,
11:
- bit 9: set if indirect gotos signing is enabled;
- bit 10: set if type info vtable pointer discrimination is enabled;
- bit 11: set if function pointer type discrimination is enabled.
This contains the fpmr register which was added in Armv9.5-a. This
register mainly contains controls for fp8 formats.
It was added to the Linux Kernel in
4035c22ef7.
Treat 8th bit of version value for llvm_linux platform as signed GOT
flag.
- clang: define `PointerAuthELFGOT` LangOption and set 8th bit of
`aarch64-elf-pauthabi-version` LLVM module flag correspondingly;
- llvm-readobj: print `PointerAuthELFGOT` or `!PointerAuthELFGOT` in
version description of llvm_linux platform depending on whether the flag
is set.
If both `-fptrauth-init-fini` and `-fptrauth-calls` are passed, sign
function pointers in `llvm.global_ctors` and `llvm.global_dtors` with
constant discriminator 0xD9D4
(`ptrauth_string_discriminator("init_fini")`). Additionally, if
`-fptrauth-init-fini-address-discrimination` is passed, address
discrimination is used for signing (otherwise, just constant
discriminator is used).
For address discrimination, we use it's special form since uses of
`llvm.global_{c|d}tors` are disallowed (see
`Verifier::visitGlobalVariable`) and we can't emit `getelementptr`
expressions referencing these special arrays. A signed ctor/dtor pointer
with special address discrimination applied looks like the following:
```
ptr ptrauth (ptr @foo, i32 0, i64 55764, ptr inttoptr (i64 1 to ptr))
```
It turns out that the notes section for corefiles (or really any elf
file with multiple notes) is set up in such a way for LLVM formatted
output that the JSON equivalent only has the last note since the notes
are held in a dictionary with every key being Note. This pr alters the
layout for the notes to a list of dictionaries to sidestep this issue
for JSON output. Prior to this pr a note section in the output looked
like (for LLVM output):
```
Notes [
NoteSection {
Name: <?>
Offset: 0x2148
Size: 0x1F864
Note {
Owner: CORE
Data size: 0x150
Type: NT_PRSTATUS (prstatus structure)
Description data (
0000: 06000000 00000000 00000000 06000000 |................|
...
)
}
Note {
Owner: CORE
Data size: 0x88
Type: NT_PRPSINFO (prpsinfo structure)
Description data (
0000: 02440000 00000000 04054040 00000000 |.D........@@....|
....
```
But is now:
```
NoteSections [
NoteSection {
Name: <?>
Offset: 0x2148
Size: 0x1F864
Notes [
{
Owner: CORE
Data size: 0x150
Type: NT_PRSTATUS (prstatus structure)
Description data (
0000: 06000000 00000000 00000000 06000000 |................|
...
)
}
{
Owner: CORE
Data size: 0x88
Type: NT_PRPSINFO (prpsinfo structure)
Description data (
0000: 02440000 00000000 04054040 00000000 |.D........@@....|
...
```
CREL is a compact relocation format for the ELF object file format.
This patch adds integrated assembler support (using the RELA form)
available with `llvm-mc -filetype=obj -crel a.s -o a.o`.
A dependent patch will add `clang -c -Wa,--crel,--allow-experimental-crel`.
Also add llvm-readobj support (for both REL and RELA forms) to
facilitate testing the assembler. Additionally, yaml2obj gains support
for the RELA form to aid testing with llvm-readobj.
We temporarily assign the section type code 0x40000020 from the generic
range to `SHT_CREL`. We avoided using `SHT_LLVM_` or `SHT_GNU_` to
avoid code churn and maintain broader applicability for interested psABIs.
Similarly, `DT_CREL` is temporarily 0x40000026.
LLVM will change the code and break compatibility. This is not an issue
if all relocatable files using CREL are regenerated (aka no prebuilt
relocatable files).
Link: https://discourse.llvm.org/t/rfc-crel-a-compact-relocation-format-for-elf/77600
Pull Request: https://github.com/llvm/llvm-project/pull/91280
In the context of #95976 it became clear that the output for readobj
implied multi valued entries in several cases in the elf headers that
the documentation only allowed for a single value. DT_NEEDED is the
example here where the value is an offset into the string table without
any sort of separator that could give you multiple entries. This patch
alters the LLVM output so that the single valued nature is emphasized.
For example the output was:
```
DynamicSection [ (35 entries)
Tag Type Name/Value
0x000000000000001D RUNPATH Library runpath: [$ORIGIN/../lib:]
0x0000000000000001 NEEDED Shared library: [libm.so.6]
0x0000000000000001 NEEDED Shared library: [libz.so.1]
0x0000000000000001 NEEDED Shared library: [libzstd.so.1]
```
and is now
```
Tag Type Name/Value
0x000000000000001D RUNPATH Library runpath: [$ORIGIN/../lib:]
0x0000000000000001 NEEDED Shared library: libm.so.6
0x0000000000000001 NEEDED Shared library: libz.so.1
0x0000000000000001 NEEDED Shared library: libzstd.so.1
```
This pr also tests that multi-valued rpaths are handled correctly in the
JSON case (i.e. they become proper lists) like:
```
{
"Tag": 15,
"Type": "RPATH",
"Value": 9,
"Path": [
"x",
"w",
"U"
]
},
```
when separated by :
When printing JSON output with --dynamic-table I noticed that the output
is invalid JSON. This patch overrides the printDynamicTable() function
in the JSONELFDumper to return a list of dictionaries for the
DynamicSection value.
Before the output was:
```
{
"FileSummary": {
"File": "bin/llvm-readelf",
"Format": "elf64-x86-64",
"Arch": "x86_64",
"AddressSize": "64bit",
"LoadName": "<Not found>"
}DynamicSection [ (35 entries)
Tag Type Name/Value
0x000000000000001D RUNPATH Library runpath: [$ORIGIN/../lib:]
0x0000000000000001 NEEDED Shared library: [libm.so.6]
0x0000000000000001 NEEDED Shared library: [libz.so.1]
0x0000000000000001 NEEDED Shared library: [libzstd.so.1]
```
Now the output looks like:
```
"DynamicSection": [
{
"Tag": 29,
"Type": "RUNPATH",
"Value": 6322,
"Path": [
"$ORIGIN/../lib"
]
},
{
"Tag": 1,
"Type": "NEEDED",
"Value": 6109,
"Library": "libm.so.6"
},
```
This patch fixes an issue where, when printing corefile notes with
llvm-readobj as json, the dumper generated llvm formatted output which
isn't valid json. This alters the dumper to, in the NT_FILE, note, dump
properly formatted json data.
Prior to this patch the JSON output was formatted like:
```
"Mapping": [
"Start": 4096,
"End": 8192,
"Offset": 12288,
"Filename": "/path/to/a.out"
],
```
Whereas now it is formatted as:
```
"Mappings": [
{
"Start": 4096,
"End": 8192,
"Offset": 12288,
"Filename": "/path/to/a.out"
},
```
Which is valid. Additionally the LLVM output has changed to match the
structure of the JSON output (i.e. instead of lists of keys it is a list
of dictionaries)
https://reviews.llvm.org/D47919 dumped RELR relocations as
`R_*_RELATIVE` and added --raw-relr (not in GNU) for testing purposes
(more readable than `llvm-readelf -x .relr.dyn`). The option is obsolete
after `llvm-readelf -r` output gets improved (#89162).
Since --raw-relr never seems to get more adoption. Let's remove it to
avoid some complexity.
Pull Request: https://github.com/llvm/llvm-project/pull/89426
llvm-readelf/llvm-readobj print RELR as REL relocations with a fixed
type (e.g. `R_*_RELATIVE`). GNU readelf printed only addresses and have
recently switched to a more descritive style that includes a symbolic
address column (symbolized using .symtab/.strtab) (milestone: binutils
2.43).
This patch implements the new GNU style, which seems superior to the
current REL style and essentially obsoletes LLVM-specific --raw-relr
(`printRelrReloc`).
Pull Request: https://github.com/llvm/llvm-project/pull/89162
Reland #85231 after fixing build failure
https://lab.llvm.org/buildbot/#/builders/186/builds/15631.
Use `PRIx64` for format output of `uint64_t` as hex.
Original PR description below.
This adds support for `GNU_PROPERTY_AARCH64_FEATURE_PAUTH` feature (as
defined in https://github.com/ARM-software/abi-aa/pull/240) handling in
llvm-readobj and llvm-readelf. The following constants for supported
platforms are also introduced:
- `AARCH64_PAUTH_PLATFORM_INVALID = 0x0`
- `AARCH64_PAUTH_PLATFORM_BAREMETAL = 0x1`
- `AARCH64_PAUTH_PLATFORM_LLVM_LINUX = 0x10000002`
For the llvm_linux platform, output of the tools contains descriptions
of PAuth features which are enabled/disabled depending on the version
value. Version value bits correspond to the following `LangOptions`
defined in #85232:
- bit 0: `PointerAuthIntrinsics`;
- bit 1: `PointerAuthCalls`;
- bit 2: `PointerAuthReturns`;
- bit 3: `PointerAuthAuthTraps`;
- bit 4: `PointerAuthVTPtrAddressDiscrimination`;
- bit 5: `PointerAuthVTPtrTypeDiscrimination`;
- bit 6: `PointerAuthInitFini`.
Support for `.note.AARCH64-PAUTH-ABI-tag` is dropped since it's deleted
from the spec in ARM-software/abi-aa#250.
This adds support for `GNU_PROPERTY_AARCH64_FEATURE_PAUTH` feature (as
defined in https://github.com/ARM-software/abi-aa/pull/240) handling in
llvm-readobj and llvm-readelf. The following constants for supported
platforms are also introduced:
- `AARCH64_PAUTH_PLATFORM_INVALID = 0x0`
- `AARCH64_PAUTH_PLATFORM_BAREMETAL = 0x1`
- `AARCH64_PAUTH_PLATFORM_LLVM_LINUX = 0x10000002`
For the llvm_linux platform, output of the tools contains descriptions
of PAuth features which are enabled/disabled depending on the version
value. Version value bits correspond to the following `LangOptions`
defined in #85232:
- bit 0: `PointerAuthIntrinsics`;
- bit 1: `PointerAuthCalls`;
- bit 2: `PointerAuthReturns`;
- bit 3: `PointerAuthAuthTraps`;
- bit 4: `PointerAuthVTPtrAddressDiscrimination`;
- bit 5: `PointerAuthVTPtrTypeDiscrimination`;
- bit 6: `PointerAuthInitFini`.
Support for `.note.AARCH64-PAUTH-ABI-tag` is dropped since it's deleted
from the spec in ARM-software/abi-aa#250.
`TargetEndianness` is long and unwieldy. "Target" in the name is confusing. Rename it to "Endianness".
I cannot find noticeable out-of-tree users of `TargetEndianness`, but
keep `TargetEndianness` to make this patch safer. `TargetEndianness`
will be removed by a subsequent change.
Defines a subset of attributes and emits them to a section called
.hexagon.attributes.
The current attributes recorded are the attributes needed by
llvm-objdump to automatically determine target features and eliminate
the need to manually pass features.
Primary change is to add a flag `--pretty-pgo-analysis-map` to
llvm-readobj and llvm-objdump that prints block frequencies and branch
probabilities in the same manner as BFI and BPI respectively. This can
be helpful if you are manually inspecting the outputs from the tools.
In order to print, I moved the `printBlockFreqImpl` function from
Analysis to Support and renamed it to `printRelativeBlockFreq`.
Linux kernel fs/binfmt_elf_fdpic.c supports FDPIC for MMU-less systems.
GCC/binutils/qemu support FDPIC ABI for ARM
(https://github.com/mickael-guene/fdpic_doc).
_ARM FDPIC Toolchain and ABI_ provides a summary.
This patch implements FDPIC relocations to the integrated assembler.
There are 6 static relocations and 2 dynamic relocations, with
R_ARM_FUNCDESC as both static and dynamic.
gas requires `--fdpic` to assemble data relocations like `.word f(FUNCDESC)`.
This patch adds `MCTargetOptions::FDPIC` and reports an error if FDPIC
is not set.
Pull Request: https://github.com/llvm/llvm-project/pull/82187
The dot is too confusing for tools. Output temporaries would have
'10.3-generic' so tools could parse it as an extension, device libs &
the associated clang driver logic are also confused by the dot.
After discussions, we decided it's better to just remove the '.' from
the target name than fix each issue one by one.
These generic targets include multiple GPUs and will, in the future,
provide a way to build once and run on multiple GPU, at the cost of less
optimization opportunities.
Note that this is just doing the compiler side of things, device libs an
runtimes/loader/etc. don't know about these targets yet, so none of them
actually work in practice right now. This is just the initial commit to
make LLVM aware of them.
This contains the documentation changes for both this change and #76954
as well.
Introduce Code Object V6 in Clang, LLD, Flang and LLVM. This is the same
as V5 except a new "generic version" flag can be present in EFLAGS. This
is related to new generic targets that'll be added in a follow-up patch.
It's also likely V6 will have new changes (possibly new metadata
entries) added later.
Docs change are part of the follow-up patch #76955
Today `-split-machine-functions` and `-fbasic-block-sections={all,list}`
cannot be combined with `-basic-block-sections=labels` (the labels
option will be ignored).
The inconsistency comes from the way basic block address map -- the
underlying mechanism for basic block labels -- encodes basic block
addresses
(https://lists.llvm.org/pipermail/llvm-dev/2020-July/143512.html).
Specifically, basic block offsets are computed relative to the function
begin symbol. This relies on functions being contiguous which is not the
case for MFS and basic block section binaries. This means Propeller
cannot use binary profiles collected from these binaries, which limits
the applicability of Propeller for iterative optimization.
To make the `SHT_LLVM_BB_ADDR_MAP` feature work with basic block section
binaries, we propose modifying the encoding of this section as follows.
First let us review the current encoding which emits the address of each
function and its number of basic blocks, followed by basic block entries
for each basic block.
| | |
|--|--|
| Address of the function | Function Address |
| Number of basic blocks in this function | NumBlocks |
| BB entry 1
| BB entry 2
| ...
| BB entry #NumBlocks
To make this work for basic block sections, we treat each basic block
section similar to a function, except that basic block sections of the
same function must be encapsulated in the same structure so we can map
all of them to their single function.
We modify the encoding to first emit the number of basic block sections
(BB ranges) in the function. Then we emit the address map of each basic
block section section as before: the base address of the section, its
number of blocks, and BB entries for its basic block. The first section
in the BB address map is always the function entry section.
| | |
|--|--|
| Number of sections for this function | NumBBRanges |
| Section 1 begin address | BaseAddress[1] |
| Number of basic blocks in section 1 | NumBlocks[1] |
| BB entries for Section 1
|..................|
| Section #NumBBRanges begin address | BaseAddress[NumBBRanges] |
| Number of basic blocks in section #NumBBRanges |
NumBlocks[NumBBRanges] |
| BB entries for Section #NumBBRanges
The encoding of basic block entries remains as before with the minor
change that each basic block offset is now computed relative to the
begin symbol of its containing BB section.
This patch adds a new boolean codegen option `-basic-block-address-map`.
Correspondingly, the front-end flag `-fbasic-block-address-map` and LLD
flag `--lto-basic-block-address-map` are introduced.
Analogously, we add a new TargetOption field `BBAddrMap`. This means BB
address maps are either generated for all functions in the compiling
unit, or for none (depending on `TargetOptions::BBAddrMap`).
This patch keeps the functionality of the old
`-fbasic-block-sections=labels` option but does not remove it. A
subsequent patch will remove the obsolete option.
We refactor the `BasicBlockSections` pass by separating the BB address
map and BB sections handing to their own functions (named
`handleBBAddrMap` and `handleBBSections`). `handleBBSections` renumbers
basic blocks and places them in their assigned sections.
`handleBBAddrMap` is invoked after `handleBBSections` (if requested) and
only renumbers the blocks.
- New tests added:
- Two tests basic-block-address-map-with-basic-block-sections.ll and
basic-block-address-map-with-mfs.ll to exercise the combination of
`-basic-block-address-map` with `-basic-block-sections=list` and
'-split-machine-functions`.
- A driver sanity test for the `-fbasic-block-address-map` option
(basic-block-address-map.c).
- An LLD test for testing the `--lto-basic-block-address-map` option.
This reuses the LLVM IR from `lld/test/ELF/lto/basic-block-sections.ll`.
- Renamed and modified the two existing codegen tests for basic block
address map (`basic-block-sections-labels-functions-sections.ll` and
`basic-block-sections-labels.ll`)
- Removed `SHT_LLVM_BB_ADDR_MAP_V0` tests. Full deprecation of
`SHT_LLVM_BB_ADDR_MAP_V0` and `SHT_LLVM_BB_ADDR_MAP` version less than 2
will happen in a separate PR in a few months.
Adds raw printing of PGOAnalysisMap in llvm-readobj.
I'm leaving the fixme's for a later patch that will provide a 'pretty'
printing for BBFreq and BrProb (i.e. relative frequencies and
probabilities) that will apply to both llvm-readobj and llvm-objdump.
Summary:
This did not need a separate struct because it is not past the
"architecture specific" ones in the identifier. This was accidentally
left when it was added somewhere else and caused unused variable
warnings.
Summary:
This patch fixes up the `makeTriple()` interface to emit append the
operating system information when it is readily avaialble from the ELF.
The main motivation for this is so the GPU architectures can be easily
identified correctly when given and ELF. E.g. we want
`amdgpu-amd-amdhsa` as the output and not `amdgpu--`.
This required adding support for the CUDA OS/ABI, which is easily found
to be `0x33` when using `readelf`.
Summary:
Currently, we don't emit any of the AMDGPU specific flags and options
when printing in GNU-mode (the default). This patch adds extra code to
handle outputting these values to match the output from GNU's `readelf`
when used on an AMDGPU image.
Summary:
The architecture that the CUDA application was compiled for is stored in
the ELF flags. This patch just adds some simple enum values to indicate
this to the user in a readable way.
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
