We currently expect that the relocation type numbers are unique across
all architectures. But RISC-V and x86_64 use the same numbers for
different relocation types (R_X86_64_COPY = R_RISCV_JUMP_SLOT = 5).
So create a generic reloc type enum which maps to the arch-specific
reloc types instead of checking for all arch reloc types individually
everywhere.
This works by defining a set of weak symbols in dynamic linker whose
value would be provided by it. This has the same effect as preloading
library that magically knows right addresses of functions shared between
dynamic linker and LibC.
We were previously passing the same information by rewriting values
based on hardcoded library name, so the new approach seems a little
nicer to me.
This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).
This commit is auto-generated:
$ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
Meta Ports Ladybird Tests Kernel)
$ perl -pie 's/\bDeprecatedString\b/ByteString/g;
s/deprecated_string/byte_string/g' $xs
$ clang-format --style=file -i \
$(git diff --name-only | grep \.cpp\|\.h)
$ gn format $(git ls-files '*.gn' '*.gni')
It's possible for a malloc inside load_program_headers() to steal the
reserved memory space we created for the program headers. Remove the
reservation later in the method.
Introduces new builders, mainly `SectionTable` and `StringTable`, and a
final `build_elf_image` to merge everything into a single memory image.
Each of the builders are fully detached from one another, although
StringTable provides an extra API to remove steps when using it with a
SectionTable.
This automates the part of figuring out and properly writing offsets to
headers, and making sure all required data is properly copied and
referenced in the final image.
The dynamic loader can't reasonably run static-pie ELF. static-pie ELFs
might run executable code that invokes syscalls outside of the defined
syscall memory executable (code) region security measure we implement.
Known examples of static-pie ELF objects are ELF packers, and the actual
system-provided dynamic loader itself.
This commit removes DeprecatedString's "null" state, and replaces all
its users with one of the following:
- A normal, empty DeprecatedString
- Optional<DeprecatedString>
Note that null states of DeprecatedFlyString/StringView/etc are *not*
affected by this commit. However, DeprecatedString::empty() is now
considered equal to a null StringView.
We currently don't call any DT_FINI_ARRAY functions, so change that.
The call to `_fini` in `exit` is unnecessary, as we now call the
function referenced by DT_FINI in `__call_fini_functions`.
The arguments are passed on registers, so if we pass only 3 defined
arguments then the fourth argument for the prctl syscall could have
garbage value within it.
To avoid possible bugs, always pass 3 arguments to a raw syscall prctl
call in addition to the prctl sub-option (the first argument).
MAP_FILE is not in POSIX, and is simply in most LibCs as a "default"
mode. Our own LibC defines it as 0, meaning "no flags". It is also not
defined in some OS's, such as Haiku. Let's be more portable and not use
the unnecessary flag.
This is a minimal set of changes to allow `serenity.sh build riscv64` to
successfully generate the build environment and start building. This
includes some, but not all, assembly stubs that will be needed later on;
they are currently empty.
This is a prerequisite for upstreaming our LLVM patches, as our current
hack forcing `-ftls-model=initial-exec` in the Clang driver is not
acceptable upstream.
Currently, our kernel-managed TLS implementation limits us to only
having a single block of storage for all thread-local variables that's
initialized at load time. This PR merely implements the dynamic TLS
interface (`__tls_get_addr` and TLSDESC) on top of our static TLS
infrastructure. The current model's limitations still stand:
- a single static TLS block is reserved at load time, `dlopen()`-ing
shared libraries that define thread-local variables might cause us to
run out of space.
- the initial TLS image is not changeable post-load, so `dlopen()`-ing
libraries with non-zero-initialized TLS variables is not supported.
The way we repurpose `ti_module` to mean "offset within static TLS
block" instead of "module index" is not ABI-compliant.
Previously, we started parsing the ELF file again in a completely
different place, and without the partial mapping that we do while
validating.
Instead of doing manual parsing in two places, just capture the
requested stack size right after we validated it.
Once LibC is installed to the sysroot and its conflicts with libc++
are resolved, including LibC headers in such a way will cause errors
with a modern LLVM-based toolchain.
This is needed to avoid including LibC headers in Lagom builds.
Unfortunately, we cannot rely on the build machine to provide a
fully POSIX-compatible ELF header for Lagom builds, so we have to
use our own.
This has KString, KBuffer, DoubleBuffer, KBufferBuilder, IOWindow,
UserOrKernelBuffer and ScopedCritical classes being moved to the
Kernel/Library subdirectory.
Also, move the panic and assertions handling code to that directory.
As IFUNC resolvers may call arbitrary functions though the PLT, they can
only be called after the PLT has been populated. This is true of the
`[[gnu::target_clones]]` attribute, which makes a call to
`__cpu_indicator_init`, which is defined in `libgcc_s.so`, through the
PLT.
`do_plt_relocation` and `do_direct_relocation` are given a parameter
that controls whether IFUNCs are immediately resolved. In the first
pass, relocations pointing to IFUNCs are put on a worklist, while all
other relocations are performed. Only after non-IFUNC relocations are
done and the PLT is set up do we deal with these.
No functional changes intended. This is in preparation of a commit that
overhauls how IFUNCs are resolved.
This commit lets us move the implementation of PLT patching from
`DynamicObject` to `DynamicLoader` where all other relocation code
lives. For this, got[2] now stores the loader's address instead of the
object's.
This is the AArch64 equivalent of `R_X86_64_IRELATIVE`, which specifies
a symbol whose address is determined by calling a local IFUNC resolver
function.
This class had slightly confusing semantics and the added weirdness
doesn't seem worth it just so we can say "." instead of "->" when
iterating over a vector of NNRPs.
This patch replaces NonnullRefPtrVector<T> with Vector<NNRP<T>>.
Instead of using a special case of the annotate_mapping syscall, let's
introduce a new prctl option to disallow further annotations of Regions
as new syscall Region(s).
This commit adds the used relocation types to elf.h, and handles the
types in DynamicLoader and DynamicObject. No new functionalitty has to
be added, as the same code can be reused between aarch64 and x86_64.
