| Age | Commit message (Collapse) | Author |
|---|
|
After handling any signal on x86, it would previously segfault.
|
|
|
|
arch bits
Flock is now equivalent to struct flock64, and the related F.* constants map to
the 64-bit variants on 32-bit systems.
|
|
|
|
|
|
|
|
This type is useful for two things:
* Doing non-local control flow with ucontext.h functions.
* Inspecting machine state in a signal handler.
The first use case is not one we support; we no longer expose bindings to those
functions in the standard library. They're also deprecated in POSIX and, as a
result, not available in musl.
The second use case is valid, but is very poorly served by the standard library.
As evidenced by my changes to std.debug.cpu_context.signal_context_t, users will
be better served rolling their own ucontext_t and especially mcontext_t types
which fit their specific situation. Further, these types tend to evolve
frequently as architectures evolve, and the standard library has not done a good
job keeping up, or even providing them for all supported targets.
|
|
Our usage of `ucontext_t` in the standard library was kind of
problematic. We unnecessarily mimiced libc-specific structures, and our
`getcontext` implementation was overkill for our use case of stack
tracing.
This commit introduces a new namespace, `std.debug.cpu_context`, which
contains "context" types for various architectures (currently x86,
x86_64, ARM, and AARCH64) containing the general-purpose CPU registers;
the ones needed in practice for stack unwinding. Each implementation has
a function `current` which populates the structure using inline
assembly. The structure is user-overrideable, though that should only be
necessary if the standard library does not have an implementation for
the *architecture*: that is to say, none of this is OS-dependent.
Of course, in POSIX signal handlers, we get a `ucontext_t` from the
kernel. The function `std.debug.cpu_context.fromPosixSignalContext`
converts this to a `std.debug.cpu_context.Native` with a big ol' target
switch.
This functionality is not exposed from `std.c` or `std.posix`, and
neither are `ucontext_t`, `mcontext_t`, or `getcontext`. The rationale
is that these types and functions do not conform to a specific ABI, and
in fact tend to get updated over time based on CPU features and
extensions; in addition, different libcs use different structures which
are "partially compatible" with the kernel structure. Overall, it's a
mess, but all we need is the kernel context, so we can just define a
kernel-compatible structure as long as we don't claim C compatibility by
putting it in `std.c` or `std.posix`.
This change resulted in a few nice `std.debug` simplifications, but
nothing too noteworthy. However, the main benefit of this change is that
DWARF unwinding---sometimes necessary for collecting stack traces
reliably---now requires far less target-specific integration.
Also fix a bug I noticed in `PageAllocator` (I found this due to a bug
in my distro's QEMU distribution; thanks, broken QEMU patch!) and I
think a couple of minor bugs in `std.debug`.
Resolves: #23801
Resolves: #23802
|
|
It was possible for `arg6` to be passed as an operand relative to esp.
In that case, the `push` at the top clobbered esp and hence made the
reference to arg6 invalid. This was manifesting in this branch as broken
stack traces on x86-linux due to an `mmap2` syscall accidentally passing
the page offset as non-zero!
This commit fixes a bug introduced in cb0e6d8aa.
|
|
Per @alexrp, this is unnecessary in naked functions.
|
|
|
|
Macos uses the BSD definition of msghdr
All linux architectures share a single msghdr definition. Many
architectures had manually inserted padding fields that were endian
specific and some had fields with different integers. This unifies all
architectures to use a single correct msghdr definition.
|
|
All the existing code that manipulates `ucontext_t` expects there to be a
glibc-compatible sigmask (1024-bit). The `ucontext_t` struct need to be
cleaned up so the glibc-dependent format is only used when linking
glibc/musl library, but that is a more involved change.
In practice, no Zig code looks at the sigset field contents, so it just
needs to be the right size.
|
|
|
|
|
|
|
|
Whatever was in the frame pointer register prior to clone() will no longer be
valid in the child process, so zero it to protect FP-based unwinders. Similarly,
mark the link register as undefined to protect DWARF-based unwinders.
This is only zeroing the frame pointer(s) on Arm/Thumb because of an LLVM
assembler bug: https://github.com/llvm/llvm-project/issues/115891
|
|
LLVM would run out of registers due to the edi usage. Just extend what we're
already doing for ebp to edi as well.
|
|
|
|
* common symbols are now public from std.c even if they live in
std.posix
* LOCK is now one of the common symbols since it is the same on 100% of
operating systems.
* flock is now void value on wasi and windows
* std.fs.Dir now uses flock being void as feature detection, avoiding
trying to call it on wasi and windows
|
|
It is now composed of these main sections:
* Declarations that are shared among all operating systems.
* Declarations that have the same name, but different type signatures
depending on the operating system. Often multiple operating systems
share the same type signatures however.
* Declarations that are specific to a single operating system.
- These are imported one per line so you can see where they come from,
protected by a comptime block to prevent accessing the wrong one.
Closes #19352 by changing the convention to making types `void` and
functions `{}`, so that it becomes possible to update `@hasDecl` sites
to use `@TypeOf(f) != void` or `T != void`. Happily, this ended up
removing some duplicate logic and update some bitrotted feature
detection checks.
A handful of types have been modified to gain namespacing and type
safety. This is a breaking change.
Oh, and the last usage of `usingnamespace` site is eliminated.
|
|
closes #5019
|
|
* std.c: consolidate some definitions, making them share code. For
example, freebsd, dragonfly, and openbsd can all share the same
`pthread_mutex_t` definition.
* add type safety to std.c.O
- this caught a bug where mode flags were incorrectly passed as the
open flags.
* 3 fewer uses of usingnamespace keyword
* as per convention, remove purposeless field prefixes from struct field
names even if they have those prefixes in the corresponding C code.
* fix incorrect wasi libc Stat definition
* remove C definitions from incorrectly being in std.os.wasi
* make std.os.wasi definitions type safe
* go through wasi native APIs even when linking libc because the libc
APIs are problematic and wasteful
* don't expose WASI definitions in std.posix
* remove std.os.wasi.rights_t.ALL: this is a footgun. should it be all
future rights too? or only all current rights known? both are
the wrong answer.
|
|
Introduces type safety to this constant. Eliminates one use of
`usingnamespace`.
|
|
This also required implementing the necessary syntax in the x86_64 backend.
|
|
After fixing some issues with inline assembly in the C backend, the std
cleanups have the side effect of making these functions compatible with
the backend, allowing it to be used on linux without linking libc.
|
|
match the state after it would return)
debug: fixup ucontext_t check
|
|
- Fix unwindFrame using the previous FDE row instead of the current one
- Handle unwinding through noreturn functions
- Add x86-linux getcontext
- Fixup x86_64-linux getcontext not restoring the fp env
- Fix start_addr filtering on x86-windows
|
|
Signed-off-by: Eric Joldasov <bratishkaerik@getgoogleoff.me>
|
|
|
|
|
|
There are still a few occurrences of "stage1" in the standard library
and self-hosted compiler source, however, these instances need a bit
more careful inspection to ensure no breakage.
|
|
|
