mirror of
https://github.com/llvm/llvm-project.git
synced 2025-04-22 23:46:04 +00:00
111 lines
3.4 KiB
C++
111 lines
3.4 KiB
C++
//===-- Classes to capture properites of linux applications -----*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_LIBC_CONFIG_LINUX_APP_H
|
|
#define LLVM_LIBC_CONFIG_LINUX_APP_H
|
|
|
|
#include "src/__support/macros/config.h"
|
|
#include "src/__support/macros/properties/architectures.h"
|
|
|
|
#include <stdint.h>
|
|
|
|
namespace LIBC_NAMESPACE_DECL {
|
|
|
|
// Data structure to capture properties of the linux/ELF TLS image.
|
|
struct TLSImage {
|
|
// The load address of the TLS.
|
|
uintptr_t address;
|
|
|
|
// The byte size of the TLS image consisting of both initialized and
|
|
// uninitialized memory. In ELF executables, it is size of .tdata + size of
|
|
// .tbss. Put in another way, it is the memsz field of the PT_TLS header.
|
|
uintptr_t size;
|
|
|
|
// The byte size of initialized memory in the TLS image. In ELF exectubles,
|
|
// this is the size of .tdata. Put in another way, it is the filesz of the
|
|
// PT_TLS header.
|
|
uintptr_t init_size;
|
|
|
|
// The alignment of the TLS layout. It assumed that the alignment
|
|
// value is a power of 2.
|
|
uintptr_t align;
|
|
};
|
|
|
|
// Linux manpage on `proc(5)` says that the aux vector is an array of
|
|
// unsigned long pairs.
|
|
// (see: https://man7.org/linux/man-pages/man5/proc.5.html)
|
|
using AuxEntryType = unsigned long;
|
|
// Using the naming convention from `proc(5)`.
|
|
// TODO: Would be nice to use the aux entry structure from elf.h when available.
|
|
struct AuxEntry {
|
|
AuxEntryType id;
|
|
AuxEntryType value;
|
|
};
|
|
|
|
struct Args {
|
|
uintptr_t argc;
|
|
|
|
// A flexible length array would be more suitable here, but C++ doesn't have
|
|
// flexible arrays: P1039 proposes to fix this. So, for now we just fake it.
|
|
// Even if argc is zero, "argv[argc] shall be a null pointer"
|
|
// (ISO C 5.1.2.2.1) so one is fine. Also, length of 1 is not really wrong as
|
|
// |argc| is guaranteed to be atleast 1, and there is an 8-byte null entry at
|
|
// the end of the argv array.
|
|
uintptr_t argv[1];
|
|
};
|
|
|
|
// Data structure which captures properties of a linux application.
|
|
struct AppProperties {
|
|
// Page size used for the application.
|
|
uintptr_t page_size;
|
|
|
|
Args *args;
|
|
|
|
// The properties of an application's TLS image.
|
|
TLSImage tls;
|
|
|
|
// Environment data.
|
|
uintptr_t *env_ptr;
|
|
|
|
// Auxiliary vector data.
|
|
AuxEntry *auxv_ptr;
|
|
};
|
|
|
|
[[gnu::weak]] extern AppProperties app;
|
|
|
|
// The descriptor of a thread's TLS area.
|
|
struct TLSDescriptor {
|
|
// The size of the TLS area.
|
|
uintptr_t size = 0;
|
|
|
|
// The address of the TLS area. This address can be passed to cleanup
|
|
// functions like munmap.
|
|
uintptr_t addr = 0;
|
|
|
|
// The value the thread pointer register should be initialized to.
|
|
// Note that, dependending the target architecture ABI, it can be the
|
|
// same as |addr| or something else.
|
|
uintptr_t tp = 0;
|
|
|
|
constexpr TLSDescriptor() = default;
|
|
};
|
|
|
|
// Create and initialize the TLS area for the current thread. Should not
|
|
// be called before app.tls has been initialized.
|
|
void init_tls(TLSDescriptor &tls);
|
|
|
|
// Cleanup the TLS area as described in |tls_descriptor|.
|
|
void cleanup_tls(uintptr_t tls_addr, uintptr_t tls_size);
|
|
|
|
// Set the thread pointer for the current thread.
|
|
bool set_thread_ptr(uintptr_t val);
|
|
|
|
} // namespace LIBC_NAMESPACE_DECL
|
|
|
|
#endif // LLVM_LIBC_CONFIG_LINUX_APP_H
|