ladybird/Userland/Utilities/kcov-example.cpp

42 lines
1.2 KiB
C++

/*
* Copyright (c) 2021, Patrick Meyer <git@the-space.agency>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/API/kcov.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
// Note: This program requires serenity to be built with the CMake build option
// ENABLE_KERNEL_COVERAGE_COLLECTION
ErrorOr<int> serenity_main(Main::Arguments)
{
constexpr size_t num_entries = 1024 * 100;
int fd = TRY(Core::System::open("/dev/kcov0"sv, O_RDWR));
TRY(Core::System::ioctl(fd, KCOV_SETBUFSIZE, num_entries));
kcov_pc_t* cover = (kcov_pc_t*)TRY(Core::System::mmap(NULL, num_entries * KCOV_ENTRY_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0));
TRY(Core::System::ioctl(fd, KCOV_ENABLE));
cover[0] = 0;
// Example syscall so we actually cover some kernel code.
getppid();
TRY(Core::System::ioctl(fd, KCOV_DISABLE));
u64 cov_idx = cover[0];
for (size_t idx = 1; idx <= cov_idx; idx++)
printf("%p\n", (void*)cover[idx]);
TRY(Core::System::munmap(const_cast<u64*>(cover), num_entries * KCOV_ENTRY_SIZE));
TRY(Core::System::close(fd));
return 0;
}