ladybird/Tests/Kernel/TestSigAltStack.cpp
Nico Weber 2af028132a AK+Everywhere: Add AK_COMPILER_{GCC,CLANG} and use them most places
Doesn't use them in libc headers so that those don't have to pull in
AK/Platform.h.

AK_COMPILER_GCC is set _only_ for gcc, not for clang too. (__GNUC__ is
defined in clang builds as well.) Using AK_COMPILER_GCC simplifies
things some.

AK_COMPILER_CLANG isn't as much of a win, other than that it's
consistent with AK_COMPILER_GCC.
2022-10-04 23:35:07 +01:00

57 lines
1.5 KiB
C++

/*
* Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Platform.h>
#if defined(AK_COMPILER_CLANG)
# pragma clang optimize off
#else
# pragma GCC optimize("O0")
#endif
#include <LibTest/TestCase.h>
#include <signal.h>
#include <unistd.h>
static void signal_handler(int)
{
// We execute this syscall in order to force the kernel to perform the syscall precondition validation which
// checks that we have correctly set up the stack region to match our currently implemented protections.
getuid();
_exit(0);
}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Winfinite-recursion"
static size_t infinite_recursion(size_t input)
{
return infinite_recursion(input) + 1;
}
#pragma GCC diagnostic pop
// This test can only pass with sigaltstack correctly enabled, as otherwise the SIGSEGV signal handler itself would also fault due to the overflown stack.
TEST_CASE(success_case)
{
static u8 alt_stack[SIGSTKSZ];
stack_t ss = {
.ss_sp = alt_stack,
.ss_flags = 0,
.ss_size = SIGSTKSZ,
};
auto res = sigaltstack(&ss, nullptr);
EXPECT_EQ(res, 0);
struct sigaction sa;
sa.sa_handler = signal_handler;
sa.sa_flags = SA_ONSTACK;
res = sigfillset(&sa.sa_mask);
EXPECT_EQ(res, 0);
res = sigaction(SIGSEGV, &sa, 0);
EXPECT_EQ(res, 0);
(void)infinite_recursion(0);
FAIL("Infinite recursion finished successfully");
}