Kernel/core/stack_check.cpp

85 lines
2.0 KiB
C++

/*
This file is part of Fennix Kernel.
Fennix Kernel is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of
the License, or (at your option) any later version.
Fennix Kernel is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
#include <types.h>
#include <debug.h>
#include <rand.hpp>
#include "../kernel.h"
extern __noreturn void HandleStackSmashing();
extern __noreturn void HandleBufferOverflow();
/* EXTERNC */ uintptr_t __stack_chk_guard = 0;
EXTERNC __no_stack_protector uintptr_t __stack_chk_guard_init(void)
{
int MaxRetries = 0;
#if UINTPTR_MAX == UINT32_MAX
uint32_t num;
Retry:
num = Random::rand32();
if (num < 0x1000 && MaxRetries++ < 10)
goto Retry;
return num;
#else
uint64_t num;
Retry:
num = Random::rand64();
if (num < 0x100000 && MaxRetries++ < 10)
goto Retry;
return num;
#endif
}
EXTERNC __constructor __no_stack_protector void __guard_setup(void)
{
debug("__guard_setup");
if (__stack_chk_guard == 0)
__stack_chk_guard = __stack_chk_guard_init();
debug("Stack guard value: %ld", __stack_chk_guard);
}
EXTERNC __noreturn __no_stack_protector void __stack_chk_fail(void)
{
CPU::PageTable(KernelPageTable);
void *Stack = nullptr;
#if defined(a64)
asmv("movq %%rsp, %0"
: "=r"(Stack));
#elif defined(a32)
asmv("movl %%esp, %0"
: "=r"(Stack));
#elif defined(aa64)
asmv("mov %%sp, %0"
: "=r"(Stack));
#endif
error("Stack address: %#lx", Stack);
HandleStackSmashing();
}
// https://github.com/gcc-mirror/gcc/blob/master/libssp/ssp.c
EXTERNC __noreturn nsa void __chk_fail(void)
{
CPU::PageTable(KernelPageTable);
HandleBufferOverflow();
}