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//===-- clear_cache_test.c - Test clear_cache -----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#if defined(_WIN32)
#include <windows.h>
void __clear_cache(void* start, void* end)
{
if (!FlushInstructionCache(GetCurrentProcess(), start, end-start))
exit(1);
}
#else
#include <sys/mman.h>
extern void __clear_cache(void* start, void* end);
#endif
typedef int (*pfunc)(void);
int func1()
{
return 1;
}
int func2()
{
return 2;
}
unsigned char execution_buffer[128];
int main()
{
// make executable the page containing execution_buffer
char* start = (char*)((uintptr_t)execution_buffer & (-4095));
char* end = (char*)((uintptr_t)(&execution_buffer[128+4096]) & (-4095));
#if defined(_WIN32)
DWORD dummy_oldProt;
MEMORY_BASIC_INFORMATION b;
if (!VirtualQuery(start, &b, sizeof(b)))
return 1;
if (!VirtualProtect(b.BaseAddress, b.RegionSize, PAGE_EXECUTE_READWRITE, &b.Protect))
#else
if (mprotect(start, end-start, PROT_READ|PROT_WRITE|PROT_EXEC) != 0)
#endif
return 1;
// verify you can copy and execute a function
memcpy(execution_buffer, (void *)(uintptr_t)&func1, 128);
__clear_cache(execution_buffer, &execution_buffer[128]);
pfunc f1 = (pfunc)(uintptr_t)execution_buffer;
if ((*f1)() != 1)
return 1;
// verify you can overwrite a function with another
memcpy(execution_buffer, (void *)(uintptr_t)&func2, 128);
__clear_cache(execution_buffer, &execution_buffer[128]);
pfunc f2 = (pfunc)(uintptr_t)execution_buffer;
if ((*f2)() != 2)
return 1;
return 0;
}
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