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#include "protect.h"
#include <util/generic/yexception.h>
#include <util/generic/string.h>
#include "yassert.h"
#if defined(_unix_) || defined(_darwin_)
#include <sys/mman.h>
#endif
#ifdef _win_
#include <Windows.h>
#endif
static TString ModeToString(const EProtectMemory mode) {
TString strMode;
if (mode == PM_NONE) {
return "PM_NONE";
}
if (mode & PM_READ) {
strMode += "PM_READ|";
}
if (mode & PM_WRITE) {
strMode += "PM_WRITE|";
}
if (mode & PM_EXEC) {
strMode += "PM_EXEC|";
}
return strMode.substr(0, strMode.size() - 1);
}
void ProtectMemory(void* addr, const size_t length, const EProtectMemory mode) {
Y_VERIFY(!(mode & ~(PM_READ | PM_WRITE | PM_EXEC)), "Invalid memory protection flag combination. ");
#if defined(_unix_) || defined(_darwin_)
int mpMode = PROT_NONE;
if (mode & PM_READ) {
mpMode |= PROT_READ;
}
if (mode & PM_WRITE) {
mpMode |= PROT_WRITE;
}
if (mode & PM_EXEC) {
mpMode |= PROT_EXEC;
}
// some old manpages for mprotect say 'const void* addr', but that's wrong
if (mprotect(addr, length, mpMode) == -1) {
ythrow TSystemError() << "Memory protection failed for mode " << ModeToString(mode) << ". ";
}
#endif
#ifdef _win_
DWORD mpMode = PAGE_NOACCESS;
// windows developers are not aware of bit flags :(
/*
* It's unclear that we should NOT fail on Windows that does not support write-only
* memory protection. As we don't know, what behavior is more correct, we choose
* one of them. A discussion was here: REVIEW: 39725
*/
switch (mode.ToBaseType()) {
case PM_READ:
mpMode = PAGE_READONLY;
break;
case PM_WRITE:
mpMode = PAGE_READWRITE;
break; // BUG: no write-only support
/*case PM_WRITE:
ythrow TSystemError() << "Write-only protection mode is not supported under Windows. ";*/
case PM_READ | PM_WRITE:
mpMode = PAGE_READWRITE;
break;
case PM_EXEC:
mpMode = PAGE_EXECUTE;
break;
case PM_READ | PM_EXEC:
mpMode = PAGE_EXECUTE_READ;
break;
case PM_WRITE | PM_EXEC:
mpMode = PAGE_EXECUTE_READWRITE;
break; // BUG: no write-only support
/*case PM_WRITE | PM_EXEC:
ythrow TSystemError() << "Write-execute-only protection mode is not supported under Windows. ";*/
case PM_READ | PM_WRITE | PM_EXEC:
mpMode = PAGE_EXECUTE_READWRITE;
break;
}
DWORD oldMode = 0;
if (!VirtualProtect(addr, length, mpMode, &oldMode))
ythrow TSystemError() << "Memory protection failed for mode " << ModeToString(mode) << ". ";
#endif
}
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