Is there any simple method for getting parent to use in kobject_add function? I want to put the file in /sys/module/mymodule/parameters. I've got already working parameter, but I create it in wrong directory. I've found that there is module_subsys in module.h, but I have no idea how to use it.
It's my code for init function:
static int __init init_hello(void)
{
subsystem_register(&module_subsys);
struct my_attr *a;
Major = misc_register(&mydevice);
mykobj = kzalloc(sizeof(*mykobj), GFP_KERNEL);
if (mykobj) {
kobject_init(mykobj, &mytype);
kobj_set_kset_s(mykobj, module_subsys);
if (kobject_add(mykobj, NULL, "%s", "sysfs_example")) {
printk("Sysfs creation failed\n");
kobject_put(mykobj);
mykobj = NULL;
return -1;
}
}
a = container_of(&(my_first.attr), struct my_attr, attr);
msg_Ptr = kzalloc(a->value, GFP_KERNEL);
bytesindev=0;
if(Major) {
printk(KERN_ALERT "Rejestrowanie urządzenia nie powiodło się\n");
return Major;
}
return SUCCESS;
}
Never tried it myself, but &THIS_MODULE->mkobj.kobj looks appropriate.
I didn't see any kernel code that uses kobject_add directly with this, so perhaps it isn't the right way.
If you've registered a device driver, then &dev->kobj looks like a good way.
Related
My code is only outputting a few modules in the process, when there are much more. The procID is correct as i've checked in task manager. I would like it to return every single module in the process.
I'm using a C compiler for this. Is this a problem?
uintptr_t findModuleAddress (char* name, DWORD procID){
MODULEENTRY32 entry;
entry.dwSize = sizeof(MODULEENTRY32);
HANDLE snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, procID);
uintptr_t cModuleAddress = 0;
Module32First(snapshot,&entry);
while (Module32Next(snapshot, &entry)){
printf("%s\n",entry.szModule);
if (!strcmp(name,entry.szModule)){
printf("Found module\n");
cModuleAddress = (uintptr_t)entry.modBaseAddr;
break;
}
}
CloseHandle(snapshot);
return cModuleAddress;
}
The output:
When creating a vfs using the tcl api how do you get the current filesystem in Tcl_Filesystem.pathInFilesystemProc
My code looks something like this:
typedef struct {
FILE* dbFile;
/*...*/
} FSBackend;
void createFS(const char* dbFile)
{
FSBackend* fsback = (FSBackend*)malloc(sizeof(FSBackend));
initDb(fsback,dbFile);
Tcl_Filesystem tfs;
tfs.typeName="Db Fs";
tfs.structureLength = sizeof(Tcl_Filesystem);
tfs.version = TCL_FILESYSTEM_VERSION_1;
tfs.pathInFilesystemProc = inFsProc;
/*...*/
Tcl_FSRegister((void*),tfs);
}
int inFsProc(Tcl_Obj* pathPtr,ClientData* cd)
{
/* How do I get my FSBackend struct here */
FSBackend* bk = /* ? */
int len;
const char* searchPath = Tcl_GetStringFromObj(pathPtr,&len);
char* foundPath = findFileInDb(searchPath,bk);
if (foundPath == 0) {
return -1;
}
cd = buildInternalRep(foundPath,bk);
return TCL_OK;
}
/**
...
*/
int main()
{
createFS("db1.db");
createFS("db2.db");
}
How do I, in inFsProc get back the struct I passed into Tcl_FSRegister?
The Tcl_FSData function says it can get it but I would then need to get a Tcl_Filesystem pointer
That's a weird one. The clientData handle there is not used to specify a mount point, but rather a separate capability of the filesystem type. Tcl's internal use of Tcl_FSRegister doesn't use it at all. The code which is as close as anything to a canonical use of it is the tclvfs package.
https://github.com/tcl-mirror/tclvfs/blob/master/generic/vfs.c#L385 shows us the use:
static void
Vfs_RegisterWithInterp(interp)
Tcl_Interp *interp;
{
ClientData vfsAlreadyRegistered;
/*
* We need to know if the interpreter is deleted, so we can
* remove all interp-specific mounts.
*/
Tcl_SetAssocData(interp, "vfs::inUse", (Tcl_InterpDeleteProc*)
Vfs_UnregisterWithInterp, (ClientData) 1);
/*
* Perform one-off registering of our filesystem if that
* has not happened before.
*/
vfsAlreadyRegistered = Tcl_FSData(&vfsFilesystem);
if (vfsAlreadyRegistered == NULL) {
Tcl_FSRegister((ClientData)1, &vfsFilesystem);
Tcl_CreateExitHandler(VfsExitProc, (ClientData)NULL);
Tcl_CreateThreadExitHandler(VfsThreadExitProc, NULL);
}
}
As you can see, the clientData there is really just being used as a marker so the code knows whether to do one-time initialisation.
To discover what the mount mapping is, you'll need to keep internal structures. You're strongly recommended to make the Tcl_Filesystem structure instance itself be global (or rather static at file scope) in your code.
I'm coding a UEFI Runtime Driver for Windows which hooks gRT->SetVariable(...)
Hooking seems to work fine but whenever I startup a user-mode application and call SetFirmwareEnvironmentVariable(...) it reults in a Bluescreen saying UNEXCEPTED_KERNEL_MODE_TRAP.
I cannot find any solution for this. Here are a few things iam aware of:
I'm raising TPL
I recalculate and set CRC32
On SetVirtualAddressMap(...) i convert all my pointer
Google didn't help at all. So i really wonder what causes this Bluescreen and how i may proceed to resolve this issue.
What am i missing? Am i doing something wrong?
Here is my code:
ExchangePointerInServiceTable((VOID**)&gST->RuntimeServices->SetVariable,
(VOID*)HookedSetVariable,
(VOID**)&gOriginalSetVariable);
static
EFI_STATUS
ExchangePointerInServiceTable(
IN OUT VOID** AddressToUpdate,
IN VOID* NewPointer,
OUT VOID** OriginalPointer OPTIONAL
)
{
EFI_STATUS status;
EFI_TPL tpl;
ASSERT(*AddressToUpdate != NewPointer);
tpl = gBS->RaiseTPL(TPL_HIGH_LEVEL);
if (OriginalPointer != NULL)
{
*OriginalPointer = *AddressToUpdate;
}
*AddressToUpdate = NewPointer;
gST->Hdr.CRC32 = 0;
status = gBS->CalculateCrc32(&gST->Hdr, gST->Hdr.HeaderSize, &gST->Hdr.CRC32);
ASSERT_EFI_ERROR(status);
gBS->RestoreTPL(tpl);
return status;
}
EFI_STATUS
EFIAPI
HookedSetVariable(
IN CHAR16* VariableName,
IN EFI_GUID* VendorGuid,
IN UINT32 Attributes,
IN UINTN DataSize,
IN VOID* Data
) {
if (StrCmp(VariableName, gStrComVarName) == 0) {
COMMUNICATION_PROTOCOL * comVarPtr = (COMMUNICATION_PROTOCOL*)Data;
switch (comVarPtr->i8OperationId) {
case COMMUNICATION_PROTOCOL_OPERATION_PING:
comVarPtr->i8OperationId = COMMUNICATION_PROTOCOL_PONG;
}
CopyMem(Data, comVarPtr, DataSize);
}
return gOriginalSetVariable(VariableName, VendorGuid, Attributes, DataSize, Data);
}
Edit: While in UEFI, other UEFI Applications correctly call the hooked SetVariable(...) without any further problems.
This may bring it down to the problem only existing after VirtualAddressSpace has been created from the OS.
After reading lots of documentation i did the first simple enclave function:
enclave {
//Include files
//Import other edl files
//Data structure declarations to be used as parameters of the
//function prototypes in edl
trusted {
public function myFirstMethod([in] int *a, [in] int *b,[out] int *sum);
};
untrusted {
};
};
Then over bash I run the edger8r:
sgx_edger8r enclave.edl
Then it generated the following files as you can see over the schema:
So I assume somewhere over the enclave_t.c the only reference I found is in this function:
static sgx_status_t SGX_CDECL sgx_myFirstMethod(void* pms)
{
CHECK_REF_POINTER(pms, sizeof(ms_myFirstMethod_t));
ms_myFirstMethod_t* ms = SGX_CAST(ms_myFirstMethod_t*, pms);
sgx_status_t status = SGX_SUCCESS;
int* _tmp_a = ms->ms_a;
size_t _len_a = sizeof(*_tmp_a);
int* _in_a = NULL;
int* _tmp_b = ms->ms_b;
size_t _len_b = sizeof(*_tmp_b);
int* _in_b = NULL;
CHECK_UNIQUE_POINTER(_tmp_a, _len_a);
CHECK_UNIQUE_POINTER(_tmp_b, _len_b);
if (_tmp_a != NULL) {
_in_a = (int*)malloc(_len_a);
if (_in_a == NULL) {
status = SGX_ERROR_OUT_OF_MEMORY;
goto err;
}
memcpy(_in_a, _tmp_a, _len_a);
}
if (_tmp_b != NULL) {
_in_b = (int*)malloc(_len_b);
if (_in_b == NULL) {
status = SGX_ERROR_OUT_OF_MEMORY;
goto err;
}
memcpy(_in_b, _tmp_b, _len_b);
}
ms->ms_retval = myFirstMethod(_in_a, _in_b);
err:
if (_in_a) free(_in_a);
if (_in_b) free(_in_b);
return status;
}
Especially in
ms->ms_retval = myFirstMethod(_in_a, _in_b);
But where to put the myFirstMethod? Also how I will compile my enclave as a part of an application as a static library.
As fas as I searched is the tutorial in theese links:
https://software.intel.com/en-us/articles/intel-software-guard-extensions-developing-a-sample-enclave-application
https://software.intel.com/en-us/sgx/code-samples
All mention Visual Studio that does not natively run over GNU/Linux so are a bit hard for me to follow.
Edit 1:
Further looking I have seen on https://github.com/01org/linux-sgx that I can compile over simulation mode as the link mentions:
make SGX_MODE=SIM
And I successfully I have installed the driver and the sdk. I want to compile over SIMULATION mode and not real one.
The autogenerated outputs of edger8r are only to provide interface between the enclave and the untrusted outside world. They are not supposed to contain your implementations.
You should define myFirstMethod in another source file, say enclave.c or enclave.cpp and link it with the rest of your project. The signature of the function being exactly what you declared in your edl, except for the pointer qualifiers, which are for edger8r to consume.
It will go like this:
enclave.cpp:
void myFirstMethod(int *a, int *b, int *sum)
{
*sum = *a + *b;
}
Dimitris first check if you have compatible hardware from this list
https://github.com/ayeks/SGX-hardware
Then try to clone an run this repo
https://github.com/digawp/hello-enclave
That will help you understand how it works
gcc 4.4.4 c89
I have always thought of using malloc for the life of the project for being the scope.
But I am just wondering if my idea is the best practice. For example, I initalize an instance of the struct in main. And create 2 functions for creating and destroying. I am just wondering if this is the right thing to do.
I have some skeleton code below.
Many thanks for any advice,
typedef struct Network_dev_t {
size_t id;
char *name;
} Network_dev;
Network_dev* create_network_device(Network_dev *network)
{
network = malloc(sizeof *network);
if(network == NULL) {
return NULL;
}
return network;
}
void do_something(Network_dev *network)
{
/* Do something with the network device */
}
void destroy_network_device(Network_dev *network)
{
free(network);
}
int main(void)
{
Network_dev *network = NULL;
network = create_network_device(network);
/* Do something with the network device */
do_something(network);
destroy_network_device(network);
return 0;
}
Looks good.
I have a point or 2 about create_network_device
Network_dev* create_network_device(Network_dev *network)
no need to pass in a pointer; I'd rather have Network_dev* create_network_device(void)
{
network = malloc(sizeof *network);
the if is not really necessary; if malloc failed the return network at the end of the function is the same as return NULL.
if(network == NULL) {
return NULL;
}
If the allocation succeeded you might want to insure the struct members are in a know state here
/* if (network) { */
/* id = 0; */
/* name = NULL; */
/* } */
return network;
}
This code looks fine to me. I agree with pmg that your create_network_device could use a little work. Just to pull together what he said and make things clearer, here is exactly how I would write the function:
Network_dev *create_network_device()
{
Network_dev *network = malloc(sizeof(*network));
if (network) {
network->id = 0;
network->name = NULL;
}
return network;
}
It is best to allocate memory and free memory in the same function. Just like you open and close files in the same function. You did this by creating and destroying a Network_dev in the main() function, which is good. This makes it easy to confirm that all malloced locations are also freed.
It is best to malloc() something as late as possible and free() it as soon as possible. That is, hold the memory for as short as possible. If your program's job is to do something with Network_dev, you did all right. If your program does a lot of other things, you should do them before malloc() or after free().