Re: [PATCH] MdeModulePkg/Core/Dxe: Acquire a lock when iterating gHandleList


Dandan Bi
 

Hi Hua,

One minor comment inline, please check.



Thanks,
Dandan

-----Original Message-----
From: Ma, Hua <hua.ma@intel.com>
Sent: Monday, October 11, 2021 6:45 PM
To: devel@edk2.groups.io
Cc: Ma, Hua <hua.ma@intel.com>; Wang, Jian J <jian.j.wang@intel.com>;
Liming Gao <gaoliming@byosoft.com.cn>; Bi, Dandan <dandan.bi@intel.com>;
Ni, Ray <ray.ni@intel.com>
Subject: [PATCH] MdeModulePkg/Core/Dxe: Acquire a lock when iterating
gHandleList

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3680

This patch fixes the following issue:

The global variable gHandleList is a linked list.
This list is locked when a entry is added or removed from the list, but there is no
lock when iterating this list in function CoreValidateHandle().
It can lead to "Handle.c (76): CR has Bad Signature" assertion if the iterated
entry in the list is just removed by other task during iterating.
Locking the list when iterating can fix this issue.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Hua Ma <hua.ma@intel.com>
---
MdeModulePkg/Core/Dxe/Hand/DriverSupport.c | 10 ++---
MdeModulePkg/Core/Dxe/Hand/Handle.c | 47 ++++++++++++++--------
MdeModulePkg/Core/Dxe/Hand/Handle.h | 3 +-
MdeModulePkg/Core/Dxe/Hand/Notify.c | 2 +-
4 files changed, 39 insertions(+), 23 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/Hand/DriverSupport.c
b/MdeModulePkg/Core/Dxe/Hand/DriverSupport.c
index feabf12faf..eb8a765d2c 100644
--- a/MdeModulePkg/Core/Dxe/Hand/DriverSupport.c
+++ b/MdeModulePkg/Core/Dxe/Hand/DriverSupport.c
@@ -68,7 +68,7 @@ CoreConnectController (
//
// Make sure ControllerHandle is valid
//
- Status = CoreValidateHandle (ControllerHandle);
+ Status = CoreValidateHandle (ControllerHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -154,7 +154,7 @@ CoreConnectController (
//
// Make sure the DriverBindingHandle is valid
//
- Status = CoreValidateHandle (ControllerHandle);
+ Status = CoreValidateHandle (ControllerHandle, TRUE);
if (EFI_ERROR (Status)) {
//
// Release the protocol lock on the handle database @@ -268,7 +268,7 @@
AddSortedDriverBindingProtocol (
//
// Make sure the DriverBindingHandle is valid
//
- Status = CoreValidateHandle (DriverBindingHandle);
+ Status = CoreValidateHandle (DriverBindingHandle, FALSE);
if (EFI_ERROR (Status)) {
return;
}
@@ -746,7 +746,7 @@ CoreDisconnectController (
//
// Make sure ControllerHandle is valid
//
- Status = CoreValidateHandle (ControllerHandle);
+ Status = CoreValidateHandle (ControllerHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -755,7 +755,7 @@ CoreDisconnectController (
// Make sure ChildHandle is valid if it is not NULL
//
if (ChildHandle != NULL) {
- Status = CoreValidateHandle (ChildHandle);
+ Status = CoreValidateHandle (ChildHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
diff --git a/MdeModulePkg/Core/Dxe/Hand/Handle.c
b/MdeModulePkg/Core/Dxe/Hand/Handle.c
index 6eccb41ecb..b4f389bb35 100644
--- a/MdeModulePkg/Core/Dxe/Hand/Handle.c
+++ b/MdeModulePkg/Core/Dxe/Hand/Handle.c
@@ -55,31 +55,46 @@ CoreReleaseProtocolLock (
Check whether a handle is a valid EFI_HANDLE

@param UserHandle The handle to check
+ @param IsLocked The protocol lock is acquried or not

@retval EFI_INVALID_PARAMETER The handle is NULL or not a valid
EFI_HANDLE.
+ @retval EFI_NOT_FOUND The handle is not found in the handle
database.
@retval EFI_SUCCESS The handle is valid EFI_HANDLE.

**/
EFI_STATUS
CoreValidateHandle (
- IN EFI_HANDLE UserHandle
+ IN EFI_HANDLE UserHandle,
+ IN BOOLEAN IsLocked
)
{
IHANDLE *Handle;
LIST_ENTRY *Link;
+ EFI_STATUS Status;

if (UserHandle == NULL) {
return EFI_INVALID_PARAMETER;
}

+ if (IsLocked) {
+ ASSERT_LOCKED(&gProtocolDatabaseLock);
+ } else {
+ CoreAcquireProtocolLock ();
+ }
+
+ Status = EFI_NOT_FOUND;
for (Link = gHandleList.BackLink; Link != &gHandleList; Link = Link->BackLink) {
Handle = CR (Link, IHANDLE, AllHandles, EFI_HANDLE_SIGNATURE);
if (Handle == (IHANDLE *) UserHandle) {
- return EFI_SUCCESS;
+ Status = EFI_SUCCESS;
+ break;
}
}

- return EFI_INVALID_PARAMETER;
+ if (!IsLocked) {
+ CoreReleaseProtocolLock ();
+ }
+ return Status;
}


@@ -428,7 +443,7 @@ CoreInstallProtocolInterfaceNotify (
//
InsertTailList (&gHandleList, &Handle->AllHandles);
} else {
- Status = CoreValidateHandle (Handle);
+ Status = CoreValidateHandle (Handle, TRUE);
if (EFI_ERROR (Status)) {
DEBUG((DEBUG_ERROR, "InstallProtocolInterface: input handle at 0x%x is
invalid\n", Handle));
goto Done;
@@ -723,7 +738,7 @@ CoreUninstallProtocolInterface (
//
// Check that UserHandle is a valid handle
//
- Status = CoreValidateHandle (UserHandle);
+ Status = CoreValidateHandle (UserHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -899,7 +914,7 @@ CoreGetProtocolInterface (
IHANDLE *Handle;
LIST_ENTRY *Link;

- Status = CoreValidateHandle (UserHandle);
+ Status = CoreValidateHandle (UserHandle, TRUE);
[Dandan] As current all callers of CoreGetProtocolInterface () has acquired the lock, it's OK to pass TRUE to indicate the lock is acquired.
I am just thinking about following small question.
Could we add some comments to explain why it's true here and also notify that caller should also acquire the lock firstly by itself if there is any new caller added to call this function?

if (EFI_ERROR (Status)) {
return NULL;
}
@@ -1013,7 +1028,7 @@ CoreOpenProtocol (
//
// Check for invalid UserHandle
//
- Status = CoreValidateHandle (UserHandle);
+ Status = CoreValidateHandle (UserHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -1023,11 +1038,11 @@ CoreOpenProtocol (
//
switch (Attributes) {
case EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER :
- Status = CoreValidateHandle (ImageHandle);
+ Status = CoreValidateHandle (ImageHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
- Status = CoreValidateHandle (ControllerHandle);
+ Status = CoreValidateHandle (ControllerHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -1037,17 +1052,17 @@ CoreOpenProtocol (
break;
case EFI_OPEN_PROTOCOL_BY_DRIVER :
case EFI_OPEN_PROTOCOL_BY_DRIVER | EFI_OPEN_PROTOCOL_EXCLUSIVE :
- Status = CoreValidateHandle (ImageHandle);
+ Status = CoreValidateHandle (ImageHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
- Status = CoreValidateHandle (ControllerHandle);
+ Status = CoreValidateHandle (ControllerHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
break;
case EFI_OPEN_PROTOCOL_EXCLUSIVE :
- Status = CoreValidateHandle (ImageHandle);
+ Status = CoreValidateHandle (ImageHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -1249,16 +1264,16 @@ CoreCloseProtocol (
//
// Check for invalid parameters
//
- Status = CoreValidateHandle (UserHandle);
+ Status = CoreValidateHandle (UserHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
- Status = CoreValidateHandle (AgentHandle);
+ Status = CoreValidateHandle (AgentHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
if (ControllerHandle != NULL) {
- Status = CoreValidateHandle (ControllerHandle);
+ Status = CoreValidateHandle (ControllerHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
@@ -1443,7 +1458,7 @@ CoreProtocolsPerHandle (
UINTN ProtocolCount;
EFI_GUID **Buffer;

- Status = CoreValidateHandle (UserHandle);
+ Status = CoreValidateHandle (UserHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
diff --git a/MdeModulePkg/Core/Dxe/Hand/Handle.h
b/MdeModulePkg/Core/Dxe/Hand/Handle.h
index 83eb2b9f3a..b962d80a29 100644
--- a/MdeModulePkg/Core/Dxe/Hand/Handle.h
+++ b/MdeModulePkg/Core/Dxe/Hand/Handle.h
@@ -251,7 +251,8 @@ CoreReleaseProtocolLock ( **/ EFI_STATUS
CoreValidateHandle (
- IN EFI_HANDLE UserHandle
+ IN EFI_HANDLE UserHandle,
+ IN BOOLEAN IsLocked
);

//
diff --git a/MdeModulePkg/Core/Dxe/Hand/Notify.c
b/MdeModulePkg/Core/Dxe/Hand/Notify.c
index 553413a350..f4e7c01e96 100644
--- a/MdeModulePkg/Core/Dxe/Hand/Notify.c
+++ b/MdeModulePkg/Core/Dxe/Hand/Notify.c
@@ -188,7 +188,7 @@ CoreReinstallProtocolInterface (
PROTOCOL_INTERFACE *Prot;
PROTOCOL_ENTRY *ProtEntry;

- Status = CoreValidateHandle (UserHandle);
+ Status = CoreValidateHandle (UserHandle, FALSE);
if (EFI_ERROR (Status)) {
return Status;
}
--
2.32.0.windows.2

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