From 9c08bbe59ca1e1667ffa4d0cf4d98b2a5d3a58f8 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Sat, 22 Mar 2014 07:13:44 +0000 Subject: [PATCH] OvmfPkg: QemuVideoDxe: serialize Start() against callbacks If Start() succeeds, the callback is only executed when the setup is complete (on the stack of RestoreTPL()), rather than on the stack of InstallMultipleProtocolInterfaces(), when the driver setup may yet be theoretically incomplete. If Start() fails, the protocol interface will have been uninstalled (rolled back) by the time the callback runs (again, on the stack of RestoreTPL()). Since protocol notification callbacks begin with locating the protocol interface in question, such attempts to locate will fail immediately and save some work in the callback. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek Reviewed-by: Jordan Justen git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15371 6f19259b-4bc3-4df7-8a09-765794883524 --- OvmfPkg/QemuVideoDxe/Driver.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/OvmfPkg/QemuVideoDxe/Driver.c b/OvmfPkg/QemuVideoDxe/Driver.c index e71af6e850..c44b8b2603 100644 --- a/OvmfPkg/QemuVideoDxe/Driver.c +++ b/OvmfPkg/QemuVideoDxe/Driver.c @@ -170,6 +170,7 @@ QemuVideoControllerDriverStart ( IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath ) { + EFI_TPL OldTpl; EFI_STATUS Status; QEMU_VIDEO_PRIVATE_DATA *Private; EFI_DEVICE_PATH_PROTOCOL *ParentDevicePath; @@ -178,12 +179,15 @@ QemuVideoControllerDriverStart ( QEMU_VIDEO_CARD *Card; EFI_PCI_IO_PROTOCOL *ChildPciIo; + OldTpl = gBS->RaiseTPL (TPL_CALLBACK); + // // Allocate Private context data for GOP inteface. // Private = AllocateZeroPool (sizeof (QEMU_VIDEO_PRIVATE_DATA)); if (Private == NULL) { - return EFI_OUT_OF_RESOURCES; + Status = EFI_OUT_OF_RESOURCES; + goto RestoreTpl; } // @@ -394,6 +398,7 @@ QemuVideoControllerDriverStart ( goto UninstallGop; } + gBS->RestoreTPL (OldTpl); return EFI_SUCCESS; UninstallGop: @@ -424,6 +429,9 @@ ClosePciIo: FreePrivate: FreePool (Private); +RestoreTpl: + gBS->RestoreTPL (OldTpl); + return Status; } -- 2.39.2