From 71914406e894c462dc9255c7a18f9cbe3651b8f8 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Thu, 12 Dec 2013 17:28:05 +0000 Subject: OvmfPkg: Virtio drivers: fix incorrect casts in init functions The recent patch OvmfPkg: Make the VirtIo devices use the new VIRTIO_DEVICE_PROTOCOL was fixed up at commit time, in order to silence warnings issued by the Visual Studio compiler. Differences between the posted and committed patch: > diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c > -index 17b9f71..96a0d9f 100644 > +index 17b9f71..f09b0d1 100644 > --- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c > +++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c > @@ -23,7 +23,6 @@ > @@ -994,7 +998,7 @@ > + // step 4c -- Report GPFN (guest-physical frame number) of queue. > + // > + Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, > -+ (UINTN) Dev->Ring.Base >> EFI_PAGE_SHIFT); > ++ (UINT32)(UINTN) Dev->Ring.Base >> EFI_PAGE_SHIFT); > + if (EFI_ERROR (Status)) { > + goto ReleaseQueue; > + } > @@ -1495,7 +1499,7 @@ > goto Exit; > } > diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c > -index 6cee014..8dcf9da 100644 > +index 6cee014..4203fbd 100644 > --- a/OvmfPkg/VirtioNetDxe/SnpInitialize.c > +++ b/OvmfPkg/VirtioNetDxe/SnpInitialize.c > @@ -57,14 +57,15 @@ VirtioNetInitRing ( > @@ -1539,7 +1543,7 @@ > - Status = VIRTIO_CFG_WRITE (Dev, Generic.VhdrQueueAddress, > - (UINTN) Ring->Base >> EFI_PAGE_SHIFT); > + Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, > -+ (UINTN) Ring->Base >> EFI_PAGE_SHIFT); > ++ (UINT32)(UINTN) Ring->Base >> EFI_PAGE_SHIFT); > if (EFI_ERROR (Status)) { > - VirtioRingUninit (Ring); > + goto ReleaseQueue; > @@ -1721,7 +1725,7 @@ > Exit: > gBS->RestoreTPL (OldTpl); > diff --git a/OvmfPkg/VirtioScsiDxe/VirtioScsi.c b/OvmfPkg/VirtioScsiDxe/VirtioScsi.c > -index b836fb3..bcec676 100644 > +index b836fb3..2223c9c 100644 > --- a/OvmfPkg/VirtioScsiDxe/VirtioScsi.c > +++ b/OvmfPkg/VirtioScsiDxe/VirtioScsi.c > @@ -38,7 +38,6 @@ > @@ -1908,7 +1912,7 @@ > + // step 4c -- Report GPFN (guest-physical frame number) of queue. > + // > + Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, > -+ (UINTN) Dev->Ring.Base >> EFI_PAGE_SHIFT); > ++ (UINT32)(UINTN) Dev->Ring.Base >> EFI_PAGE_SHIFT); > if (EFI_ERROR (Status)) { > goto ReleaseQueue; > } These casts are incorrect -- they throw away address bits >=32 before shifting, which can break the drivers in guests with more than 4GB RAM. The bug is clearly an artifact of the edk2 coding style, which requires cast expressions to be written as (type) expression rather than the usual (type)expression The latter correctly reflects that casts have one of the strongest bindings in C. The former actively obscures that fact. Cf. (type) expr1 >> expr2 vs. (type)expr1 >> expr2 Make sure we shift before we truncate. 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@14970 6f19259b-4bc3-4df7-8a09-765794883524 --- OvmfPkg/VirtioNetDxe/SnpInitialize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'OvmfPkg/VirtioNetDxe') diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c index 4203fbd6c1..223030af9e 100644 --- a/OvmfPkg/VirtioNetDxe/SnpInitialize.c +++ b/OvmfPkg/VirtioNetDxe/SnpInitialize.c @@ -96,7 +96,7 @@ VirtioNetInitRing ( // step 4c -- report GPFN (guest-physical frame number) of queue // Status = Dev->VirtIo->SetQueueAddress (Dev->VirtIo, - (UINT32)(UINTN) Ring->Base >> EFI_PAGE_SHIFT); + (UINT32) ((UINTN) Ring->Base >> EFI_PAGE_SHIFT)); if (EFI_ERROR (Status)) { goto ReleaseQueue; } -- cgit v1.2.3