Message ID | 20190913145100.303433-9-anthony.perard@citrix.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | OvmfPkg/XenBusDxe: Fix ExitBootServices handler to avoid allocation | expand |
On 09/13/19 16:50, Anthony PERARD wrote: > XsRead and XsBackendRead of the XENBUS_PROTOCOL return allocated > memory but this isn't allowed during the ExitBootServices call. We > need XsRead and XsBackendRead to disconnect from the device so > XENBUS_PROTOCOL is changed to use a buffer supplied by a child driver. > > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2190 > Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> > --- > OvmfPkg/Include/Protocol/XenBus.h | 32 ++++++++++++---------- > OvmfPkg/XenBusDxe/XenStore.c | 44 +++++------------------------- > OvmfPkg/XenBusDxe/XenStore.h | 6 +++-- > OvmfPkg/XenPvBlkDxe/BlockFront.c | 45 ++++++++++++++++++------------- > 4 files changed, 54 insertions(+), 73 deletions(-) > > diff --git a/OvmfPkg/Include/Protocol/XenBus.h b/OvmfPkg/Include/Protocol/XenBus.h > index 8ff5ca3575..c22bdfb368 100644 > --- a/OvmfPkg/Include/Protocol/XenBus.h > +++ b/OvmfPkg/Include/Protocol/XenBus.h > @@ -35,6 +35,12 @@ typedef struct > > #define XST_NIL ((XENSTORE_TRANSACTION *) NULL) > > +// > +// When reading a node from xenstore, if the size of the data to be read is > +// unknown, this value can be use for the size of the buffer. > +// > +#define XENSTORE_PAYLOAD_MAX 4096 > + This macro is already defined in "IndustryStandard/Xen/io/xs_wire.h". Can we get it from there? The extra documentation is OK, of course (replacing "this value" with "XENSTORE_PAYLOAD_MAX"). Other than that, I'm going to have to ACK this after a brief skim only. Acked-by: Laszlo Ersek <lersek@redhat.com> Thanks Laszlo > typedef enum { > XENSTORE_STATUS_SUCCESS = 0, > XENSTORE_STATUS_FAIL, > @@ -64,19 +70,17 @@ typedef enum { > /// > > /** > - Get the contents of the node Node of the PV device. Returns the contents in > - *Result which should be freed after use. > + Get the contents of the node Node of the PV device. > > @param This A pointer to XENBUS_PROTOCOL instance. > @param Transaction The XenStore transaction covering this request. > @param Node The basename of the file to read. > - @param Result The returned contents from this file. > + @param BufferSize On input, a pointer to the size of the buffer at Buffer. > + On output, the size of the data written to Buffer. > + @param Buffer A pointer to a buffer into which the data read will be saved. > > @return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value > indicating the type of failure. > - > - @note The results buffer is malloced and should be free'd by the > - caller. > **/ > typedef > XENSTORE_STATUS > @@ -84,23 +88,22 @@ XENSTORE_STATUS > IN XENBUS_PROTOCOL *This, > IN CONST XENSTORE_TRANSACTION *Transaction, > IN CONST CHAR8 *Node, > - OUT VOID **Result > + IN OUT UINTN *BufferSize, > + OUT VOID *Buffer > ); > > /** > - Get the contents of the node Node of the PV device's backend. Returns the > - contents in *Result which should be freed after use. > + Get the contents of the node Node of the PV device's backend. > > @param This A pointer to XENBUS_PROTOCOL instance. > @param Transaction The XenStore transaction covering this request. > @param Node The basename of the file to read. > - @param Result The returned contents from this file. > + @param BufferSize On input, a pointer to the size of the buffer at Buffer. > + On output, the size of the data written to Buffer. > + @param Buffer A pointer to a buffer into which the data read will be saved. > > @return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value > indicating the type of failure. > - > - @note The results buffer is malloced and should be free'd by the > - caller. > **/ > typedef > XENSTORE_STATUS > @@ -108,7 +111,8 @@ XENSTORE_STATUS > IN XENBUS_PROTOCOL *This, > IN CONST XENSTORE_TRANSACTION *Transaction, > IN CONST CHAR8 *Node, > - OUT VOID **Result > + IN OUT UINTN *BufferSize, > + OUT VOID *Buffer > ); > > /** > diff --git a/OvmfPkg/XenBusDxe/XenStore.c b/OvmfPkg/XenBusDxe/XenStore.c > index b9588bb8c6..cb2d9e1215 100644 > --- a/OvmfPkg/XenBusDxe/XenStore.c > +++ b/OvmfPkg/XenBusDxe/XenStore.c > @@ -1336,27 +1336,11 @@ XenBusXenStoreRead ( > IN XENBUS_PROTOCOL *This, > IN CONST XENSTORE_TRANSACTION *Transaction, > IN CONST CHAR8 *Node, > - OUT VOID **Value > + IN OUT UINTN *BufferSize, > + OUT VOID *Buffer > ) > { > - XENSTORE_STATUS Status; > - UINTN BufferSize; > - VOID *Buffer; > - > - BufferSize = XENSTORE_PAYLOAD_MAX + 1; > - Buffer = AllocatePool (BufferSize); > - if (Buffer == NULL) { > - return XENSTORE_STATUS_ENOMEM; > - } > - > - Status = XenStoreRead (Transaction, This->Node, Node, &BufferSize, Buffer); > - > - if (Status == XENSTORE_STATUS_SUCCESS) { > - *Value = Buffer; > - } else { > - FreePool (Buffer); > - } > - return Status; > + return XenStoreRead (Transaction, This->Node, Node, BufferSize, Buffer); > } > > XENSTORE_STATUS > @@ -1365,27 +1349,11 @@ XenBusXenStoreBackendRead ( > IN XENBUS_PROTOCOL *This, > IN CONST XENSTORE_TRANSACTION *Transaction, > IN CONST CHAR8 *Node, > - OUT VOID **Value > + IN OUT UINTN *BufferSize, > + OUT VOID *Buffer > ) > { > - XENSTORE_STATUS Status; > - UINTN BufferSize; > - VOID *Buffer; > - > - BufferSize = XENSTORE_PAYLOAD_MAX + 1; > - Buffer = AllocatePool (BufferSize); > - if (Buffer == NULL) { > - return XENSTORE_STATUS_ENOMEM; > - } > - > - Status = XenStoreRead (Transaction, This->Backend, Node, &BufferSize, Buffer); > - > - if (Status == XENSTORE_STATUS_SUCCESS) { > - *Value = Buffer; > - } else { > - FreePool (Buffer); > - } > - return Status; > + return XenStoreRead (Transaction, This->Backend, Node, BufferSize, Buffer); > } > > XENSTORE_STATUS > diff --git a/OvmfPkg/XenBusDxe/XenStore.h b/OvmfPkg/XenBusDxe/XenStore.h > index 13f7d132e6..ca8c080433 100644 > --- a/OvmfPkg/XenBusDxe/XenStore.h > +++ b/OvmfPkg/XenBusDxe/XenStore.h > @@ -289,7 +289,8 @@ XenBusXenStoreRead ( > IN XENBUS_PROTOCOL *This, > IN CONST XENSTORE_TRANSACTION *Transaction, > IN CONST CHAR8 *Node, > - OUT VOID **Value > + IN OUT UINTN *BufferSize, > + OUT VOID *Buffer > ); > > XENSTORE_STATUS > @@ -298,7 +299,8 @@ XenBusXenStoreBackendRead ( > IN XENBUS_PROTOCOL *This, > IN CONST XENSTORE_TRANSACTION *Transaction, > IN CONST CHAR8 *Node, > - OUT VOID **Value > + IN OUT UINTN *BufferSize, > + OUT VOID *Buffer > ); > > XENSTORE_STATUS > diff --git a/OvmfPkg/XenPvBlkDxe/BlockFront.c b/OvmfPkg/XenPvBlkDxe/BlockFront.c > index 8dca4c82f0..25a398ccc4 100644 > --- a/OvmfPkg/XenPvBlkDxe/BlockFront.c > +++ b/OvmfPkg/XenPvBlkDxe/BlockFront.c > @@ -41,19 +41,22 @@ XenBusReadUint64 ( > ) > { > XENSTORE_STATUS Status; > - CHAR8 *Ptr; > + CHAR8 Buffer[22]; > + UINTN BufferSize; > + > + BufferSize = sizeof (Buffer) - 1; > > if (!FromBackend) { > - Status = This->XsRead (This, XST_NIL, Node, (VOID**)&Ptr); > + Status = This->XsRead (This, XST_NIL, Node, &BufferSize, Buffer); > } else { > - Status = This->XsBackendRead (This, XST_NIL, Node, (VOID**)&Ptr); > + Status = This->XsBackendRead (This, XST_NIL, Node, &BufferSize, Buffer); > } > if (Status != XENSTORE_STATUS_SUCCESS) { > return Status; > } > + Buffer[BufferSize] = '\0'; > // AsciiStrDecimalToUint64 will ASSERT if Ptr overflow UINT64. > - *ValuePtr = AsciiStrDecimalToUint64 (Ptr); > - FreePool (Ptr); > + *ValuePtr = AsciiStrDecimalToUint64 (Buffer); > return Status; > } > > @@ -143,43 +146,47 @@ XenPvBlockFrontInitialization ( > OUT XEN_BLOCK_FRONT_DEVICE **DevPtr > ) > { > - XENSTORE_TRANSACTION Transaction; > - CHAR8 *DeviceType; > - blkif_sring_t *SharedRing; > - XENSTORE_STATUS Status; > + XENSTORE_TRANSACTION Transaction; > + CHAR8 Buffer[XENSTORE_PAYLOAD_MAX + 1]; > + UINTN BufferSize; > + blkif_sring_t *SharedRing; > + XENSTORE_STATUS Status; > XEN_BLOCK_FRONT_DEVICE *Dev; > - XenbusState State; > - UINT64 Value; > - CHAR8 *Params; > + XenbusState State; > + UINT64 Value; > > ASSERT (NodeName != NULL); > > + BufferSize = sizeof (Buffer) - 1; > + > Dev = AllocateZeroPool (sizeof (XEN_BLOCK_FRONT_DEVICE)); > Dev->Signature = XEN_BLOCK_FRONT_SIGNATURE; > Dev->NodeName = NodeName; > Dev->XenBusIo = XenBusIo; > Dev->DeviceId = XenBusIo->DeviceId; > > - XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", (VOID**)&DeviceType); > - if (AsciiStrCmp (DeviceType, "cdrom") == 0) { > + BufferSize = sizeof (Buffer) - 1; > + XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", &BufferSize, Buffer); > + Buffer[BufferSize] = '\0'; > + if (AsciiStrCmp (Buffer, "cdrom") == 0) { > Dev->MediaInfo.CdRom = TRUE; > } else { > Dev->MediaInfo.CdRom = FALSE; > } > - FreePool (DeviceType); > > if (Dev->MediaInfo.CdRom) { > - Status = XenBusIo->XsBackendRead (XenBusIo, XST_NIL, "params", (VOID**)&Params); > + BufferSize = sizeof (Buffer) - 1; > + Status = XenBusIo->XsBackendRead (XenBusIo, XST_NIL, "params", > + &BufferSize, Buffer); > if (Status != XENSTORE_STATUS_SUCCESS) { > DEBUG ((EFI_D_ERROR, "%a: Failed to read params (%d)\n", __FUNCTION__, Status)); > goto Error; > } > - if (AsciiStrLen (Params) == 0 || AsciiStrCmp (Params, "aio:") == 0) { > - FreePool (Params); > + Buffer[BufferSize] = '\0'; > + if (AsciiStrLen (Buffer) == 0 || AsciiStrCmp (Buffer, "aio:") == 0) { > DEBUG ((EFI_D_INFO, "%a: Empty cdrom\n", __FUNCTION__)); > goto Error; > } > - FreePool (Params); > } > > Status = XenBusReadUint64 (XenBusIo, "backend-id", FALSE, &Value); >
diff --git a/OvmfPkg/Include/Protocol/XenBus.h b/OvmfPkg/Include/Protocol/XenBus.h index 8ff5ca3575..c22bdfb368 100644 --- a/OvmfPkg/Include/Protocol/XenBus.h +++ b/OvmfPkg/Include/Protocol/XenBus.h @@ -35,6 +35,12 @@ typedef struct #define XST_NIL ((XENSTORE_TRANSACTION *) NULL) +// +// When reading a node from xenstore, if the size of the data to be read is +// unknown, this value can be use for the size of the buffer. +// +#define XENSTORE_PAYLOAD_MAX 4096 + typedef enum { XENSTORE_STATUS_SUCCESS = 0, XENSTORE_STATUS_FAIL, @@ -64,19 +70,17 @@ typedef enum { /// /** - Get the contents of the node Node of the PV device. Returns the contents in - *Result which should be freed after use. + Get the contents of the node Node of the PV device. @param This A pointer to XENBUS_PROTOCOL instance. @param Transaction The XenStore transaction covering this request. @param Node The basename of the file to read. - @param Result The returned contents from this file. + @param BufferSize On input, a pointer to the size of the buffer at Buffer. + On output, the size of the data written to Buffer. + @param Buffer A pointer to a buffer into which the data read will be saved. @return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value indicating the type of failure. - - @note The results buffer is malloced and should be free'd by the - caller. **/ typedef XENSTORE_STATUS @@ -84,23 +88,22 @@ XENSTORE_STATUS IN XENBUS_PROTOCOL *This, IN CONST XENSTORE_TRANSACTION *Transaction, IN CONST CHAR8 *Node, - OUT VOID **Result + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ); /** - Get the contents of the node Node of the PV device's backend. Returns the - contents in *Result which should be freed after use. + Get the contents of the node Node of the PV device's backend. @param This A pointer to XENBUS_PROTOCOL instance. @param Transaction The XenStore transaction covering this request. @param Node The basename of the file to read. - @param Result The returned contents from this file. + @param BufferSize On input, a pointer to the size of the buffer at Buffer. + On output, the size of the data written to Buffer. + @param Buffer A pointer to a buffer into which the data read will be saved. @return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value indicating the type of failure. - - @note The results buffer is malloced and should be free'd by the - caller. **/ typedef XENSTORE_STATUS @@ -108,7 +111,8 @@ XENSTORE_STATUS IN XENBUS_PROTOCOL *This, IN CONST XENSTORE_TRANSACTION *Transaction, IN CONST CHAR8 *Node, - OUT VOID **Result + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ); /** diff --git a/OvmfPkg/XenBusDxe/XenStore.c b/OvmfPkg/XenBusDxe/XenStore.c index b9588bb8c6..cb2d9e1215 100644 --- a/OvmfPkg/XenBusDxe/XenStore.c +++ b/OvmfPkg/XenBusDxe/XenStore.c @@ -1336,27 +1336,11 @@ XenBusXenStoreRead ( IN XENBUS_PROTOCOL *This, IN CONST XENSTORE_TRANSACTION *Transaction, IN CONST CHAR8 *Node, - OUT VOID **Value + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ) { - XENSTORE_STATUS Status; - UINTN BufferSize; - VOID *Buffer; - - BufferSize = XENSTORE_PAYLOAD_MAX + 1; - Buffer = AllocatePool (BufferSize); - if (Buffer == NULL) { - return XENSTORE_STATUS_ENOMEM; - } - - Status = XenStoreRead (Transaction, This->Node, Node, &BufferSize, Buffer); - - if (Status == XENSTORE_STATUS_SUCCESS) { - *Value = Buffer; - } else { - FreePool (Buffer); - } - return Status; + return XenStoreRead (Transaction, This->Node, Node, BufferSize, Buffer); } XENSTORE_STATUS @@ -1365,27 +1349,11 @@ XenBusXenStoreBackendRead ( IN XENBUS_PROTOCOL *This, IN CONST XENSTORE_TRANSACTION *Transaction, IN CONST CHAR8 *Node, - OUT VOID **Value + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ) { - XENSTORE_STATUS Status; - UINTN BufferSize; - VOID *Buffer; - - BufferSize = XENSTORE_PAYLOAD_MAX + 1; - Buffer = AllocatePool (BufferSize); - if (Buffer == NULL) { - return XENSTORE_STATUS_ENOMEM; - } - - Status = XenStoreRead (Transaction, This->Backend, Node, &BufferSize, Buffer); - - if (Status == XENSTORE_STATUS_SUCCESS) { - *Value = Buffer; - } else { - FreePool (Buffer); - } - return Status; + return XenStoreRead (Transaction, This->Backend, Node, BufferSize, Buffer); } XENSTORE_STATUS diff --git a/OvmfPkg/XenBusDxe/XenStore.h b/OvmfPkg/XenBusDxe/XenStore.h index 13f7d132e6..ca8c080433 100644 --- a/OvmfPkg/XenBusDxe/XenStore.h +++ b/OvmfPkg/XenBusDxe/XenStore.h @@ -289,7 +289,8 @@ XenBusXenStoreRead ( IN XENBUS_PROTOCOL *This, IN CONST XENSTORE_TRANSACTION *Transaction, IN CONST CHAR8 *Node, - OUT VOID **Value + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ); XENSTORE_STATUS @@ -298,7 +299,8 @@ XenBusXenStoreBackendRead ( IN XENBUS_PROTOCOL *This, IN CONST XENSTORE_TRANSACTION *Transaction, IN CONST CHAR8 *Node, - OUT VOID **Value + IN OUT UINTN *BufferSize, + OUT VOID *Buffer ); XENSTORE_STATUS diff --git a/OvmfPkg/XenPvBlkDxe/BlockFront.c b/OvmfPkg/XenPvBlkDxe/BlockFront.c index 8dca4c82f0..25a398ccc4 100644 --- a/OvmfPkg/XenPvBlkDxe/BlockFront.c +++ b/OvmfPkg/XenPvBlkDxe/BlockFront.c @@ -41,19 +41,22 @@ XenBusReadUint64 ( ) { XENSTORE_STATUS Status; - CHAR8 *Ptr; + CHAR8 Buffer[22]; + UINTN BufferSize; + + BufferSize = sizeof (Buffer) - 1; if (!FromBackend) { - Status = This->XsRead (This, XST_NIL, Node, (VOID**)&Ptr); + Status = This->XsRead (This, XST_NIL, Node, &BufferSize, Buffer); } else { - Status = This->XsBackendRead (This, XST_NIL, Node, (VOID**)&Ptr); + Status = This->XsBackendRead (This, XST_NIL, Node, &BufferSize, Buffer); } if (Status != XENSTORE_STATUS_SUCCESS) { return Status; } + Buffer[BufferSize] = '\0'; // AsciiStrDecimalToUint64 will ASSERT if Ptr overflow UINT64. - *ValuePtr = AsciiStrDecimalToUint64 (Ptr); - FreePool (Ptr); + *ValuePtr = AsciiStrDecimalToUint64 (Buffer); return Status; } @@ -143,43 +146,47 @@ XenPvBlockFrontInitialization ( OUT XEN_BLOCK_FRONT_DEVICE **DevPtr ) { - XENSTORE_TRANSACTION Transaction; - CHAR8 *DeviceType; - blkif_sring_t *SharedRing; - XENSTORE_STATUS Status; + XENSTORE_TRANSACTION Transaction; + CHAR8 Buffer[XENSTORE_PAYLOAD_MAX + 1]; + UINTN BufferSize; + blkif_sring_t *SharedRing; + XENSTORE_STATUS Status; XEN_BLOCK_FRONT_DEVICE *Dev; - XenbusState State; - UINT64 Value; - CHAR8 *Params; + XenbusState State; + UINT64 Value; ASSERT (NodeName != NULL); + BufferSize = sizeof (Buffer) - 1; + Dev = AllocateZeroPool (sizeof (XEN_BLOCK_FRONT_DEVICE)); Dev->Signature = XEN_BLOCK_FRONT_SIGNATURE; Dev->NodeName = NodeName; Dev->XenBusIo = XenBusIo; Dev->DeviceId = XenBusIo->DeviceId; - XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", (VOID**)&DeviceType); - if (AsciiStrCmp (DeviceType, "cdrom") == 0) { + BufferSize = sizeof (Buffer) - 1; + XenBusIo->XsRead (XenBusIo, XST_NIL, "device-type", &BufferSize, Buffer); + Buffer[BufferSize] = '\0'; + if (AsciiStrCmp (Buffer, "cdrom") == 0) { Dev->MediaInfo.CdRom = TRUE; } else { Dev->MediaInfo.CdRom = FALSE; } - FreePool (DeviceType); if (Dev->MediaInfo.CdRom) { - Status = XenBusIo->XsBackendRead (XenBusIo, XST_NIL, "params", (VOID**)&Params); + BufferSize = sizeof (Buffer) - 1; + Status = XenBusIo->XsBackendRead (XenBusIo, XST_NIL, "params", + &BufferSize, Buffer); if (Status != XENSTORE_STATUS_SUCCESS) { DEBUG ((EFI_D_ERROR, "%a: Failed to read params (%d)\n", __FUNCTION__, Status)); goto Error; } - if (AsciiStrLen (Params) == 0 || AsciiStrCmp (Params, "aio:") == 0) { - FreePool (Params); + Buffer[BufferSize] = '\0'; + if (AsciiStrLen (Buffer) == 0 || AsciiStrCmp (Buffer, "aio:") == 0) { DEBUG ((EFI_D_INFO, "%a: Empty cdrom\n", __FUNCTION__)); goto Error; } - FreePool (Params); } Status = XenBusReadUint64 (XenBusIo, "backend-id", FALSE, &Value);
XsRead and XsBackendRead of the XENBUS_PROTOCOL return allocated memory but this isn't allowed during the ExitBootServices call. We need XsRead and XsBackendRead to disconnect from the device so XENBUS_PROTOCOL is changed to use a buffer supplied by a child driver. Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2190 Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> --- OvmfPkg/Include/Protocol/XenBus.h | 32 ++++++++++++---------- OvmfPkg/XenBusDxe/XenStore.c | 44 +++++------------------------- OvmfPkg/XenBusDxe/XenStore.h | 6 +++-- OvmfPkg/XenPvBlkDxe/BlockFront.c | 45 ++++++++++++++++++------------- 4 files changed, 54 insertions(+), 73 deletions(-)