This reverts commit 58766a4729.
In edk2 commit 58766a4, validation of the two reserved FAT entries
was added.
However, it also checked the return of FatGetFatEntry to MAX_UINT32,
which is what FatGetFatEntry returns when it encounters an error,
e.g. not being able to read the disk. However, MAX_UINT32 is also a
valid value for the reserved FAT entries and under some conditions
these will be returned in the success case.
A FAT volume formatted with these valid values of the reserved FAT
entries will fail to boot an OS because the opening of the volume
will fail.
However, the reason FatGetFatEntry returns MAX_UINT32 is that most
other uses of the function are comparing it against the END_OF_CHAIN
mark, which MAX_UINT32 will trip and those functions will fail out.
Because this is a critical bug that can prevent OS booting and the
bug the original commit was solving was accounting for a bad FAT
filesystem formatting tool, this commit is reverted for now.
Future work will clean up FatGetFatEntry so that it returns an
EFI_STATUS, but that involves more work and this bug needs to be
resolved in the meantime.
Signed-off-by: Oliver Smith-Denny <osde@microsoft.com>
There are two reserved FAT entries in the FAT filesystem that
are expected to have valid contents in them. Today the FAT drivers
do not validate these entries when reading from a device for the
first time. This can cause infinite loops in the FAT driver when
trying to read corrupted disks as reported in
https://github.com/tianocore/edk2/issues/9679.
This PR follows the recommended update requested in that bug to
check the two reserved FAT entries and validate their contents
against the spec defined values in both FatPei and EnhancedFatDxe
when opening a device for the first time.
Signed-off-by: Oliver Smith-Denny <osde@microsoft.com>
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3737
Apply uncrustify changes to .c/.h files in the FatPkg package
Cc: Andrew Fish <afish@apple.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
In FatPkg, cluster-related varibles are declared as unsigned type (e.g.
UINT32/UINTN). To keep the comparisions involving those variables
type-matched, declare the definition FAT_CLUSTER_SPECIAL as unsigned type
explicitly.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
Oliver Smith-Denny
Michael Kubacki
Michael D Kinney
Hao Wu
Jordan Justen