In the method DumpGuardedMemoryBitmap() and SetAllGuardPages(), the code
didn't check if the global mMapLevel is legal value or not, which leaves
a logic hole causing potential array overflow in code followed.
This patch adds sanity check before any array reference in those methods.
Cc: Wu Hao <hao.a.wu@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Wu Hao <hao.a.wu@intel.com>
The build error is introduced by following check in:
2930ef9809976ce693d1d377851344c3b06bd926
235a4490c8ce8b6dbac49e6ae3559cb73d6bf620
The Visual Studio older than 2015 doesn't support constant integer
in binary format (0bxxx). This patch changes them to BIT macro to
fix it. This patch also cleans up coding style about unmatched
comment for return value.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Bi Dandan <dandan.bi@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
This feature makes use of paging mechanism to add a hidden (not present)
page just before and after the allocated memory block. If the code tries
to access memory outside of the allocated part, page fault exception will
be triggered.
This feature is controlled by three PCDs:
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPageType
BIT2 and BIT3 of PcdHeapGuardPropertyMask can be used to enable or disable
memory guard for SMM page and pool respectively. PcdHeapGuardPoolType and/or
PcdHeapGuardPageType are used to enable or disable guard for specific type
of memory. For example, we can turn on guard only for EfiRuntimeServicesCode
and EfiRuntimeServicesData by setting the PCD with value 0x60.
Pool memory is not ususally integer multiple of one page, and is more likely
less than a page. There's no way to monitor the overflow at both top and
bottom of pool memory. BIT7 of PcdHeapGuardPropertyMask is used to control
how to position the head of pool memory so that it's easier to catch memory
overflow in memory growing direction or in decreasing direction.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Suggested-by: Ayellet Wolman <ayellet.wolman@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
