mirror of https://github.com/acidanthera/audk.git
4bfd668e5e
A memory range can be submitted for attribute changes which is large enough to not require a page split during the attribute update. Consider the following scenario: 1. An attribute update removed the RW attribute on a range large enough to not require a page split. 2. Later, an attributes update is called to re-add the RW attribute for a subsection of that larger page which requires a split 3. The attribute update logic performs a page split, so now the parent and child pages have matching attributes 4. Then, the attribute update logic changes the child page to have the RW attribute. 5. The child page would then correctly have the RW attribute added but the parent page would still have the RW attribute removed which will cause an improper access violation. The page being split should have loose attributes to accommodate the above case. The split page should always have the attributes set so the lowest level page frame determines the access rights as detailed in 4.10.2.2 of the Intel 64 and IA-32 Architectures Software Developer Manual. Setting the User/Supervisor attribute shouldn't be necessary. Cc: Eric Dong <eric.dong@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com> Cc: Rahul Kumar <rahul1.kumar@intel.com> Signed-off-by: Taylor Beebe <t@taylorbeebe.com> |
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| .. | ||
| Ia32 | ||
| X64 | ||
| CpuDxe.c | ||
| CpuDxe.h | ||
| CpuDxe.inf | ||
| CpuDxe.uni | ||
| CpuDxeExtra.uni | ||
| CpuGdt.c | ||
| CpuGdt.h | ||
| CpuMp.c | ||
| CpuMp.h | ||
| CpuPageTable.c | ||
| CpuPageTable.h | ||