Skip to content

flush instruction cache after performing relocations #59

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
hMihaiDavid wants to merge 5 commits into
base: master
Choose a base branch
from
Open

flush instruction cache after performing relocations #59

Changes from 1 commit
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
be65681
flush instruction cache after performing relocations
hMihaiDavid Dec 31, 2016
16e5869
Merge pull request #1 from hMihaiDavid/hMihaiDavid-patch-1
hMihaiDavid Dec 31, 2016
124759b
flush instruction cache of each base relocation block
hMihaiDavid Jan 4, 2017
e1037a7
Merge pull request #2 from hMihaiDavid/patch-2
hMihaiDavid Jan 4, 2017
61b2140
Update MemoryModule.c
hMihaiDavid Jan 4, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
flush instruction cache after performing relocations 
Flush instruction cache to avoid executing stale code after performing relocations.
According to MSDN: "Applications should call FlushInstructionCache if they generate or modify code in memory. The CPU cannot detect the change, and may execute the old code it cached.".
After performing relocation we have modified executable code, so if we don't flush the cache maybe the old code without relocation is executed instead. So far the code has woked without flushing instruction cache but it's better to be safe.

https://msdn.microsoft.com/en-us/library/windows/desktop/ms679350(v=vs.85).aspx
  • Loading branch information
@hMihaiDavid
hMihaiDavid authored Dec 31, 2016
commit be6568111d709ac1c64fb70aeecf1ffc4a217c9a
3 changes: 3 additions & 0 deletions MemoryModule.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -645,6 +645,9 @@ HMEMORYMODULE MemoryLoadLibraryEx(const void *data, size_t size,
} else {
result->isRelocated = TRUE;
}

// flush instruction cache to avoid executing stale code after performing relocations
FlushInstructionCache((HANDLE)-1, NULL, 0);
Comment thread
hMihaiDavid marked this conversation as resolved.
Outdated

// load required dlls and adjust function table of imports
if (!BuildImportTable(result)) {
Expand Down