Skip to content

[ASan][Windows] Fix rip-relative instruction replacement #68432

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

Merged
merged 1 commit into from
Oct 9, 2023
Merged

[ASan][Windows] Fix rip-relative instruction replacement #68432

Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
20 changes: 13 additions & 7 deletions compiler-rt/lib/interception/interception_win.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -726,16 +726,22 @@ static bool CopyInstructions(uptr to, uptr from, size_t size) {
size_t instruction_size = GetInstructionSize(from + cursor, &rel_offset);
if (!instruction_size)
return false;
_memcpy((void*)(to + cursor), (void*)(from + cursor),
_memcpy((void *)(to + cursor), (void *)(from + cursor),
Copy link
Collaborator

@vitalybuka vitalybuka Oct 9, 2023 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Is this clang-formated?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yeah.

(size_t)instruction_size);
if (rel_offset) {
uptr delta = to - from;
uptr relocated_offset = *(u32*)(to + cursor + rel_offset) - delta;
#if SANITIZER_WINDOWS64
if (relocated_offset + 0x80000000U >= 0xFFFFFFFFU)
# if SANITIZER_WINDOWS64
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

maybe if constexpr (SANITIZER_WINDOWS64) to compile it always

// we want to make sure that the new relative offset still fits in 32-bits
// this will be untrue if relocated_offset \notin [-2**31, 2**31)
s64 delta = to - from;
s64 relocated_offset = *(s32 *)(to + cursor + rel_offset) - delta;
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I guess you can use same code if use s64/s32 -> sptr

if (-0x8000'0000ll > relocated_offset || relocated_offset > 0x7FFF'FFFFll)
return false;
#endif
*(u32*)(to + cursor + rel_offset) = relocated_offset;
# else
// on 32-bit, the relative offset will always be correct
s32 delta = to - from;
s32 relocated_offset = *(s32 *)(to + cursor + rel_offset) - delta;
# endif
*(s32 *)(to + cursor + rel_offset) = relocated_offset;
}
cursor += instruction_size;
}
Expand Down