Skip to content

Revert "[msan] Detect dereferencing zero-alloc as use-of-uninitialized-value" #156148

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
wants to merge 1 commit into
base: main
Choose a base branch
from
+4 −6
Open

Revert "[msan] Detect dereferencing zero-alloc as use-of-uninitialized-value" #156148

Show file tree
Hide file tree
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
6 changes: 0 additions & 6 deletions compiler-rt/lib/msan/msan_allocator.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -230,12 +230,6 @@ static void *MsanAllocate(BufferedStackTrace *stack, uptr size, uptr alignment,
__msan_set_origin(allocated, size, o.raw_id());
}
}

uptr actually_allocated_size = allocator.GetActuallyAllocatedSize(allocated);
// For compatibility, the allocator converted 0-sized allocations into 1 byte
if (size == 0 && actually_allocated_size > 0 && flags()->poison_in_malloc)
__msan_poison(allocated, 1);

UnpoisonParam(2);
RunMallocHooks(allocated, size);
return allocated;
Expand Down
4 changes: 4 additions & 0 deletions compiler-rt/test/msan/zero_alloc.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,9 @@
// RUN: %clang_msan -Wno-alloc-size -fsanitize-recover=memory %s -o %t && not %run %t 2>&1 | FileCheck %s

// MSan doesn't catch this because internally it translates 0-byte allocations
// into 1-byte
// XFAIL: *

#include <malloc.h>
#include <stdio.h>

Expand Down