Currently 1 byte global object has a ridiculous 63 bytes redzone.
This patch reduces the redzone size to be less than 32 if the size of global object is less than or equal to half of 32 (the minimal size of redzone).
A 12 bytes object has a 20 bytes redzone, a 20 bytes object has a 44 bytes redzone.
Reviewed By: MaskRay, #sanitizers, vitalybuka
Differential Revision: https://reviews.llvm.org/D102469
Under NPM, the asan-globals-md analysis is required but cannot be run
within the asan function pass due to module analyses not being able to
run from a function pass. So this pins all tests using "-asan" to the
legacy PM and adds a corresponding RUN line with
-passes='require<asan-globals-md>,function(asan)'.
Now all tests in Instrumentation/AddressSanitizer pass when
-enable-new-pm is by default on.
Tests were automatically converted using the following python script and
failures were manually fixed up.
import sys
for i in sys.argv:
with open(i, 'r') as f:
s = f.read()
with open(i, 'w') as f:
for l in s.splitlines():
if "RUN:" in l and ' -asan -asan-module ' in l and '\\' not in l:
f.write(l.replace(' -asan -asan-module ', ' -asan -asan-module -enable-new-pm=0 '))
f.write('\n')
f.write(l.replace(' -asan -asan-module ', " -passes='require<asan-globals-md>,function(asan),module(asan-module)' "))
f.write('\n')
elif "RUN:" in l and ' -asan ' in l and '\\' not in l:
f.write(l.replace(' -asan ', ' -asan -enable-new-pm=0 '))
f.write('\n')
f.write(l.replace(' -asan ', " -passes='require<asan-globals-md>,function(asan)' "))
f.write('\n')
else:
f.write(l)
f.write('\n')
See https://bugs.llvm.org/show_bug.cgi?id=46611.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D83921
Summary:
ICF prevented by removing unnamed_addr and local_unnamed_addr for all sanitized
globals.
Also in general unnamed_addr is not valid here as address now is important for
ODR violation detector and redzone poisoning.
Before the patch ICF on globals caused:
1. false ODR reports when we register global on the same address more than once
2. globals buffer overflow if we fold variables of smaller type inside of large
type. Then the smaller one will poison redzone which overlaps with the larger one.
Reviewers: eugenis, pcc
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D55857
llvm-svn: 349706
On Darwin, simple C null-terminated constant strings normally end up in the __TEXT,__cstring section of the resulting Mach-O binary. When instrumented with ASan, these strings are transformed in a way that they cannot be in __cstring (the linker unifies the content of this section and strips extra NUL bytes, which would break instrumentation), and are put into a generic __const section. This breaks some of the tools that we have: Some tools need to scan all C null-terminated strings in Mach-O binaries, and scanning all the contents of __const has a large performance penalty. This patch instead introduces a special section, __asan_cstring which will now hold the instrumented null-terminated strings.
Differential Revision: https://reviews.llvm.org/D25026
llvm-svn: 285619
Arthur Eubanks