In 829c089f83, we disabled all
FORTIFY_SOURCE support when compiling under clang. At the time,
we didn't have proper test cases, and couldn't easily create targeted
clang tests.
This change re-enables FORTIFY_SOURCE support under clang for a
limited set of functions, where we have explicit unittests available.
The functions are:
* memcpy
* memmove
* strcpy
* strncpy
* strcat
* strncat
* memset
* strlen (with modifications)
* strchr (with modifications)
* strrchr (with modifications)
It may be possible, in the future, to enable other functions. However,
I need to write unittests first.
For strlen, strchr, and strrchr, clang unconditionally calls the
fortified version of the relevant function. If it doesn't know the
size of the buffer it's dealing with, it passes in ((size_t) -1),
which is the largest possible size_t.
I added two new clang specific unittest files, primarily copied
from fortify?_test.cpp.
I've also rebuild the entire system with these changes, and didn't
observe any obvious problems.
Change-Id: If12a15089bb0ffe93824b485290d05b14355fcaa
7e6ce1a3c5 fixed abort() to raise
SIGABRT rather than causing SIGSEGV. However, the unittests were
not updated.
Fix unittests.
Change-Id: I73db194127b9b9e9440358aa94273863765a736b
__strcat_chk and __strncat_chk are slightly inefficient,
because they end up traversing over the same memory region
two times.
This change optimizes __strcat_chk / __strncat_chk so they
only access the memory once. Although I haven't benchmarked these
changes, it should improve the performance of these functions.
__strlen_chk - expose this function, even if -D_FORTIFY_SOURCE
isn't defined. This is needed to compile libc itself without
-D_FORTIFY_SOURCE.
Change-Id: Id2c70dff55a276b47c59db27a03734d659f84b74
Add support for fortify source level 2 to strncpy.
This will enable detection of more areas where strncpy
is used inappropriately. For example, this would have detected
bug 8727221.
Move the fortify_source tests out of string_test.cpp, and
put it into fortify1_test.cpp.
Create a new fortify2_test.cpp file, which copies all
the tests in fortify1_test.cpp, and adds fortify_source level
2 specific tests.
Change-Id: Ica0fba531cc7d0609e4f23b8176739b13f7f7a83