Tag Archives: yosemite
The Case of the Apparent NSS Memory Corruption
This is a story of my encounter with an apparent memory corruption issue in the Netscape Security Services library.
The source I’m discussing can be found on Github.
Usually, when I try to get acquainted with a new API, I start to write simple program, one API call by call, which I compile and run after each step.
Imagine my surprise, when after adding the following function call (the only thing I added)
PK11_FindKeyByAnyCert( certificate, passwd );
I got this memory corruption error.
dblfree(56630,0x7fff73f61300) malloc: *** error for object 0x7fd39250ce70: pointer being freed was not allocated *** set a breakpoint in malloc_error_break to debug zsh: abort ./dblfree
The above error is taken from my minimal example of the problem, not the actual program I was working on at the time. The only difference is the name of the binary and the hex numbers.
So what is happening here? I didn’t know. And to find out, it’s really important to use the right tool for the job.
So the first thing I did was to instrument my code with the built-in OS X tools, instruments(1). That didn’t tell me much; either because it doesn’t help in this particular instance, or that I just don’t know how to use it.
I will make a note that some people suggested Valgrind. I didn’t go that way because the problem seems to be adequately described with the Clang Address Sanitizer.
Continue reading The Case of the Apparent NSS Memory Corruption
Building SBCL on OS X Yosemite
A month or two ago, it did not work to build Steel Banks Common Lisp on OS X Yosemite. Or at least it never worked for me.
This has been fixed now, at least as of recent git checkout, and quite possibly SBCL 1.3.10.
If you get an error like the following,
ld: library not found for -lgcc_s.10.4
then you can try this (as far as I know) totally undocumented switch
SBCL_MACOSX_VERSION_MIN=10.10 sh make.sh
and the build will succeed.
Happy lisping with SBCL!