It looks to be the case that Rust's standard allocator, jemalloc, is
incompatible with sanitizers. The incompatibility, for whatever reason,
seems to cause segfaults at runtime when jemalloc is linked with
sanitizers.
Without actually trying to figure out what's going on here this commit
instead takes the hammer of "let's remove jemalloc when testing". The
`tor_allocate` crate now by default switches to the system allocator
(eventually this will want to be the tor allocator). Most crates then
link to `tor_allocate` ot pick this up, but the `smartlist` crate had to
manually switch to the system allocator in testing and the `external`
crate had to be sure to link to `tor_allocate`.
The final gotcha here is that this patch also switches to
unconditionally passing `--target` to Cargo. For weird and arcane
reasons passing `--target` with the host target of the compiler (which
Cargo otherwise uses as the default) is different than not passing
`--target` at all. This ensure that our custom `RUSTFLAGS` with
sanitizer options doesn't make its way into build scripts, just the
final testing artifacts.
This is no longer necessary with upstream rust-lang/rust changes as well
as some local tweaks. Namely:
* The `-fsanitize=address`-style options are now passed via `-C
link-args` through `RUSTFLAGS`. This obviates the need for the shell
script.
* The `-C default-linker-libraries`, disabling `-nodefaultlibs`, is
passed through `RUSTFLAGS`, which is necessary to ensure that
`-fsanitize=address` links correctly.
* The `-C linker` option is passed to ensure we're using the same C
compiler as normal C code, although it has a bit of hackery to only
get the `gcc` out of `gcc -std=c99`
Previously the sanitizers are forcibly disabled as they were found to be
incompatible with Rust code. The nightly channel of Rust, however, now
has some fixes which should make this disabling no longer necessary.
Various places in our code try to activate these events or check
their status, so we should make sure they're initialized as early as
possible. Fixes bug 27861; bugfix on 0.3.5.1-alpha.
When freeing a configuration object from confparse.c in
dump_config(), we need to call the appropriate higher-level free
function (like or_options_free()) and not just config_free().
This only happens with options (since they're the one where
options_validate allocates extra stuff) and only when running
--dump-config with something other than minimal (since
OPTIONS_DUMP_MINIMAL doesn't hit this code).
Fixes bug 27893; bugfix on 0.3.2.1-alpha.
It differs from the rest of the rephist code in that it's actually
necessary for Tor to operate, so it should probably go somewhere
else. I'm not sure where yet, so I'll leave it in the same
directory, but give it its own file.
Since this is completely core functionality, I'm putting it in
core/mainloop, even though it depends on feature/hibernate. We'll
have to sort that out in the future.
Alex Crichton
Nick Mathewson
rl1987
cypherpunks