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Add LLVM KCFI support to the Rust compiler

This commit adds LLVM Kernel Control Flow Integrity (KCFI) support to
the Rust compiler. It initially provides forward-edge control flow
protection for operating systems kernels for Rust-compiled code only by
aggregating function pointers in groups identified by their return and
parameter types. (See llvm/llvm-project@cff5bef.)

Forward-edge control flow protection for C or C++ and Rust -compiled
code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code
share the same virtual address space) will be provided in later work as
part of this project by identifying C char and integer type uses at the
time types are encoded (see Type metadata in the design document in the
tracking issue #89653).

LLVM KCFI can be enabled with -Zsanitizer=kcfi.

Co-authored-by: bjorn3 <17426603+bjorn3@users.noreply.github.com>
This commit is contained in:
Ramon de C Valle 2022-11-21 21:29:00 -08:00
parent b7bc90fea3
commit 65698ae9f3
26 changed files with 231 additions and 28 deletions

View file

@ -368,7 +368,7 @@ mod desc {
pub const parse_opt_panic_strategy: &str = parse_panic_strategy;
pub const parse_oom_strategy: &str = "either `panic` or `abort`";
pub const parse_relro_level: &str = "one of: `full`, `partial`, or `off`";
pub const parse_sanitizers: &str = "comma separated list of sanitizers: `address`, `cfi`, `hwaddress`, `leak`, `memory`, `memtag`, `shadow-call-stack`, or `thread`";
pub const parse_sanitizers: &str = "comma separated list of sanitizers: `address`, `cfi`, `hwaddress`, `kcfi`, `leak`, `memory`, `memtag`, `shadow-call-stack`, or `thread`";
pub const parse_sanitizer_memory_track_origins: &str = "0, 1, or 2";
pub const parse_cfguard: &str =
"either a boolean (`yes`, `no`, `on`, `off`, etc), `checks`, or `nochecks`";
@ -675,6 +675,7 @@ mod parse {
*slot |= match s {
"address" => SanitizerSet::ADDRESS,
"cfi" => SanitizerSet::CFI,
"kcfi" => SanitizerSet::KCFI,
"leak" => SanitizerSet::LEAK,
"memory" => SanitizerSet::MEMORY,
"memtag" => SanitizerSet::MEMTAG,

View file

@ -683,6 +683,10 @@ impl Session {
self.opts.unstable_opts.sanitizer.contains(SanitizerSet::CFI)
}
pub fn is_sanitizer_kcfi_enabled(&self) -> bool {
self.opts.unstable_opts.sanitizer.contains(SanitizerSet::KCFI)
}
/// Check whether this compile session and crate type use static crt.
pub fn crt_static(&self, crate_type: Option<CrateType>) -> bool {
if !self.target.crt_static_respected {
@ -1530,6 +1534,14 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
}
}
// LLVM CFI and KCFI are mutually exclusive
if sess.is_sanitizer_cfi_enabled() && sess.is_sanitizer_kcfi_enabled() {
sess.emit_err(CannotMixAndMatchSanitizers {
first: "cfi".to_string(),
second: "kcfi".to_string(),
});
}
if sess.opts.unstable_opts.stack_protector != StackProtector::None {
if !sess.target.options.supports_stack_protector {
sess.emit_warning(StackProtectorNotSupportedForTarget {