Skip to content

Commit a98546b

Browse files
rcvallercvalle
committed
KCFI: Add KCFI arity indicator support
Adds KCFI arity indicator support to the Rust compiler (see rust-lang#138311, llvm/llvm-project#121070, and https://lore.kernel.org/lkml/CANiq72=3ghFxy8E=AU9p+0imFxKr5iU3sd0hVUXed5BA+KjdNQ@mail.gmail.com/).
1 parent bad13a9 commit a98546b

File tree

14 files changed

+148
-0
lines changed

14 files changed

+148
-0
lines changed

‎compiler/rustc_codegen_llvm/messages.ftl‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -56,6 +56,8 @@ codegen_llvm_prepare_thin_lto_module_with_llvm_err = failed to prepare thin LTO
5656
codegen_llvm_run_passes = failed to run LLVM passes
5757
codegen_llvm_run_passes_with_llvm_err = failed to run LLVM passes: {$llvm_err}
5858
59+
codegen_llvm_sanitizer_kcfi_arity_requires_llvm_21_0_0 = `-Zsanitizer-kcfi-arity` requires LLVM 21.0.0 or later.
60+
5961
codegen_llvm_sanitizer_memtag_requires_mte =
6062
`-Zsanitizer=memtag` requires `-Ctarget-feature=+mte`
6163

‎compiler/rustc_codegen_llvm/src/context.rs‎

Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -327,6 +327,22 @@ pub(crate) unsafe fn create_module<'ll>(
327327
pfe.prefix().into(),
328328
);
329329
}
330+
331+
// Add "kcfi-arity" module flag if KCFI arity indicator is enabled. (See
332+
// https://github.com/llvm/llvm-project/pull/117121.)
333+
if sess.is_sanitizer_kcfi_arity_enabled() {
334+
// KCFI arity indicator requires LLVM 21.0.0 or later.
335+
if llvm_version < (21, 0, 0) {
336+
tcx.dcx().emit_err(crate::errors::SanitizerKcfiArityRequiresLLVM2100);
337+
}
338+
339+
llvm::add_module_flag_u32(
340+
llmod,
341+
llvm::ModuleFlagMergeBehavior::Override,
342+
"kcfi-arity",
343+
1,
344+
);
345+
}
330346
}
331347

332348
// Control Flow Guard is currently only supported by MSVC and LLVM on Windows.

‎compiler/rustc_codegen_llvm/src/errors.rs‎

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -217,3 +217,7 @@ pub(crate) struct MismatchedDataLayout<'a> {
217217
pub(crate) struct FixedX18InvalidArch<'a> {
218218
pub arch: &'a str,
219219
}
220+
221+
#[derive(Diagnostic)]
222+
#[diag(codegen_llvm_sanitizer_kcfi_arity_requires_llvm_21_0_0)]
223+
pub(crate) struct SanitizerKcfiArityRequiresLLVM2100;

‎compiler/rustc_interface/src/tests.rs‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -853,6 +853,7 @@ fn test_unstable_options_tracking_hash() {
853853
tracked!(sanitizer_cfi_generalize_pointers, Some(true));
854854
tracked!(sanitizer_cfi_normalize_integers, Some(true));
855855
tracked!(sanitizer_dataflow_abilist, vec![String::from("/rustc/abc")]);
856+
tracked!(sanitizer_kcfi_arity, Some(true));
856857
tracked!(sanitizer_memory_track_origins, 2);
857858
tracked!(sanitizer_recover, SanitizerSet::ADDRESS);
858859
tracked!(saturating_float_casts, Some(true));

‎compiler/rustc_session/messages.ftl‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -94,6 +94,8 @@ session_sanitizer_cfi_requires_lto = `-Zsanitizer=cfi` requires `-Clto` or `-Cli
9494
9595
session_sanitizer_cfi_requires_single_codegen_unit = `-Zsanitizer=cfi` with `-Clto` requires `-Ccodegen-units=1`
9696
97+
session_sanitizer_kcfi_arity_requires_kcfi = `-Zsanitizer-kcfi-arity` requires `-Zsanitizer=kcfi`
98+
9799
session_sanitizer_kcfi_requires_panic_abort = `-Z sanitizer=kcfi` requires `-C panic=abort`
98100
99101
session_sanitizer_not_supported = {$us} sanitizer is not supported for this target

‎compiler/rustc_session/src/errors.rs‎

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -147,6 +147,10 @@ pub(crate) struct SanitizerCfiGeneralizePointersRequiresCfi;
147147
#[diag(session_sanitizer_cfi_normalize_integers_requires_cfi)]
148148
pub(crate) struct SanitizerCfiNormalizeIntegersRequiresCfi;
149149

150+
#[derive(Diagnostic)]
151+
#[diag(session_sanitizer_kcfi_arity_requires_kcfi)]
152+
pub(crate) struct SanitizerKcfiArityRequiresKcfi;
153+
150154
#[derive(Diagnostic)]
151155
#[diag(session_sanitizer_kcfi_requires_panic_abort)]
152156
pub(crate) struct SanitizerKcfiRequiresPanicAbort;

‎compiler/rustc_session/src/options.rs‎

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2443,6 +2443,8 @@ written to standard error output)"),
24432443
"enable normalizing integer types (default: no)"),
24442444
sanitizer_dataflow_abilist: Vec<String> = (Vec::new(), parse_comma_list, [TRACKED],
24452445
"additional ABI list files that control how shadow parameters are passed (comma separated)"),
2446+
sanitizer_kcfi_arity: Option<bool> = (None, parse_opt_bool, [TRACKED],
2447+
"enable KCFI arity indicator (default: no)"),
24462448
sanitizer_memory_track_origins: usize = (0, parse_sanitizer_memory_track_origins, [TRACKED],
24472449
"enable origins tracking in MemorySanitizer"),
24482450
sanitizer_recover: SanitizerSet = (SanitizerSet::empty(), parse_sanitizers, [TRACKED],

‎compiler/rustc_session/src/session.rs‎

Lines changed: 9 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -381,6 +381,10 @@ impl Session {
381381
self.opts.unstable_opts.sanitizer_cfi_normalize_integers == Some(true)
382382
}
383383

384+
pub fn is_sanitizer_kcfi_arity_enabled(&self) -> bool {
385+
self.opts.unstable_opts.sanitizer_kcfi_arity == Some(true)
386+
}
387+
384388
pub fn is_sanitizer_kcfi_enabled(&self) -> bool {
385389
self.opts.unstable_opts.sanitizer.contains(SanitizerSet::KCFI)
386390
}
@@ -1211,6 +1215,11 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
12111215
}
12121216
}
12131217

1218+
// KCFI arity indicator requires KCFI.
1219+
if sess.is_sanitizer_kcfi_arity_enabled() && !sess.is_sanitizer_kcfi_enabled() {
1220+
sess.dcx().emit_err(errors::SanitizerKcfiArityRequiresKcfi);
1221+
}
1222+
12141223
// LLVM CFI pointer generalization requires CFI or KCFI.
12151224
if sess.is_sanitizer_cfi_generalize_pointers_enabled() {
12161225
if !(sess.is_sanitizer_cfi_enabled() || sess.is_sanitizer_kcfi_enabled()) {

‎tests/assembly/sanitizer/kcfi/emit-arity-indicator.rs‎

Lines changed: 61 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,61 @@
1+
// Verifies that KCFI arity indicator is emitted.
2+
//
3+
//@ add-core-stubs
4+
//@ revisions: x86_64
5+
//@ assembly-output: emit-asm
6+
//@[x86_64] compile-flags: --target x86_64-unknown-linux-gnu -Cllvm-args=-x86-asm-syntax=intel -Ctarget-feature=-crt-static -Cpanic=abort -Zsanitizer=kcfi -Zsanitizer-kcfi-arity -Copt-level=0
7+
//@ [x86_64] needs-llvm-components: x86
8+
//@ min-llvm-version: 21.0.0
9+
10+
#![crate_type = "lib"]
11+
12+
pub fn add_one(x: i32) -> i32 {
13+
// CHECK-LABEL: __cfi__{{.*}}7add_one{{.*}}:
14+
// CHECK-NEXT: nop
15+
// CHECK-NEXT: nop
16+
// CHECK-NEXT: nop
17+
// CHECK-NEXT: nop
18+
// CHECK-NEXT: nop
19+
// CHECK-NEXT: nop
20+
// CHECK-NEXT: nop
21+
// CHECK-NEXT: nop
22+
// CHECK-NEXT: nop
23+
// CHECK-NEXT: nop
24+
// CHECK-NEXT: nop
25+
// CHECK-NEXT: mov ecx, 2628068948
26+
x + 1
27+
}
28+
29+
pub fn add_two(x: i32, _y: i32) -> i32 {
30+
// CHECK-LABEL: __cfi__{{.*}}7add_two{{.*}}:
31+
// CHECK-NEXT: nop
32+
// CHECK-NEXT: nop
33+
// CHECK-NEXT: nop
34+
// CHECK-NEXT: nop
35+
// CHECK-NEXT: nop
36+
// CHECK-NEXT: nop
37+
// CHECK-NEXT: nop
38+
// CHECK-NEXT: nop
39+
// CHECK-NEXT: nop
40+
// CHECK-NEXT: nop
41+
// CHECK-NEXT: nop
42+
// CHECK-NEXT: mov edx, 2505940310
43+
x + 2
44+
}
45+
46+
pub fn do_twice(f: fn(i32) -> i32, arg: i32) -> i32 {
47+
// CHECK-LABEL: __cfi__{{.*}}8do_twice{{.*}}:
48+
// CHECK-NEXT: nop
49+
// CHECK-NEXT: nop
50+
// CHECK-NEXT: nop
51+
// CHECK-NEXT: nop
52+
// CHECK-NEXT: nop
53+
// CHECK-NEXT: nop
54+
// CHECK-NEXT: nop
55+
// CHECK-NEXT: nop
56+
// CHECK-NEXT: nop
57+
// CHECK-NEXT: nop
58+
// CHECK-NEXT: nop
59+
// CHECK-NEXT: mov edx, 653723426
60+
f(arg) + f(arg)
61+
}

‎tests/codegen/sanitizer/kcfi/add-kcfi-arity-flag.rs‎

Lines changed: 19 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,19 @@
1+
// Verifies that "kcfi-arity" module flag is added.
2+
//
3+
//@ add-core-stubs
4+
//@ revisions: x86_64
5+
//@ [x86_64] compile-flags: --target x86_64-unknown-none
6+
//@ [x86_64] needs-llvm-components: x86
7+
//@ compile-flags: -Ctarget-feature=-crt-static -Cpanic=abort -Zsanitizer=kcfi -Zsanitizer-kcfi-arity
8+
//@ min-llvm-version: 21.0.0
9+
10+
#![feature(no_core, lang_items)]
11+
#![crate_type = "lib"]
12+
#![no_core]
13+
14+
extern crate minicore;
15+
use minicore::*;
16+
17+
pub fn foo() {}
18+
19+
// CHECK: !{{[0-9]+}} = !{i32 4, !"kcfi-arity", i32 1}

0 commit comments

Comments
 (0)