From 10edeea4b48d852fb9366a2d4d4dde5055501a7c Mon Sep 17 00:00:00 2001 From: Kajetan Puchalski Date: Wed, 16 Oct 2024 15:39:58 +0100 Subject: [PATCH] rustc_codegen_llvm: Add a new 'pc' option to branch-protection Add a new 'pc' option to -Z branch-protection for aarch64 that enables the use of PC as a diversifier in PAC branch protection code. When the pauth-lr target feature is enabled in combination with -Z branch-protection=pac-ret,pc, the new 9.5-a instructions (pacibsppc, retaasppc, etc) will be generated. --- compiler/rustc_codegen_llvm/src/attributes.rs | 5 ++- compiler/rustc_codegen_llvm/src/context.rs | 8 +++- compiler/rustc_interface/src/tests.rs | 2 +- compiler/rustc_session/src/config.rs | 1 + compiler/rustc_session/src/options.rs | 9 ++-- .../src/compiler-flags/branch-protection.md | 3 +- tests/assembly/aarch64-pointer-auth.rs | 17 ++++++-- tests/codegen/branch-protection.rs | 42 ++++++++++++++++++- .../pointer-auth-link-with-c/rmake.rs | 14 ++++++- ...protection-missing-pac-ret.BADFLAGS.stderr | 2 +- ...otection-missing-pac-ret.BADFLAGSPC.stderr | 2 + .../branch-protection-missing-pac-ret.rs | 9 ++-- 12 files changed, 97 insertions(+), 17 deletions(-) create mode 100644 tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGSPC.stderr diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index 2c5ec9dad59..2af90142d2f 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -424,7 +424,10 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>( if bti { to_add.push(llvm::CreateAttrString(cx.llcx, "branch-target-enforcement")); } - if let Some(PacRet { leaf, key }) = pac_ret { + if let Some(PacRet { leaf, pc, key }) = pac_ret { + if pc { + to_add.push(llvm::CreateAttrString(cx.llcx, "branch-protection-pauth-lr")); + } to_add.push(llvm::CreateAttrStringValue( cx.llcx, "sign-return-address", diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs index 9778ff4918c..924137e02b1 100644 --- a/compiler/rustc_codegen_llvm/src/context.rs +++ b/compiler/rustc_codegen_llvm/src/context.rs @@ -302,7 +302,13 @@ pub(crate) unsafe fn create_module<'ll>( "sign-return-address", pac_ret.is_some().into(), ); - let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, key: PAuthKey::A }); + let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, pc: false, key: PAuthKey::A }); + llvm::add_module_flag_u32( + llmod, + llvm::ModuleFlagMergeBehavior::Min, + "branch-protection-pauth-lr", + pac_opts.pc.into(), + ); llvm::add_module_flag_u32( llmod, llvm::ModuleFlagMergeBehavior::Min, diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs index d3762e739db..546addf2232 100644 --- a/compiler/rustc_interface/src/tests.rs +++ b/compiler/rustc_interface/src/tests.rs @@ -764,7 +764,7 @@ macro_rules! tracked { branch_protection, Some(BranchProtection { bti: true, - pac_ret: Some(PacRet { leaf: true, key: PAuthKey::B }) + pac_ret: Some(PacRet { leaf: true, pc: true, key: PAuthKey::B }) }) ); tracked!(codegen_backend, Some("abc".to_string())); diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs index d733e32f209..66312d300da 100644 --- a/compiler/rustc_session/src/config.rs +++ b/compiler/rustc_session/src/config.rs @@ -1319,6 +1319,7 @@ pub enum PAuthKey { #[derive(Clone, Copy, Hash, Debug, PartialEq)] pub struct PacRet { pub leaf: bool, + pub pc: bool, pub key: PAuthKey, } diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index 54a4621db24..8eba4c68990 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -442,8 +442,7 @@ mod desc { pub(crate) const parse_polonius: &str = "either no value or `legacy` (the default), or `next`"; pub(crate) const parse_stack_protector: &str = "one of (`none` (default), `basic`, `strong`, or `all`)"; - pub(crate) const parse_branch_protection: &str = - "a `,` separated combination of `bti`, `b-key`, `pac-ret`, or `leaf`"; + pub(crate) const parse_branch_protection: &str = "a `,` separated combination of `bti`, `pac-ret`, followed by a combination of `pc`, `b-key`, or `leaf`"; pub(crate) const parse_proc_macro_execution_strategy: &str = "one of supported execution strategies (`same-thread`, or `cross-thread`)"; pub(crate) const parse_remap_path_scope: &str = @@ -1396,7 +1395,7 @@ pub(crate) fn parse_branch_protection( match opt { "bti" => slot.bti = true, "pac-ret" if slot.pac_ret.is_none() => { - slot.pac_ret = Some(PacRet { leaf: false, key: PAuthKey::A }) + slot.pac_ret = Some(PacRet { leaf: false, pc: false, key: PAuthKey::A }) } "leaf" => match slot.pac_ret.as_mut() { Some(pac) => pac.leaf = true, @@ -1406,6 +1405,10 @@ pub(crate) fn parse_branch_protection( Some(pac) => pac.key = PAuthKey::B, _ => return false, }, + "pc" => match slot.pac_ret.as_mut() { + Some(pac) => pac.pc = true, + _ => return false, + }, _ => return false, }; } diff --git a/src/doc/unstable-book/src/compiler-flags/branch-protection.md b/src/doc/unstable-book/src/compiler-flags/branch-protection.md index 9276220f447..f0cc44a07f3 100644 --- a/src/doc/unstable-book/src/compiler-flags/branch-protection.md +++ b/src/doc/unstable-book/src/compiler-flags/branch-protection.md @@ -9,11 +9,12 @@ This option is only accepted when targeting AArch64 architectures. It takes some combination of the following values, separated by a `,`. - `pac-ret` - Enable pointer authentication for non-leaf functions. +- `pc` - Use PC as a diversifier using PAuthLR instructions - `leaf` - Enable pointer authentication for all functions, including leaf functions. - `b-key` - Sign return addresses with key B, instead of the default key A. - `bti` - Enable branch target identification. -`leaf` and `b-key` are only valid if `pac-ret` was previously specified. +`leaf`, `b-key` and `pc` are only valid if `pac-ret` was previously specified. For example, `-Z branch-protection=bti,pac-ret,leaf` is valid, but `-Z branch-protection=bti,leaf,pac-ret` is not. diff --git a/tests/assembly/aarch64-pointer-auth.rs b/tests/assembly/aarch64-pointer-auth.rs index 1e53878a2cc..344e9e74bc2 100644 --- a/tests/assembly/aarch64-pointer-auth.rs +++ b/tests/assembly/aarch64-pointer-auth.rs @@ -1,9 +1,13 @@ // Test that PAC instructions are emitted when branch-protection is specified. +//@ revisions: PACRET PAUTHLR_NOP PAUTHLR //@ assembly-output: emit-asm -//@ compile-flags: --target aarch64-unknown-linux-gnu -//@ compile-flags: -Z branch-protection=pac-ret,leaf //@ needs-llvm-components: aarch64 +//@ compile-flags: --target aarch64-unknown-linux-gnu +//@ [PACRET] compile-flags: -Z branch-protection=pac-ret,leaf +//@ [PAUTHLR_NOP] compile-flags: -Z branch-protection=pac-ret,pc,leaf +//@ [PAUTHLR] compile-flags: -C target-feature=+pauth-lr -Z branch-protection=pac-ret,pc,leaf +//@ min-llvm-version: 19 #![feature(no_core, lang_items)] #![no_std] @@ -13,8 +17,13 @@ #[lang = "sized"] trait Sized {} -// CHECK: hint #25 -// CHECK: hint #29 +// PACRET: hint #25 +// PACRET: hint #29 +// PAUTHLR_NOP: hint #25 +// PAUTHLR_NOP: hint #39 +// PAUTHLR_NOP: hint #29 +// PAUTHLR: paciasppc +// PAUTHLR: autiasppc #[no_mangle] pub fn test() -> u8 { 42 diff --git a/tests/codegen/branch-protection.rs b/tests/codegen/branch-protection.rs index 2f5ff9e98c2..945bad05625 100644 --- a/tests/codegen/branch-protection.rs +++ b/tests/codegen/branch-protection.rs @@ -1,11 +1,15 @@ // Test that the correct module flags are emitted with different branch protection flags. -//@ revisions: BTI PACRET LEAF BKEY NONE +//@ revisions: BTI PACRET LEAF BKEY PAUTHLR PAUTHLR_BKEY PAUTHLR_LEAF PAUTHLR_BTI NONE //@ needs-llvm-components: aarch64 //@ [BTI] compile-flags: -Z branch-protection=bti //@ [PACRET] compile-flags: -Z branch-protection=pac-ret //@ [LEAF] compile-flags: -Z branch-protection=pac-ret,leaf //@ [BKEY] compile-flags: -Z branch-protection=pac-ret,b-key +//@ [PAUTHLR] compile-flags: -Z branch-protection=pac-ret,pc +//@ [PAUTHLR_BKEY] compile-flags: -Z branch-protection=pac-ret,pc,b-key +//@ [PAUTHLR_LEAF] compile-flags: -Z branch-protection=pac-ret,pc,leaf +//@ [PAUTHLR_BTI] compile-flags: -Z branch-protection=bti,pac-ret,pc //@ compile-flags: --target aarch64-unknown-linux-gnu //@ min-llvm-version: 19 @@ -24,6 +28,7 @@ pub fn test() {} // BTI: attributes [[ATTR]] = {{.*}} "branch-target-enforcement" // BTI: !"branch-target-enforcement", i32 1 // BTI: !"sign-return-address", i32 0 +// BTI: !"branch-protection-pauth-lr", i32 0 // BTI: !"sign-return-address-all", i32 0 // BTI: !"sign-return-address-with-bkey", i32 0 @@ -31,6 +36,7 @@ pub fn test() {} // PACRET-SAME: "sign-return-address-key"="a_key" // PACRET: !"branch-target-enforcement", i32 0 // PACRET: !"sign-return-address", i32 1 +// PACRET: !"branch-protection-pauth-lr", i32 0 // PACRET: !"sign-return-address-all", i32 0 // PACRET: !"sign-return-address-with-bkey", i32 0 @@ -38,6 +44,7 @@ pub fn test() {} // LEAF-SAME: "sign-return-address-key"="a_key" // LEAF: !"branch-target-enforcement", i32 0 // LEAF: !"sign-return-address", i32 1 +// LEAF: !"branch-protection-pauth-lr", i32 0 // LEAF: !"sign-return-address-all", i32 1 // LEAF: !"sign-return-address-with-bkey", i32 0 @@ -45,9 +52,42 @@ pub fn test() {} // BKEY-SAME: "sign-return-address-key"="b_key" // BKEY: !"branch-target-enforcement", i32 0 // BKEY: !"sign-return-address", i32 1 +// BKEY: !"branch-protection-pauth-lr", i32 0 // BKEY: !"sign-return-address-all", i32 0 // BKEY: !"sign-return-address-with-bkey", i32 1 +// PAUTHLR: attributes [[ATTR]] = {{.*}} "sign-return-address"="non-leaf" +// PAUTHLR-SAME: "sign-return-address-key"="a_key" +// PAUTHLR: !"branch-target-enforcement", i32 0 +// PAUTHLR: !"sign-return-address", i32 1 +// PAUTHLR: !"branch-protection-pauth-lr", i32 1 +// PAUTHLR: !"sign-return-address-all", i32 0 +// PAUTHLR: !"sign-return-address-with-bkey", i32 0 + +// PAUTHLR_BKEY: attributes [[ATTR]] = {{.*}} "sign-return-address"="non-leaf" +// PAUTHLR_BKEY-SAME: "sign-return-address-key"="b_key" +// PAUTHLR_BKEY: !"branch-target-enforcement", i32 0 +// PAUTHLR_BKEY: !"sign-return-address", i32 1 +// PAUTHLR_BKEY: !"branch-protection-pauth-lr", i32 1 +// PAUTHLR_BKEY: !"sign-return-address-all", i32 0 +// PAUTHLR_BKEY: !"sign-return-address-with-bkey", i32 1 + +// PAUTHLR_LEAF: attributes [[ATTR]] = {{.*}} "sign-return-address"="all" +// PAUTHLR_LEAF-SAME: "sign-return-address-key"="a_key" +// PAUTHLR_LEAF: !"branch-target-enforcement", i32 0 +// PAUTHLR_LEAF: !"sign-return-address", i32 1 +// PAUTHLR_LEAF: !"branch-protection-pauth-lr", i32 1 +// PAUTHLR_LEAF: !"sign-return-address-all", i32 1 +// PAUTHLR_LEAF: !"sign-return-address-with-bkey", i32 0 + +// PAUTHLR_BTI: attributes [[ATTR]] = {{.*}} "sign-return-address"="non-leaf" +// PAUTHLR_BTI-SAME: "sign-return-address-key"="a_key" +// PAUTHLR_BTI: !"branch-target-enforcement", i32 1 +// PAUTHLR_BTI: !"sign-return-address", i32 1 +// PAUTHLR_BTI: !"branch-protection-pauth-lr", i32 1 +// PAUTHLR_BTI: !"sign-return-address-all", i32 0 +// PAUTHLR_BTI: !"sign-return-address-with-bkey", i32 0 + // NONE-NOT: branch-target-enforcement // NONE-NOT: sign-return-address // NONE-NOT: sign-return-address-all diff --git a/tests/run-make/pointer-auth-link-with-c/rmake.rs b/tests/run-make/pointer-auth-link-with-c/rmake.rs index 960eafa546b..7b6dff10eae 100644 --- a/tests/run-make/pointer-auth-link-with-c/rmake.rs +++ b/tests/run-make/pointer-auth-link-with-c/rmake.rs @@ -1,7 +1,7 @@ // `-Z branch protection` is an unstable compiler feature which adds pointer-authentication // code (PAC), a useful hashing measure for verifying that pointers have not been modified. // This test checks that compilation and execution is successful when this feature is activated, -// with some of its possible extra arguments (bti, pac-ret, leaf). +// with some of its possible extra arguments (bti, pac-ret, pc, leaf, b-key). // See https://github.com/rust-lang/rust/pull/88354 //@ only-aarch64 @@ -25,4 +25,16 @@ fn main() { llvm_ar().obj_to_ar().output_input("libtest.a", &obj_file).run(); rustc().arg("-Zbranch-protection=bti,pac-ret,leaf").input("test.rs").run(); run("test"); + + // FIXME: +pc was only recently added to LLVM + // cc().arg("-v") + // .arg("-c") + // .out_exe("test") + // .input("test.c") + // .arg("-mbranch-protection=bti+pac-ret+pc+leaf") + // .run(); + // let obj_file = if is_msvc() { "test.obj" } else { "test" }; + // llvm_ar().obj_to_ar().output_input("libtest.a", &obj_file).run(); + // rustc().arg("-Zbranch-protection=bti,pac-ret,pc,leaf").input("test.rs").run(); + // run("test"); } diff --git a/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGS.stderr b/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGS.stderr index d0e8d4719d3..dae08119dbc 100644 --- a/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGS.stderr +++ b/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGS.stderr @@ -1,2 +1,2 @@ -error: incorrect value `leaf` for unstable option `branch-protection` - a `,` separated combination of `bti`, `b-key`, `pac-ret`, or `leaf` was expected +error: incorrect value `leaf` for unstable option `branch-protection` - a `,` separated combination of `bti`, `pac-ret`, followed by a combination of `pc`, `b-key`, or `leaf` was expected diff --git a/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGSPC.stderr b/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGSPC.stderr new file mode 100644 index 00000000000..13f79e94674 --- /dev/null +++ b/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.BADFLAGSPC.stderr @@ -0,0 +1,2 @@ +error: incorrect value `pc` for unstable option `branch-protection` - a `,` separated combination of `bti`, `pac-ret`, followed by a combination of `pc`, `b-key`, or `leaf` was expected + diff --git a/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.rs b/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.rs index c0a4bcac11b..b4025080034 100644 --- a/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.rs +++ b/tests/ui/invalid-compile-flags/branch-protection-missing-pac-ret.rs @@ -1,7 +1,10 @@ -//@ revisions: BADFLAGS BADTARGET +//@ revisions: BADFLAGS BADFLAGSPC BADTARGET //@ [BADFLAGS] compile-flags: --target=aarch64-unknown-linux-gnu -Zbranch-protection=leaf //@ [BADFLAGS] check-fail //@ [BADFLAGS] needs-llvm-components: aarch64 +//@ [BADFLAGSPC] compile-flags: --target=aarch64-unknown-linux-gnu -Zbranch-protection=pc +//@ [BADFLAGSPC] check-fail +//@ [BADFLAGSPC] needs-llvm-components: aarch64 //@ [BADTARGET] compile-flags: --target=x86_64-unknown-linux-gnu -Zbranch-protection=bti //@ [BADTARGET] check-fail //@ [BADTARGET] needs-llvm-components: x86 @@ -10,5 +13,5 @@ #![feature(no_core, lang_items)] #![no_core] -#[lang="sized"] -trait Sized { } +#[lang = "sized"] +trait Sized {}