Pointer authentication config and user facing options by jchlanda · Pull Request #156712 · rust-lang/rust

jchlanda · 2026-05-18T13:03:50Z

This patch brings:

unified handling of pointer authentication options through:
-Zpointer-authentication, with possible values:
aarch64-jump-table-hardening, auth-traps, calls, elf-got,
function-pointer-type-discrimination, indirect-gotos, init-fini,
init-fini-address-discrimination, return-addresses. Toggled with
+/-.
centralized handling of pointer authentication features. Session holds
pointer_auth_config: Option<PointerAuthConfig>
encapsulation of schema for function pointers and init/fini through
PointerAuthSchema. This allowed for retiring of PacMetadata.
refactor enabling of pointer authentication in code, instead of
relying on the target (pauthtest) use the session

jchlanda · 2026-05-19T12:17:23Z

@davidtwco, @folkertdev, @tgross35, @madsmtm FWI this is a follow up to #155722 and #156548
This will have to be rebased once the above are merged.

rustbot · 2026-05-19T12:17:28Z

This PR modifies src/bootstrap/src/core/config.

If appropriate, please update CONFIG_CHANGE_HISTORY in src/bootstrap/src/utils/change_tracker.rs.

Some changes occurred in src/tools/compiletest

cc @jieyouxu

The GCC codegen subtree was changed

cc @antoyo, @GuillaumeGomez

compiletest directives have been modified. Please add or update docs for the
new or modified directive in src/doc/rustc-dev-guide/.

Some changes occurred in src/doc/rustc/src/platform-support

cc @Noratrieb

This PR modifies tests/auxiliary/minicore.rs.

cc @jieyouxu

These commits modify compiler targets.
(See the Target Tier Policy.)

rustbot · 2026-05-19T12:17:31Z

r? @mejrs

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mejrs · 2026-05-24T15:46:34Z

Hi, I am not qualified to review this.

r? madsmtm or reroll maybe

madsmtm

Quick look, will go over in more detail after #155722 (and perhaps a bit before if I get the time).

View changes since this review

madsmtm · 2026-05-28T16:32:49Z

        }
    }

+    pub(crate) fn parse_pointer_authentication_list_with_polarity(


Remark: Huh, I thought we'd be better at doing this parsing... I get the sense that this entire module could be simplified a bunch, but the impl you've done here is fine for now.

madsmtm · 2026-05-28T16:38:29Z

+            "indirect-gotos" => Some(Self::IndirectGotos),
+            "init-fini" => Some(Self::InitFini),
+            "init-fini-address-discrimination" => Some(Self::InitFiniAddressDiscrimination),
+            "intrinsics" => Some(Self::Intrinsics),


Nit: This seems like it should just be part of core_intrinsics?

I'm not sure, probably not.

Intrinsics here refer to the set introduced in <ptrauth.h>. And we only need it for the calculation of the pauth ABI version.

For reference, -fptrauth-intrinsics was introduced to clang here.

madsmtm · 2026-05-28T16:45:18Z

+            "vt-ptr-addr-discrimination" => Some(Self::VTPtrAddrDisc),
+            "vt-ptr-type-discrimination" => Some(Self::VTPtrTypeDisc),
+            _ => None,
+        }


Hmm, we're not following the same naming scheme here as Clang, maybe we should? In particular:

-Zpointer-authentication=+return-addresses <-> -fptrauth-returns

-Zpointer-authentication=+typeinfo-vt-ptr-discrimination <-> -fptrauth-type-info-vtable-pointer-discrimination

-Zpointer-authentication=+vt-ptr-addr-discrimination <-> -fptrauth-vtable-pointer-address-discrimination

-Zpointer-authentication=+vt-ptr-type-discrimination <-> -fptrauth-vtable-pointer-type-discrimination

In any case, could you link to Clang's or LLVM's docs on the enum variants for reference?

I've linked clang's command line reference, slight complication is that we only support a subset of those (for instance we are unlikely to ever interact with obj-c).

Are you saying that:

we should get rid of -Zpointer-authentication all together,

or that the values that the option takes should match exactly how they are spelled out in clang (i.e. -Zpointer-authentication=+ptrauth-returns instead of what it is now: -Zpointer-authentication=+return-addresses)?

One thing that I would say is that the list with polarity provides a nice way to opt-in/opt-out. Without it we would have to duplicate every entry with -Zno-.....

madsmtm · 2026-05-28T20:53:07Z

        "whether to use the PLT when calling into shared libraries;
        only has effect for PIC code on systems with ELF binaries
        (default: PLT is disabled if full relro is enabled on x86_64)"),
+    pointer_authentication: Vec<(PointerAuthOption, bool)> = (Vec::new(), parse_pointer_authentication_list_with_polarity, [TRACKED],


Could you create a new tracking issue for these options, and add docs for this to doc/unstable-book/compiler-flags?

One unresolved question I'd like to add before we can consider stabilizing this is "correctness"; how do we ensure the security correctness of the implementation, both for the initial implementation, and as the compiler evolves.

This patch brings: * unified handling of pointer authentication options through: `-Zpointer-authentication`, with possible values: `aarch64-jump-table-hardening`, `auth-traps`, `calls`, `elf-got`, `function-pointer-type-discrimination`, `indirect-gotos`, `init-fini`, `init-fini-address-discrimination`, `return-addresses`. Toggled with `+`/`-`. * centralized handling of pointer authentication features. Session holds `pointer_auth_config: Option<PointerAuthConfig>` * encapsulation of schema for function pointers and init/fini through `PointerAuthSchema`. This allowed for retiring of `PacMetadata`. * refactor enabling of pointer authentication in code, instead of relying on the target (`pauthtest`) use the session

- warning on unsupported test - error on type discrimination - removal of PointerAuthKind

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jchlanda marked this pull request as ready for review May 19, 2026 12:17

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels May 19, 2026

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jchlanda force-pushed the jakub/pac_config branch from 82f7a40 to 1c7ac6d Compare May 20, 2026 14:41

jchlanda mentioned this pull request May 21, 2026

Unify handling of pointer authentication features #155868

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rustbot assigned madsmtm May 24, 2026

jchlanda force-pushed the jakub/pac_config branch from 57246bd to b185861 Compare May 27, 2026 08:40

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madsmtm mentioned this pull request May 28, 2026

Introduce aarch64-unknown-linux-pauthtest target #155722

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madsmtm reviewed May 28, 2026

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jchlanda mentioned this pull request Jun 1, 2026

Add support for AArch64 Pointer Authentication ABI in Rust #148640

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jchlanda force-pushed the jakub/pac_config branch from 68d5206 to f7791c4 Compare June 1, 2026 11:13

PR feedback: Introduce

6da24b0

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jchlanda force-pushed the jakub/pac_config branch from 90c3ab6 to 503d1e6 Compare June 1, 2026 13:07

jchlanda added 12 commits June 1, 2026 15:04

PR feedback: Attributes

b9c1650

PR feedback: Init/Fini

1fc3327

PR feedback: Teach bootstrap

c117a49

PR feedback: Override static

2db4afd

PR feedback: Use target_env

b0e8e26

Add library support for aarch64-unknown-linux-pauthtest

df350ce

Use target_env = "musl" & target_abi = "pauthtest" instead of env

b56662b

Extend version support with C++ specifics

7df7cd8

Document -Zpointer-authentication option

52a63a7

PR feedback

046ee9f

- warning on unsupported test - error on type discrimination - removal of PointerAuthKind

PR feedback

d601217

jchlanda force-pushed the jakub/pac_config branch from 361b585 to d601217 Compare June 1, 2026 15:07

madsmtm linked an issue Jun 2, 2026 that may be closed by this pull request

Unify handling of pointer authentication features #155868

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