bjoernager/rust
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rustc_codegen_llvm: Add a new 'pc' option to branch-protection

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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.
This commit is contained in:
Kajetan Puchalski 2024-10-16 15:39:58 +01:00
parent 4d296eabe4
commit 10edeea4b4
12 changed files with 97 additions and 17 deletions
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1
compiler/rustc_session/src/config.rs
View file

@ -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,
}

9
compiler/rustc_session/src/options.rs
View file

@ -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 @@ mod parse {
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 @@ mod parse {
Some(pac) => pac.key = PAuthKey::B,
_ => return false,
},
"pc" => match slot.pac_ret.as_mut() {
Some(pac) => pac.pc = true,
_ => return false,
},
_ => return false,
};
}