2d476222e8
This is intended to be used for Linux kernel RETHUNK builds. With this commit (optionally backported to Rust 1.73.0), plus a patched Linux kernel to pass the flag, I get a RETHUNK build with Rust enabled that is `objtool`-warning-free and is able to boot in QEMU and load a sample Rust kernel module. Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
31 lines
1.1 KiB
Rust
31 lines
1.1 KiB
Rust
// Test that the function return is (not) converted into a jump to the thunk
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// when the `-Zfunction-return={keep,thunk-extern}` flag is (not) set.
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// revisions: unset keep thunk-extern keep-thunk-extern thunk-extern-keep
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// assembly-output: emit-asm
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// compile-flags: -O
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// [keep] compile-flags: -Zfunction-return=keep
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// [thunk-extern] compile-flags: -Zfunction-return=thunk-extern
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// [keep-thunk-extern] compile-flags: -Zfunction-return=keep -Zfunction-return=thunk-extern
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// [thunk-extern-keep] compile-flags: -Zfunction-return=thunk-extern -Zfunction-return=keep
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// only-x86_64
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// ignore-x86_64-apple-darwin Symbol is called `___x86_return_thunk` (Darwin's extra underscore)
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// ignore-sgx Tests incompatible with LVI mitigations
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#![crate_type = "lib"]
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// CHECK-LABEL: foo:
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#[no_mangle]
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pub unsafe fn foo() {
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// unset: ret
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// unset-NOT: jmp __x86_return_thunk
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// keep: ret
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// keep-NOT: jmp __x86_return_thunk
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// thunk-extern: jmp __x86_return_thunk
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// thunk-extern-NOT: ret
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// keep-thunk-extern: jmp __x86_return_thunk
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// keep-thunk-extern-NOT: ret
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// thunk-extern-keep: ret
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// thunk-extern-keep-NOT: jmp __x86_return_thunk
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}
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