# RUN: llc -verify-machineinstrs -mtriple=aarch64-none-linux-gnu \ # RUN: -start-before aarch64-sls-hardening \ # RUN: -stop-after aarch64-sls-hardening -o - %s \ # RUN: | FileCheck %s --check-prefixes=CHECK # Check when the BLR SLS hardening encounters a BLR/BTI bundle, the BTI # instruction remains after the BLR is replaced with a BL. # These BLR/BTI bundles are produced when calling a returns_twice function # (like setjmp) indirectly. --- | $__llvm_slsblr_thunk_x8 = comdat any define dso_local void @fn() #0 { entry: %fnptr = alloca ptr, align 8 store ptr @setjmp, ptr %fnptr, align 8 %0 = load ptr, ptr %fnptr, align 8 %call1 = call i32 %0(ptr noundef null) #1 ret void } ; Function Attrs: returns_twice declare i32 @setjmp(ptr noundef) #1 ; Function Attrs: naked nounwind define linkonce_odr hidden void @__llvm_slsblr_thunk_x8() #2 comdat { entry: ret void } attributes #0 = { "target-features"="+harden-sls-blr" } attributes #1 = { returns_twice } attributes #2 = { naked nounwind } !llvm.module.flags = !{!0} !0 = !{i32 8, !"branch-target-enforcement", i32 1} ... --- name: fn exposesReturnsTwice: true tracksRegLiveness: true fixedStack: [] stack: - { id: 0, name: fnptr, type: default, offset: -8, size: 8, alignment: 8, stack-id: default, callee-saved-register: '', callee-saved-restored: true, local-offset: -8, debug-info-variable: '', debug-info-expression: '', debug-info-location: '' } - { id: 1, name: '', type: spill-slot, offset: -16, size: 8, alignment: 16, stack-id: default, callee-saved-register: '$lr', callee-saved-restored: true, debug-info-variable: '', debug-info-expression: '', debug-info-location: '' } callSites: [] debugValueSubstitutions: [] constants: [] machineFunctionInfo: hasRedZone: false body: | bb.0.entry: liveins: $lr early-clobber $sp = frame-setup STRXpre killed $lr, $sp, -16 :: (store (s64) into %stack.1) frame-setup CFI_INSTRUCTION def_cfa_offset 16 frame-setup CFI_INSTRUCTION offset $w30, -16 $x8 = ADRP target-flags(aarch64-page, aarch64-got) @setjmp renamable $x8 = LDRXui killed $x8, target-flags(aarch64-pageoff, aarch64-got, aarch64-nc) @setjmp STRXui renamable $x8, $sp, 1 :: (store (s64) into %ir.fnptr) $x0 = ORRXrs $xzr, $xzr, 0 BUNDLE implicit-def $lr, implicit-def $w30, implicit killed $x8, implicit $sp { BLR killed renamable $x8, implicit-def $lr, implicit $sp HINT 36 } ; CHECK: BUNDLE implicit-def $lr, implicit-def $w30, implicit killed $x8, implicit $sp { ; CHECK-NEXT: BL , implicit-def $lr, implicit $sp, implicit killed $x8 ; CHECK-NEXT: HINT 36 ; CHECK-NEXT: } early-clobber $sp, $lr = frame-destroy LDRXpost $sp, 16 :: (load (s64) from %stack.1) RET undef $lr ... --- name: __llvm_slsblr_thunk_x8 tracksRegLiveness: true body: | bb.0.entry: liveins: $x8 $x16 = ORRXrs $xzr, $x8, 0 BR $x16 SpeculationBarrierISBDSBEndBB ...