llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Ard Biesheuvel (ardbiesheuvel) <details> <summary>Changes</summary> Even though the command line option suggests that arbitrary system registers may be chosen, the sysreg option for the stack protector guard currently only permits SP_EL0, as this is what the Linux kernel uses. While it makes no sense to permit arbitrary system registers here (which usually have side effects), there is a desire to switch to TPIDR_EL0 or TPIDRRO_EL0 from the Linux side, both of which are part of the base v8.0 AArch64 ISA, and can hold arbitrary 64-bit values without side effects. So add TPIDR_EL0 and TPIDDRO_EL0 to the set of accepted arguments for the -mstack-protected-guard-reg= command line option. For good measure, add TPIDR_EL1, TPIDR_EL2, FAR_EL1 and FAR_EL2 as well, all of which could potentially be useful to privileged software such as the Linux kernel to stash a per-thread pointer to the stack protector guard value. --- Full diff: https://github.com/llvm/llvm-project/pull/188054.diff 3 Files Affected: - (modified) clang/lib/Driver/ToolChains/Clang.cpp (+7-2) - (modified) clang/test/CodeGen/stack-protector-guard.c (+21-5) - (modified) clang/test/Driver/stack-protector-guard.c (+6-1) ``````````diff diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 6416baf9126ff..36b93b0f50583 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -3588,8 +3588,13 @@ static void RenderSSPOptions(const Driver &D, const ToolChain &TC, << A->getOption().getName() << Value << "fs gs"; return; } - if (EffectiveTriple.isAArch64() && Value != "sp_el0") { - D.Diag(diag::err_drv_invalid_value) << A->getOption().getName() << Value; + if (EffectiveTriple.isAArch64() && + (Value != "sp_el0" && Value != "tpidrro_el0" && Value != "tpidr_el0" && + Value != "tpidr_el1" && Value != "tpidr_el2" && Value != "far_el1" && + Value != "far_el2")) { + D.Diag(diag::err_drv_invalid_value_with_suggestion) + << A->getOption().getName() << Value + << "sp_el0 tpidrro_el0 tpidr_el0 tpidr_el1 tpidr_el2 far_el1 far_el2"; return; } if (EffectiveTriple.isRISCV() && Value != "tp") { diff --git a/clang/test/CodeGen/stack-protector-guard.c b/clang/test/CodeGen/stack-protector-guard.c index 0a4da13eed95c..49358da3f558e 100644 --- a/clang/test/CodeGen/stack-protector-guard.c +++ b/clang/test/CodeGen/stack-protector-guard.c @@ -8,7 +8,13 @@ // RUN: -mstack-protector-guard-offset=1024 -emit-llvm %s -o - | FileCheck %s // RUN: %clang_cc1 -mstack-protector-guard=sysreg -triple aarch64-linux-gnu \ // RUN: -mstack-protector-guard-offset=1024 -mstack-protector-guard-reg=sp_el0 \ -// RUN: -emit-llvm %s -o - | FileCheck %s --check-prefix=AARCH64 +// RUN: -emit-llvm %s -o - | FileCheck %s --check-prefix=AARCH64-SP +// RUN: %clang_cc1 -mstack-protector-guard=sysreg -triple aarch64-linux-gnu \ +// RUN: -mstack-protector-guard-offset=1024 -mstack-protector-guard-reg=tpidr_el0 \ +// RUN: -emit-llvm %s -o - | FileCheck %s --check-prefix=AARCH64-TPIDR +// RUN: %clang_cc1 -mstack-protector-guard=sysreg -triple aarch64-linux-gnu \ +// RUN: -mstack-protector-guard-offset=1024 -mstack-protector-guard-reg=tpidrro_el0 \ +// RUN: -emit-llvm %s -o - | FileCheck %s --check-prefix=AARCH64-TPIDRRO // RUN: %clang_cc1 -mstack-protector-guard=tls -triple riscv64-unknown-elf \ // RUN: -mstack-protector-guard-offset=44 -mstack-protector-guard-reg=tp \ // RUN: -emit-llvm %s -o - | FileCheck %s --check-prefix=RISCV @@ -28,10 +34,20 @@ void bar(int x) { // CHECK: [[ATTR1]] = !{i32 1, !"stack-protector-guard", !"sysreg"} // CHECK: [[ATTR2]] = !{i32 1, !"stack-protector-guard-offset", i32 1024} -// AARCH64: !llvm.module.flags = !{{{.*}}[[ATTR1:![0-9]+]], [[ATTR2:![0-9]+]], [[ATTR3:![0-9]+]]} -// AARCH64: [[ATTR1]] = !{i32 1, !"stack-protector-guard", !"sysreg"} -// AARCH64: [[ATTR2]] = !{i32 1, !"stack-protector-guard-reg", !"sp_el0"} -// AARCH64: [[ATTR3]] = !{i32 1, !"stack-protector-guard-offset", i32 1024} +// AARCH64-SP: !llvm.module.flags = !{{{.*}}[[ATTR1:![0-9]+]], [[ATTR2:![0-9]+]], [[ATTR3:![0-9]+]]} +// AARCH64-SP: [[ATTR1]] = !{i32 1, !"stack-protector-guard", !"sysreg"} +// AARCH64-SP: [[ATTR2]] = !{i32 1, !"stack-protector-guard-reg", !"sp_el0"} +// AARCH64-SP: [[ATTR3]] = !{i32 1, !"stack-protector-guard-offset", i32 1024} + +// AARCH64-TPIDR: !llvm.module.flags = !{{{.*}}[[ATTR1:![0-9]+]], [[ATTR2:![0-9]+]], [[ATTR3:![0-9]+]]} +// AARCH64-TPIDR: [[ATTR1]] = !{i32 1, !"stack-protector-guard", !"sysreg"} +// AARCH64-TPIDR: [[ATTR2]] = !{i32 1, !"stack-protector-guard-reg", !"tpidr_el0"} +// AARCH64-TPIDR: [[ATTR3]] = !{i32 1, !"stack-protector-guard-offset", i32 1024} + +// AARCH64-TPIDRRO: !llvm.module.flags = !{{{.*}}[[ATTR1:![0-9]+]], [[ATTR2:![0-9]+]], [[ATTR3:![0-9]+]]} +// AARCH64-TPIDRRO: [[ATTR1]] = !{i32 1, !"stack-protector-guard", !"sysreg"} +// AARCH64-TPIDRRO: [[ATTR2]] = !{i32 1, !"stack-protector-guard-reg", !"tpidrro_el0"} +// AARCH64-TPIDRRO: [[ATTR3]] = !{i32 1, !"stack-protector-guard-offset", i32 1024} // RISCV: !llvm.module.flags = !{{{.*}}[[ATTR1:![0-9]+]], [[ATTR2:![0-9]+]], [[ATTR3:![0-9]+]], [[ATTR4:![0-9]+]]} // RISCV: [[ATTR1]] = !{i32 1, !"stack-protector-guard", !"tls"} diff --git a/clang/test/Driver/stack-protector-guard.c b/clang/test/Driver/stack-protector-guard.c index 666c83079e519..3b12a57f867e8 100644 --- a/clang/test/Driver/stack-protector-guard.c +++ b/clang/test/Driver/stack-protector-guard.c @@ -81,10 +81,15 @@ // RUN: -mstack-protector-guard-reg=foo \ // RUN: -mstack-protector-guard-offset=0 %s 2>&1 | \ // RUN: FileCheck -check-prefix=INVALID-REG-AARCH64 %s +// RUN: %clang -### -target aarch64-linux-gnu -mstack-protector-guard=sysreg \ +// RUN: -mstack-protector-guard-reg=tpidr_el0 \ +// RUN: -mstack-protector-guard-offset=0 %s 2>&1 | \ +// RUN: FileCheck -check-prefix=CHECK-AARCH64-TPIDR %s // CHECK-AARCH64: "-cc1" {{.*}}"-mstack-protector-guard=sysreg" "-mstack-protector-guard-offset=0" "-mstack-protector-guard-reg=sp_el0" // INVALID-VALUE-AARCH64: error: invalid value 'tls' in 'mstack-protector-guard=', expected one of: sysreg global -// INVALID-REG-AARCH64: error: invalid value 'foo' in 'mstack-protector-guard-reg=' +// INVALID-REG-AARCH64: error: invalid value 'foo' in 'mstack-protector-guard-reg=', expected one of: sp_el0 tpidrro_el0 tpidr_el0 tpidr_el1 tpidr_el2 far_el1 far_el2 +// CHECK-AARCH64-TPIDR: "-cc1" {{.*}}"-mstack-protector-guard=sysreg" "-mstack-protector-guard-offset=0" "-mstack-protector-guard-reg=tpidr_el0" // RUN: %clang -### -target riscv64-unknown-elf -mstack-protector-guard=tls -mstack-protector-guard-offset=24 -mstack-protector-guard-reg=tp %s 2>&1 | \ // RUN: FileCheck -v -check-prefix=CHECK-TLS-RISCV %s `````````` </details> https://github.com/llvm/llvm-project/pull/188054 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
