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Thu, 24 Jul 2025 16:37:18 -0700 (PDT) From: Deepak Gupta Date: Thu, 24 Jul 2025 16:36:59 -0700 Subject: [PATCH 06/11] mm: Introduce ARCH_HAS_KERNEL_SHADOW_STACK Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250724-riscv_kcfi-v1-6-04b8fa44c98c@rivosinc.com> References: <20250724-riscv_kcfi-v1-0-04b8fa44c98c@rivosinc.com> In-Reply-To: <20250724-riscv_kcfi-v1-0-04b8fa44c98c@rivosinc.com> To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Nick Desaulniers , Bill Wendling , Monk Chiang , Kito Cheng , Justin Stitt Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-mm@kvack.org, llvm@lists.linux.dev, rick.p.edgecombe@intel.com, broonie@kernel.org, cleger@rivosinc.com, samitolvanen@google.com, apatel@ventanamicro.com, ajones@ventanamicro.com, conor.dooley@microchip.com, charlie@rivosinc.com, samuel.holland@sifive.com, bjorn@rivosinc.com, fweimer@redhat.com, jeffreyalaw@gmail.com, heinrich.schuchardt@canonical.com, andrew@sifive.com, ved@rivosinc.com, Deepak Gupta X-Mailer: b4 0.13.0 commit bcc9d04e74 ("mm: Introduce ARCH_HAS_USER_SHADOW_STACK") introduced `ARCH_HAS_USER_SHADOW_STACK`. Introducing `ARCH_HAS_KERNEL_SHADOW_STACK` so that arches can enable hardware assistance for kernel shadow stack. If `CONFIG_DYNAMIC_SCS` or `CONFIG_ARCH_HAS_KERNEL_SHADOW_STACK` are selected, skip compiler flag `-fsanitizer=3Dshadow-call-stack`. Signed-off-by: Deepak Gupta --- Makefile | 2 +- mm/Kconfig | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 35e6e5240c61..7e3ecca9353d 100644 --- a/Makefile +++ b/Makefile @@ -987,7 +987,7 @@ LDFLAGS_vmlinux +=3D --gc-sections endif =20 ifdef CONFIG_SHADOW_CALL_STACK -ifndef CONFIG_DYNAMIC_SCS +ifeq ($(or $(CONFIG_DYNAMIC_SCS),$(CONFIG_ARCH_HAS_KERNEL_SHADOW_STACK)),f= alse) CC_FLAGS_SCS :=3D -fsanitize=3Dshadow-call-stack KBUILD_CFLAGS +=3D $(CC_FLAGS_SCS) KBUILD_RUSTFLAGS +=3D -Zsanitizer=3Dshadow-call-stack diff --git a/mm/Kconfig b/mm/Kconfig index 781be3240e21..f295ea611cdb 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1367,6 +1367,12 @@ config ARCH_HAS_USER_SHADOW_STACK The architecture has hardware support for userspace shadow call stacks (eg, x86 CET, arm64 GCS or RISC-V Zicfiss). =20 +config ARCH_HAS_KERNEL_SHADOW_STACK + bool + help + The architecture has hardware support for kernel shadow call + stacks (eg, x86 CET, arm64 GCS or RISC-V Zicfiss). + config ARCH_SUPPORTS_PT_RECLAIM def_bool n =20 --=20 2.43.0