[PATCH 14/17] arm64: add __nocfi to functions that jump to a physical address
From: Sami Tolvanen <samitolvanen@google.com>
Date: 2021-03-12 00:50:51
Also in:
bpf, linux-arm-kernel, linux-hardening, linux-kbuild, linux-pci, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Disable CFI checking for functions that switch to linear mapping and make an indirect call to a physical address, since the compiler only understands virtual addresses and the CFI check for such indirect calls would always fail. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> --- arch/arm64/include/asm/mmu_context.h | 2 +- arch/arm64/kernel/cpu-reset.h | 8 ++++---- arch/arm64/kernel/cpufeature.c | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index 519d535532be..27f3797baa2e 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h@@ -136,7 +136,7 @@ static inline void cpu_install_idmap(void) * Atomically replaces the active TTBR1_EL1 PGD with a new VA-compatible PGD, * avoiding the possibility of conflicting TLB entries being allocated. */ -static inline void cpu_replace_ttbr1(pgd_t *pgdp) +static inline void __nocfi cpu_replace_ttbr1(pgd_t *pgdp) { typedef void (ttbr_replace_func)(phys_addr_t); extern ttbr_replace_func idmap_cpu_replace_ttbr1;
diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
index dfba8cf921e5..a05bda363272 100644
--- a/arch/arm64/kernel/cpu-reset.h
+++ b/arch/arm64/kernel/cpu-reset.h@@ -13,10 +13,10 @@ void __cpu_soft_restart(unsigned long el2_switch, unsigned long entry, unsigned long arg0, unsigned long arg1, unsigned long arg2); -static inline void __noreturn cpu_soft_restart(unsigned long entry, - unsigned long arg0, - unsigned long arg1, - unsigned long arg2) +static inline void __noreturn __nocfi cpu_soft_restart(unsigned long entry, + unsigned long arg0, + unsigned long arg1, + unsigned long arg2) { typeof(__cpu_soft_restart) *restart;
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 7ec1c2ccdc0b..473212ff4d70 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c@@ -1443,7 +1443,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, } #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -static void +static void __nocfi kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) { typedef void (kpti_remap_fn)(int, int, phys_addr_t);
--
2.31.0.rc2.261.g7f71774620-goog