diff mbox

[v2,29/30] arm: Implement thread_struct whitelist for hardened usercopy

Message ID 1503956111-36652-30-git-send-email-keescook@chromium.org (mailing list archive)
State New, archived
Headers show

Commit Message

Kees Cook Aug. 28, 2017, 9:35 p.m. UTC 
ARM does not carry FPU state in the thread structure, so it can declare
no usercopy whitelist at all.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm/Kconfig                 | 1 +
 arch/arm/include/asm/processor.h | 7 +++++++
 2 files changed, 8 insertions(+)
diff mbox

Patch

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a208bfe367b5..3781f08d00fa 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -48,6 +48,7 @@  config ARM
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
 	select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
+	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARM_SMCCC if CPU_V7
 	select HAVE_CBPF_JIT
diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index c3d5fc124a05..d6dc45c92ee5 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -45,6 +45,13 @@  struct thread_struct {
 	struct debug_info	debug;
 };
 
+/* Nothing needs to be usercopy-whitelisted from thread_struct. */
+static inline void arch_thread_struct_whitelist(unsigned long *offset,
+						unsigned long *size)
+{
+	*offset = *size = 0;
+}
+
 #define INIT_THREAD  {	}
 
 #ifdef CONFIG_MMU