diff mbox

[PATCHv3,REBASED] arm64: Add CONFIG_CC_STACKPROTECTOR

Message ID 1403736903-25594-1-git-send-email-lauraa@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Laura Abbott June 25, 2014, 10:55 p.m. UTC
arm64 currently lacks support for -fstack-protector. Add
similar functionality to arm to detect stack corruption.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
---
 arch/arm64/Kconfig                      |  1 +
 arch/arm64/include/asm/stackprotector.h | 38 +++++++++++++++++++++++++++++++++
 arch/arm64/kernel/process.c             |  6 ++++++
 3 files changed, 45 insertions(+)
 create mode 100644 arch/arm64/include/asm/stackprotector.h

Comments

Will Deacon June 27, 2014, 9:44 a.m. UTC | #1
On Wed, Jun 25, 2014 at 11:55:03PM +0100, Laura Abbott wrote:
> arm64 currently lacks support for -fstack-protector. Add
> similar functionality to arm to detect stack corruption.
> 
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

  Acked-by: Will Deacon <will.deacon@arm.com>

Will
Catalin Marinas July 10, 2014, 9:22 a.m. UTC | #2
On Wed, Jun 25, 2014 at 11:55:03PM +0100, Laura Abbott wrote:
> arm64 currently lacks support for -fstack-protector. Add
> similar functionality to arm to detect stack corruption.
> 
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Acked-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
> ---
>  arch/arm64/Kconfig                      |  1 +
>  arch/arm64/include/asm/stackprotector.h | 38 +++++++++++++++++++++++++++++++++
>  arch/arm64/kernel/process.c             |  6 ++++++
>  3 files changed, 45 insertions(+)
>  create mode 100644 arch/arm64/include/asm/stackprotector.h

Applied for 3.17. Thanks.
diff mbox

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a474de34..f865436 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -32,6 +32,7 @@  config ARM64
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_C_RECORDMCOUNT
+	select HAVE_CC_STACKPROTECTOR
 	select HAVE_DEBUG_BUGVERBOSE
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_API_DEBUG
diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h
new file mode 100644
index 0000000..fe5e287
--- /dev/null
+++ b/arch/arm64/include/asm/stackprotector.h
@@ -0,0 +1,38 @@ 
+/*
+ * GCC stack protector support.
+ *
+ * Stack protector works by putting predefined pattern at the start of
+ * the stack frame and verifying that it hasn't been overwritten when
+ * returning from the function.  The pattern is called stack canary
+ * and gcc expects it to be defined by a global variable called
+ * "__stack_chk_guard" on ARM.  This unfortunately means that on SMP
+ * we cannot have a different canary value per task.
+ */
+
+#ifndef __ASM_STACKPROTECTOR_H
+#define __ASM_STACKPROTECTOR_H
+
+#include <linux/random.h>
+#include <linux/version.h>
+
+extern unsigned long __stack_chk_guard;
+
+/*
+ * Initialize the stackprotector canary value.
+ *
+ * NOTE: this must only be called from functions that never return,
+ * and it must always be inlined.
+ */
+static __always_inline void boot_init_stack_canary(void)
+{
+	unsigned long canary;
+
+	/* Try to get a semi random initial value. */
+	get_random_bytes(&canary, sizeof(canary));
+	canary ^= LINUX_VERSION_CODE;
+
+	current->stack_canary = canary;
+	__stack_chk_guard = current->stack_canary;
+}
+
+#endif	/* _ASM_STACKPROTECTOR_H */
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 43b7c34..1309d64 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -51,6 +51,12 @@ 
 #include <asm/processor.h>
 #include <asm/stacktrace.h>
 
+#ifdef CONFIG_CC_STACKPROTECTOR
+#include <linux/stackprotector.h>
+unsigned long __stack_chk_guard __read_mostly;
+EXPORT_SYMBOL(__stack_chk_guard);
+#endif
+
 static void setup_restart(void)
 {
 	/*