| Message ID | 1576486038-9899-9-git-send-email-amit.kachhap@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: return address signing | expand |
On Mon, Dec 16, 2019 at 02:17:10PM +0530, Amit Daniel Kachhap wrote: > diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h > index aa956ca..0f89f59 100644 > --- a/arch/arm64/include/asm/pointer_auth.h > +++ b/arch/arm64/include/asm/pointer_auth.h > @@ -60,6 +60,12 @@ static inline void ptrauth_keys_init_kernel(struct ptrauth_keys_kernel *keys) > get_random_bytes(&keys->apia, sizeof(keys->apia)); > } > > +static inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kernel *keys) I think we should use __always_inline here, just in case the compiler ignores the hint. Otherwise: Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
On 1/16/20 11:29 PM, Catalin Marinas wrote: > On Mon, Dec 16, 2019 at 02:17:10PM +0530, Amit Daniel Kachhap wrote: >> diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h >> index aa956ca..0f89f59 100644 >> --- a/arch/arm64/include/asm/pointer_auth.h >> +++ b/arch/arm64/include/asm/pointer_auth.h >> @@ -60,6 +60,12 @@ static inline void ptrauth_keys_init_kernel(struct ptrauth_keys_kernel *keys) >> get_random_bytes(&keys->apia, sizeof(keys->apia)); >> } >> >> +static inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kernel *keys) > > I think we should use __always_inline here, just in case the compiler > ignores the hint. yes agreed. Even the other function ptrauth_keys_init_kernel. > > Otherwise: > > Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Thanks. >
diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h index aa956ca..0f89f59 100644 --- a/arch/arm64/include/asm/pointer_auth.h +++ b/arch/arm64/include/asm/pointer_auth.h @@ -60,6 +60,12 @@ static inline void ptrauth_keys_init_kernel(struct ptrauth_keys_kernel *keys) get_random_bytes(&keys->apia, sizeof(keys->apia)); } +static inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kernel *keys) +{ + if (system_supports_address_auth()) + __ptrauth_key_install(APIA, keys->apia); +} + extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg); /* @@ -78,12 +84,15 @@ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr) ptrauth_keys_init_user(&(tsk)->thread.keys_user) #define ptrauth_thread_init_kernel(tsk) \ ptrauth_keys_init_kernel(&(tsk)->thread.keys_kernel) +#define ptrauth_thread_switch_kernel(tsk) \ + ptrauth_keys_switch_kernel(&(tsk)->thread.keys_kernel) #else /* CONFIG_ARM64_PTR_AUTH */ #define ptrauth_prctl_reset_keys(tsk, arg) (-EINVAL) #define ptrauth_strip_insn_pac(lr) (lr) #define ptrauth_thread_init_user(tsk) #define ptrauth_thread_init_kernel(tsk) +#define ptrauth_thread_switch_kernel(tsk) #endif /* CONFIG_ARM64_PTR_AUTH */ #endif /* __ASM_POINTER_AUTH_H */ diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h index 5884a2b..7263e0b 100644 --- a/arch/arm64/include/asm/stackprotector.h +++ b/arch/arm64/include/asm/stackprotector.h @@ -15,6 +15,7 @@ #include <linux/random.h> #include <linux/version.h> +#include <asm/pointer_auth.h> extern unsigned long __stack_chk_guard; @@ -26,6 +27,7 @@ extern unsigned long __stack_chk_guard; */ static __always_inline void boot_init_stack_canary(void) { +#if defined(CONFIG_STACKPROTECTOR) unsigned long canary; /* Try to get a semi random initial value. */ @@ -36,6 +38,9 @@ static __always_inline void boot_init_stack_canary(void) current->stack_canary = canary; if (!IS_ENABLED(CONFIG_STACKPROTECTOR_PER_TASK)) __stack_chk_guard = current->stack_canary; +#endif + ptrauth_thread_init_kernel(current); + ptrauth_thread_switch_kernel(current); } #endif /* _ASM_STACKPROTECTOR_H */ diff --git a/include/linux/stackprotector.h b/include/linux/stackprotector.h index 6b792d0..4c678c4 100644 --- a/include/linux/stackprotector.h +++ b/include/linux/stackprotector.h @@ -6,7 +6,7 @@ #include <linux/sched.h> #include <linux/random.h> -#ifdef CONFIG_STACKPROTECTOR +#if defined(CONFIG_STACKPROTECTOR) || defined(CONFIG_ARM64_PTR_AUTH) # include <asm/stackprotector.h> #else static inline void boot_init_stack_canary(void)
This patch uses the existing boot_init_stack_canary arch function to initialize the ptrauth keys for the booting task in the primary core. The requirement here is that it should be always inline and the caller must never return. As pointer authentication too detects a subset of stack corruption so it makes sense to place this code here. Both pointer authentication and stack canary codes are protected by their respective config option. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> --- Changes since last version: * New patch. arch/arm64/include/asm/pointer_auth.h | 9 +++++++++ arch/arm64/include/asm/stackprotector.h | 5 +++++ include/linux/stackprotector.h | 2 +- 3 files changed, 15 insertions(+), 1 deletion(-)