From: Mark Rutland <mark.rutland@xxxxxxx> This will mean we do more work per EL0 exception return, but is a stepping-stone to enable keys within the kernel. Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Kristina Martsenko <kristina.martsenko@xxxxxxx> --- arch/arm64/include/asm/pointer_auth.h | 7 +------ arch/arm64/include/asm/ptrauth-asm.h | 26 ++++++++++++++++++++++++++ arch/arm64/kernel/asm-offsets.c | 7 +++++++ arch/arm64/kernel/entry.S | 9 +++++++-- arch/arm64/kernel/process.c | 1 - 5 files changed, 41 insertions(+), 9 deletions(-) create mode 100644 arch/arm64/include/asm/ptrauth-asm.h diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h index cedb03bd175b..5e40533f4ea2 100644 --- a/arch/arm64/include/asm/pointer_auth.h +++ b/arch/arm64/include/asm/pointer_auth.h @@ -64,16 +64,11 @@ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr) } #define ptrauth_task_init_user(tsk) \ - ptrauth_keys_init(&(tsk)->thread_info.keys_user); \ - ptrauth_keys_switch(&(tsk)->thread_info.keys_user) - -#define ptrauth_task_switch(tsk) \ - ptrauth_keys_switch(&(tsk)->thread_info.keys_user) + ptrauth_keys_init(&(tsk)->thread_info.keys_user) #else /* CONFIG_ARM64_PTR_AUTH */ #define ptrauth_strip_insn_pac(lr) (lr) #define ptrauth_task_init_user(tsk) -#define ptrauth_task_switch(tsk) #endif /* CONFIG_ARM64_PTR_AUTH */ #endif /* __ASM_POINTER_AUTH_H */ diff --git a/arch/arm64/include/asm/ptrauth-asm.h b/arch/arm64/include/asm/ptrauth-asm.h new file mode 100644 index 000000000000..f50bdfc4046c --- /dev/null +++ b/arch/arm64/include/asm/ptrauth-asm.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_PTRAUTH_ASM_H +#define __ASM_PTRAUTH_ASM_H + +#include <asm/asm-offsets.h> +#include <asm/sysreg.h> + +#ifdef CONFIG_ARM64_PTR_AUTH + + .macro ptrauth_keys_install_user tsk, tmp +alternative_if ARM64_HAS_ADDRESS_AUTH + ldr \tmp, [\tsk, #(TSK_TI_KEYS_USER + PTRAUTH_KEY_APIALO)] + msr_s SYS_APIAKEYLO_EL1, \tmp + ldr \tmp, [\tsk, #(TSK_TI_KEYS_USER + PTRAUTH_KEY_APIAHI)] + msr_s SYS_APIAKEYHI_EL1, \tmp +alternative_else_nop_endif + .endm + +#else /* CONFIG_ARM64_PTR_AUTH */ + + .macro ptrauth_keys_install_user tsk, tmp + .endm + +#endif /* CONFIG_ARM64_PTR_AUTH */ + +#endif /* __ASM_PTRAUTH_ASM_H */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 323aeb5f2fe6..b6be0dd037fd 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -45,6 +45,9 @@ int main(void) #ifdef CONFIG_ARM64_SW_TTBR0_PAN DEFINE(TSK_TI_TTBR0, offsetof(struct task_struct, thread_info.ttbr0)); #endif +#ifdef CONFIG_ARM64_PTR_AUTH + DEFINE(TSK_TI_KEYS_USER, offsetof(struct task_struct, thread_info.keys_user)); +#endif DEFINE(TSK_STACK, offsetof(struct task_struct, stack)); BLANK(); DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); @@ -169,5 +172,9 @@ int main(void) DEFINE(SDEI_EVENT_INTREGS, offsetof(struct sdei_registered_event, interrupted_regs)); DEFINE(SDEI_EVENT_PRIORITY, offsetof(struct sdei_registered_event, priority)); #endif +#ifdef CONFIG_ARM64_PTR_AUTH + DEFINE(PTRAUTH_KEY_APIALO, offsetof(struct ptrauth_keys, apia.lo)); + DEFINE(PTRAUTH_KEY_APIAHI, offsetof(struct ptrauth_keys, apia.hi)); +#endif return 0; } diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 09dbea221a27..1e925f6d2978 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -23,8 +23,9 @@ #include <linux/linkage.h> #include <asm/alternative.h> -#include <asm/assembler.h> #include <asm/asm-offsets.h> +#include <asm/asm-uaccess.h> +#include <asm/assembler.h> #include <asm/cpufeature.h> #include <asm/errno.h> #include <asm/esr.h> @@ -33,8 +34,8 @@ #include <asm/mmu.h> #include <asm/processor.h> #include <asm/ptrace.h> +#include <asm/ptrauth-asm.h> #include <asm/thread_info.h> -#include <asm/asm-uaccess.h> #include <asm/unistd.h> /* @@ -325,6 +326,10 @@ alternative_else_nop_endif apply_ssbd 0, x0, x1 .endif + .if \el == 0 + ptrauth_keys_install_user tsk, x0 + .endif + msr elr_el1, x21 // set up the return data msr spsr_el1, x22 ldp x0, x1, [sp, #16 * 0] diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index fae52be66c92..857ae05cd04c 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -426,7 +426,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, contextidr_thread_switch(next); entry_task_switch(next); uao_thread_switch(next); - ptrauth_task_switch(next); /* * Complete any pending TLB or cache maintenance on this CPU in case -- 2.11.0
