diff options
Diffstat (limited to 'arch/x86/kernel/shstk.c')
| -rw-r--r-- | arch/x86/kernel/shstk.c | 76 |
1 files changed, 66 insertions, 10 deletions
diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 6f1e9883f074..978232b6d48d 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -173,8 +173,8 @@ static int shstk_setup(void) return PTR_ERR((void *)addr); fpregs_lock_and_load(); - wrmsrl(MSR_IA32_PL3_SSP, addr + size); - wrmsrl(MSR_IA32_U_CET, CET_SHSTK_EN); + wrmsrq(MSR_IA32_PL3_SSP, addr + size); + wrmsrq(MSR_IA32_U_CET, CET_SHSTK_EN); fpregs_unlock(); shstk->base = addr; @@ -191,7 +191,7 @@ void reset_thread_features(void) current->thread.features_locked = 0; } -unsigned long shstk_alloc_thread_stack(struct task_struct *tsk, unsigned long clone_flags, +unsigned long shstk_alloc_thread_stack(struct task_struct *tsk, u64 clone_flags, unsigned long stack_size) { struct thread_shstk *shstk = &tsk->thread.shstk; @@ -239,13 +239,53 @@ static unsigned long get_user_shstk_addr(void) fpregs_lock_and_load(); - rdmsrl(MSR_IA32_PL3_SSP, ssp); + rdmsrq(MSR_IA32_PL3_SSP, ssp); fpregs_unlock(); return ssp; } +int shstk_pop(u64 *val) +{ + int ret = 0; + u64 ssp; + + if (!features_enabled(ARCH_SHSTK_SHSTK)) + return -ENOTSUPP; + + fpregs_lock_and_load(); + + rdmsrq(MSR_IA32_PL3_SSP, ssp); + if (val && get_user(*val, (__user u64 *)ssp)) + ret = -EFAULT; + else + wrmsrq(MSR_IA32_PL3_SSP, ssp + SS_FRAME_SIZE); + fpregs_unlock(); + + return ret; +} + +int shstk_push(u64 val) +{ + u64 ssp; + int ret; + + if (!features_enabled(ARCH_SHSTK_SHSTK)) + return -ENOTSUPP; + + fpregs_lock_and_load(); + + rdmsrq(MSR_IA32_PL3_SSP, ssp); + ssp -= SS_FRAME_SIZE; + ret = write_user_shstk_64((__user void *)ssp, val); + if (!ret) + wrmsrq(MSR_IA32_PL3_SSP, ssp); + fpregs_unlock(); + + return ret; +} + #define SHSTK_DATA_BIT BIT(63) static int put_shstk_data(u64 __user *addr, u64 data) @@ -372,7 +412,7 @@ int setup_signal_shadow_stack(struct ksignal *ksig) return -EFAULT; fpregs_lock_and_load(); - wrmsrl(MSR_IA32_PL3_SSP, ssp); + wrmsrq(MSR_IA32_PL3_SSP, ssp); fpregs_unlock(); return 0; @@ -396,7 +436,7 @@ int restore_signal_shadow_stack(void) return err; fpregs_lock_and_load(); - wrmsrl(MSR_IA32_PL3_SSP, ssp); + wrmsrq(MSR_IA32_PL3_SSP, ssp); fpregs_unlock(); return 0; @@ -460,7 +500,7 @@ static int wrss_control(bool enable) return 0; fpregs_lock_and_load(); - rdmsrl(MSR_IA32_U_CET, msrval); + rdmsrq(MSR_IA32_U_CET, msrval); if (enable) { features_set(ARCH_SHSTK_WRSS); @@ -473,7 +513,7 @@ static int wrss_control(bool enable) msrval &= ~CET_WRSS_EN; } - wrmsrl(MSR_IA32_U_CET, msrval); + wrmsrq(MSR_IA32_U_CET, msrval); unlock: fpregs_unlock(); @@ -492,8 +532,8 @@ static int shstk_disable(void) fpregs_lock_and_load(); /* Disable WRSS too when disabling shadow stack */ - wrmsrl(MSR_IA32_U_CET, 0); - wrmsrl(MSR_IA32_PL3_SSP, 0); + wrmsrq(MSR_IA32_U_CET, 0); + wrmsrq(MSR_IA32_PL3_SSP, 0); fpregs_unlock(); shstk_free(current); @@ -577,3 +617,19 @@ long shstk_prctl(struct task_struct *task, int option, unsigned long arg2) return wrss_control(true); return -EINVAL; } + +int shstk_update_last_frame(unsigned long val) +{ + unsigned long ssp; + + if (!features_enabled(ARCH_SHSTK_SHSTK)) + return 0; + + ssp = get_user_shstk_addr(); + return write_user_shstk_64((u64 __user *)ssp, (u64)val); +} + +bool shstk_is_enabled(void) +{ + return features_enabled(ARCH_SHSTK_SHSTK); +} |