diff options
Diffstat (limited to 'arch/x86/kernel/shstk.c')
| -rw-r--r-- | arch/x86/kernel/shstk.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c index 2ddf23387c7e..978232b6d48d 100644 --- a/arch/x86/kernel/shstk.c +++ b/arch/x86/kernel/shstk.c @@ -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; @@ -246,6 +246,46 @@ static unsigned long get_user_shstk_addr(void) 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) |