diff options
| -rw-r--r-- | arch/x86/kernel/i387.c | 11 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/xsave.c | 13 |
3 files changed, 14 insertions, 17 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index f59d80622e60..8416b5f85806 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -41,8 +41,8 @@ void kernel_fpu_enable(void) * be set (so that the clts/stts pair does nothing that is * visible in the interrupted kernel thread). * - * Except for the eagerfpu case when we return 1 unless we've already - * been eager and saved the state in kernel_fpu_begin(). + * Except for the eagerfpu case when we return true; in the likely case + * the thread has FPU but we are not going to set/clear TS. */ static inline bool interrupted_kernel_fpu_idle(void) { @@ -50,7 +50,7 @@ static inline bool interrupted_kernel_fpu_idle(void) return false; if (use_eager_fpu()) - return __thread_has_fpu(current); + return true; return !__thread_has_fpu(current) && (read_cr0() & X86_CR0_TS); @@ -93,9 +93,10 @@ void __kernel_fpu_begin(void) if (__thread_has_fpu(me)) { __save_init_fpu(me); - } else if (!use_eager_fpu()) { + } else { this_cpu_write(fpu_owner_task, NULL); - clts(); + if (!use_eager_fpu()) + clts(); } } EXPORT_SYMBOL(__kernel_fpu_begin); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ce8b10351e28..83480373a642 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -130,6 +130,7 @@ void flush_thread(void) flush_ptrace_hw_breakpoint(tsk); memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); + drop_init_fpu(tsk); /* * Free the FPU state for non xsave platforms. They get reallocated @@ -137,6 +138,12 @@ void flush_thread(void) */ if (!use_eager_fpu()) free_thread_xstate(tsk); + else if (!used_math()) { + /* kthread execs. TODO: cleanup this horror. */ + if (WARN_ON(init_fpu(current))) + force_sig(SIGKILL, current); + math_state_restore(); + } } static void hard_disable_TSC(void) diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index 0de1fae2bdf0..de9dcf89a302 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -688,7 +688,7 @@ void eager_fpu_init(void) { static __refdata void (*boot_func)(void) = eager_fpu_init_bp; - clear_used_math(); + WARN_ON(used_math()); current_thread_info()->status = 0; if (eagerfpu == ENABLE) @@ -703,17 +703,6 @@ void eager_fpu_init(void) boot_func(); boot_func = NULL; } - - /* - * This is same as math_state_restore(). But use_xsave() is - * not yet patched to use math_state_restore(). - */ - init_fpu(current); - __thread_fpu_begin(current); - if (cpu_has_xsave) - xrstor_state(init_xstate_buf, -1); - else - fxrstor_checking(&init_xstate_buf->i387); } /* |