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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-13 13:24:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-13 13:24:23 -0700 |
| commit | 421ec9017f3a1f3f032d894c55c15870f3d474aa (patch) | |
| tree | 06ee21cf5ecdf87c40b30502faa3e0d1145004dd /arch/x86/kernel/process.c | |
| parent | 64f004a2ab68691b5a2e3db4cb460fcd31b6abc6 (diff) | |
| parent | 7fc253e277ecf1ea57c2d670bdbcda3dffd19453 (diff) | |
Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu changes from Ingo Molnar:
"Various x86 FPU handling cleanups, refactorings and fixes (Borislav
Petkov, Oleg Nesterov, Rik van Riel)"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/fpu: Kill eager_fpu_init_bp()
x86/fpu: Don't allocate fpu->state for swapper/0
x86/fpu: Rename drop_init_fpu() to fpu_reset_state()
x86/fpu: Fold __drop_fpu() into its sole user
x86/fpu: Don't abuse drop_init_fpu() in flush_thread()
x86/fpu: Use restore_init_xstate() instead of math_state_restore() on kthread exec
x86/fpu: Introduce restore_init_xstate()
x86/fpu: Document user_fpu_begin()
x86/fpu: Factor out memset(xstate, 0) in fpu_finit() paths
x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave
x86/fpu: Don't abuse FPU in kernel threads if use_eager_fpu()
x86/fpu: Always allow FPU in interrupt if use_eager_fpu()
x86/fpu: __kernel_fpu_begin() should clear fpu_owner_task even if use_eager_fpu()
x86/fpu: Also check fpu_lazy_restore() when use_eager_fpu()
x86/fpu: Use task_disable_lazy_fpu_restore() helper
x86/fpu: Use an explicit if/else in switch_fpu_prepare()
x86/fpu: Introduce task_disable_lazy_fpu_restore() helper
x86/fpu: Move lazy restore functions up a few lines
x86/fpu: Change math_error() to use unlazy_fpu(), kill (now) unused save_init_fpu()
x86/fpu: Don't do __thread_fpu_end() if use_eager_fpu()
...
Diffstat (limited to 'arch/x86/kernel/process.c')
| -rw-r--r-- | arch/x86/kernel/process.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 0c8992dbead5..8213da62b1b7 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -89,8 +89,8 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) dst->thread.fpu_counter = 0; dst->thread.fpu.has_fpu = 0; - dst->thread.fpu.last_cpu = ~0; dst->thread.fpu.state = NULL; + task_disable_lazy_fpu_restore(dst); if (tsk_used_math(src)) { int err = fpu_alloc(&dst->thread.fpu); if (err) @@ -151,13 +151,18 @@ 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 - * lazily at the first use. - */ - if (!use_eager_fpu()) + + if (!use_eager_fpu()) { + /* FPU state will be reallocated lazily at the first use. */ + drop_fpu(tsk); free_thread_xstate(tsk); + } else if (!used_math()) { + /* kthread execs. TODO: cleanup this horror. */ + if (WARN_ON(init_fpu(tsk))) + force_sig(SIGKILL, tsk); + user_fpu_begin(); + restore_init_xstate(); + } } static void hard_disable_TSC(void) |