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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-02-20 10:24:09 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-02-20 10:24:09 -0800 |
| commit | cea20ca3f3181fc36788a15bc65d1062b96a0a6c (patch) | |
| tree | 86c646c0d228d1fe265536b81d86af406ff92c8e /arch/x86/kernel | |
| parent | b01543dfe67bb1d191998e90d20534dc354de059 (diff) | |
| download | linux-cea20ca3f3181fc36788a15bc65d1062b96a0a6c.tar.bz2 | |
i387: fix up some fpu_counter confusion
This makes sure we clear the FPU usage counter for newly created tasks,
just so that we start off in a known state (for example, don't try to
preload the FPU state on the first task switch etc).
It also fixes a thinko in when we increment the fpu_counter at task
switch time, introduced by commit 34ddc81a230b ("i387: re-introduce FPU
state preloading at context switch time"). We should increment the
*new* task fpu_counter, not the old task, and only if we decide to use
that state (whether lazily or preloaded).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/process_32.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/process_64.c | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index 80bfe1ab0031..bc32761bc27a 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -214,6 +214,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, task_user_gs(p) = get_user_gs(regs); + p->fpu_counter = 0; p->thread.io_bitmap_ptr = NULL; tsk = current; err = -ENOMEM; diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 1fd94bc4279d..8ad880b3bc1c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -286,6 +286,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, set_tsk_thread_flag(p, TIF_FORK); + p->fpu_counter = 0; p->thread.io_bitmap_ptr = NULL; savesegment(gs, p->thread.gsindex); |