diff options
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 93103a909c47..afd3f2a5c64e 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -254,18 +254,21 @@ EXPORT_SYMBOL_GPL(fpu__activate_curr); /* * This function must be called before we read a task's fpstate. * - * If the task has not used the FPU before then initialize its - * fpstate. + * There's two cases where this gets called: + * + * - for the current task (when coredumping), in which case we have + * to save the latest FPU registers into the fpstate, + * + * - or it's called for stopped tasks (ptrace), in which case the + * registers were already saved by the context-switch code when + * the task scheduled out - we only have to initialize the registers + * if they've never been initialized. * * If the task has used the FPU before then save it. */ void fpu__activate_fpstate_read(struct fpu *fpu) { - /* - * If fpregs are active (in the current CPU), then - * copy them to the fpstate: - */ - if (fpu->fpstate_active) { + if (fpu == ¤t->thread.fpu) { fpu__save(fpu); } else { if (!fpu->fpstate_active) { |