-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 01/13/2015 11:19 AM, Oleg Nesterov wrote: > On 01/11, r...@redhat.com wrote: >> >> @@ -412,8 +412,14 @@ static inline void switch_fpu_prepare(struct >> task_struct *old, struct task_struc bool preload = >> tsk_used_math(new) && (use_eager_fpu() || new->thread.fpu_counter >> > 5); if (__thread_has_fpu(old)) { - if (!__save_init_fpu(old)) >> + /* + * Make sure the FPU state is restored from >> memory next >> time, + * if the task has an FPU exception pending, or the >> task's in + * memory FPU state could be changed by a debugger. >> + */ + if (!__save_init_fpu(old) || >> task_is_stopped_or_traced(old)) cpu = ~0; > > Well, if debugger wants to change FPU state, it should call > init_fpu() which resets .last_cpu ?
Does the ptrace (and utrace, and ... ) code actually do that? > Plus "is_stopped" is not needed, ptracer no longer can do STOPPED > -> TRACED transition. I will remove _is_stopped. - -- All rights reversed -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUtUjqAAoJEM553pKExN6DtXIIAKzZj0zbQq4cQ08oKr6zMZqn qz0MyTD91+1phywX+CFOoQ45tQUzAzpAw2k+2yGUFWhMsdEQEaANirK3stZj2Lte Jh/VTlX1Y2ZpjoHFH69S6+5jy6nAqHaUTsMQ3jiXvi4YkzjYn9JGYY/N1E7BgRV/ T2HozdKD9+h27NetPaVPymZOwgIP5Qykbl77mH3SqwFaah/8DI3K3rMem5Ze88op hlk3FFAgB4n8WsHDKtDXOARnF1dYCnxyR9f+3mRIuLgCdYDvktXOizTUumsbojE6 hMN9lwM/r469kVh3L20asAbXNdCAAG6U/tZcoQOizGrj/L9M4V5ACAzn7w+y+kE= =8971 -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/