Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH v11 16/29] x86/fpu/xstate: Support both legacy and expanded signal XSTATE size | Date | Tue, 05 Oct 2021 17:19:04 +0200 |
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On Fri, Oct 01 2021 at 15:37, Chang S. Bae wrote: > @@ -1252,6 +1267,13 @@ long do_arch_prctl_state(struct task_struct *tsk, int option, unsigned long arg2 > if (!state_perm) > return 0; > > + /* > + * Disallow when sigaltstack is not enough for the > + * AT_MINSIGSTKSZ value. > + */ > + if (tsk->sas_ss_size > 0 && tsk->sas_ss_size < get_sigframe_size()) > + return -EPERM;
This is not enough:
T1 sigaltstack(minsize) ... T2 libinit() prctl(....) --> success enable_amx()
libfunc() if (amx_enabled()) AMXINSN -->#NM --> success
handle_signal() die(because altstack too small);
Thanks,
tglx
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