x86, xsave: save/restore the extended state context in sigframe
On cpu's supporting xsave/xrstor, fpstate pointer in the sigcontext, will
include the extended state information along with fpstate information. Presence
of extended state information is indicated by the presence
of FP_XSTATE_MAGIC1 at fpstate.sw_reserved.magic1 and FP_XSTATE_MAGIC2
at fpstate + (fpstate.sw_reserved.extended_size - FP_XSTATE_MAGIC2_SIZE).
Extended feature bit mask that is saved in the memory layout is represented
by the fpstate.sw_reserved.xstate_bv
For RT signal frames, UC_FP_XSTATE in the uc_flags also indicate the
presence of extended state information in the sigcontext's fpstate
pointer.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index ddf6123..2621b98 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -192,7 +192,7 @@
sp = current->sas_ss_sp + current->sas_ss_size;
}
- return (void __user *)round_down(sp - size, 16);
+ return (void __user *)round_down(sp - size, 64);
}
static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
@@ -226,7 +226,10 @@
}
/* Create the ucontext. */
- err |= __put_user(0, &frame->uc.uc_flags);
+ if (cpu_has_xsave)
+ err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+ else
+ err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->sp),