svn commit: r354179 - in head/sys/arm64: arm64 include

[Andrew Turner]

Author: andrew
Date: Wed Oct 30 14:05:50 2019
New Revision: 354179
URL: https://svnweb.freebsd.org/changeset/base/354179

Log:
  Allow exceptions to be masked when in userspace
  
  We may want to mask exceptions when in userspace. This was previously
  impossible as threads are created with all exceptions unmasked and
  signals expected userspace to mask any. Fix these by copying the
  mask state on thread creation and allow exceptions to be masked on
  signal return, as long as they don't change.
  
  Sponsored by:	DARPA, AFRL

Modified:
  head/sys/arm64/arm64/machdep.c
  head/sys/arm64/arm64/vm_machdep.c
  head/sys/arm64/include/armreg.h

Modified: head/sys/arm64/arm64/machdep.c
==============================================================================
--- head/sys/arm64/arm64/machdep.c	Wed Oct 30 13:45:40 2019	(r354178)
+++ head/sys/arm64/arm64/machdep.c	Wed Oct 30 14:05:50 2019	(r354179)
@@ -441,7 +441,8 @@ set_mcontext(struct thread *td, mcontext_t *mcp)
 
 	spsr = mcp->mc_gpregs.gp_spsr;
 	if ((spsr & PSR_M_MASK) != PSR_M_EL0t ||
-	    (spsr & (PSR_AARCH32 | PSR_F | PSR_I | PSR_A | PSR_D)) != 0)
+	    (spsr & PSR_AARCH32) != 0 ||
+	    (spsr & PSR_DAIF) != (td->td_frame->tf_spsr & PSR_DAIF))
 		return (EINVAL); 
 
 	memcpy(tf->tf_x, mcp->mc_gpregs.gp_x, sizeof(tf->tf_x));

Modified: head/sys/arm64/arm64/vm_machdep.c
==============================================================================
--- head/sys/arm64/arm64/vm_machdep.c	Wed Oct 30 13:45:40 2019	(r354178)
+++ head/sys/arm64/arm64/vm_machdep.c	Wed Oct 30 14:05:50 2019	(r354179)
@@ -98,7 +98,7 @@ cpu_fork(struct thread *td1, struct proc *p2, struct t
 	bcopy(td1->td_frame, tf, sizeof(*tf));
 	tf->tf_x[0] = 0;
 	tf->tf_x[1] = 0;
-	tf->tf_spsr = td1->td_frame->tf_spsr & PSR_M_32;
+	tf->tf_spsr = td1->td_frame->tf_spsr & (PSR_M_32 | PSR_DAIF);
 
 	td2->td_frame = tf;
 

Modified: head/sys/arm64/include/armreg.h
==============================================================================
--- head/sys/arm64/include/armreg.h	Wed Oct 30 13:45:40 2019	(r354178)
+++ head/sys/arm64/include/armreg.h	Wed Oct 30 14:05:50 2019	(r354179)
@@ -608,6 +608,7 @@
 #define	PSR_I		0x00000080
 #define	PSR_A		0x00000100
 #define	PSR_D		0x00000200
+#define	PSR_DAIF	(PSR_D | PSR_A | PSR_I | PSR_F)
 #define	PSR_IL		0x00100000
 #define	PSR_SS		0x00200000
 #define	PSR_V		0x10000000