From: Kees Jongenburger <keesj@minix3.org>
Date: Sat, 16 Feb 2013 21:32:19 +0000 (+0100)
Subject: kernel:enable trace on arm.
X-Git-Tag: v3.3.0~1145
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=eff37b8a8b2378a784041a70fd8d29bc44a093fa;p=minix.git

kernel:enable trace on arm.

Change-Id: Iabe6dfd758e8f1cdb4a18e2f2ab8f8ca988f3c86
---

diff --git a/kernel/arch/earm/include/archconst.h b/kernel/arch/earm/include/archconst.h
index 48307638b..96999e898 100644
--- a/kernel/arch/earm/include/archconst.h
+++ b/kernel/arch/earm/include/archconst.h
@@ -26,6 +26,15 @@
  */
 #define ARM_STACK_TOP_RESERVED	(2 * sizeof(reg_t))
 
+/* only selected bits are changeable by user e.g.[31:9] and skip the 
+ * mode bits. It is probably is a better idea to look at the current 
+ * status to determine if one is allowed to write these values. This 
+ * might allow debugging of privileged processes 
+ */
+#define SET_USR_PSR(rp, npsr) \
+	rp->p_reg.psr = ( rp->p_reg.psr & 0x1F) | ( npsr & ~0x1F)
+
+
 #define PG_ALLOCATEME ((phys_bytes)-1)
 
 #endif /* _ARM_ACONST_H */
diff --git a/kernel/system/do_trace.c b/kernel/system/do_trace.c
index 24bfcc588..1bcb8fe21 100644
--- a/kernel/system/do_trace.c
+++ b/kernel/system/do_trace.c
@@ -154,6 +154,13 @@ int do_trace(struct proc * caller, message * m_ptr)
 		SETPSW(rp, tr_data);
 	else
 		*(reg_t *) ((char *) &rp->p_reg + i) = (reg_t) tr_data;
+#else 
+	if (i == (int) &((struct proc *) 0)->p_reg.psr) {
+		/* only selected bits are changeable */
+		SET_USR_PSR(rp, tr_data);
+	} else {
+		*(reg_t *) ((char *) &rp->p_reg + i) = (reg_t) tr_data;
+	}
 #endif
 	m_ptr->CTL_DATA = 0;
 	break;