Re: PR/49104 CVS commit: src/sys/kern

[christos%zoulas.com@localhost (Christos Zoulas)]

The following reply was made to PR port-i386/49104; it has been noted by GNATS.

From: christos%zoulas.com@localhost (Christos Zoulas)
To: gnats-bugs%NetBSD.org@localhost, port-i386-maintainer%netbsd.org@localhost, 
	gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, jarle%uninett.no@localhost
Cc: 
Subject: Re: PR/49104 CVS commit: src/sys/kern
Date: Mon, 12 Jan 2015 09:15:58 -0500

 On Jan 12, 10:50am, jarle%uninett.no@localhost (Jarle Greipsland) wrote:
 -- Subject: Re: PR/49104 CVS commit: src/sys/kern
 
 |  Unfortunately, this only fixes the second bug in PR49104, where
 |  cpu_counter32 is called.  The original problem still persists,
 |  i.e. where cpu_init unconditionally calls the rcr4 function.
 
 Does this fix the problem?
 
 Index: cpu.c
 ===================================================================
 RCS file: /cvsroot/src/sys/arch/x86/x86/cpu.c,v
 retrieving revision 1.111
 diff -u -u -r1.111 cpu.c
 --- cpu.c	12 May 2014 11:56:02 -0000	1.111
 +++ cpu.c	12 Jan 2015 14:15:22 -0000
 @@ -552,11 +552,10 @@
  void
  cpu_init(struct cpu_info *ci)
  {
 -	uint32_t cr4;
 +	uint32_t cr4 = 0;
  
  	lcr0(rcr0() | CR0_WP);
  
 -	cr4 = rcr4();
  	/*
  	 * On a P6 or above, enable global TLB caching if the
  	 * hardware supports it.
 @@ -581,7 +580,10 @@
  	if (cpu_feature[1] & CPUID2_XSAVE)
  		cr4 |= CR4_OSXSAVE;
  
 -	lcr4(cr4);
 +	if (cr4) {
 +		cr4 |= rcr4();
 +		lcr4(cr4);
 +	}
  
  	/* If xsave is enabled, enable all fpu features */
  	if (cr4 & CR4_OSXSAVE)