From: David S. Miller <davem@davemloft.net>
Date: Thu, 10 May 2012 18:00:46 +0000 (-0700)
Subject: sparc64: Do not clobber %g2 in xcall_fetch_glob_regs().
X-Git-Tag: firefly_0821_release~7541^2~1199
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1c1cb5756a8d296bbc33fc844f97048dc09ee172;p=firefly-linux-kernel-4.4.55.git

sparc64: Do not clobber %g2 in xcall_fetch_glob_regs().

[ Upstream commit a5a737e090e25981e99d69f01400e3a80356581c ]

%g2 is meant to hold the CPUID number throughout this routine, since
at the very beginning, and at the very end, we use %g2 to calculate
indexes into per-cpu arrays.

However we erroneously clobber it in order to hold the %cwp register
value mid-stream.

Fix this code to use %g3 for the %cwp read and related calulcations
instead.

Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/sparc/kernel/central.c b/arch/sparc/kernel/central.c
index 7eef3f741963..f5ddc0bae38d 100644
--- a/arch/sparc/kernel/central.c
+++ b/arch/sparc/kernel/central.c
@@ -268,4 +268,4 @@ static int __init sunfire_init(void)
 	return 0;
 }
 
-subsys_initcall(sunfire_init);
+fs_initcall(sunfire_init);
diff --git a/arch/sparc/mm/ultra.S b/arch/sparc/mm/ultra.S
index b57a5942ba64..874162a11ceb 100644
--- a/arch/sparc/mm/ultra.S
+++ b/arch/sparc/mm/ultra.S
@@ -495,11 +495,11 @@ xcall_fetch_glob_regs:
 	stx		%o7, [%g1 + GR_SNAP_O7]
 	stx		%i7, [%g1 + GR_SNAP_I7]
 	/* Don't try this at home kids... */
-	rdpr		%cwp, %g2
-	sub		%g2, 1, %g7
+	rdpr		%cwp, %g3
+	sub		%g3, 1, %g7
 	wrpr		%g7, %cwp
 	mov		%i7, %g7
-	wrpr		%g2, %cwp
+	wrpr		%g3, %cwp
 	stx		%g7, [%g1 + GR_SNAP_RPC]
 	sethi		%hi(trap_block), %g7
 	or		%g7, %lo(trap_block), %g7