4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dave Aldridge <david.j.aldri...@oracle.com>
commit 3c7f62212018b904ae17f5636ead18a4dca3a88f upstream.
When any of the functions contained in NGbzero.S and GENbzero.S
vector through *bzero_from_clear_user, we may end up taking a
fault when executing one of the store alternate address space
instructions. If this happens, the exception handler does not
restore the %asi register.
This commit fixes the issue by introducing a new exception
handler that ensures the %asi register is restored when
a fault is handled.
Orabug: 25577560
Signed-off-by: Dave Aldridge <david.j.aldri...@oracle.com>
Reviewed-by: Rob Gardner <rob.gard...@oracle.com>
Reviewed-by: Babu Moger <babu.mo...@oracle.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/sparc/kernel/head_64.S | 6 ++++++
arch/sparc/lib/GENbzero.S | 2 +-
arch/sparc/lib/NGbzero.S | 2 +-
3 files changed, 8 insertions(+), 2 deletions(-)
--- a/arch/sparc/kernel/head_64.S
+++ b/arch/sparc/kernel/head_64.S
@@ -935,3 +935,9 @@ ENTRY(__retl_o1)
retl
mov %o1, %o0
ENDPROC(__retl_o1)
+
+ENTRY(__retl_o1_asi)
+ wr %o5, 0x0, %asi
+ retl
+ mov %o1, %o0
+ENDPROC(__retl_o1_asi)
--- a/arch/sparc/lib/GENbzero.S
+++ b/arch/sparc/lib/GENbzero.S
@@ -8,7 +8,7 @@
98: x,y; \
.section __ex_table,"a";\
.align 4; \
- .word 98b, __retl_o1; \
+ .word 98b, __retl_o1_asi;\
.text; \
.align 4;
--- a/arch/sparc/lib/NGbzero.S
+++ b/arch/sparc/lib/NGbzero.S
@@ -8,7 +8,7 @@
98: x,y; \
.section __ex_table,"a";\
.align 4; \
- .word 98b, __retl_o1; \
+ .word 98b, __retl_o1_asi;\
.text; \
.align 4;
