4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Aldridge <david.j.aldridge@xxxxxxxxxx> 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.aldridge@xxxxxxxxxx> Reviewed-by: Rob Gardner <rob.gardner@xxxxxxxxxx> Reviewed-by: Babu Moger <babu.moger@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -939,3 +939,9 @@ 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;