* Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> [2017-01-06 22:44:39]: > 4.4-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx> > > commit 80f23935cadb1c654e81951f5a8b7ceae0acc1b4 upstream. > > PowerPC's "cmp" instruction has four operands. Normally people write > "cmpw" or "cmpd" for the second cmp operand 0 or 1. But, frequently > people forget, and write "cmp" with just three operands. > > With older binutils this is silently accepted as if this was "cmpw", > while often "cmpd" is wanted. With newer binutils GAS will complain > about this for 64-bit code. For 32-bit code it still silently assumes > "cmpw" is what is meant. > > In this instance the code comes directly from ISA v2.07, including the > cmp, but cmpd is correct. Backport to stable so that new toolchains can > build old kernels. > > Fixes: 948cf67c4726 ("powerpc: Add NAP mode support on Power7 in HV mode") > Reviewed-by: Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx> > Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > Signed-off-by: Joel Stanley <joel@xxxxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Acked-by: Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx> The change from cmp to cmpd is correct. This code will execute in 64-bit mode only and fix applies to stable as described above. > > > --- > arch/powerpc/kernel/idle_power7.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/arch/powerpc/kernel/idle_power7.S > +++ b/arch/powerpc/kernel/idle_power7.S > @@ -44,7 +44,7 @@ > std r0,0(r1); \ > ptesync; \ > ld r0,0(r1); \ > -1: cmp cr0,r0,r0; \ > +1: cmpd cr0,r0,r0; \ > bne 1b; \ > IDLE_INST; \ > b . > > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html