From: Balamuruhan S bala24@linux.ibm.com
[ Upstream commit ef6879f8c8053cc3b493f400a06d452d7fb13650 ]
Unconditional emulation of prefixed instructions will allow emulation of them on Power10 predecessors which might cause issues. Restrict that.
Fixes: 3920742b92f5 ("powerpc sstep: Add support for prefixed fixed-point arithmetic") Fixes: 50b80a12e4cc ("powerpc sstep: Add support for prefixed load/stores") Signed-off-by: Balamuruhan S bala24@linux.ibm.com Signed-off-by: Ravi Bangoria ravi.bangoria@linux.ibm.com Reviewed-by: Sandipan Das sandipan@linux.ibm.com Reviewed-by: Daniel Axtens dja@axtens.net Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20201011050908.72173-2-ravi.bangoria@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/lib/sstep.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 855457ed09b54..bf2cd3d42125d 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -1346,6 +1346,9 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, switch (opcode) { #ifdef __powerpc64__ case 1: + if (!cpu_has_feature(CPU_FTR_ARCH_31)) + return -1; + prefix_r = GET_PREFIX_R(word); ra = GET_PREFIX_RA(suffix); rd = (suffix >> 21) & 0x1f; @@ -2733,6 +2736,9 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, } break; case 1: /* Prefixed instructions */ + if (!cpu_has_feature(CPU_FTR_ARCH_31)) + return -1; + prefix_r = GET_PREFIX_R(word); ra = GET_PREFIX_RA(suffix); op->update_reg = ra;