From: Balamuruhan S <bal...@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 <bal...@linux.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com>
Reviewed-by: Sandipan Das <sandi...@linux.ibm.com>
Reviewed-by: Daniel Axtens <d...@axtens.net>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Link:
https://lore.kernel.org/r/20201011050908.72173-2-ravi.bango...@linux.ibm.com
Signed-off-by: Sasha Levin <sas...@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;
--
2.27.0
