[PATCH v5 1/5] powerpc/sstep: Emulate prefixed instructions only when CPU_FTR_ARCH_31 is set
From: Ravi Bangoria <hidden>
Date: 2020-10-11 05:13:09
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: Balamuruhan S <redacted>
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 <redacted>
Signed-off-by: Ravi Bangoria <redacted>
---
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 e9dcaba9a4f8..e6242744c71b 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;
--
2.26.2