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authorBalamuruhan S <bala24@linux.ibm.com>2020-10-11 08:09:04 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2020-12-10 16:09:09 +0300
commitef6879f8c8053cc3b493f400a06d452d7fb13650 (patch)
treec0fed89657017893685c03c83fe84c1c6aaba355
parent02b02ee1b05ef225525835b2d45faf31b3420bdd (diff)
downloadlinux-ef6879f8c8053cc3b493f400a06d452d7fb13650.tar.xz
powerpc/sstep: Emulate prefixed instructions only when CPU_FTR_ARCH_31 is set
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
-rw-r--r--arch/powerpc/lib/sstep.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 855457ed09b5..bf2cd3d42125 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;