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authorBalamuruhan S <bala24@linux.ibm.com>2020-10-11 08:09:04 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-12-30 13:53:47 +0300
commitbf608cf329a3c6cd77ca02ae11870866fd04a20e (patch)
tree4a538c0145ad7cd62b87a19b3c8a4bd36bf81d3d /arch/powerpc/lib
parent62cd477bbdffb7bbd6c88c038a90289cdc27c606 (diff)
downloadlinux-bf608cf329a3c6cd77ca02ae11870866fd04a20e.tar.xz
powerpc/sstep: Emulate prefixed instructions only when CPU_FTR_ARCH_31 is set
[ 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>
Diffstat (limited to 'arch/powerpc/lib')
-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;