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| author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2018-05-21 09:51:07 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-06-04 00:39:08 +1000 |
| commit | 83afab4ce05660c728f4a5d45f5970d9cc9ee6d2 (patch) | |
| tree | 4576c783dbe2f437c1e9f41196f98142629d6f35 /arch/powerpc/lib/sstep.c | |
| parent | e6684d07e4308430b9b6497265781a6fb9fd87a0 (diff) | |
| download | linux-83afab4ce05660c728f4a5d45f5970d9cc9ee6d2.tar.bz2 | |
powerpc/sstep: Fix kernel crash if VSX is not present
emulate_step() is not checking runtime VSX feature flag before
emulating an instruction. This is causing kernel crash when kernel
is compiled with CONFIG_VSX=y but running on a machine where VSX
is not supported or disabled. Ex, while running emulate_step tests
on P6 machine:
Oops: Exception in kernel mode, sig: 4 [#1]
NIP [c000000000095c24] .load_vsrn+0x28/0x54
LR [c000000000094bdc] .emulate_loadstore+0x167c/0x17b0
Call Trace:
0x40fe240c7ae147ae (unreliable)
.emulate_loadstore+0x167c/0x17b0
.emulate_step+0x25c/0x5bc
.test_lxvd2x_stxvd2x+0x64/0x154
.test_emulate_step+0x38/0x4c
.do_one_initcall+0x5c/0x2c0
.kernel_init_freeable+0x314/0x4cc
.kernel_init+0x24/0x160
.ret_from_kernel_thread+0x58/0xb4
With fix:
emulate_step_test: lxvd2x : FAIL
emulate_step_test: stxvd2x : FAIL
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/lib/sstep.c')
| -rw-r--r-- | arch/powerpc/lib/sstep.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index f18d70449255..d81568f783e5 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -2545,6 +2545,15 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs, #endif /* __powerpc64__ */ } + +#ifdef CONFIG_VSX + if ((GETTYPE(op->type) == LOAD_VSX || + GETTYPE(op->type) == STORE_VSX) && + !cpu_has_feature(CPU_FTR_VSX)) { + return -1; + } +#endif /* CONFIG_VSX */ + return 0; logical_done: |