s390/cachinfo: add missing facility check to init_cache_level()

Stephen Powell reported the following crash on a z890 machine:

Kernel BUG at 00000000001219d0 [verbose debug info unavailable]
illegal operation: 0001 ilc:3 [#1] SMP
Krnl PSW : 0704e00180000000 00000000001219d0 (init_cache_level+0x38/0xe0)
	   R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3
Krnl Code: 00000000001219c2: a7840056		brc	8,121a6e
	   00000000001219c6: a7190000		lghi	%r1,0
	  #00000000001219ca: eb101000004c	ecag	%r1,%r0,0(%r1)
	  >00000000001219d0: a7390000		lghi	%r3,0
	   00000000001219d4: e310f0a00024	stg	%r1,160(%r15)
	   00000000001219da: a7080000		lhi	%r0,0
	   00000000001219de: a7b9f000		lghi	%r11,-4096
	   00000000001219e2: c0a0002899d9	larl	%r10,634d94
Call Trace:
 [<0000000000478ee2>] detect_cache_attributes+0x2a/0x2b8
 [<000000000097c9b0>] cacheinfo_sysfs_init+0x60/0xc8
 [<00000000001001c0>] do_one_initcall+0x98/0x1c8
 [<000000000094fdc2>] kernel_init_freeable+0x212/0x2d8
 [<000000000062352e>] kernel_init+0x26/0x118
 [<000000000062fd2e>] kernel_thread_starter+0x6/0xc

The illegal operation was executed because of a missing facility check,
which should have made sure that the ECAG execution would only be executed
on machines which have the general-instructions-extension facility
installed.

Reported-and-tested-by: Stephen Powell <zlinuxman@wowway.com>
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/cache.c b/arch/s390/kernel/cache.c
index bff5e3b6d8223b8f9a9c84d8f99235d3d4e648bc..8ba32436effe4b9da0a271ae1ec0ad2a2bd689e7 100644 (file)
--- a/arch/s390/kernel/cache.c
+++ b/arch/s390/kernel/cache.c
@@ -138,6 +138,8 @@ int init_cache_level(unsigned int cpu)
        union cache_topology ct;
        enum cache_type ctype;
 
+       if (!test_facility(34))
+               return -EOPNOTSUPP;
        if (!this_cpu_ci)
                return -EINVAL;
        ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);