From 0b991f5cdcd6201e5401f83ca3a672343c3bfc49 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 27 Jul 2015 09:53:49 +0200 Subject: [PATCH] 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 Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/cache.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kernel/cache.c b/arch/s390/kernel/cache.c index bff5e3b..8ba3243 100644 --- 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); -- 2.7.4