From 30342fe65e511007672437741158d493472f427f Mon Sep 17 00:00:00 2001 From: Michael Holzheu Date: Thu, 23 Jul 2015 19:26:15 +0200 Subject: [PATCH 1/2] s390/bpf: clear correct BPF accumulator register Currently we assumed the following BPF to eBPF register mapping: - BPF_REG_A -> BPF_REG_7 - BPF_REG_X -> BPF_REG_8 Unfortunately this mapping is wrong. The correct mapping is: - BPF_REG_A -> BPF_REG_0 - BPF_REG_X -> BPF_REG_7 So clear the correct registers and use the BPF_REG_A and BPF_REG_X macros instead of BPF_REG_0/7. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Cc: stable@vger.kernel.org # 4.0+ Signed-off-by: Michael Holzheu Signed-off-by: Martin Schwidefsky --- arch/s390/net/bpf_jit_comp.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index fee782acc2ee..8d2e5165865f 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -448,13 +448,13 @@ static void bpf_jit_prologue(struct bpf_jit *jit) EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0, BPF_REG_1, offsetof(struct sk_buff, data)); } - /* BPF compatibility: clear A (%b7) and X (%b8) registers */ - if (REG_SEEN(BPF_REG_7)) - /* lghi %b7,0 */ - EMIT4_IMM(0xa7090000, BPF_REG_7, 0); - if (REG_SEEN(BPF_REG_8)) - /* lghi %b8,0 */ - EMIT4_IMM(0xa7090000, BPF_REG_8, 0); + /* BPF compatibility: clear A (%b0) and X (%b7) registers */ + if (REG_SEEN(BPF_REG_A)) + /* lghi %ba,0 */ + EMIT4_IMM(0xa7090000, BPF_REG_A, 0); + if (REG_SEEN(BPF_REG_X)) + /* lghi %bx,0 */ + EMIT4_IMM(0xa7090000, BPF_REG_X, 0); } /* From 0b991f5cdcd6201e5401f83ca3a672343c3bfc49 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 27 Jul 2015 09:53:49 +0200 Subject: [PATCH 2/2] 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 bff5e3b6d822..8ba32436effe 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);