From db490cb9aeb77b392f4bdaad3ebe96ea1d5c7bfe Mon Sep 17 00:00:00 2001 From: Ingo Tuchscherer Date: Tue, 17 Mar 2015 16:02:20 +0100 Subject: [PATCH 1/7] s390/zcrypt: enable s390 hwrng to seed kernel entropy Set the 'quality' property in the zcrypt rng device structure to enable the zcrypt hwrng device to take part in the kernel entropy seeding process. A module parameter named hwrng_seed will be introduced to disable the participation. By default this parameter is set to 1 (enabled). Signed-off-by: Ingo Tuchscherer Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky --- drivers/s390/crypto/zcrypt_api.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c index 08f1830cbfc4..01bf1f5cf2e9 100644 --- a/drivers/s390/crypto/zcrypt_api.c +++ b/drivers/s390/crypto/zcrypt_api.c @@ -54,6 +54,10 @@ MODULE_DESCRIPTION("Cryptographic Coprocessor interface, " \ "Copyright IBM Corp. 2001, 2012"); MODULE_LICENSE("GPL"); +static int zcrypt_hwrng_seed = 1; +module_param_named(hwrng_seed, zcrypt_hwrng_seed, int, S_IRUSR|S_IRGRP); +MODULE_PARM_DESC(hwrng_seed, "Turn on/off hwrng auto seed, default is 1 (on)."); + static DEFINE_SPINLOCK(zcrypt_device_lock); static LIST_HEAD(zcrypt_device_list); static int zcrypt_device_count = 0; @@ -1373,6 +1377,7 @@ static int zcrypt_rng_data_read(struct hwrng *rng, u32 *data) static struct hwrng zcrypt_rng_dev = { .name = "zcrypt", .data_read = zcrypt_rng_data_read, + .quality = 990, }; static int zcrypt_rng_device_add(void) @@ -1387,6 +1392,8 @@ static int zcrypt_rng_device_add(void) goto out; } zcrypt_rng_buffer_index = 0; + if (!zcrypt_hwrng_seed) + zcrypt_rng_dev.quality = 0; rc = hwrng_register(&zcrypt_rng_dev); if (rc) goto out_free; From a313bdc5310dd807655d3ca3eb2219cd65dfe45a Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Jun 2015 09:32:22 +0200 Subject: [PATCH 2/7] s390/sclp: fix compile error Fix this error when compiling with CONFIG_SMP=n and CONFIG_DYNAMIC_DEBUG=y: drivers/s390/char/sclp_early.c: In function 'sclp_read_info_early': drivers/s390/char/sclp_early.c:87:19: error: 'EBUSY' undeclared (first use in this function) } while (rc == -EBUSY); ^ Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- drivers/s390/char/sclp_early.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c index aeed7969fd79..7bc6df3100ef 100644 --- a/drivers/s390/char/sclp_early.c +++ b/drivers/s390/char/sclp_early.c @@ -7,6 +7,7 @@ #define KMSG_COMPONENT "sclp_early" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt +#include #include #include #include From a215c8fbde8600d133f122691d0f8c30de6dda02 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Jun 2015 14:52:13 +0200 Subject: [PATCH 3/7] s390/oprofile: fix compile error MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix these errors when compiling with CONFIG_OPROFILE=y and CONFIG_PERF_EVENTS=n: arch/s390/oprofile/init.c: In function ‘oprofile_hwsampler_start’: arch/s390/oprofile/init.c:93:2: error: implicit declaration of function 'perf_reserve_sampling' [-Werror=implicit-function-declaration] retval = perf_reserve_sampling(); ^ arch/s390/oprofile/init.c:99:3: error: implicit declaration of function 'perf_release_sampling' [-Werror=implicit-function-declaration] perf_release_sampling(); ^ Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/perf_event.h | 8 ++++++++ arch/s390/oprofile/init.c | 1 + 2 files changed, 9 insertions(+) diff --git a/arch/s390/include/asm/perf_event.h b/arch/s390/include/asm/perf_event.h index 4cb19fe76dd9..f897ec73dc8c 100644 --- a/arch/s390/include/asm/perf_event.h +++ b/arch/s390/include/asm/perf_event.h @@ -87,7 +87,15 @@ struct sf_raw_sample { } __packed; /* Perf hardware reserve and release functions */ +#ifdef CONFIG_PERF_EVENTS int perf_reserve_sampling(void); void perf_release_sampling(void); +#else /* CONFIG_PERF_EVENTS */ +static inline int perf_reserve_sampling(void) +{ + return 0; +} +static inline void perf_release_sampling(void) {} +#endif /* CONFIG_PERF_EVENTS */ #endif /* _ASM_S390_PERF_EVENT_H */ diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c index bc927a09a172..9cfa2ffaa9d6 100644 --- a/arch/s390/oprofile/init.c +++ b/arch/s390/oprofile/init.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "../../../drivers/oprofile/oprof.h" From f9c87a6f46d508eae0d9ae640be98d50f237f827 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 6 Jul 2015 17:58:19 +0200 Subject: [PATCH 4/7] s390/sclp: clear upper register halves in _sclp_print_early If the kernel is compiled with gcc 5.1 and the XZ compression option the decompress_kernel function calls _sclp_print_early in 64-bit mode while the content of the upper register half of %r6 is non-zero. This causes a specification exception on the servc instruction in _sclp_servc. The _sclp_print_early function saves and restores the upper registers halves but it fails to clear them for the 31-bit code of the mini sclp driver. Cc: Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/sclp.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S index 43c3169ea49c..ada0c07fe1a8 100644 --- a/arch/s390/kernel/sclp.S +++ b/arch/s390/kernel/sclp.S @@ -270,6 +270,8 @@ ENTRY(_sclp_print_early) jno .Lesa2 ahi %r15,-80 stmh %r6,%r15,96(%r15) # store upper register halves + basr %r13,0 + lmh %r0,%r15,.Lzeroes-.(%r13) # clear upper register halves .Lesa2: lr %r10,%r2 # save string pointer lhi %r2,0 @@ -291,6 +293,8 @@ ENTRY(_sclp_print_early) .Lesa3: lm %r6,%r15,120(%r15) # restore registers br %r14 +.Lzeroes: + .fill 64,4,0 .LwritedataS4: .long 0x00760005 # SCLP command for write data From f81a49d13b3014c2b7c424628779a8af93f25c04 Mon Sep 17 00:00:00 2001 From: Stefan Haberland Date: Fri, 10 Jul 2015 10:47:09 +0200 Subject: [PATCH 5/7] s390/dasd: fix kernel panic when alias is set offline The dasd device driver selects which (alias or base) device is used for a given requests when the request is build. If the chosen alias device is set offline before the request gets queued to the device queue the starting function may use device structures that are already freed. This might lead to a hanging offline process or a kernel panic. Add a check to the starting function that returns the request to the upper layer if the device is already in offline processing. In addition to that prevent that an alias device that's already in offline processing gets chosen as start device. Reviewed-by: Sebastian Ott Reviewed-by: Peter Oberparleiter Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky --- drivers/s390/block/dasd.c | 36 ++++++++++++++++++++++++++------- drivers/s390/block/dasd_alias.c | 3 ++- 2 files changed, 31 insertions(+), 8 deletions(-) diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 1aec8ff0b587..f73d2f579a7e 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -1862,6 +1862,33 @@ static void __dasd_device_check_expire(struct dasd_device *device) } } +/* + * return 1 when device is not eligible for IO + */ +static int __dasd_device_is_unusable(struct dasd_device *device, + struct dasd_ccw_req *cqr) +{ + int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM); + + if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) { + /* dasd is being set offline. */ + return 1; + } + if (device->stopped) { + if (device->stopped & mask) { + /* stopped and CQR will not change that. */ + return 1; + } + if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) { + /* CQR is not able to change device to + * operational. */ + return 1; + } + /* CQR required to get device operational. */ + } + return 0; +} + /* * Take a look at the first request on the ccw queue and check * if it needs to be started. @@ -1876,13 +1903,8 @@ static void __dasd_device_start_head(struct dasd_device *device) cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist); if (cqr->status != DASD_CQR_QUEUED) return; - /* when device is stopped, return request to previous layer - * exception: only the disconnect or unresumed bits are set and the - * cqr is a path verification request - */ - if (device->stopped && - !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM)) - && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) { + /* if device is not usable return request to upper layer */ + if (__dasd_device_is_unusable(device, cqr)) { cqr->intrc = -EAGAIN; cqr->status = DASD_CQR_CLEARED; dasd_schedule_device_bh(device); diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index a2597e683e79..ee3a6faae22a 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -699,7 +699,8 @@ struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *base_device) struct dasd_device, alias_list); spin_unlock_irqrestore(&lcu->lock, flags); alias_priv = (struct dasd_eckd_private *) alias_device->private; - if ((alias_priv->count < private->count) && !alias_device->stopped) + if ((alias_priv->count < private->count) && !alias_device->stopped && + !test_bit(DASD_FLAG_OFFLINE, &alias_device->flags)) return alias_device; else return NULL; From e47994dd44bcb4a77b4152bd0eada585934703c0 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 6 Jul 2015 15:02:37 +0200 Subject: [PATCH 6/7] s390/process: fix sfpc inline assembly The sfpc inline assembly within execve_tail() may incorrectly set bits 28-31 of the sfpc instruction to a value which is not zero. These bits however are currently unused and therefore should be zero so we won't get surprised if these bits will be used in the future. Therefore remove the second operand from the inline assembly. Cc: Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/process.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index dc5edc29b73a..8f587d871b9f 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -163,7 +163,7 @@ int copy_thread(unsigned long clone_flags, unsigned long new_stackp, asmlinkage void execve_tail(void) { current->thread.fp_regs.fpc = 0; - asm volatile("sfpc %0,%0" : : "d" (0)); + asm volatile("sfpc %0" : : "d" (0)); } /* From cad49cfc44a5160e3fa09b18e4e7f7cacd13f27d Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 7 Jul 2015 08:40:49 +0200 Subject: [PATCH 7/7] s390/nmi: fix vector register corruption If a machine check happens, the machine has the vector facility installed and the extended save area exists, the cpu will save vector register contents into the extended save area. This is regardless of control register 0 contents, which enables and disables the vector facility during runtime. On each machine check we should validate the vector registers. The current code however tries to validate the registers only if the running task is using vector registers in user space. However even the current code is broken and causes vector register corruption on machine checks, if user space uses them: the prefix area contains a pointer (absolute address) to the machine check extended save area. In order to save some space the save area was put into an unused area of the second prefix page. When validating vector register contents the code uses the absolute address of the extended save area, which is wrong. Due to prefixing the vector instructions will then access contents using absolute addresses instead of real addresses, where the machine stored the contents. If the above would work there is still the problem that register validition would only happen if user space uses vector registers. If kernel space uses them also, this may also lead to vector register content corruption: if the kernel makes use of vector instructions, but the current running user space context does not, the machine check handler will validate floating point registers instead of vector registers. Given the fact that writing to a floating point register may change the upper halve of the corresponding vector register, we also experience vector register corruption in this case. Fix all of these issues, and always validate vector registers on each machine check, if the machine has the vector facility installed and the extended save area is defined. Cc: # 4.1+ Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/ctl_reg.h | 5 +++- arch/s390/kernel/nmi.c | 51 +++++++++++++++++++-------------- 2 files changed, 34 insertions(+), 22 deletions(-) diff --git a/arch/s390/include/asm/ctl_reg.h b/arch/s390/include/asm/ctl_reg.h index cfad7fca01d6..d7697ab802f6 100644 --- a/arch/s390/include/asm/ctl_reg.h +++ b/arch/s390/include/asm/ctl_reg.h @@ -57,7 +57,10 @@ union ctlreg0 { unsigned long lap : 1; /* Low-address-protection control */ unsigned long : 4; unsigned long edat : 1; /* Enhanced-DAT-enablement control */ - unsigned long : 23; + unsigned long : 4; + unsigned long afp : 1; /* AFP-register control */ + unsigned long vx : 1; /* Vector enablement control */ + unsigned long : 17; }; }; diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 505c17c0ae1a..56b550893593 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -21,6 +21,7 @@ #include #include #include +#include struct mcck_struct { int kill_task; @@ -129,26 +130,30 @@ static int notrace s390_revalidate_registers(struct mci *mci) } else asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area)); - asm volatile( - " ld 0,0(%0)\n" - " ld 1,8(%0)\n" - " ld 2,16(%0)\n" - " ld 3,24(%0)\n" - " ld 4,32(%0)\n" - " ld 5,40(%0)\n" - " ld 6,48(%0)\n" - " ld 7,56(%0)\n" - " ld 8,64(%0)\n" - " ld 9,72(%0)\n" - " ld 10,80(%0)\n" - " ld 11,88(%0)\n" - " ld 12,96(%0)\n" - " ld 13,104(%0)\n" - " ld 14,112(%0)\n" - " ld 15,120(%0)\n" - : : "a" (fpt_save_area)); - /* Revalidate vector registers */ - if (MACHINE_HAS_VX && current->thread.vxrs) { + if (!MACHINE_HAS_VX) { + /* Revalidate floating point registers */ + asm volatile( + " ld 0,0(%0)\n" + " ld 1,8(%0)\n" + " ld 2,16(%0)\n" + " ld 3,24(%0)\n" + " ld 4,32(%0)\n" + " ld 5,40(%0)\n" + " ld 6,48(%0)\n" + " ld 7,56(%0)\n" + " ld 8,64(%0)\n" + " ld 9,72(%0)\n" + " ld 10,80(%0)\n" + " ld 11,88(%0)\n" + " ld 12,96(%0)\n" + " ld 13,104(%0)\n" + " ld 14,112(%0)\n" + " ld 15,120(%0)\n" + : : "a" (fpt_save_area)); + } else { + /* Revalidate vector registers */ + union ctlreg0 cr0; + if (!mci->vr) { /* * Vector registers can't be restored and therefore @@ -156,8 +161,12 @@ static int notrace s390_revalidate_registers(struct mci *mci) */ kill_task = 1; } + cr0.val = S390_lowcore.cregs_save_area[0]; + cr0.afp = cr0.vx = 1; + __ctl_load(cr0.val, 0, 0); restore_vx_regs((__vector128 *) - S390_lowcore.vector_save_area_addr); + &S390_lowcore.vector_save_area); + __ctl_load(S390_lowcore.cregs_save_area[0], 0, 0); } /* Revalidate access registers */ asm volatile(