[GIT PULL] s390 patches for 2.6.37-rc2

From: Martin Schwidefsky
Date: Tue Nov 16 2010 - 06:49:45 EST


Hi Linus,

please pull from 'for-linus' branch of

git://git390.marist.edu/pub/scm/linux-2.6.git for-linus

to receive the following updates:

Heiko Carstens (1):
[S390] ftrace: build without frame pointers on s390

Hendrik Brueckner (1):
[S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking

Martin Schwidefsky (4):
[S390] fix get_user_pages_fast
[S390] tape: add medium state notifications
[S390] kprobes: disable interrupts throughout
[S390] kprobes: Fix the return address of multiple kretprobes

Sebastian Ott (1):
[S390] cio: fix incorrect ccw_device_init_count

Stefan Weinhuber (1):
[S390] vmlogrdr: purge after recording is switched off

arch/s390/Kconfig.debug | 12 +++++++
arch/s390/include/asm/page.h | 5 +++
arch/s390/kernel/kprobes.c | 70 +++++++++++++++++++++++++++++++----------
arch/s390/mm/gup.c | 7 ++--
drivers/s390/char/tape_core.c | 68 ++++++++++++++++++++++++++++++++++-----
drivers/s390/char/vmlogrdr.c | 36 ++++++++++++++-------
drivers/s390/cio/device.c | 11 ++++++-
kernel/trace/Kconfig | 2 +-
8 files changed, 167 insertions(+), 44 deletions(-)

diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug
index 45e0c61..05221b1 100644
--- a/arch/s390/Kconfig.debug
+++ b/arch/s390/Kconfig.debug
@@ -6,6 +6,18 @@ config TRACE_IRQFLAGS_SUPPORT

source "lib/Kconfig.debug"

+config STRICT_DEVMEM
+ def_bool y
+ prompt "Filter access to /dev/mem"
+ ---help---
+ This option restricts access to /dev/mem. If this option is
+ disabled, you allow userspace access to all memory, including
+ kernel and userspace memory. Accidental memory access is likely
+ to be disastrous.
+ Memory access is required for experts who want to debug the kernel.
+
+ If you are unsure, say Y.
+
config DEBUG_STRICT_USER_COPY_CHECKS
bool "Strict user copy size checks"
---help---
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index a8729ea..3c987e9 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -130,6 +130,11 @@ struct page;
void arch_free_page(struct page *page, int order);
void arch_alloc_page(struct page *page, int order);

+static inline int devmem_is_allowed(unsigned long pfn)
+{
+ return 0;
+}
+
#define HAVE_ARCH_FREE_PAGE
#define HAVE_ARCH_ALLOC_PAGE

diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index d60fc43..2564793 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -30,6 +30,7 @@
#include <asm/sections.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/hardirq.h>

DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -212,7 +213,7 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
/* Set the PER control regs, turns on single step for this address */
__ctl_load(kprobe_per_regs, 9, 11);
regs->psw.mask |= PSW_MASK_PER;
- regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
+ regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
}

static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -239,7 +240,7 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
__get_cpu_var(current_kprobe) = p;
/* Save the interrupt and per flags */
kcb->kprobe_saved_imask = regs->psw.mask &
- (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
+ (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT);
/* Save the control regs that govern PER */
__ctl_store(kcb->kprobe_saved_ctl, 9, 11);
}
@@ -316,8 +317,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
return 1;

ss_probe:
- if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
- local_irq_disable();
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
@@ -350,6 +349,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
struct hlist_node *node, *tmp;
unsigned long flags, orig_ret_address = 0;
unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
+ kprobe_opcode_t *correct_ret_addr = NULL;

INIT_HLIST_HEAD(&empty_rp);
kretprobe_hash_lock(current, &head, &flags);
@@ -372,10 +372,32 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
/* another task is sharing our hash bucket */
continue;

- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
+ orig_ret_address = (unsigned long)ri->ret_addr;
+
+ if (orig_ret_address != trampoline_address)
+ /*
+ * This is the real return address. Any other
+ * instances associated with this task are for
+ * other calls deeper on the call stack
+ */
+ break;
+ }
+
+ kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
+ correct_ret_addr = ri->ret_addr;
+ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+ if (ri->task != current)
+ /* another task is sharing our hash bucket */
+ continue;

orig_ret_address = (unsigned long)ri->ret_addr;
+
+ if (ri->rp && ri->rp->handler) {
+ ri->ret_addr = correct_ret_addr;
+ ri->rp->handler(ri, regs);
+ }
+
recycle_rp_inst(ri, &empty_rp);

if (orig_ret_address != trampoline_address) {
@@ -387,7 +409,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
break;
}
}
- kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;

reset_current_kprobe();
@@ -465,8 +487,6 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
goto out;
}
reset_current_kprobe();
- if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
- local_irq_enable();
out:
preempt_enable_no_resched();

@@ -482,7 +502,7 @@ out:
return 1;
}

-int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@@ -508,8 +528,6 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
restore_previous_kprobe(kcb);
else {
reset_current_kprobe();
- if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
- local_irq_enable();
}
preempt_enable_no_resched();
break;
@@ -553,6 +571,18 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
return 0;
}

+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+ int ret;
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_disable();
+ ret = kprobe_trap_handler(regs, trapnr);
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+ return ret;
+}
+
/*
* Wrapper routine to for handling exceptions.
*/
@@ -560,8 +590,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct die_args *args = (struct die_args *)data;
+ struct pt_regs *regs = args->regs;
int ret = NOTIFY_DONE;

+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_disable();
+
switch (val) {
case DIE_BPT:
if (kprobe_handler(args->regs))
@@ -572,16 +606,17 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
ret = NOTIFY_STOP;
break;
case DIE_TRAP:
- /* kprobe_running() needs smp_processor_id() */
- preempt_disable();
- if (kprobe_running() &&
- kprobe_fault_handler(args->regs, args->trapnr))
+ if (!preemptible() && kprobe_running() &&
+ kprobe_trap_handler(args->regs, args->trapnr))
ret = NOTIFY_STOP;
- preempt_enable();
break;
default:
break;
}
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+
return ret;
}

@@ -595,6 +630,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)

/* setup return addr to the jprobe handler routine */
regs->psw.addr = (unsigned long)(jp->entry) | PSW_ADDR_AMODE;
+ regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);

/* r14 is the function return address */
kcb->jprobe_saved_r14 = (unsigned long)regs->gprs[14];
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index 38e641c..45b405c 100644
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -20,18 +20,17 @@
static inline int gup_pte_range(pmd_t *pmdp, pmd_t pmd, unsigned long addr,
unsigned long end, int write, struct page **pages, int *nr)
{
- unsigned long mask, result;
+ unsigned long mask;
pte_t *ptep, pte;
struct page *page;

- result = write ? 0 : _PAGE_RO;
- mask = result | _PAGE_INVALID | _PAGE_SPECIAL;
+ mask = (write ? _PAGE_RO : 0) | _PAGE_INVALID | _PAGE_SPECIAL;

ptep = ((pte_t *) pmd_deref(pmd)) + pte_index(addr);
do {
pte = *ptep;
barrier();
- if ((pte_val(pte) & mask) != result)
+ if ((pte_val(pte) & mask) != 0)
return 0;
VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
page = pte_page(pte);
diff --git a/drivers/s390/char/tape_core.c b/drivers/s390/char/tape_core.c
index 6c40867..b3a3e8e 100644
--- a/drivers/s390/char/tape_core.c
+++ b/drivers/s390/char/tape_core.c
@@ -209,29 +209,79 @@ tape_state_set(struct tape_device *device, enum tape_state newstate)
wake_up(&device->state_change_wq);
}

+struct tape_med_state_work_data {
+ struct tape_device *device;
+ enum tape_medium_state state;
+ struct work_struct work;
+};
+
+static void
+tape_med_state_work_handler(struct work_struct *work)
+{
+ static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
+ static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
+ struct tape_med_state_work_data *p =
+ container_of(work, struct tape_med_state_work_data, work);
+ struct tape_device *device = p->device;
+ char *envp[] = { NULL, NULL };
+
+ switch (p->state) {
+ case MS_UNLOADED:
+ pr_info("%s: The tape cartridge has been successfully "
+ "unloaded\n", dev_name(&device->cdev->dev));
+ envp[0] = env_state_unloaded;
+ kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
+ break;
+ case MS_LOADED:
+ pr_info("%s: A tape cartridge has been mounted\n",
+ dev_name(&device->cdev->dev));
+ envp[0] = env_state_loaded;
+ kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
+ break;
+ default:
+ break;
+ }
+ tape_put_device(device);
+ kfree(p);
+}
+
+static void
+tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
+{
+ struct tape_med_state_work_data *p;
+
+ p = kzalloc(sizeof(*p), GFP_ATOMIC);
+ if (p) {
+ INIT_WORK(&p->work, tape_med_state_work_handler);
+ p->device = tape_get_device(device);
+ p->state = state;
+ schedule_work(&p->work);
+ }
+}
+
void
tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
{
- if (device->medium_state == newstate)
+ enum tape_medium_state oldstate;
+
+ oldstate = device->medium_state;
+ if (oldstate == newstate)
return;
+ device->medium_state = newstate;
switch(newstate){
case MS_UNLOADED:
device->tape_generic_status |= GMT_DR_OPEN(~0);
- if (device->medium_state == MS_LOADED)
- pr_info("%s: The tape cartridge has been successfully "
- "unloaded\n", dev_name(&device->cdev->dev));
+ if (oldstate == MS_LOADED)
+ tape_med_state_work(device, MS_UNLOADED);
break;
case MS_LOADED:
device->tape_generic_status &= ~GMT_DR_OPEN(~0);
- if (device->medium_state == MS_UNLOADED)
- pr_info("%s: A tape cartridge has been mounted\n",
- dev_name(&device->cdev->dev));
+ if (oldstate == MS_UNLOADED)
+ tape_med_state_work(device, MS_LOADED);
break;
default:
- // print nothing
break;
}
- device->medium_state = newstate;
wake_up(&device->state_change_wq);
}

diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index 9f66142..1cc726b 100644
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -249,27 +249,25 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr,
char cp_command[80];
char cp_response[160];
char *onoff, *qid_string;
+ int rc;

- memset(cp_command, 0x00, sizeof(cp_command));
- memset(cp_response, 0x00, sizeof(cp_response));
-
- onoff = ((action == 1) ? "ON" : "OFF");
+ onoff = ((action == 1) ? "ON" : "OFF");
qid_string = ((recording_class_AB == 1) ? " QID * " : "");

- /*
+ /*
* The recording commands needs to be called with option QID
* for guests that have previlege classes A or B.
* Purging has to be done as separate step, because recording
* can't be switched on as long as records are on the queue.
* Doing both at the same time doesn't work.
*/
-
- if (purge) {
+ if (purge && (action == 1)) {
+ memset(cp_command, 0x00, sizeof(cp_command));
+ memset(cp_response, 0x00, sizeof(cp_response));
snprintf(cp_command, sizeof(cp_command),
"RECORDING %s PURGE %s",
logptr->recording_name,
qid_string);
-
cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
}

@@ -279,19 +277,33 @@ static int vmlogrdr_recording(struct vmlogrdr_priv_t * logptr,
logptr->recording_name,
onoff,
qid_string);
-
cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
/* The recording command will usually answer with 'Command complete'
* on success, but when the specific service was never connected
* before then there might be an additional informational message
* 'HCPCRC8072I Recording entry not found' before the
- * 'Command complete'. So I use strstr rather then the strncmp.
+ * 'Command complete'. So I use strstr rather then the strncmp.
*/
if (strstr(cp_response,"Command complete"))
- return 0;
+ rc = 0;
else
- return -EIO;
+ rc = -EIO;
+ /*
+ * If we turn recording off, we have to purge any remaining records
+ * afterwards, as a large number of queued records may impact z/VM
+ * performance.
+ */
+ if (purge && (action == 0)) {
+ memset(cp_command, 0x00, sizeof(cp_command));
+ memset(cp_response, 0x00, sizeof(cp_response));
+ snprintf(cp_command, sizeof(cp_command),
+ "RECORDING %s PURGE %s",
+ logptr->recording_name,
+ qid_string);
+ cpcmd(cp_command, cp_response, sizeof(cp_response), NULL);
+ }

+ return rc;
}


diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 2ff8a22..e8391b8 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1455,7 +1455,16 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
break;
case IO_SCH_UNREG_ATTACH:
case IO_SCH_UNREG:
- if (cdev)
+ if (!cdev)
+ break;
+ if (cdev->private->state == DEV_STATE_SENSE_ID) {
+ /*
+ * Note: delayed work triggered by this event
+ * and repeated calls to sch_event are synchronized
+ * by the above check for work_pending(cdev).
+ */
+ dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
+ } else
ccw_device_set_notoper(cdev);
break;
case IO_SCH_NOP:
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index e04b8bc..ea37e2f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -126,7 +126,7 @@ if FTRACE
config FUNCTION_TRACER
bool "Kernel Function Tracer"
depends on HAVE_FUNCTION_TRACER
- select FRAME_POINTER if (!ARM_UNWIND)
+ select FRAME_POINTER if !ARM_UNWIND && !S390
select KALLSYMS
select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
--
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