[GIT PULL] s390 patches for 4.5-rc5

From: Martin Schwidefsky
Date: Fri Feb 19 2016 - 10:43:01 EST


Hi Linus,

please pull from the 'for-linus' branch of

git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git for-linus

to receive the following updates:

Several bug fixes
* There are four different stack tracers, and three of them have bugs.
For 4.5 the bugs are fix and we prepare a cleanup patch for the next
merge window.
* Three bug fixes for the dasd driver in regard to parallel access volumes
and the new max_dev_sectors block device queue limit
* The irq restore optimization needs a fixup for memcpy_real
* The diagnose trace code has a conflict with lockdep

Christian Borntraeger (1):
s390: fix DAT off memory access, e.g. on kdump

Heiko Carstens (8):
s390/stacktrace: fix save_stack_trace_tsk() for current task
s390/stacktrace: fix address ranges for asynchronous and panic stack
s390/stacktrace: add missing end marker
s390/stacktrace: save full stack traces
s390/perf_event: fix address range for asynchronous stack
s390/oprofile: fix address range for asynchronous stack
s390/diag: avoid lockdep recursion
s390/maccess: reduce stnsm instructions

Pratyush Anand (1):
s390/stacktrace: add save_stack_trace_regs()

Stefan Haberland (3):
s390/dasd: prevent incorrect length error under z/VM after PAV changes
s390/dasd: fix refcount for PAV reassignment
s390/dasd: fix performance drop

arch/s390/kernel/perf_event.c | 8 ++++---
arch/s390/kernel/stacktrace.c | 47 +++++++++++++++++++++++++++++------------
arch/s390/kernel/trace.c | 3 +++
arch/s390/mm/maccess.c | 12 +++++++----
arch/s390/oprofile/backtrace.c | 8 ++++---
drivers/s390/block/dasd.c | 1 +
drivers/s390/block/dasd_alias.c | 23 ++++++++++++++------
7 files changed, 73 insertions(+), 29 deletions(-)

diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c
index cfcba2d..0943b11 100644
--- a/arch/s390/kernel/perf_event.c
+++ b/arch/s390/kernel/perf_event.c
@@ -260,12 +260,13 @@ static unsigned long __store_trace(struct perf_callchain_entry *entry,
void perf_callchain_kernel(struct perf_callchain_entry *entry,
struct pt_regs *regs)
{
- unsigned long head;
+ unsigned long head, frame_size;
struct stack_frame *head_sf;

if (user_mode(regs))
return;

+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
head = regs->gprs[15];
head_sf = (struct stack_frame *) head;

@@ -273,8 +274,9 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry,
return;

head = head_sf->back_chain;
- head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE,
- S390_lowcore.async_stack);
+ head = __store_trace(entry, head,
+ S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
+ S390_lowcore.async_stack + frame_size);

__store_trace(entry, head, S390_lowcore.thread_info,
S390_lowcore.thread_info + THREAD_SIZE);
diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c
index 5acba3c..8f64ebd 100644
--- a/arch/s390/kernel/stacktrace.c
+++ b/arch/s390/kernel/stacktrace.c
@@ -59,26 +59,32 @@ static unsigned long save_context_stack(struct stack_trace *trace,
}
}

-void save_stack_trace(struct stack_trace *trace)
+static void __save_stack_trace(struct stack_trace *trace, unsigned long sp)
{
- register unsigned long sp asm ("15");
- unsigned long orig_sp, new_sp;
+ unsigned long new_sp, frame_size;

- orig_sp = sp;
- new_sp = save_context_stack(trace, orig_sp,
- S390_lowcore.panic_stack - PAGE_SIZE,
- S390_lowcore.panic_stack, 1);
- if (new_sp != orig_sp)
- return;
+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+ new_sp = save_context_stack(trace, sp,
+ S390_lowcore.panic_stack + frame_size - PAGE_SIZE,
+ S390_lowcore.panic_stack + frame_size, 1);
new_sp = save_context_stack(trace, new_sp,
- S390_lowcore.async_stack - ASYNC_SIZE,
- S390_lowcore.async_stack, 1);
- if (new_sp != orig_sp)
- return;
+ S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
+ S390_lowcore.async_stack + frame_size, 1);
save_context_stack(trace, new_sp,
S390_lowcore.thread_info,
S390_lowcore.thread_info + THREAD_SIZE, 1);
}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+ register unsigned long r15 asm ("15");
+ unsigned long sp;
+
+ sp = r15;
+ __save_stack_trace(trace, sp);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
EXPORT_SYMBOL_GPL(save_stack_trace);

void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
@@ -86,6 +92,10 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
unsigned long sp, low, high;

sp = tsk->thread.ksp;
+ if (tsk == current) {
+ /* Get current stack pointer. */
+ asm volatile("la %0,0(15)" : "=a" (sp));
+ }
low = (unsigned long) task_stack_page(tsk);
high = (unsigned long) task_pt_regs(tsk);
save_context_stack(trace, sp, low, high, 0);
@@ -93,3 +103,14 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
trace->entries[trace->nr_entries++] = ULONG_MAX;
}
EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
+
+void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
+{
+ unsigned long sp;
+
+ sp = kernel_stack_pointer(regs);
+ __save_stack_trace(trace, sp);
+ if (trace->nr_entries < trace->max_entries)
+ trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_regs);
diff --git a/arch/s390/kernel/trace.c b/arch/s390/kernel/trace.c
index 21a5df9..dde7654 100644
--- a/arch/s390/kernel/trace.c
+++ b/arch/s390/kernel/trace.c
@@ -18,6 +18,9 @@ void trace_s390_diagnose_norecursion(int diag_nr)
unsigned long flags;
unsigned int *depth;

+ /* Avoid lockdep recursion. */
+ if (IS_ENABLED(CONFIG_LOCKDEP))
+ return;
local_irq_save(flags);
depth = this_cpu_ptr(&diagnose_trace_depth);
if (*depth == 0) {
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index fec59c0..792f9c6 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -93,15 +93,19 @@ static int __memcpy_real(void *dest, void *src, size_t count)
*/
int memcpy_real(void *dest, void *src, size_t count)
{
+ int irqs_disabled, rc;
unsigned long flags;
- int rc;

if (!count)
return 0;
- local_irq_save(flags);
- __arch_local_irq_stnsm(0xfbUL);
+ flags = __arch_local_irq_stnsm(0xf8UL);
+ irqs_disabled = arch_irqs_disabled_flags(flags);
+ if (!irqs_disabled)
+ trace_hardirqs_off();
rc = __memcpy_real(dest, src, count);
- local_irq_restore(flags);
+ if (!irqs_disabled)
+ trace_hardirqs_on();
+ __arch_local_irq_ssm(flags);
return rc;
}

diff --git a/arch/s390/oprofile/backtrace.c b/arch/s390/oprofile/backtrace.c
index fe0bfe3..1884e17 100644
--- a/arch/s390/oprofile/backtrace.c
+++ b/arch/s390/oprofile/backtrace.c
@@ -54,12 +54,13 @@ __show_trace(unsigned int *depth, unsigned long sp,

void s390_backtrace(struct pt_regs * const regs, unsigned int depth)
{
- unsigned long head;
+ unsigned long head, frame_size;
struct stack_frame* head_sf;

if (user_mode(regs))
return;

+ frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
head = regs->gprs[15];
head_sf = (struct stack_frame*)head;

@@ -68,8 +69,9 @@ void s390_backtrace(struct pt_regs * const regs, unsigned int depth)

head = head_sf->back_chain;

- head = __show_trace(&depth, head, S390_lowcore.async_stack - ASYNC_SIZE,
- S390_lowcore.async_stack);
+ head = __show_trace(&depth, head,
+ S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
+ S390_lowcore.async_stack + frame_size);

__show_trace(&depth, head, S390_lowcore.thread_info,
S390_lowcore.thread_info + THREAD_SIZE);
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 41605da..c78db05 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -3035,6 +3035,7 @@ static void dasd_setup_queue(struct dasd_block *block)
max = block->base->discipline->max_blocks << block->s2b_shift;
}
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, block->request_queue);
+ block->request_queue->limits.max_dev_sectors = max;
blk_queue_logical_block_size(block->request_queue,
block->bp_block);
blk_queue_max_hw_sectors(block->request_queue, max);
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c
index 184b1db..286782c 100644
--- a/drivers/s390/block/dasd_alias.c
+++ b/drivers/s390/block/dasd_alias.c
@@ -264,8 +264,10 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
spin_unlock_irqrestore(&lcu->lock, flags);
cancel_work_sync(&lcu->suc_data.worker);
spin_lock_irqsave(&lcu->lock, flags);
- if (device == lcu->suc_data.device)
+ if (device == lcu->suc_data.device) {
+ dasd_put_device(device);
lcu->suc_data.device = NULL;
+ }
}
was_pending = 0;
if (device == lcu->ruac_data.device) {
@@ -273,8 +275,10 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device)
was_pending = 1;
cancel_delayed_work_sync(&lcu->ruac_data.dwork);
spin_lock_irqsave(&lcu->lock, flags);
- if (device == lcu->ruac_data.device)
+ if (device == lcu->ruac_data.device) {
+ dasd_put_device(device);
lcu->ruac_data.device = NULL;
+ }
}
private->lcu = NULL;
spin_unlock_irqrestore(&lcu->lock, flags);
@@ -549,8 +553,10 @@ static void lcu_update_work(struct work_struct *work)
if ((rc && (rc != -EOPNOTSUPP)) || (lcu->flags & NEED_UAC_UPDATE)) {
DBF_DEV_EVENT(DBF_WARNING, device, "could not update"
" alias data in lcu (rc = %d), retry later", rc);
- schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ);
+ if (!schedule_delayed_work(&lcu->ruac_data.dwork, 30*HZ))
+ dasd_put_device(device);
} else {
+ dasd_put_device(device);
lcu->ruac_data.device = NULL;
lcu->flags &= ~UPDATE_PENDING;
}
@@ -593,8 +599,10 @@ static int _schedule_lcu_update(struct alias_lcu *lcu,
*/
if (!usedev)
return -EINVAL;
+ dasd_get_device(usedev);
lcu->ruac_data.device = usedev;
- schedule_delayed_work(&lcu->ruac_data.dwork, 0);
+ if (!schedule_delayed_work(&lcu->ruac_data.dwork, 0))
+ dasd_put_device(usedev);
return 0;
}

@@ -723,7 +731,7 @@ static int reset_summary_unit_check(struct alias_lcu *lcu,
ASCEBC((char *) &cqr->magic, 4);
ccw = cqr->cpaddr;
ccw->cmd_code = DASD_ECKD_CCW_RSCK;
- ccw->flags = 0 ;
+ ccw->flags = CCW_FLAG_SLI;
ccw->count = 16;
ccw->cda = (__u32)(addr_t) cqr->data;
((char *)cqr->data)[0] = reason;
@@ -930,6 +938,7 @@ static void summary_unit_check_handling_work(struct work_struct *work)
/* 3. read new alias configuration */
_schedule_lcu_update(lcu, device);
lcu->suc_data.device = NULL;
+ dasd_put_device(device);
spin_unlock_irqrestore(&lcu->lock, flags);
}

@@ -989,6 +998,8 @@ void dasd_alias_handle_summary_unit_check(struct dasd_device *device,
}
lcu->suc_data.reason = reason;
lcu->suc_data.device = device;
+ dasd_get_device(device);
spin_unlock(&lcu->lock);
- schedule_work(&lcu->suc_data.worker);
+ if (!schedule_work(&lcu->suc_data.worker))
+ dasd_put_device(device);
};