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authorTejun Heo <tj@kernel.org>2010-04-05 11:37:28 +0900
committerTejun Heo <tj@kernel.org>2010-04-05 11:37:28 +0900
commit336f5899d287f06d8329e208fc14ce50f7ec9698 (patch)
tree9b762d450d5eb248a6ff8317badb7e223d93ed58 /kernel
parenta4ab2773205e8b94c18625455f85e3b6bb9d7ad6 (diff)
parentdb217dece3003df0841bacf9556b5c06aa097dae (diff)
downloadlwn-336f5899d287f06d8329e208fc14ce50f7ec9698.tar.gz
lwn-336f5899d287f06d8329e208fc14ce50f7ec9698.zip
Merge branch 'master' into export-slabh
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup_freezer.c9
-rw-r--r--kernel/cred.c6
-rw-r--r--kernel/early_res.c6
-rw-r--r--kernel/kgdb.c205
-rw-r--r--kernel/perf_event.c22
-rw-r--r--kernel/power/process.c5
-rw-r--r--kernel/sched.c2
-rw-r--r--kernel/sched_debug.c4
-rw-r--r--kernel/trace/ring_buffer.c8
-rw-r--r--kernel/trace/trace_clock.c4
-rw-r--r--kernel/trace/trace_event_perf.c11
11 files changed, 153 insertions, 129 deletions
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index d2ccd2798d7a..da5e13975531 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -48,17 +48,20 @@ static inline struct freezer *task_freezer(struct task_struct *task)
struct freezer, css);
}
-int cgroup_frozen(struct task_struct *task)
+int cgroup_freezing_or_frozen(struct task_struct *task)
{
struct freezer *freezer;
enum freezer_state state;
task_lock(task);
freezer = task_freezer(task);
- state = freezer->state;
+ if (!freezer->css.cgroup->parent)
+ state = CGROUP_THAWED; /* root cgroup can't be frozen */
+ else
+ state = freezer->state;
task_unlock(task);
- return state == CGROUP_FROZEN;
+ return (state == CGROUP_FREEZING) || (state == CGROUP_FROZEN);
}
/*
diff --git a/kernel/cred.c b/kernel/cred.c
index d84bdef17c9f..e1dbe9eef800 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -365,7 +365,7 @@ struct cred *prepare_usermodehelper_creds(void)
new = kmem_cache_alloc(cred_jar, GFP_ATOMIC);
if (!new)
- return NULL;
+ goto free_tgcred;
kdebug("prepare_usermodehelper_creds() alloc %p", new);
@@ -398,6 +398,10 @@ struct cred *prepare_usermodehelper_creds(void)
error:
put_cred(new);
+free_tgcred:
+#ifdef CONFIG_KEYS
+ kfree(tgcred);
+#endif
return NULL;
}
diff --git a/kernel/early_res.c b/kernel/early_res.c
index 3cb2c661bb78..31aa9332ef3f 100644
--- a/kernel/early_res.c
+++ b/kernel/early_res.c
@@ -333,6 +333,12 @@ void __init free_early_partial(u64 start, u64 end)
struct early_res *r;
int i;
+ if (start == end)
+ return;
+
+ if (WARN_ONCE(start > end, " wrong range [%#llx, %#llx]\n", start, end))
+ return;
+
try_next:
i = find_overlapped_early(start, end);
if (i >= max_early_res)
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 761fdd2b3034..11f3515ca83f 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -69,9 +69,16 @@ struct kgdb_state {
struct pt_regs *linux_regs;
};
+/* Exception state values */
+#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */
+#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */
+#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */
+#define DCPU_SSTEP 0x8 /* CPU is single stepping */
+
static struct debuggerinfo_struct {
void *debuggerinfo;
struct task_struct *task;
+ int exception_state;
} kgdb_info[NR_CPUS];
/**
@@ -391,27 +398,22 @@ int kgdb_mem2hex(char *mem, char *buf, int count)
/*
* Copy the binary array pointed to by buf into mem. Fix $, #, and
- * 0x7d escaped with 0x7d. Return a pointer to the character after
- * the last byte written.
+ * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
+ * The input buf is overwitten with the result to write to mem.
*/
static int kgdb_ebin2mem(char *buf, char *mem, int count)
{
- int err = 0;
- char c;
+ int size = 0;
+ char *c = buf;
while (count-- > 0) {
- c = *buf++;
- if (c == 0x7d)
- c = *buf++ ^ 0x20;
-
- err = probe_kernel_write(mem, &c, 1);
- if (err)
- break;
-
- mem++;
+ c[size] = *buf++;
+ if (c[size] == 0x7d)
+ c[size] = *buf++ ^ 0x20;
+ size++;
}
- return err;
+ return probe_kernel_write(mem, c, size);
}
/*
@@ -563,49 +565,6 @@ static struct task_struct *getthread(struct pt_regs *regs, int tid)
}
/*
- * CPU debug state control:
- */
-
-#ifdef CONFIG_SMP
-static void kgdb_wait(struct pt_regs *regs)
-{
- unsigned long flags;
- int cpu;
-
- local_irq_save(flags);
- cpu = raw_smp_processor_id();
- kgdb_info[cpu].debuggerinfo = regs;
- kgdb_info[cpu].task = current;
- /*
- * Make sure the above info reaches the primary CPU before
- * our cpu_in_kgdb[] flag setting does:
- */
- smp_wmb();
- atomic_set(&cpu_in_kgdb[cpu], 1);
-
- /* Disable any cpu specific hw breakpoints */
- kgdb_disable_hw_debug(regs);
-
- /* Wait till primary CPU is done with debugging */
- while (atomic_read(&passive_cpu_wait[cpu]))
- cpu_relax();
-
- kgdb_info[cpu].debuggerinfo = NULL;
- kgdb_info[cpu].task = NULL;
-
- /* fix up hardware debug registers on local cpu */
- if (arch_kgdb_ops.correct_hw_break)
- arch_kgdb_ops.correct_hw_break();
-
- /* Signal the primary CPU that we are done: */
- atomic_set(&cpu_in_kgdb[cpu], 0);
- touch_softlockup_watchdog_sync();
- clocksource_touch_watchdog();
- local_irq_restore(flags);
-}
-#endif
-
-/*
* Some architectures need cache flushes when we set/clear a
* breakpoint:
*/
@@ -1400,34 +1359,13 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
return 1;
}
-/*
- * kgdb_handle_exception() - main entry point from a kernel exception
- *
- * Locking hierarchy:
- * interface locks, if any (begin_session)
- * kgdb lock (kgdb_active)
- */
-int
-kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
{
- struct kgdb_state kgdb_var;
- struct kgdb_state *ks = &kgdb_var;
unsigned long flags;
int sstep_tries = 100;
int error = 0;
int i, cpu;
-
- ks->cpu = raw_smp_processor_id();
- ks->ex_vector = evector;
- ks->signo = signo;
- ks->ex_vector = evector;
- ks->err_code = ecode;
- ks->kgdb_usethreadid = 0;
- ks->linux_regs = regs;
-
- if (kgdb_reenter_check(ks))
- return 0; /* Ouch, double exception ! */
-
+ int trace_on = 0;
acquirelock:
/*
* Interrupts will be restored by the 'trap return' code, except when
@@ -1435,13 +1373,43 @@ acquirelock:
*/
local_irq_save(flags);
- cpu = raw_smp_processor_id();
+ cpu = ks->cpu;
+ kgdb_info[cpu].debuggerinfo = regs;
+ kgdb_info[cpu].task = current;
+ /*
+ * Make sure the above info reaches the primary CPU before
+ * our cpu_in_kgdb[] flag setting does:
+ */
+ atomic_inc(&cpu_in_kgdb[cpu]);
/*
- * Acquire the kgdb_active lock:
+ * CPU will loop if it is a slave or request to become a kgdb
+ * master cpu and acquire the kgdb_active lock:
*/
- while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
+ while (1) {
+ if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) {
+ if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu)
+ break;
+ } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
+ if (!atomic_read(&passive_cpu_wait[cpu]))
+ goto return_normal;
+ } else {
+return_normal:
+ /* Return to normal operation by executing any
+ * hw breakpoint fixup.
+ */
+ if (arch_kgdb_ops.correct_hw_break)
+ arch_kgdb_ops.correct_hw_break();
+ if (trace_on)
+ tracing_on();
+ atomic_dec(&cpu_in_kgdb[cpu]);
+ touch_softlockup_watchdog_sync();
+ clocksource_touch_watchdog();
+ local_irq_restore(flags);
+ return 0;
+ }
cpu_relax();
+ }
/*
* For single stepping, try to only enter on the processor
@@ -1475,9 +1443,6 @@ acquirelock:
if (kgdb_io_ops->pre_exception)
kgdb_io_ops->pre_exception();
- kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
- kgdb_info[ks->cpu].task = current;
-
kgdb_disable_hw_debug(ks->linux_regs);
/*
@@ -1486,15 +1451,9 @@ acquirelock:
*/
if (!kgdb_single_step) {
for (i = 0; i < NR_CPUS; i++)
- atomic_set(&passive_cpu_wait[i], 1);
+ atomic_inc(&passive_cpu_wait[i]);
}
- /*
- * spin_lock code is good enough as a barrier so we don't
- * need one here:
- */
- atomic_set(&cpu_in_kgdb[ks->cpu], 1);
-
#ifdef CONFIG_SMP
/* Signal the other CPUs to enter kgdb_wait() */
if ((!kgdb_single_step) && kgdb_do_roundup)
@@ -1518,6 +1477,9 @@ acquirelock:
kgdb_single_step = 0;
kgdb_contthread = current;
exception_level = 0;
+ trace_on = tracing_is_on();
+ if (trace_on)
+ tracing_off();
/* Talk to debugger with gdbserial protocol */
error = gdb_serial_stub(ks);
@@ -1526,13 +1488,11 @@ acquirelock:
if (kgdb_io_ops->post_exception)
kgdb_io_ops->post_exception();
- kgdb_info[ks->cpu].debuggerinfo = NULL;
- kgdb_info[ks->cpu].task = NULL;
- atomic_set(&cpu_in_kgdb[ks->cpu], 0);
+ atomic_dec(&cpu_in_kgdb[ks->cpu]);
if (!kgdb_single_step) {
for (i = NR_CPUS-1; i >= 0; i--)
- atomic_set(&passive_cpu_wait[i], 0);
+ atomic_dec(&passive_cpu_wait[i]);
/*
* Wait till all the CPUs have quit
* from the debugger.
@@ -1551,6 +1511,8 @@ kgdb_restore:
else
kgdb_sstep_pid = 0;
}
+ if (trace_on)
+ tracing_on();
/* Free kgdb_active */
atomic_set(&kgdb_active, -1);
touch_softlockup_watchdog_sync();
@@ -1560,13 +1522,52 @@ kgdb_restore:
return error;
}
+/*
+ * kgdb_handle_exception() - main entry point from a kernel exception
+ *
+ * Locking hierarchy:
+ * interface locks, if any (begin_session)
+ * kgdb lock (kgdb_active)
+ */
+int
+kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+{
+ struct kgdb_state kgdb_var;
+ struct kgdb_state *ks = &kgdb_var;
+ int ret;
+
+ ks->cpu = raw_smp_processor_id();
+ ks->ex_vector = evector;
+ ks->signo = signo;
+ ks->ex_vector = evector;
+ ks->err_code = ecode;
+ ks->kgdb_usethreadid = 0;
+ ks->linux_regs = regs;
+
+ if (kgdb_reenter_check(ks))
+ return 0; /* Ouch, double exception ! */
+ kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER;
+ ret = kgdb_cpu_enter(ks, regs);
+ kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER;
+ return ret;
+}
+
int kgdb_nmicallback(int cpu, void *regs)
{
#ifdef CONFIG_SMP
+ struct kgdb_state kgdb_var;
+ struct kgdb_state *ks = &kgdb_var;
+
+ memset(ks, 0, sizeof(struct kgdb_state));
+ ks->cpu = cpu;
+ ks->linux_regs = regs;
+
if (!atomic_read(&cpu_in_kgdb[cpu]) &&
- atomic_read(&kgdb_active) != cpu &&
- atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
- kgdb_wait((struct pt_regs *)regs);
+ atomic_read(&kgdb_active) != -1 &&
+ atomic_read(&kgdb_active) != cpu) {
+ kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
+ kgdb_cpu_enter(ks, regs);
+ kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE;
return 0;
}
#endif
@@ -1742,11 +1743,11 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
*/
void kgdb_breakpoint(void)
{
- atomic_set(&kgdb_setting_breakpoint, 1);
+ atomic_inc(&kgdb_setting_breakpoint);
wmb(); /* Sync point before breakpoint */
arch_kgdb_breakpoint();
wmb(); /* Sync point after breakpoint */
- atomic_set(&kgdb_setting_breakpoint, 0);
+ atomic_dec(&kgdb_setting_breakpoint);
}
EXPORT_SYMBOL_GPL(kgdb_breakpoint);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index a77266e3e3e1..2f3fbf84215a 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1165,11 +1165,9 @@ void perf_event_task_sched_out(struct task_struct *task,
struct perf_event_context *ctx = task->perf_event_ctxp;
struct perf_event_context *next_ctx;
struct perf_event_context *parent;
- struct pt_regs *regs;
int do_switch = 1;
- regs = task_pt_regs(task);
- perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
+ perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
if (likely(!ctx || !cpuctx->task_ctx))
return;
@@ -2787,12 +2785,11 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
return NULL;
}
-#ifdef CONFIG_EVENT_TRACING
__weak
void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
{
}
-#endif
+
/*
* Output
@@ -3379,15 +3376,23 @@ static void perf_event_task_output(struct perf_event *event,
struct perf_task_event *task_event)
{
struct perf_output_handle handle;
- int size;
struct task_struct *task = task_event->task;
- int ret;
+ unsigned long flags;
+ int size, ret;
+
+ /*
+ * If this CPU attempts to acquire an rq lock held by a CPU spinning
+ * in perf_output_lock() from interrupt context, it's game over.
+ */
+ local_irq_save(flags);
size = task_event->event_id.header.size;
ret = perf_output_begin(&handle, event, size, 0, 0);
- if (ret)
+ if (ret) {
+ local_irq_restore(flags);
return;
+ }
task_event->event_id.pid = perf_event_pid(event, task);
task_event->event_id.ppid = perf_event_pid(event, current);
@@ -3398,6 +3403,7 @@ static void perf_event_task_output(struct perf_event *event,
perf_output_put(&handle, task_event->event_id);
perf_output_end(&handle);
+ local_irq_restore(flags);
}
static int perf_event_task_match(struct perf_event *event)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 5ade1bdcf366..71ae29052ab6 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -88,12 +88,11 @@ static int try_to_freeze_tasks(bool sig_only)
printk(KERN_ERR "Freezing of tasks failed after %d.%02d seconds "
"(%d tasks refusing to freeze):\n",
elapsed_csecs / 100, elapsed_csecs % 100, todo);
- show_state();
read_lock(&tasklist_lock);
do_each_thread(g, p) {
task_lock(p);
if (freezing(p) && !freezer_should_skip(p))
- printk(KERN_ERR " %s\n", p->comm);
+ sched_show_task(p);
cancel_freezing(p);
task_unlock(p);
} while_each_thread(g, p);
@@ -145,7 +144,7 @@ static void thaw_tasks(bool nosig_only)
if (nosig_only && should_send_signal(p))
continue;
- if (cgroup_frozen(p))
+ if (cgroup_freezing_or_frozen(p))
continue;
thaw_process(p);
diff --git a/kernel/sched.c b/kernel/sched.c
index 86c7cc1d7c9d..a3dff1f3f9b0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5388,7 +5388,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
get_task_struct(mt);
task_rq_unlock(rq, &flags);
- wake_up_process(rq->migration_thread);
+ wake_up_process(mt);
put_task_struct(mt);
wait_for_completion(&req.done);
tlb_migrate_finish(p->mm);
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 67f95aada4b9..9b49db144037 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -518,8 +518,4 @@ void proc_sched_set_task(struct task_struct *p)
p->se.nr_wakeups_idle = 0;
p->sched_info.bkl_count = 0;
#endif
- p->se.sum_exec_runtime = 0;
- p->se.prev_sum_exec_runtime = 0;
- p->nvcsw = 0;
- p->nivcsw = 0;
}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2c839ca5e5ce..41ca394feb22 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1210,18 +1210,19 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
for (i = 0; i < nr_pages; i++) {
if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
- return;
+ goto out;
p = cpu_buffer->pages->next;
bpage = list_entry(p, struct buffer_page, list);
list_del_init(&bpage->list);
free_buffer_page(bpage);
}
if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
- return;
+ goto out;
rb_reset_cpu(cpu_buffer);
rb_check_pages(cpu_buffer);
+out:
spin_unlock_irq(&cpu_buffer->reader_lock);
}
@@ -1238,7 +1239,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
for (i = 0; i < nr_pages; i++) {
if (RB_WARN_ON(cpu_buffer, list_empty(pages)))
- return;
+ goto out;
p = pages->next;
bpage = list_entry(p, struct buffer_page, list);
list_del_init(&bpage->list);
@@ -1247,6 +1248,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
rb_reset_cpu(cpu_buffer);
rb_check_pages(cpu_buffer);
+out:
spin_unlock_irq(&cpu_buffer->reader_lock);
}
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 6fbfb8f417b9..9d589d8dcd1a 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -84,7 +84,7 @@ u64 notrace trace_clock_global(void)
int this_cpu;
u64 now;
- raw_local_irq_save(flags);
+ local_irq_save(flags);
this_cpu = raw_smp_processor_id();
now = cpu_clock(this_cpu);
@@ -110,7 +110,7 @@ u64 notrace trace_clock_global(void)
arch_spin_unlock(&trace_clock_struct.lock);
out:
- raw_local_irq_restore(flags);
+ local_irq_restore(flags);
return now;
}
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 81f691eb3a30..0565bb42566f 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -17,7 +17,12 @@ EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs);
static char *perf_trace_buf;
static char *perf_trace_buf_nmi;
-typedef typeof(char [PERF_MAX_TRACE_SIZE]) perf_trace_t ;
+/*
+ * Force it to be aligned to unsigned long to avoid misaligned accesses
+ * suprises
+ */
+typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
+ perf_trace_t;
/* Count the events in use (per event id, not per instance) */
static int total_ref_count;
@@ -130,6 +135,8 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
char *trace_buf, *raw_data;
int pc, cpu;
+ BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
+
pc = preempt_count();
/* Protect the per cpu buffer, begin the rcu read side */
@@ -152,7 +159,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
raw_data = per_cpu_ptr(trace_buf, cpu);
/* zero the dead bytes from align to not leak stack to user */
- *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+ memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));
entry = (struct trace_entry *)raw_data;
tracing_generic_entry_update(entry, *irq_flags, pc);