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-rw-r--r--kernel/cgroup/rstat.c13
-rw-r--r--kernel/kcov.c98
-rw-r--r--kernel/ksysfs.c3
-rw-r--r--kernel/panic.c37
-rw-r--r--kernel/resource.c41
-rw-r--r--kernel/taskstats.c5
6 files changed, 97 insertions, 100 deletions
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 29ea74f0eab3..24b5c2ab5598 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -153,8 +153,17 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep)
raw_spinlock_t *cpu_lock = per_cpu_ptr(&cgroup_rstat_cpu_lock,
cpu);
struct cgroup *pos = NULL;
+ unsigned long flags;
- raw_spin_lock(cpu_lock);
+ /*
+ * The _irqsave() is needed because cgroup_rstat_lock is
+ * spinlock_t which is a sleeping lock on PREEMPT_RT. Acquiring
+ * this lock with the _irq() suffix only disables interrupts on
+ * a non-PREEMPT_RT kernel. The raw_spinlock_t below disables
+ * interrupts on both configurations. The _irqsave() ensures
+ * that interrupts are always disabled and later restored.
+ */
+ raw_spin_lock_irqsave(cpu_lock, flags);
while ((pos = cgroup_rstat_cpu_pop_updated(pos, cgrp, cpu))) {
struct cgroup_subsys_state *css;
@@ -166,7 +175,7 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep)
css->ss->css_rstat_flush(css, cpu);
rcu_read_unlock();
}
- raw_spin_unlock(cpu_lock);
+ raw_spin_unlock_irqrestore(cpu_lock, flags);
/* if @may_sleep, play nice and yield if necessary */
if (may_sleep && (need_resched() ||
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 36ca640c4f8e..475524bd900a 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -459,37 +459,28 @@ void kcov_task_exit(struct task_struct *t)
static int kcov_mmap(struct file *filep, struct vm_area_struct *vma)
{
int res = 0;
- void *area;
struct kcov *kcov = vma->vm_file->private_data;
unsigned long size, off;
struct page *page;
unsigned long flags;
- area = vmalloc_user(vma->vm_end - vma->vm_start);
- if (!area)
- return -ENOMEM;
-
spin_lock_irqsave(&kcov->lock, flags);
size = kcov->size * sizeof(unsigned long);
- if (kcov->mode != KCOV_MODE_INIT || vma->vm_pgoff != 0 ||
+ if (kcov->area == NULL || vma->vm_pgoff != 0 ||
vma->vm_end - vma->vm_start != size) {
res = -EINVAL;
goto exit;
}
- if (!kcov->area) {
- kcov->area = area;
- vma->vm_flags |= VM_DONTEXPAND;
- spin_unlock_irqrestore(&kcov->lock, flags);
- for (off = 0; off < size; off += PAGE_SIZE) {
- page = vmalloc_to_page(kcov->area + off);
- if (vm_insert_page(vma, vma->vm_start + off, page))
- WARN_ONCE(1, "vm_insert_page() failed");
- }
- return 0;
+ spin_unlock_irqrestore(&kcov->lock, flags);
+ vma->vm_flags |= VM_DONTEXPAND;
+ for (off = 0; off < size; off += PAGE_SIZE) {
+ page = vmalloc_to_page(kcov->area + off);
+ if (vm_insert_page(vma, vma->vm_start + off, page))
+ WARN_ONCE(1, "vm_insert_page() failed");
}
+ return 0;
exit:
spin_unlock_irqrestore(&kcov->lock, flags);
- vfree(area);
return res;
}
@@ -564,31 +555,12 @@ static int kcov_ioctl_locked(struct kcov *kcov, unsigned int cmd,
unsigned long arg)
{
struct task_struct *t;
- unsigned long size, unused;
+ unsigned long flags, unused;
int mode, i;
struct kcov_remote_arg *remote_arg;
struct kcov_remote *remote;
- unsigned long flags;
switch (cmd) {
- case KCOV_INIT_TRACE:
- /*
- * Enable kcov in trace mode and setup buffer size.
- * Must happen before anything else.
- */
- if (kcov->mode != KCOV_MODE_DISABLED)
- return -EBUSY;
- /*
- * Size must be at least 2 to hold current position and one PC.
- * Later we allocate size * sizeof(unsigned long) memory,
- * that must not overflow.
- */
- size = arg;
- if (size < 2 || size > INT_MAX / sizeof(unsigned long))
- return -EINVAL;
- kcov->size = size;
- kcov->mode = KCOV_MODE_INIT;
- return 0;
case KCOV_ENABLE:
/*
* Enable coverage for the current task.
@@ -692,9 +664,37 @@ static long kcov_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
struct kcov_remote_arg *remote_arg = NULL;
unsigned int remote_num_handles;
unsigned long remote_arg_size;
- unsigned long flags;
+ unsigned long size, flags;
+ void *area;
- if (cmd == KCOV_REMOTE_ENABLE) {
+ kcov = filep->private_data;
+ switch (cmd) {
+ case KCOV_INIT_TRACE:
+ /*
+ * Enable kcov in trace mode and setup buffer size.
+ * Must happen before anything else.
+ *
+ * First check the size argument - it must be at least 2
+ * to hold the current position and one PC.
+ */
+ size = arg;
+ if (size < 2 || size > INT_MAX / sizeof(unsigned long))
+ return -EINVAL;
+ area = vmalloc_user(size * sizeof(unsigned long));
+ if (area == NULL)
+ return -ENOMEM;
+ spin_lock_irqsave(&kcov->lock, flags);
+ if (kcov->mode != KCOV_MODE_DISABLED) {
+ spin_unlock_irqrestore(&kcov->lock, flags);
+ vfree(area);
+ return -EBUSY;
+ }
+ kcov->area = area;
+ kcov->size = size;
+ kcov->mode = KCOV_MODE_INIT;
+ spin_unlock_irqrestore(&kcov->lock, flags);
+ return 0;
+ case KCOV_REMOTE_ENABLE:
if (get_user(remote_num_handles, (unsigned __user *)(arg +
offsetof(struct kcov_remote_arg, num_handles))))
return -EFAULT;
@@ -710,16 +710,18 @@ static long kcov_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
return -EINVAL;
}
arg = (unsigned long)remote_arg;
+ fallthrough;
+ default:
+ /*
+ * All other commands can be normally executed under a spin lock, so we
+ * obtain and release it here in order to simplify kcov_ioctl_locked().
+ */
+ spin_lock_irqsave(&kcov->lock, flags);
+ res = kcov_ioctl_locked(kcov, cmd, arg);
+ spin_unlock_irqrestore(&kcov->lock, flags);
+ kfree(remote_arg);
+ return res;
}
-
- kcov = filep->private_data;
- spin_lock_irqsave(&kcov->lock, flags);
- res = kcov_ioctl_locked(kcov, cmd, arg);
- spin_unlock_irqrestore(&kcov->lock, flags);
-
- kfree(remote_arg);
-
- return res;
}
static const struct file_operations kcov_fops = {
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 35859da8bd4f..b1292a57c2a5 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -24,8 +24,7 @@
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
#define KERNEL_ATTR_RW(_name) \
-static struct kobj_attribute _name##_attr = \
- __ATTR(_name, 0644, _name##_show, _name##_store)
+static struct kobj_attribute _name##_attr = __ATTR_RW(_name)
/* current uevent sequence number */
static ssize_t uevent_seqnum_show(struct kobject *kobj,
diff --git a/kernel/panic.c b/kernel/panic.c
index 55b50e052ec3..eb4dfb932c85 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -66,6 +66,7 @@ EXPORT_SYMBOL_GPL(panic_timeout);
#define PANIC_PRINT_LOCK_INFO 0x00000008
#define PANIC_PRINT_FTRACE_INFO 0x00000010
#define PANIC_PRINT_ALL_PRINTK_MSG 0x00000020
+#define PANIC_PRINT_ALL_CPU_BT 0x00000040
unsigned long panic_print;
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
@@ -147,10 +148,16 @@ void nmi_panic(struct pt_regs *regs, const char *msg)
}
EXPORT_SYMBOL(nmi_panic);
-static void panic_print_sys_info(void)
+static void panic_print_sys_info(bool console_flush)
{
- if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
- console_flush_on_panic(CONSOLE_REPLAY_ALL);
+ if (console_flush) {
+ if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
+ console_flush_on_panic(CONSOLE_REPLAY_ALL);
+ return;
+ }
+
+ if (panic_print & PANIC_PRINT_ALL_CPU_BT)
+ trigger_all_cpu_backtrace();
if (panic_print & PANIC_PRINT_TASK_INFO)
show_state();
@@ -185,6 +192,16 @@ void panic(const char *fmt, ...)
int old_cpu, this_cpu;
bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
+ if (panic_on_warn) {
+ /*
+ * This thread may hit another WARN() in the panic path.
+ * Resetting this prevents additional WARN() from panicking the
+ * system on this thread. Other threads are blocked by the
+ * panic_mutex in panic().
+ */
+ panic_on_warn = 0;
+ }
+
/*
* Disable local interrupts. This will prevent panic_smp_self_stop
* from deadlocking the first cpu that invokes the panic, since
@@ -272,6 +289,8 @@ void panic(const char *fmt, ...)
*/
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
+ panic_print_sys_info(false);
+
kmsg_dump(KMSG_DUMP_PANIC);
/*
@@ -302,7 +321,7 @@ void panic(const char *fmt, ...)
debug_locks_off();
console_flush_on_panic(CONSOLE_FLUSH_PENDING);
- panic_print_sys_info();
+ panic_print_sys_info(true);
if (!panic_blink)
panic_blink = no_blink;
@@ -576,16 +595,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint,
if (regs)
show_regs(regs);
- if (panic_on_warn) {
- /*
- * This thread may hit another WARN() in the panic path.
- * Resetting this prevents additional WARN() from panicking the
- * system on this thread. Other threads are blocked by the
- * panic_mutex in panic().
- */
- panic_on_warn = 0;
+ if (panic_on_warn)
panic("panic_on_warn set ...\n");
- }
if (!regs)
dump_stack();
diff --git a/kernel/resource.c b/kernel/resource.c
index 9c08d6e9eef2..34eaee179689 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -56,14 +56,6 @@ struct resource_constraint {
static DEFINE_RWLOCK(resource_lock);
-/*
- * For memory hotplug, there is no way to free resource entries allocated
- * by boot mem after the system is up. So for reusing the resource entry
- * we need to remember the resource.
- */
-static struct resource *bootmem_resource_free;
-static DEFINE_SPINLOCK(bootmem_resource_lock);
-
static struct resource *next_resource(struct resource *p)
{
if (p->child)
@@ -160,36 +152,19 @@ __initcall(ioresources_init);
static void free_resource(struct resource *res)
{
- if (!res)
- return;
-
- if (!PageSlab(virt_to_head_page(res))) {
- spin_lock(&bootmem_resource_lock);
- res->sibling = bootmem_resource_free;
- bootmem_resource_free = res;
- spin_unlock(&bootmem_resource_lock);
- } else {
+ /**
+ * If the resource was allocated using memblock early during boot
+ * we'll leak it here: we can only return full pages back to the
+ * buddy and trying to be smart and reusing them eventually in
+ * alloc_resource() overcomplicates resource handling.
+ */
+ if (res && PageSlab(virt_to_head_page(res)))
kfree(res);
- }
}
static struct resource *alloc_resource(gfp_t flags)
{
- struct resource *res = NULL;
-
- spin_lock(&bootmem_resource_lock);
- if (bootmem_resource_free) {
- res = bootmem_resource_free;
- bootmem_resource_free = res->sibling;
- }
- spin_unlock(&bootmem_resource_lock);
-
- if (res)
- memset(res, 0, sizeof(struct resource));
- else
- res = kzalloc(sizeof(struct resource), flags);
-
- return res;
+ return kzalloc(sizeof(struct resource), flags);
}
/* Return the conflict entry if you can't request it */
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 2b4898b4752e..bcac5a9043aa 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -113,13 +113,14 @@ static void send_cpu_listeners(struct sk_buff *skb,
struct listener *s, *tmp;
struct sk_buff *skb_next, *skb_cur = skb;
void *reply = genlmsg_data(genlhdr);
- int rc, delcount = 0;
+ int delcount = 0;
genlmsg_end(skb, reply);
- rc = 0;
down_read(&listeners->sem);
list_for_each_entry(s, &listeners->list, list) {
+ int rc;
+
skb_next = NULL;
if (!list_is_last(&s->list, &listeners->list)) {
skb_next = skb_clone(skb_cur, GFP_KERNEL);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 01:20:00 +0000