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-rw-r--r--kernel/capability.c21
-rw-r--r--kernel/kexec.c66
-rw-r--r--kernel/ptrace.c5
-rw-r--r--kernel/sched.c46
-rw-r--r--kernel/sys.c2
5 files changed, 86 insertions, 54 deletions
diff --git a/kernel/capability.c b/kernel/capability.c
index 0101e847603e..33e51e78c2d8 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -486,17 +486,22 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
return ret;
}
-int __capable(struct task_struct *t, int cap)
+/**
+ * capable - Determine if the current task has a superior capability in effect
+ * @cap: The capability to be tested for
+ *
+ * Return true if the current task has the given superior capability currently
+ * available for use, false if not.
+ *
+ * This sets PF_SUPERPRIV on the task if the capability is available on the
+ * assumption that it's about to be used.
+ */
+int capable(int cap)
{
- if (security_capable(t, cap) == 0) {
- t->flags |= PF_SUPERPRIV;
+ if (has_capability(current, cap)) {
+ current->flags |= PF_SUPERPRIV;
return 1;
}
return 0;
}
-
-int capable(int cap)
-{
- return __capable(current, cap);
-}
EXPORT_SYMBOL(capable);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index c8a4370e2a34..59f3f0df35d4 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -12,7 +12,7 @@
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/kexec.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/highmem.h>
#include <linux/syscalls.h>
@@ -77,7 +77,7 @@ int kexec_should_crash(struct task_struct *p)
*
* The code for the transition from the current kernel to the
* the new kernel is placed in the control_code_buffer, whose size
- * is given by KEXEC_CONTROL_CODE_SIZE. In the best case only a single
+ * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single
* page of memory is necessary, but some architectures require more.
* Because this memory must be identity mapped in the transition from
* virtual to physical addresses it must live in the range
@@ -242,7 +242,7 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
*/
result = -ENOMEM;
image->control_code_page = kimage_alloc_control_pages(image,
- get_order(KEXEC_CONTROL_CODE_SIZE));
+ get_order(KEXEC_CONTROL_PAGE_SIZE));
if (!image->control_code_page) {
printk(KERN_ERR "Could not allocate control_code_buffer\n");
goto out;
@@ -317,7 +317,7 @@ static int kimage_crash_alloc(struct kimage **rimage, unsigned long entry,
*/
result = -ENOMEM;
image->control_code_page = kimage_alloc_control_pages(image,
- get_order(KEXEC_CONTROL_CODE_SIZE));
+ get_order(KEXEC_CONTROL_PAGE_SIZE));
if (!image->control_code_page) {
printk(KERN_ERR "Could not allocate control_code_buffer\n");
goto out;
@@ -924,19 +924,14 @@ static int kimage_load_segment(struct kimage *image,
*/
struct kimage *kexec_image;
struct kimage *kexec_crash_image;
-/*
- * A home grown binary mutex.
- * Nothing can wait so this mutex is safe to use
- * in interrupt context :)
- */
-static int kexec_lock;
+
+static DEFINE_MUTEX(kexec_mutex);
asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
struct kexec_segment __user *segments,
unsigned long flags)
{
struct kimage **dest_image, *image;
- int locked;
int result;
/* We only trust the superuser with rebooting the system. */
@@ -972,8 +967,7 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
*
* KISS: always take the mutex.
*/
- locked = xchg(&kexec_lock, 1);
- if (locked)
+ if (!mutex_trylock(&kexec_mutex))
return -EBUSY;
dest_image = &kexec_image;
@@ -1015,8 +1009,7 @@ asmlinkage long sys_kexec_load(unsigned long entry, unsigned long nr_segments,
image = xchg(dest_image, image);
out:
- locked = xchg(&kexec_lock, 0); /* Release the mutex */
- BUG_ON(!locked);
+ mutex_unlock(&kexec_mutex);
kimage_free(image);
return result;
@@ -1063,10 +1056,7 @@ asmlinkage long compat_sys_kexec_load(unsigned long entry,
void crash_kexec(struct pt_regs *regs)
{
- int locked;
-
-
- /* Take the kexec_lock here to prevent sys_kexec_load
+ /* Take the kexec_mutex here to prevent sys_kexec_load
* running on one cpu from replacing the crash kernel
* we are using after a panic on a different cpu.
*
@@ -1074,8 +1064,7 @@ void crash_kexec(struct pt_regs *regs)
* of memory the xchg(&kexec_crash_image) would be
* sufficient. But since I reuse the memory...
*/
- locked = xchg(&kexec_lock, 1);
- if (!locked) {
+ if (mutex_trylock(&kexec_mutex)) {
if (kexec_crash_image) {
struct pt_regs fixed_regs;
crash_setup_regs(&fixed_regs, regs);
@@ -1083,8 +1072,7 @@ void crash_kexec(struct pt_regs *regs)
machine_crash_shutdown(&fixed_regs);
machine_kexec(kexec_crash_image);
}
- locked = xchg(&kexec_lock, 0);
- BUG_ON(!locked);
+ mutex_unlock(&kexec_mutex);
}
}
@@ -1426,25 +1414,23 @@ static int __init crash_save_vmcoreinfo_init(void)
module_init(crash_save_vmcoreinfo_init)
-/**
- * kernel_kexec - reboot the system
- *
- * Move into place and start executing a preloaded standalone
- * executable. If nothing was preloaded return an error.
+/*
+ * Move into place and start executing a preloaded standalone
+ * executable. If nothing was preloaded return an error.
*/
int kernel_kexec(void)
{
int error = 0;
- if (xchg(&kexec_lock, 1))
+ if (!mutex_trylock(&kexec_mutex))
return -EBUSY;
if (!kexec_image) {
error = -EINVAL;
goto Unlock;
}
- if (kexec_image->preserve_context) {
#ifdef CONFIG_KEXEC_JUMP
+ if (kexec_image->preserve_context) {
mutex_lock(&pm_mutex);
pm_prepare_console();
error = freeze_processes();
@@ -1459,6 +1445,7 @@ int kernel_kexec(void)
error = disable_nonboot_cpus();
if (error)
goto Resume_devices;
+ device_pm_lock();
local_irq_disable();
/* At this point, device_suspend() has been called,
* but *not* device_power_down(). We *must*
@@ -1470,26 +1457,22 @@ int kernel_kexec(void)
error = device_power_down(PMSG_FREEZE);
if (error)
goto Enable_irqs;
- save_processor_state();
+ } else
#endif
- } else {
- blocking_notifier_call_chain(&reboot_notifier_list,
- SYS_RESTART, NULL);
- system_state = SYSTEM_RESTART;
- device_shutdown();
- sysdev_shutdown();
+ {
+ kernel_restart_prepare(NULL);
printk(KERN_EMERG "Starting new kernel\n");
machine_shutdown();
}
machine_kexec(kexec_image);
- if (kexec_image->preserve_context) {
#ifdef CONFIG_KEXEC_JUMP
- restore_processor_state();
+ if (kexec_image->preserve_context) {
device_power_up(PMSG_RESTORE);
Enable_irqs:
local_irq_enable();
+ device_pm_unlock();
enable_nonboot_cpus();
Resume_devices:
device_resume(PMSG_RESTORE);
@@ -1499,11 +1482,10 @@ int kernel_kexec(void)
Restore_console:
pm_restore_console();
mutex_unlock(&pm_mutex);
-#endif
}
+#endif
Unlock:
- xchg(&kexec_lock, 0);
-
+ mutex_unlock(&kexec_mutex);
return error;
}
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 082b3fcb32a0..356699a96d56 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -140,7 +140,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode)
if (!dumpable && !capable(CAP_SYS_PTRACE))
return -EPERM;
- return security_ptrace(current, task, mode);
+ return security_ptrace_may_access(task, mode);
}
bool ptrace_may_access(struct task_struct *task, unsigned int mode)
@@ -499,8 +499,7 @@ repeat:
goto repeat;
}
- ret = security_ptrace(current->parent, current,
- PTRACE_MODE_ATTACH);
+ ret = security_ptrace_traceme(current->parent);
/*
* Set the ptrace bit in the process ptrace flags.
diff --git a/kernel/sched.c b/kernel/sched.c
index 040807196b33..9a1ddb84e26d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4669,6 +4669,52 @@ int __sched wait_for_completion_killable(struct completion *x)
}
EXPORT_SYMBOL(wait_for_completion_killable);
+/**
+ * try_wait_for_completion - try to decrement a completion without blocking
+ * @x: completion structure
+ *
+ * Returns: 0 if a decrement cannot be done without blocking
+ * 1 if a decrement succeeded.
+ *
+ * If a completion is being used as a counting completion,
+ * attempt to decrement the counter without blocking. This
+ * enables us to avoid waiting if the resource the completion
+ * is protecting is not available.
+ */
+bool try_wait_for_completion(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ else
+ x->done--;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+EXPORT_SYMBOL(try_wait_for_completion);
+
+/**
+ * completion_done - Test to see if a completion has any waiters
+ * @x: completion structure
+ *
+ * Returns: 0 if there are waiters (wait_for_completion() in progress)
+ * 1 if there are no waiters.
+ *
+ */
+bool completion_done(struct completion *x)
+{
+ int ret = 1;
+
+ spin_lock_irq(&x->wait.lock);
+ if (!x->done)
+ ret = 0;
+ spin_unlock_irq(&x->wait.lock);
+ return ret;
+}
+EXPORT_SYMBOL(completion_done);
+
static long __sched
sleep_on_common(wait_queue_head_t *q, int state, long timeout)
{
diff --git a/kernel/sys.c b/kernel/sys.c
index c01858090a98..3dacb00a7f76 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -274,7 +274,7 @@ void emergency_restart(void)
}
EXPORT_SYMBOL_GPL(emergency_restart);
-static void kernel_restart_prepare(char *cmd)
+void kernel_restart_prepare(char *cmd)
{
blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
system_state = SYSTEM_RESTART;

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