Revision d26d45253b78ec0a67003eea25bd08fceaa5b78c authored by Linus Torvalds on 22 January 2013, 18:30:49 UTC, committed by Linus Torvalds on 22 January 2013, 18:30:49 UTC
Pull ftrace fix from Steven Rostedt: "Kprobes now uses the function tracer if it can. That is, if a probe is placed on a function mcount/nop location, and the arch supports it, instead of adding a breakpoint, kprobes will register a function callback as that is much more efficient. The function tracer requires to update modules before they run, and uses the module notifier to do so. But if something else in the module notifiers registers a kprobe at one of these locations, before ftrace can get to it, then the system could fail. The function tracer must be initialized early, otherwise module notifiers that probe will only work by chance." * tag 'trace-3.8-rc4-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Be first to run code modification on modules
internal.h
#ifndef _KERNEL_EVENTS_INTERNAL_H
#define _KERNEL_EVENTS_INTERNAL_H
#include <linux/hardirq.h>
#include <linux/uaccess.h>
/* Buffer handling */
#define RING_BUFFER_WRITABLE 0x01
struct ring_buffer {
atomic_t refcount;
struct rcu_head rcu_head;
#ifdef CONFIG_PERF_USE_VMALLOC
struct work_struct work;
int page_order; /* allocation order */
#endif
int nr_pages; /* nr of data pages */
int writable; /* are we writable */
atomic_t poll; /* POLL_ for wakeups */
local_t head; /* write position */
local_t nest; /* nested writers */
local_t events; /* event limit */
local_t wakeup; /* wakeup stamp */
local_t lost; /* nr records lost */
long watermark; /* wakeup watermark */
/* poll crap */
spinlock_t event_lock;
struct list_head event_list;
struct perf_event_mmap_page *user_page;
void *data_pages[0];
};
extern void rb_free(struct ring_buffer *rb);
extern struct ring_buffer *
rb_alloc(int nr_pages, long watermark, int cpu, int flags);
extern void perf_event_wakeup(struct perf_event *event);
extern void
perf_event_header__init_id(struct perf_event_header *header,
struct perf_sample_data *data,
struct perf_event *event);
extern void
perf_event__output_id_sample(struct perf_event *event,
struct perf_output_handle *handle,
struct perf_sample_data *sample);
extern struct page *
perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff);
#ifdef CONFIG_PERF_USE_VMALLOC
/*
* Back perf_mmap() with vmalloc memory.
*
* Required for architectures that have d-cache aliasing issues.
*/
static inline int page_order(struct ring_buffer *rb)
{
return rb->page_order;
}
#else
static inline int page_order(struct ring_buffer *rb)
{
return 0;
}
#endif
static inline unsigned long perf_data_size(struct ring_buffer *rb)
{
return rb->nr_pages << (PAGE_SHIFT + page_order(rb));
}
#define DEFINE_OUTPUT_COPY(func_name, memcpy_func) \
static inline unsigned int \
func_name(struct perf_output_handle *handle, \
const void *buf, unsigned int len) \
{ \
unsigned long size, written; \
\
do { \
size = min_t(unsigned long, handle->size, len); \
\
written = memcpy_func(handle->addr, buf, size); \
\
len -= written; \
handle->addr += written; \
buf += written; \
handle->size -= written; \
if (!handle->size) { \
struct ring_buffer *rb = handle->rb; \
\
handle->page++; \
handle->page &= rb->nr_pages - 1; \
handle->addr = rb->data_pages[handle->page]; \
handle->size = PAGE_SIZE << page_order(rb); \
} \
} while (len && written == size); \
\
return len; \
}
static inline int memcpy_common(void *dst, const void *src, size_t n)
{
memcpy(dst, src, n);
return n;
}
DEFINE_OUTPUT_COPY(__output_copy, memcpy_common)
#define MEMCPY_SKIP(dst, src, n) (n)
DEFINE_OUTPUT_COPY(__output_skip, MEMCPY_SKIP)
#ifndef arch_perf_out_copy_user
#define arch_perf_out_copy_user __copy_from_user_inatomic
#endif
DEFINE_OUTPUT_COPY(__output_copy_user, arch_perf_out_copy_user)
/* Callchain handling */
extern struct perf_callchain_entry *
perf_callchain(struct perf_event *event, struct pt_regs *regs);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);
static inline int get_recursion_context(int *recursion)
{
int rctx;
if (in_nmi())
rctx = 3;
else if (in_irq())
rctx = 2;
else if (in_softirq())
rctx = 1;
else
rctx = 0;
if (recursion[rctx])
return -1;
recursion[rctx]++;
barrier();
return rctx;
}
static inline void put_recursion_context(int *recursion, int rctx)
{
barrier();
recursion[rctx]--;
}
#ifdef CONFIG_HAVE_PERF_USER_STACK_DUMP
static inline bool arch_perf_have_user_stack_dump(void)
{
return true;
}
#define perf_user_stack_pointer(regs) user_stack_pointer(regs)
#else
static inline bool arch_perf_have_user_stack_dump(void)
{
return false;
}
#define perf_user_stack_pointer(regs) 0
#endif /* CONFIG_HAVE_PERF_USER_STACK_DUMP */
#endif /* _KERNEL_EVENTS_INTERNAL_H */
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