fnrec.c File Reference

Function trace recorder for crash and hang debugging. More...

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <gpxe/init.h>
#include <gpxe/uaccess.h>

Go to the source code of this file.

Data Structures
struct	fnrec_buffer
	A trace buffer. More...
Enumerations
enum	{ fnrec_magic = 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e', fnrec_buffer_length = 4096 / sizeof ( unsigned long ) }
Functions
	FILE_LICENCE (GPL2_OR_LATER)
static int	fnrec_is_valid (void)
	Test whether the trace buffer is valid.
static void	fnrec_reset (void)
	Reset the trace buffer and clear entries.
static void	fnrec_append_unique (unsigned long l)
	Write a value to the end of the buffer if it is not a repetition.
static void	fnrec_dump (void)
	Print the contents of the trace buffer in chronological order.
static void	fnrec_init (void)
	Function tracer initialisation function.
struct init_fn fnrec_init_fn	__init_fn (INIT_NORMAL)
void	__cyg_profile_func_enter (void *called_fn, void *call_site __unused)
void	__cyg_profile_func_exit (void *called_fn __unused, void *call_site __unused)
Variables
static struct fnrec_buffer *	fnrec_buffer
	The trace buffer.

---

Detailed Description

Function trace recorder for crash and hang debugging.

Definition in file fnrec.c.

---

Enumeration Type Documentation

anonymous enum

Enumerator:

fnrec_magic	Constant for identifying valid trace buffers.
fnrec_buffer_length	Trace buffer length.

Definition at line 33 of file fnrec.c.

     {
        /** Constant for identifying valid trace buffers */
        fnrec_magic = 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e',

        /** Trace buffer length */
        fnrec_buffer_length = 4096 / sizeof ( unsigned long ),
};

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

static int fnrec_is_valid

(

void

)

[static]

Test whether the trace buffer is valid.

Return values:

is_valid

Buffer is valid

Definition at line 61 of file fnrec.c.

References fnrec_magic, and fnrec_buffer::magic.

Referenced by __cyg_profile_func_enter(), and fnrec_dump().

                                   {
        return fnrec_buffer && fnrec_buffer->magic == fnrec_magic;
}

static void fnrec_reset

(

void

)

[static]

Reset the trace buffer and clear entries.

Definition at line 68 of file fnrec.c.

References fnrec_magic, fnrec_buffer::magic, and memset().

Referenced by fnrec_init().

                                 {
        memset ( fnrec_buffer, 0, sizeof ( *fnrec_buffer ) );
        fnrec_buffer->magic = fnrec_magic;
}

static void fnrec_append_unique

(

unsigned long

l

)

[static]

Write a value to the end of the buffer if it is not a repetition.

Parameters:

l

Value to append

Definition at line 78 of file fnrec.c.

References fnrec_buffer::data, fnrec_buffer_length, and fnrec_buffer::idx.

Referenced by __cyg_profile_func_enter().

                                                    {
        static unsigned long lastval;
        uint32_t idx = fnrec_buffer->idx;

        /* Avoid recording the same value repeatedly */
        if ( l == lastval )
                return;

        fnrec_buffer->data[idx] = l;
        fnrec_buffer->idx = ( idx + 1 ) % fnrec_buffer_length;
        lastval = l;
}

static void fnrec_dump

(

void

)

[static]

Print the contents of the trace buffer in chronological order.

Definition at line 94 of file fnrec.c.

References fnrec_buffer::data, fnrec_buffer_length, fnrec_is_valid(), fnrec_buffer::idx, and printf().

Referenced by fnrec_init().

                                {
        size_t i;

        if ( !fnrec_is_valid() ) {
                printf ( "fnrec buffer not found\n" );
                return;
        }

        printf ( "fnrec buffer dump:\n" );
        for ( i = 0; i < fnrec_buffer_length; i++ ) {
                unsigned long l = fnrec_buffer->data[
                        ( fnrec_buffer->idx + i ) % fnrec_buffer_length];
                printf ( "%08lx%c", l, i % 8 == 7 ? '\n' : ' ' );
        }
}

static void fnrec_init

(

void

)

[static]

Function tracer initialisation function.

Definition at line 113 of file fnrec.c.

References fnrec_dump(), fnrec_reset(), and phys_to_virt().

                                {
        /* Hardcoded to 17 MB */
        fnrec_buffer = phys_to_virt ( 17 * 1024 * 1024 );
        fnrec_dump();
        fnrec_reset();
}

struct init_fn fnrec_init_fn __init_fn

(

INIT_NORMAL

)

[read]

void __cyg_profile_func_enter	(	void *	called_fn,
		void *call_site	__unused
	)

Definition at line 128 of file fnrec.c.

References fnrec_append_unique(), and fnrec_is_valid().

                                                                            {
        if ( fnrec_is_valid() )
                fnrec_append_unique ( ( unsigned long ) called_fn );
}

void __cyg_profile_func_exit	(	void *called_fn	__unused,
		void *call_site	__unused
	)

Definition at line 133 of file fnrec.c.

                                                                                    {
}

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Variable Documentation

struct fnrec_buffer* fnrec_buffer [static]

The trace buffer.

Definition at line 54 of file fnrec.c.