% PT_IMAGE_SET_CALLBACK(3)

 ! Copyright (c) 2015-2017, Intel Corporation

 !

 ! Redistribution and use in source and binary forms, with or without

 ! modification, are permitted provided that the following conditions are met:

 !

 !  * Redistributions of source code must retain the above copyright notice,

 !    this list of conditions and the following disclaimer.

 !  * Redistributions in binary form must reproduce the above copyright notice,

 !    this list of conditions and the following disclaimer in the documentation

 !    and/or other materials provided with the distribution.

 !  * Neither the name of Intel Corporation nor the names of its contributors

 !    may be used to endorse or promote products derived from this software

 !    without specific prior written permission.

 !

 ! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 ! AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 ! IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 ! ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 ! LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 ! CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 ! SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 ! INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 ! CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 ! ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 ! POSSIBILITY OF SUCH DAMAGE.

 !-->

# NAME

pt_image_set_callback - set a traced memory image read memory callback

# SYNOPSIS

| **\#include `<intel-pt.h>`**

|

| **typedef int (read_memory_callback_t)(uint8_t \**buffer*, size_t *size*,**

|				                       **const struct pt_asid \**asid*,**

|				                       **uint64_t *ip*, void \**context*);**

|

| **int pt_image_set_callback(struct pt_image \**image*,**

|					        **read_memory_callback_t \**callback*,**

|                           **void \**context*);**

Link with *-lipt*.

# DESCRIPTION

**pt_image_set_callback**() sets the function pointed to by *callback* as the

read-memory callback function in the *pt_image* object pointed to by *image*.

Any previous read-memory callback function is replaced.  The read-memory

callback function can be removed by passing NULL as *callback* argument.

When the Intel(R) Processor Trace (Intel PT) instruction flow decoder that is

using *image* tries to read memory from a location that is not contained in any

of the file sections in *image*, it calls the read-memory callback function with

the following arguments:

buffer

:   A pre-allocated memory buffer to hold the to-be-read memory.  The callback

    function shall provide the read memory in that buffer.

size

:   The size of the memory buffer pointed to by the *buffer* argument.

asid

:   The address-space identifier specifying the process, guest, or hypervisor,

    in which context the *ip* argument is to be interpreted.  See

    **pt_image_add_file**(3).

ip

:   The virtual address from which *size* bytes of memory shall be read.

context

:   The *context* argument passed to **pt_image_set_callback**().

The callback function shall return the number of bytes read on success (no more

than *size*) or a negative *pt_error_code* enumeration constant in case of an

error.

# RETURN VALUE

**pt_image_set_callback**() returns zero on success or a negative

*pt_error_code* enumeration constant in case of an error.

# ERRORS

pte_invalid

:   If the *image* argument is NULL.

# SEE ALSO

**pt_image_alloc**(3), **pt_image_free**(3), **pt_image_add_file**(3),

**pt_image_add_cached**(3), pt_image_copy**(3),

**pt_image_remove_by_filename**(3), pt_image_remove_by_asid**(3),

**pt_insn_set_image**(3), pt_insn_get_image**(3)