% PT_ISCACHE_READ(3)

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# NAME

pt_iscache_read - read memory from a cached file section

# SYNOPSIS

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

|

| **int pt_iscache_read(struct pt_image_section_cache \**iscache*,**

|                     **uint8_t \**buffer*, uint64_t *size*, int *isid*,**

|                     **uint64_t *vaddr*);**

Link with *-lipt*.

# DESCRIPTION

**pt_iscache_read**() reads memory from a cached file section.  The file section

must have previously been added by a call to **pt_iscache_add**(3).  The

*iscache* argument points to the *pt_image_section_cache* object.  It must be

the same that was used in the corresponding **pt_iscache_add**(3) call.  The

*buffer* argument must point to a memory buffer of at least *size* bytes.  The

*isid* argument identifies the file section from which memory is read.  It must

be the same identifier that was returned from the corresponding

**pt_iscache_add**(3) call that added the file section to the cache.  The *vaddr*

argument gives the virtual address from which *size* bytes of memory shall be

read.

On success, **pt_iscache_read**() copies at most *size* bytes of memory from the

cached file section identified by *isid* in *iscache* starting at virtual

address *vaddr* into *buffer* and returns the number of bytes that were copied.

Multiple calls to **pt_iscache_read**() may be necessary if *size* is bigger

than 4Kbyte or if the read crosses a section boundary.

# RETURN VALUE

**pt_iscache_read**() returns the number of bytes that were read on success

or a negative *pt_error_code* enumeration constant in case of an error.

# ERRORS

pte_invalid

:   The *iscache* or *buffer* argument is NULL or the *size* argument is zero.

pte_bad_image

:   The *iscache* does not contain a section identified by *isid*.

pte_nomap

:   The *vaddr* argument lies outside of the virtual address range of the cached

    section.

# SEE ALSO

**pt_iscache_alloc**(3), **pt_iscache_free**(3), **pt_iscache_add**(3)