Table 6 options to change various attributes (continued)

To do this

Use the option

Enable or disable the modification bit for the file's data segment(s). If this is enabled, it

+md flag

is denoted by the +m flag for the segment listing in the chatr output.

 

 

 

Enable or disable the automatic preloading of librtc.so runtime library for the specified

+mem_check

executable to support runtime memory leak checking. The +mem_check option also directs

<enabledisable>

the loader to map all shared library text into the private address space of the process.

 

 

 

Enable or disable the shared library segment merging features. When enabled, all data

+mergeseg flag

segments of shared libraries loaded at program start-up are merged into a single block.

 

Data segments for each dynamically loaded library are merged with the data segments

 

of its dependent libraries. Merging of these segments increases run-time performance by

 

allowing the kernel to use larger size page table entries.

 

 

 

Enable or disable the modification bit for the file's text segment(s). If this is enabled, it is

+mi flag

denoted by the +m flag for the segment listing in the chatr output.

 

 

 

Enable or disable the DF_ORIGIN flag to control use of $ORIGIN in calculating the

+o flag

absolute path of the load module directory. Enabling the flag instructs the dynamic loader

 

to calculate the absolute path of the parent module (object module, shared library, or

 

executable) when it is first loaded. The loader then uses this path for all occurrences of

 

$ORIGIN. If there are no occurrences of $ORIGIN, you should disable the DF_ORIGIN

 

flag, to avoid calculating the absolute path. By default, if $ORIGIN is not present, the

 

DF_ORIGIN flag is disabled.

 

 

 

Format 2 only: Set the page size for a specified segment.

+p size

 

 

Request a particular virtual memory page size that must be used for data. Sizes of 4K,

+pd size

16K, 64K, 256K, 1M, 4M, 16M, 64M, 256M, 1G, 4G, D, and L are supported. A size

 

of D results in using the default page size. A size of L results in using the largest page

 

size available. The actual page size may vary if the requested size cannot be fulfilled.

 

 

 

Request a particular virtual memory page size that should be used for text (instructions).

+pi size

See the +pd option for additional information.

 

 

 

Request static branch prediction when executing this program. The flags enable and

+r flag

disable this request. If this request is enabled, it is denoted by the +r flag for the segment

 

listing in the chatr output.

 

 

 

Control whether the directory path list specified with the LD_LIBRARY_PATH and

+s flag

SHLIB_PATH environment variables can be used to locate shared libraries needed by

 

the program. The two flag values, enable and disable, respectively enable and disable

 

use of the environment variable. If both +s and +b are used, their relative order on the

 

command line indicates which path list is searched first. See the +b option.

 

 

 

Format 2 only: Specify a segment using an address for a set of attribute modifications.

+sa address

 

 

Format 2 only: Use all segments in the file for a set of attribute modifications.

+sall

 

 

Format 2 only: Specify a segment using a segment index number for a set of attribute

+si index

modifications.

 

 

 

Enable or disable lazy swap on all data segments (using Format 1) or on a specific

+z flag

segment (using Format 2). The flags enable and disable, this request. Cannot be used

 

with non-data segments.

 

 

 

Enable or disable dynamic instrumentation by /opt/langtools/bin/caliper. If

+I flag

enabled, the dynamic loader (see dld.so(5)) automatically invokes caliper upon program

 

execution to collect profile information.

 

 

 

Disable linkage table protection. Once you disable, you cannot use +protect to enable

+protect disable

linkage table protection. You have to relink the executable to turn on the linkage table

flag

protection.

 

Changing a Program's Attributes with chatr(1) 55