Info Catalog gdb: Library List Format gdb: Remote Protocol gdb: Memory Map Format

gdb: Library List Format for SVR4 Targets

 
 E.15 Library List Format for SVR4 Targets
 =========================================
 
 On SVR4 platforms GDB can use the symbol table of a dynamic loader (e.g.
 'ld.so') and normal memory operations to maintain a list of shared
 libraries.  Still a special library list provided by this packet is more
 efficient for the GDB remote protocol.
 
    The 'qXfer:libraries-svr4:read' packet returns an XML document which
 lists loaded libraries and their SVR4 linker parameters.  For each
 library on SVR4 target, the following parameters are reported:
 
    - 'name', the absolute file name from the 'l_name' field of 'struct
      link_map'.
    - 'lm' with address of 'struct link_map' used for TLS (Thread Local
      Storage) access.
    - 'l_addr', the displacement as read from the field 'l_addr' of
      'struct link_map'.  For prelinked libraries this is not an absolute
      memory address.  It is a displacement of absolute memory address
      against address the file was prelinked to during the library load.
    - 'l_ld', which is memory address of the 'PT_DYNAMIC' segment
 
    Additionally the single 'main-lm' attribute specifies address of
 'struct link_map' used for the main executable.  This parameter is used
 for TLS access and its presence is optional.
 
    GDB must be linked with the Expat library to support XML SVR4 library
 lists.  Expat.
 
    A simple memory map, with two loaded libraries (which do not use
 prelink), looks like this:
 
      <library-list-svr4 version="1.0" main-lm="0xe4f8f8">
        <library name="/lib/ld-linux.so.2" lm="0xe4f51c" l_addr="0xe2d000"
                 l_ld="0xe4eefc"/>
        <library name="/lib/libc.so.6" lm="0xe4fbe8" l_addr="0x154000"
                 l_ld="0x152350"/>
      </library-list-svr>
 
    The format of an SVR4 library list is described by this DTD:
 
      <!-- library-list-svr4: Root element with versioning -->
      <!ELEMENT library-list-svr4  (library)*>
      <!ATTLIST library-list-svr4  version CDATA   #FIXED  "1.0">
      <!ATTLIST library-list-svr4  main-lm CDATA   #IMPLIED>
      <!ELEMENT library            EMPTY>
      <!ATTLIST library            name    CDATA   #REQUIRED>
      <!ATTLIST library            lm      CDATA   #REQUIRED>
      <!ATTLIST library            l_addr  CDATA   #REQUIRED>
      <!ATTLIST library            l_ld    CDATA   #REQUIRED>
 

Info Catalog gdb: Library List Format gdb: Remote Protocol gdb: Memory Map Format