freebsd man page for dl_iterate_phdr

DL_ITERATE_PHDR(3)					   BSD Library Functions Manual 					DL_ITERATE_PHDR(3)

NAME
     dl_iterate_phdr -- iterate over program headers

LIBRARY
     For the dynamically linked binaries, the service is provided by ld-elf.so.1(1) dynamic linker.  Statically linked programs use an implementa-
     tion of dl_iterate_phdr() from libc.

SYNOPSIS
     #include <link.h>

     int
     dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), void *data);

DESCRIPTION
     The dl_iterate_phdr() function iterates over all ELF objects loaded into a process's address space, calling callback for each object, passing
     it information about the object's program headers and the data argument.  The iteration is aborted when all objects are passed, or when the
     next callback call returns non-zero value.  The information about the program headers is passed in a structure that is defined as:

     struct dl_phdr_info {
	     Elf_Addr	     dlpi_addr;
	     const char      *dlpi_name;
	     const Elf_Phdr  *dlpi_phdr;
	     Elf_Half	     dlpi_phnum;
	     unsigned long long int dlpi_adds;
	     unsigned long long int dlpi_subs;
	     size_t	     dlpi_tls_modid;
	     void	     *dlpi_tls_data;
     };

     The members of struct dl_phdr_info have the following meaning:

     dlpi_addr	     The base address at which the object is mapped into the address space of the calling process.

     dlpi_name	     The pathname of the ELF object.

     dlpi_phdr	     A pointer to the object's program headers.

     dlpi_phnum      The number of program headers in the object.

     dlpi_adds	     The counter of the object loads performed by the dynamic linker.

     dlpi_subs	     The counter of the object unloads performed by the dynamic linker.

     dlpi_tls_modid  The TLS index of the object.

     dlpi_tls_data   A pointer to the initialization data for the object TLS segment.

     Future versions of FreeBSD might add more members to this structure.  To make it possible for programs to check whether any new members have
     been added, the size of the structure is passed as an second argument to callback.

     The third argument to callback is the data value passed to the call to dl_iterate_phdr(), allowing the callback to have a context.

RETURN VALUES
     The dl_iterate_phdr() returns the value returned by the last callback call executed.

SEE ALSO
     ld(1), ld-elf.so.1(1), dlopen(3), elf(5)

HISTORY
     The dl_iterate_phdr function first appeared in FreeBSD 7.0.

BSD
								  October 9, 2014							       BSD