DL_ITERATE_PHDR(3)     FreeBSD 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
     implementation of dl_iterate_phdr() from libc.

SYNOPSIS
     #include <link.h>

     int
     dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),)(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 calling thread' TLS data segment for
                     this module, if it was allocated, NULL otherwise.

     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.

FreeBSD 13.1-RELEASE-p6          April 5, 2021         FreeBSD 13.1-RELEASE-p6