glibc/elf/pldd-xx.c
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30

217 lines
5.8 KiB
C

/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#define E(name) E_(name, CLASS)
#define E_(name, cl) E__(name, cl)
#define E__(name, cl) name##cl
#define EW(type) EW_(Elf, CLASS, type)
#define EW_(e, w, t) EW__(e, w, _##t)
#define EW__(e, w, t) e##w##t
struct E(link_map)
{
EW(Addr) l_addr;
EW(Addr) l_name;
EW(Addr) l_ld;
EW(Addr) l_next;
EW(Addr) l_prev;
EW(Addr) l_real;
Lmid_t l_ns;
EW(Addr) l_libname;
};
#if CLASS == __ELF_NATIVE_CLASS
_Static_assert (offsetof (struct link_map, l_addr)
== offsetof (struct E(link_map), l_addr), "l_addr");
_Static_assert (offsetof (struct link_map, l_name)
== offsetof (struct E(link_map), l_name), "l_name");
_Static_assert (offsetof (struct link_map, l_next)
== offsetof (struct E(link_map), l_next), "l_next");
#endif
struct E(libname_list)
{
EW(Addr) name;
EW(Addr) next;
};
#if CLASS == __ELF_NATIVE_CLASS
_Static_assert (offsetof (struct libname_list, name)
== offsetof (struct E(libname_list), name), "name");
_Static_assert (offsetof (struct libname_list, next)
== offsetof (struct E(libname_list), next), "next");
#endif
struct E(r_debug)
{
int r_version;
#if CLASS == 64
int pad;
#endif
EW(Addr) r_map;
};
#if CLASS == __ELF_NATIVE_CLASS
_Static_assert (offsetof (struct r_debug, r_version)
== offsetof (struct E(r_debug), r_version), "r_version");
_Static_assert (offsetof (struct r_debug, r_map)
== offsetof (struct E(r_debug), r_map), "r_map");
#endif
static int
E(find_maps) (const char *exe, int memfd, pid_t pid, void *auxv,
size_t auxv_size)
{
EW(Addr) phdr = 0;
unsigned int phnum = 0;
unsigned int phent = 0;
EW(auxv_t) *auxvXX = (EW(auxv_t) *) auxv;
for (int i = 0; i < auxv_size / sizeof (EW(auxv_t)); ++i)
switch (auxvXX[i].a_type)
{
case AT_PHDR:
phdr = auxvXX[i].a_un.a_val;
break;
case AT_PHNUM:
phnum = auxvXX[i].a_un.a_val;
break;
case AT_PHENT:
phent = auxvXX[i].a_un.a_val;
break;
default:
break;
}
if (phdr == 0 || phnum == 0 || phent == 0)
error (EXIT_FAILURE, 0, gettext ("cannot find program header of process"));
EW(Phdr) *p = xmalloc (phnum * phent);
if (pread (memfd, p, phnum * phent, phdr) != phnum * phent)
error (EXIT_FAILURE, 0, gettext ("cannot read program header"));
/* Determine the load offset. We need this for interpreting the
other program header entries so we do this in a separate loop.
Fortunately it is the first time unless someone does something
stupid when linking the application. */
EW(Addr) offset = 0;
for (unsigned int i = 0; i < phnum; ++i)
if (p[i].p_type == PT_PHDR)
{
offset = phdr - p[i].p_vaddr;
break;
}
EW(Addr) list = 0;
char *interp = NULL;
for (unsigned int i = 0; i < phnum; ++i)
if (p[i].p_type == PT_DYNAMIC)
{
EW(Dyn) *dyn = xmalloc (p[i].p_filesz);
if (pread (memfd, dyn, p[i].p_filesz, offset + p[i].p_vaddr)
!= p[i].p_filesz)
error (EXIT_FAILURE, 0, gettext ("cannot read dynamic section"));
/* Search for the DT_DEBUG entry. */
for (unsigned int j = 0; j < p[i].p_filesz / sizeof (EW(Dyn)); ++j)
if (dyn[j].d_tag == DT_DEBUG && dyn[j].d_un.d_ptr != 0)
{
struct E(r_debug) r;
if (pread (memfd, &r, sizeof (r), dyn[j].d_un.d_ptr)
!= sizeof (r))
error (EXIT_FAILURE, 0, gettext ("cannot read r_debug"));
if (r.r_map != 0)
{
list = r.r_map;
break;
}
}
free (dyn);
break;
}
else if (p[i].p_type == PT_INTERP)
{
interp = xmalloc (p[i].p_filesz);
if (pread (memfd, interp, p[i].p_filesz, offset + p[i].p_vaddr)
!= p[i].p_filesz)
error (EXIT_FAILURE, 0, gettext ("cannot read program interpreter"));
}
if (list == 0)
{
if (interp == NULL)
{
// XXX check whether the executable itself is the loader
exit (EXIT_FAILURE);
}
// XXX perhaps try finding ld.so and _r_debug in it
exit (EXIT_FAILURE);
}
free (p);
free (interp);
/* Print the PID and program name first. */
printf ("%lu:\t%s\n", (unsigned long int) pid, exe);
/* Iterate over the list of objects and print the information. */
struct scratch_buffer tmpbuf;
scratch_buffer_init (&tmpbuf);
int status = 0;
do
{
struct E(link_map) m;
if (pread (memfd, &m, sizeof (m), list) != sizeof (m))
error (EXIT_FAILURE, 0, gettext ("cannot read link map"));
EW(Addr) name_offset = m.l_name;
while (1)
{
ssize_t n = pread (memfd, tmpbuf.data, tmpbuf.length, name_offset);
if (n == -1)
error (EXIT_FAILURE, 0, gettext ("cannot read object name"));
if (memchr (tmpbuf.data, '\0', n) != NULL)
break;
if (!scratch_buffer_grow (&tmpbuf))
error (EXIT_FAILURE, 0,
gettext ("cannot allocate buffer for object name"));
}
/* The m.l_name and m.l_libname.name for loader linkmap points to same
values (since BZ#387 fix). Trying to use l_libname name as the
shared object name might lead to an infinite loop (BZ#18035). */
/* Skip over the executable. */
if (((char *)tmpbuf.data)[0] != '\0')
printf ("%s\n", (char *)tmpbuf.data);
list = m.l_next;
}
while (list != 0);
scratch_buffer_free (&tmpbuf);
return status;
}
#undef CLASS