glibc/sysdeps/unix/sysv/linux/readonly-area.c
Paul Eggert 5a82c74822 Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:

sed -ri '
  s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
  s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
  $(find $(git ls-files) -prune -type f \
      ! -name '*.po' \
      ! -name 'ChangeLog*' \
      ! -path COPYING ! -path COPYING.LIB \
      ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
      ! -path manual/texinfo.tex ! -path scripts/config.guess \
      ! -path scripts/config.sub ! -path scripts/install-sh \
      ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
      ! -path INSTALL ! -path  locale/programs/charmap-kw.h \
      ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
      ! '(' -name configure \
            -execdir test -f configure.ac -o -f configure.in ';' ')' \
      ! '(' -name preconfigure \
            -execdir test -f preconfigure.ac ';' ')' \
      -print)

and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:

  chmod a+x sysdeps/unix/sysv/linux/riscv/configure
  # Omit irrelevant whitespace and comment-only changes,
  # perhaps from a slightly-different Autoconf version.
  git checkout -f \
    sysdeps/csky/configure \
    sysdeps/hppa/configure \
    sysdeps/riscv/configure \
    sysdeps/unix/sysv/linux/csky/configure
  # Omit changes that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
  git checkout -f \
    sysdeps/powerpc/powerpc64/ppc-mcount.S \
    sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
  # Omit change that caused a pre-commit check to fail like this:
  # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
  git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 02:43:31 -07:00

103 lines
2.7 KiB
C

/* Copyright (C) 2004-2019 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/>. */
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <string.h>
#include "libio/libioP.h"
/* Return 1 if the whole area PTR .. PTR+SIZE is not writable.
Return -1 if it is writable. */
int
__readonly_area (const char *ptr, size_t size)
{
const void *ptr_end = ptr + size;
FILE *fp = fopen ("/proc/self/maps", "rce");
if (fp == NULL)
{
/* It is the system administrator's choice to not have /proc
available to this process (e.g., because it runs in a chroot
environment. Don't fail in this case. */
if (errno == ENOENT
/* The kernel has a bug in that a process is denied access
to the /proc filesystem if it is set[ug]id. There has
been no willingness to change this in the kernel so
far. */
|| errno == EACCES)
return 1;
return -1;
}
/* We need no locking. */
__fsetlocking (fp, FSETLOCKING_BYCALLER);
char *line = NULL;
size_t linelen = 0;
while (! __feof_unlocked (fp))
{
if (_IO_getdelim (&line, &linelen, '\n', fp) <= 0)
break;
char *p;
uintptr_t from = strtoul (line, &p, 16);
if (p == line || *p++ != '-')
break;
char *q;
uintptr_t to = strtoul (p, &q, 16);
if (q == p || *q++ != ' ')
break;
if (from < (uintptr_t) ptr_end && to > (uintptr_t) ptr)
{
/* Found an entry that at least partially covers the area. */
if (*q++ != 'r' || *q++ != '-')
break;
if (from <= (uintptr_t) ptr && to >= (uintptr_t) ptr_end)
{
size = 0;
break;
}
else if (from <= (uintptr_t) ptr)
size -= to - (uintptr_t) ptr;
else if (to >= (uintptr_t) ptr_end)
size -= (uintptr_t) ptr_end - from;
else
size -= to - from;
if (!size)
break;
}
}
fclose (fp);
free (line);
/* If the whole area between ptr and ptr_end is covered by read-only
VMAs, return 1. Otherwise return -1. */
return size == 0 ? 1 : -1;
}