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	I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
		
			
				
	
	
		
			120 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			120 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* Stack executability handling for GNU dynamic linker.  Linux version.
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   Copyright (C) 2003-2022 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library is distributed in the hope that it will be useful,
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   but WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, see
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   <https://www.gnu.org/licenses/>.  */
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#include <errno.h>
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#include <ldsodefs.h>
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#include <libintl.h>
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#include <list.h>
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#include <pthreadP.h>
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#include <stackinfo.h>
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#include <stdbool.h>
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#include <sys/mman.h>
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#include <sysdep.h>
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#include <unistd.h>
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extern int __stack_prot attribute_relro attribute_hidden;
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static int
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make_main_stack_executable (void **stack_endp)
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{
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  /* This gives us the highest/lowest page that needs to be changed.  */
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  uintptr_t page = ((uintptr_t) *stack_endp
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		    & -(intptr_t) GLRO(dl_pagesize));
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  int result = 0;
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  if (__builtin_expect (__mprotect ((void *) page, GLRO(dl_pagesize),
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				    __stack_prot) == 0, 1))
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    goto return_success;
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  result = errno;
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  goto out;
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 return_success:
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  /* Clear the address.  */
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  *stack_endp = NULL;
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  /* Remember that we changed the permission.  */
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  GL(dl_stack_flags) |= PF_X;
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 out:
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#ifdef check_consistency
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  check_consistency ();
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#endif
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  return result;
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}
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int
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_dl_make_stacks_executable (void **stack_endp)
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{
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  /* First the main thread's stack.  */
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  int err = make_main_stack_executable (stack_endp);
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  if (err != 0)
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    return err;
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  lll_lock (GL (dl_stack_cache_lock), LLL_PRIVATE);
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  list_t *runp;
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  list_for_each (runp, &GL (dl_stack_used))
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    {
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      err = __nptl_change_stack_perm (list_entry (runp, struct pthread, list));
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      if (err != 0)
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	break;
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    }
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  /* Also change the permission for the currently unused stacks.  This
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     might be wasted time but better spend it here than adding a check
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     in the fast path.  */
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  if (err == 0)
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    list_for_each (runp, &GL (dl_stack_cache))
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      {
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	err = __nptl_change_stack_perm (list_entry (runp, struct pthread,
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						    list));
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	if (err != 0)
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	  break;
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      }
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  lll_unlock (GL (dl_stack_cache_lock), LLL_PRIVATE);
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  return err;
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}
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int
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__nptl_change_stack_perm (struct pthread *pd)
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{
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#ifdef NEED_SEPARATE_REGISTER_STACK
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  size_t pagemask = __getpagesize () - 1;
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  void *stack = (pd->stackblock
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		 + (((((pd->stackblock_size - pd->guardsize) / 2)
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		      & pagemask) + pd->guardsize) & pagemask));
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  size_t len = pd->stackblock + pd->stackblock_size - stack;
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#elif _STACK_GROWS_DOWN
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  void *stack = pd->stackblock + pd->guardsize;
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  size_t len = pd->stackblock_size - pd->guardsize;
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#elif _STACK_GROWS_UP
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  void *stack = pd->stackblock;
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  size_t len = (uintptr_t) pd - pd->guardsize - (uintptr_t) pd->stackblock;
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#else
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# error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
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#endif
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  if (__mprotect (stack, len, PROT_READ | PROT_WRITE | PROT_EXEC) != 0)
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    return errno;
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  return 0;
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}
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rtld_hidden_def (__nptl_change_stack_perm)
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