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			50 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			50 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Utilities functions to name memory mappings.
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|    Copyright (C) 2023-2024 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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| 
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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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| 
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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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| 
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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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| 
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| #include <ldsodefs.h>
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| #include <setvmaname.h>
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| #include <sys/prctl.h>
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| #include <sysdep.h>
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| #include <elf/dl-tunables.h>
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| 
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| /* If PR_SET_VMA_ANON_NAME is not supported by the kernel, prctl returns
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|    EINVAL.  However, it also returns the same error for invalid argument.
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|    Since it is an internal-only API, it assumes well formatted input:
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|    aligned START, with (START, START+LEN) being a valid memory range,
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|    and NAME with a limit of 80 characters without invalid one ("\\`$[]").  */
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| 
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| void
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| __set_vma_name (void *start, size_t len, const char *name)
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| {
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|   static int prctl_supported = 1;
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|   if (atomic_load_relaxed (&prctl_supported) == 0)
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|     return;
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| 
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|   /* Set the prctl as not supported to avoid checking the tunable on every
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|      call.  */
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|   if (TUNABLE_GET (glibc, mem, decorate_maps, int32_t, NULL) != 0)
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|     {
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|       int r = INTERNAL_SYSCALL_CALL (prctl, PR_SET_VMA, PR_SET_VMA_ANON_NAME,
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| 				     start, len, name);
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|       if (r == 0 || r != -EINVAL)
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| 	return;
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|     }
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|   atomic_store_relaxed (&prctl_supported, 0);
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|   return;
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| }
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