62 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
			
		
		
	
	
			62 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
| /*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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| │vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
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| ╞══════════════════════════════════════════════════════════════════════════════╡
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| │ Copyright 2020 Justine Alexandra Roberts Tunney                              │
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| │                                                                              │
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| │ Permission to use, copy, modify, and/or distribute this software for         │
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| │ any purpose with or without fee is hereby granted, provided that the         │
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| │ above copyright notice and this permission notice appear in all copies.      │
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| │                                                                              │
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| │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
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| │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
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| │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
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| │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
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| │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
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| │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
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| │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
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| │ PERFORMANCE OF THIS SOFTWARE.                                                │
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| ╚─────────────────────────────────────────────────────────────────────────────*/
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| #define ShouldUseMsabiAttribute() 1
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| #include "libc/bits/bits.h"
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| #include "libc/calls/internal.h"
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| #include "libc/dce.h"
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| #include "libc/errno.h"
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| #include "libc/nt/memory.h"
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| #include "libc/nt/thunk/msabi.h"
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| #include "libc/sysv/consts/nr.h"
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| 
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| extern __msabi typeof(VirtualProtect) *const __imp_VirtualProtect;
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| 
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| /**
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|  * Modifies restrictions on virtual memory address range.
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|  *
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|  * @param prot can have PROT_{NONE,READ,WRITE,EXEC,GROWSDOWN}
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|  * @return 0 on success, or -1 w/ errno
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|  * @see mmap()
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|  */
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| int mprotect(void *addr, uint64_t len, int prot) {
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|   bool cf;
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|   int64_t rc;
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|   uint32_t oldprot;
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|   if (!IsWindows()) {
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|     asm volatile(CFLAG_ASM("syscall")
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|                  : CFLAG_CONSTRAINT(cf), "=a"(rc)
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|                  : "1"(__NR_mprotect), "D"(addr), "S"(len), "d"(prot)
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|                  : "rcx", "r11", "memory", "cc");
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|     if (cf) {
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|       rc = -rc;
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|       rc = -1;
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|     } else if (rc > -4096ul) {
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|       errno = -rc;
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|       rc = -1;
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|     }
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|     return rc;
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|   } else {
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|     if (__imp_VirtualProtect(addr, len, prot2nt(prot, 0), &oldprot)) {
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|       return 0;
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|     } else {
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|       return __winerr();
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|     }
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|   }
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| }
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