1 //===-- trusty.cpp ---------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "platform.h"
10 
11 #if SCUDO_TRUSTY
12 
13 #include "common.h"
14 #include "mutex.h"
15 #include "string_utils.h"
16 #include "trusty.h"
17 
18 #include <errno.h>           // for errno
19 #include <stdio.h>           // for printf()
20 #include <stdlib.h>          // for getenv()
21 #include <sys/auxv.h>        // for getauxval()
22 #include <time.h>            // for clock_gettime()
23 #include <trusty_syscalls.h> // for _trusty_brk()
24 
25 #define SBRK_ALIGN 32
26 
27 namespace scudo {
28 
29 uptr getPageSize() { return getauxval(AT_PAGESZ); }
30 
31 void NORETURN die() { abort(); }
32 
33 void *map(UNUSED void *Addr, uptr Size, UNUSED const char *Name, uptr Flags,
34           UNUSED MapPlatformData *Data) {
35   // Calling _trusty_brk(0) returns the current program break.
36   uptr ProgramBreak = reinterpret_cast<uptr>(_trusty_brk(0));
37   uptr Start;
38   uptr End;
39 
40   Start = roundUpTo(ProgramBreak, SBRK_ALIGN);
41   // Don't actually extend the heap if MAP_NOACCESS flag is set since this is
42   // the case where Scudo tries to reserve a memory region without mapping
43   // physical pages.
44   if (Flags & MAP_NOACCESS)
45     return reinterpret_cast<void *>(Start);
46 
47   // Attempt to extend the heap by Size bytes using _trusty_brk.
48   End = roundUpTo(Start + Size, SBRK_ALIGN);
49   ProgramBreak =
50       reinterpret_cast<uptr>(_trusty_brk(reinterpret_cast<void *>(End)));
51   if (ProgramBreak < End) {
52     errno = ENOMEM;
53     dieOnMapUnmapError(Size);
54     return nullptr;
55   }
56   return reinterpret_cast<void *>(Start); // Base of new reserved region.
57 }
58 
59 // Unmap is a no-op since Trusty uses sbrk instead of memory mapping.
60 void unmap(UNUSED void *Addr, UNUSED uptr Size, UNUSED uptr Flags,
61            UNUSED MapPlatformData *Data) {}
62 
63 void setMemoryPermission(UNUSED uptr Addr, UNUSED uptr Size, UNUSED uptr Flags,
64                          UNUSED MapPlatformData *Data) {}
65 
66 void releasePagesToOS(UNUSED uptr BaseAddress, UNUSED uptr Offset,
67                       UNUSED uptr Size, UNUSED MapPlatformData *Data) {}
68 
69 const char *getEnv(const char *Name) { return getenv(Name); }
70 
71 // All mutex operations are a no-op since Trusty doesn't currently support
72 // threads.
73 bool HybridMutex::tryLock() { return true; }
74 
75 void HybridMutex::lockSlow() {}
76 
77 void HybridMutex::unlock() {}
78 
79 u64 getMonotonicTime() {
80   timespec TS;
81   clock_gettime(CLOCK_MONOTONIC, &TS);
82   return static_cast<u64>(TS.tv_sec) * (1000ULL * 1000 * 1000) +
83          static_cast<u64>(TS.tv_nsec);
84 }
85 
86 u32 getNumberOfCPUs() { return 0; }
87 
88 u32 getThreadID() { return 0; }
89 
90 bool getRandom(UNUSED void *Buffer, UNUSED uptr Length, UNUSED bool Blocking) {
91   return false;
92 }
93 
94 void outputRaw(const char *Buffer) { printf("%s", Buffer); }
95 
96 void setAbortMessage(UNUSED const char *Message) {}
97 
98 } // namespace scudo
99 
100 #endif // SCUDO_TRUSTY
101