Mu - 020syscalls.cc

From 3350c34a74844e21ea69077e01efff3bae64bdcd Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Tue, 23 Mar 2021 17:31:08 -0700 Subject: . --- html/020syscalls.cc.html | 190 ----------------------------------------------- 1 file changed, 190 deletions(-) delete mode 100644 html/020syscalls.cc.html (limited to 'html/020syscalls.cc.html') diff --git a/html/020syscalls.cc.html b/html/020syscalls.cc.html deleted file mode 100644 index 4e744513..00000000 --- a/html/020syscalls.cc.html +++ /dev/null @@ -1,190 +0,0 @@ - - - - -Mu - 020syscalls.cc - - - - - - - - - - -https://github.com/akkartik/mu/blob/main/020syscalls.cc -
-  1 :(before "End Initialize Op Names")
-  2 put_new(Name, "cd", "software interrupt (int)");
-  3 
-  4 :(before "End Single-Byte Opcodes")
-  5 case 0xcd: {  // int imm8 (software interrupt)
-  6   trace(Callstack_depth+1, "run") << "syscall" << end();
-  7   uint8_t code = next();
-  8   if (code != 0x80) {
-  9     raise << "Unimplemented interrupt code " << HEXBYTE << code << '\n' << end();
- 10     raise << "  Only `int 80h` supported for now.\n" << end();
- 11     break;
- 12   }
- 13   process_int80();
- 14   break;
- 15 }
- 16 
- 17 :(code)
- 18 void process_int80() {
- 19   switch (Reg[EAX].u) {
- 20   case 1:
- 21     exit(/*exit code*/Reg[EBX].u);
- 22     break;
- 23   case 3:
- 24     trace(Callstack_depth+1, "run") << "read: " << Reg[EBX].u << ' ' << Reg[ECX].u << ' ' << Reg[EDX].u << end();
- 25     Reg[EAX].i = read(/*file descriptor*/Reg[EBX].u, /*memory buffer*/mem_addr_u8(Reg[ECX].u), /*size*/Reg[EDX].u);
- 26     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 27     if (Reg[EAX].i == -1) raise << "read: " << strerror(errno) << '\n' << end();
- 28     break;
- 29   case 4:
- 30     trace(Callstack_depth+1, "run") << "write: " << Reg[EBX].u << ' ' << Reg[ECX].u << ' ' << Reg[EDX].u << end();
- 31     trace(Callstack_depth+1, "run") << Reg[ECX].u << " => " << mem_addr_string(Reg[ECX].u, Reg[EDX].u) << end();
- 32     Reg[EAX].i = write(/*file descriptor*/Reg[EBX].u, /*memory buffer*/mem_addr_u8(Reg[ECX].u), /*size*/Reg[EDX].u);
- 33     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 34     if (Reg[EAX].i == -1) raise << "write: " << strerror(errno) << '\n' << end();
- 35     break;
- 36   case 5: {
- 37     check_flags(ECX);
- 38     check_mode(EDX);
- 39     trace(Callstack_depth+1, "run") << "open: " << Reg[EBX].u << ' ' << Reg[ECX].u << end();
- 40     trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end();
- 41     Reg[EAX].i = open(/*filename*/mem_addr_kernel_string(Reg[EBX].u), /*flags*/Reg[ECX].u, /*mode*/0640);
- 42     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 43     if (Reg[EAX].i == -1) raise << "open: " << strerror(errno) << '\n' << end();
- 44     break;
- 45   }
- 46   case 6:
- 47     trace(Callstack_depth+1, "run") << "close: " << Reg[EBX].u << end();
- 48     Reg[EAX].i = close(/*file descriptor*/Reg[EBX].u);
- 49     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 50     if (Reg[EAX].i == -1) raise << "close: " << strerror(errno) << '\n' << end();
- 51     break;
- 52   case 8:
- 53     check_mode(ECX);
- 54     trace(Callstack_depth+1, "run") << "creat: " << Reg[EBX].u << end();
- 55     trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end();
- 56     Reg[EAX].i = creat(/*filename*/mem_addr_kernel_string(Reg[EBX].u), /*mode*/0640);
- 57     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 58     if (Reg[EAX].i == -1) raise << "creat: " << strerror(errno) << '\n' << end();
- 59     break;
- 60   case 10:
- 61     trace(Callstack_depth+1, "run") << "unlink: " << Reg[EBX].u << end();
- 62     trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end();
- 63     Reg[EAX].i = unlink(/*filename*/mem_addr_kernel_string(Reg[EBX].u));
- 64     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 65     if (Reg[EAX].i == -1) raise << "unlink: " << strerror(errno) << '\n' << end();
- 66     break;
- 67   case 38:
- 68     trace(Callstack_depth+1, "run") << "rename: " << Reg[EBX].u << " -> " << Reg[ECX].u << end();
- 69     trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end();
- 70     trace(Callstack_depth+1, "run") << Reg[ECX].u << " => " << mem_addr_kernel_string(Reg[ECX].u) << end();
- 71     Reg[EAX].i = rename(/*old filename*/mem_addr_kernel_string(Reg[EBX].u), /*new filename*/mem_addr_kernel_string(Reg[ECX].u));
- 72     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end();
- 73     if (Reg[EAX].i == -1) raise << "rename: " << strerror(errno) << '\n' << end();
- 74     break;
- 75   case 90:  // mmap: allocate memory outside existing segment allocations
- 76     trace(Callstack_depth+1, "run") << "mmap: allocate new segment" << end();
- 77     // Ignore most arguments for now: address hint, protection flags, sharing flags, fd, offset.
- 78     // We only support anonymous maps.
- 79     Reg[EAX].u = new_segment(/*length*/read_mem_u32(Reg[EBX].u+0x4));
- 80     trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].u << end();
- 81     break;
- 82   case 0xa2:  // nanosleep
- 83     cerr << "not sleeping\n";
- 84     break;
- 85   default:
- 86     raise << HEXWORD << EIP << ": unimplemented syscall " << Reg[EAX].u << '\n' << end();
- 87   }
- 88 }
- 89 
- 90 // SubX is oblivious to file permissions, directories, symbolic links, terminals, and much else besides.
- 91 // Also ignoring any concurrency considerations for now.
- 92 void check_flags(int reg) {
- 93   uint32_t flags = Reg[reg].u;
- 94   if (flags != ((flags & O_RDONLY) | (flags & O_WRONLY))) {
- 95     cerr << HEXWORD << EIP << ": most POSIX flags to the open() syscall are not supported. Just O_RDONLY and O_WRONLY for now. Zero concurrent access support.\n";
- 96     exit(1);
- 97   }
- 98   if ((flags & O_RDONLY) && (flags & O_WRONLY)) {
- 99     cerr << HEXWORD << EIP << ": can't open a file for both reading and writing at once. See http://man7.org/linux/man-pages/man2/open.2.html.\n";
-100     exit(1);
-101   }
-102 }
-103 
-104 void check_mode(int reg) {
-105   if (Reg[reg].u != 0600) {
-106     cerr << HEXWORD << EIP << ": SubX is oblivious to file permissions; register " << reg << " must be 0x180.\n";
-107     exit(1);
-108   }
-109 }
-110 
-111 :(before "End Globals")
-112 // Very primitive/fixed/insecure mmap segments for now.
-113 uint32_t Segments_allocated_above = END_HEAP;
-114 :(code)
-115 // always allocate multiples of the segment size
-116 uint32_t new_segment(uint32_t length) {
-117   assert(length > 0);
-118   uint32_t result = (Segments_allocated_above - length) & 0xff000000;  // same number of zeroes as SEGMENT_ALIGNMENT
-119   if (result <= START_HEAP) {
-120     raise << "Allocated too many segments; the VM ran out of memory. "
-121           << "Maybe SEGMENT_ALIGNMENT can be smaller?\n" << die();
-122   }
-123   Mem.push_back(vma(result, result+length));
-124   Segments_allocated_above = result;
-125   return result;
-126 }
-
- - - -- cgit 1.4.1-2-gfad0