From c88b9e31259d433c7e63fcb19d430daf9b1c723c Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Fri, 10 May 2019 16:45:22 -0700 Subject: 5151 - use mmap everywhere we need a heap All tests passing now. Things are very explicit; before a program can `allocate` memory, it has to first obtain a segment from the OS using `new-segment`. --- subx/020syscalls.cc | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'subx/020syscalls.cc') diff --git a/subx/020syscalls.cc b/subx/020syscalls.cc index a17e9525..6b9faa2c 100644 --- a/subx/020syscalls.cc +++ b/subx/020syscalls.cc @@ -24,14 +24,14 @@ void process_int80() { trace(Callstack_depth+1, "run") << "read: " << Reg[EBX].u << ' ' << Reg[ECX].u << ' ' << Reg[EDX].u << end(); Reg[EAX].i = read(/*file descriptor*/Reg[EBX].u, /*memory buffer*/mem_addr_u8(Reg[ECX].u), /*size*/Reg[EDX].u); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "read: " << strerror(errno) << '\n' << end(); break; case 4: trace(Callstack_depth+1, "run") << "write: " << Reg[EBX].u << ' ' << Reg[ECX].u << ' ' << Reg[EDX].u << end(); trace(Callstack_depth+1, "run") << Reg[ECX].u << " => " << mem_addr_string(Reg[ECX].u, Reg[EDX].u) << end(); Reg[EAX].i = write(/*file descriptor*/Reg[EBX].u, /*memory buffer*/mem_addr_u8(Reg[ECX].u), /*size*/Reg[EDX].u); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "write: " << strerror(errno) << '\n' << end(); break; case 5: { check_flags(ECX); @@ -40,14 +40,14 @@ void process_int80() { trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end(); Reg[EAX].i = open(/*filename*/mem_addr_kernel_string(Reg[EBX].u), /*flags*/Reg[ECX].u, /*mode*/0640); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "open: " << strerror(errno) << '\n' << end(); break; } case 6: trace(Callstack_depth+1, "run") << "close: " << Reg[EBX].u << end(); Reg[EAX].i = close(/*file descriptor*/Reg[EBX].u); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "close: " << strerror(errno) << '\n' << end(); break; case 8: check_mode(ECX); @@ -55,14 +55,14 @@ void process_int80() { trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end(); Reg[EAX].i = creat(/*filename*/mem_addr_kernel_string(Reg[EBX].u), /*mode*/0640); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "creat: " << strerror(errno) << '\n' << end(); break; case 10: trace(Callstack_depth+1, "run") << "unlink: " << Reg[EBX].u << end(); trace(Callstack_depth+1, "run") << Reg[EBX].u << " => " << mem_addr_kernel_string(Reg[EBX].u) << end(); Reg[EAX].i = unlink(/*filename*/mem_addr_kernel_string(Reg[EBX].u)); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "unlink: " << strerror(errno) << '\n' << end(); break; case 38: trace(Callstack_depth+1, "run") << "rename: " << Reg[EBX].u << " -> " << Reg[ECX].u << end(); @@ -70,7 +70,7 @@ void process_int80() { trace(Callstack_depth+1, "run") << Reg[ECX].u << " => " << mem_addr_kernel_string(Reg[ECX].u) << end(); Reg[EAX].i = rename(/*old filename*/mem_addr_kernel_string(Reg[EBX].u), /*new filename*/mem_addr_kernel_string(Reg[ECX].u)); trace(Callstack_depth+1, "run") << "result: " << Reg[EAX].i << end(); - if (Reg[EAX].i == -1) raise << strerror(errno) << '\n' << end(); + if (Reg[EAX].i == -1) raise << "rename: " << strerror(errno) << '\n' << end(); break; case 45: // brk: modify size of data segment trace(Callstack_depth+1, "run") << "grow data segment to " << Reg[EBX].u << end(); @@ -110,7 +110,12 @@ void check_mode(int reg) { } :(before "End Globals") -uint32_t Next_segment = 0xb0000000; // 0xc0000000 and up is reserved for Linux kernel +// Very primitive/fixed/insecure mmap segments for now. +// For now we avoid addresses with the most significant bit set; SubX doesn't +// support unsigned comparison yet (https://github.com/akkartik/mu/issues/30) +// Once we do, we can go up to 0xc0000000; higher addresses are reserved for +// the Linux kernel. +uint32_t Next_segment = 0x7c000000; const uint32_t SPACE_FOR_SEGMENT = 0x01000000; :(code) uint32_t new_segment(uint32_t length) { -- cgit 1.4.1-2-gfad0