diff options
| author | Thomas Voss <mail@thomasvoss.com> | 2024-02-16 21:05:28 +0100 |
|---|---|---|
| committer | Thomas Voss <mail@thomasvoss.com> | 2024-02-16 21:05:28 +0100 |
| commit | 5e8ac2432d5d1b327be9b8d406b78f008c77bcd5 (patch) | |
| tree | 2b401a628afe5d4640027bc94ee14b71606b9777 /src | |
| parent | b490528bd4097030298bd251fdef2c74a4bfb14b (diff) | |
Add extra bounds checking
Diffstat (limited to 'src')
| -rw-r--r-- | src/ahoy/emulator.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/ahoy/emulator.c b/src/ahoy/emulator.c index cffc4a9..f774b54 100644 --- a/src/ahoy/emulator.c +++ b/src/ahoy/emulator.c @@ -66,6 +66,8 @@ emuinit(struct u8view prog, const char *fn) void emutick(void) { + if ((size_t)c8.PC + 1 >= lengthof(mem)) + diex("%s: attempted to read instruction beyond end of RAM", filename); opexec((mem[c8.PC] << 8) | mem[c8.PC + 1]); c8.PC += 2; } @@ -209,8 +211,10 @@ opexec(uint16_t op) unsigned y = (op & 0x00F0) >> 4; unsigned n = (op & 0x000F) >> 0; + if (c8.I + n > lengthof(mem)) + diex("%s: attempted to draw sprite beyond bounds of RAM", filename); + for (unsigned i = 0; i < n; i++) { - /* TODO: bounds check? */ uint8_t spr_row = mem[c8.I + i]; uint8_t scr_row = c8.V[y] + i; uint64_t msk; |