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| author | Kartik Agaram <vc@akkartik.com> | 2019-05-11 22:44:49 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-05-11 22:44:49 -0700 |
| commit | e59a74abddaf0b4f9a39432da21c6a98eae46df6 (patch) | |
| tree | b21109b5889dcdb9011e5a8559e7fb8e0ba00c4c /subx/062write-stream.subx | |
| parent | 6362c51d11ef27335875469e0ff06347357f46b1 (diff) | |
| download | mu-e59a74abddaf0b4f9a39432da21c6a98eae46df6.tar.gz | |
5156 - error-checking on writes to file
Pretty blunt for now; just abort the entire program on any failure to write. I'm encountering it because I'm somehow treating a stream address as a file descriptor. Maybe mmap is returning addresses below 0x08000000?
Diffstat (limited to 'subx/062write-stream.subx')
| -rw-r--r-- | subx/062write-stream.subx | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/subx/062write-stream.subx b/subx/062write-stream.subx index eb2df0c5..83268422 100644 --- a/subx/062write-stream.subx +++ b/subx/062write-stream.subx @@ -102,6 +102,9 @@ _write-stream: # fd : int, s : (address stream) -> <void> # . . syscall b8/copy-to-EAX 4/imm32/write cd/syscall 0x80/imm8 + # if (EAX < 0) abort + 3d/compare-EAX-with 0/imm32 + 0f 8c/jump-if-lesser $_write-stream:abort/disp32 # s->read += EAX 01/add 1/mod/*+disp8 6/rm32/ESI . . . 0/r32/EAX 4/disp8 . # add EAX to *(ESI+4) # . restore registers @@ -116,6 +119,21 @@ _write-stream: # fd : int, s : (address stream) -> <void> 5d/pop-to-EBP c3/return +$_write-stream:abort: + # . _write(2/stderr, error) + # . . push args + 68/push "_write-stream: failed to write to file"/imm32 + 68/push 2/imm32/stderr + # . . call + e8/call _write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # . syscall(exit, 1) + bb/copy-to-EBX 1/imm32 + b8/copy-to-EAX 1/imm32/exit + cd/syscall 0x80/imm8 + # never gets here + test-write-stream-single: # setup # . clear-stream(_test-stream) |