authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2025-07-09 10:47:36-07:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2025-07-09 10:47:36-07:00
log5bc95a6fa2af86689c37a87a5899e7e34d6084ee
tree69a32d806f4a84a3891d4daa0f7b5f370b677440
parent5c6679922d69285ebf807b268d8ca10cf1dbe4c0

wasi.c: fix pread/pwrite

When stream is NULL it means reads should read 0 bytes and writes should fake success with no side effects.

1 files changed, 18 insertions(+), 6 deletions(-)

stage1/wasi.c+18-6
......@@ -520,12 +520,15 @@ uint32_t wasi_snapshot_preview1_fd_read(uint32_t fd, uint32_t iovs, uint32_t iov
520520 default: panic("unimplemented: fd_read special file");
521521 }
522522
523 if (fds[fd].stream == NULL) {
524 store32_align2(res_size_ptr, 0);
525 return wasi_errno_success;
526 }
527
523528 size_t size = 0;
524529 for (uint32_t i = 0; i < iovs_len; i += 1) {
525530 uint32_t len = load32_align2(&iovs_ptr[i].len);
526 size_t read_size = 0;
527 if (fds[fd].stream != NULL)
528 read_size = fread(&m[load32_align2(&iovs_ptr[i].ptr)], 1, len, fds[fd].stream);
531 size_t read_size = fread(&m[load32_align2(&iovs_ptr[i].ptr)], 1, len, fds[fd].stream);
529532 size += read_size;
530533 if (read_size < len) break;
531534 }
......@@ -633,8 +636,10 @@ uint32_t wasi_snapshot_preview1_fd_pwrite(uint32_t fd, uint32_t iovs, uint32_t i
633636 }
634637
635638 fpos_t pos;
636 if (fgetpos(fds[fd].stream, &pos) < 0) return wasi_errno_io;
637 if (fseek(fds[fd].stream, offset, SEEK_SET) < 0) return wasi_errno_io;
639 if (fds[fd].stream != NULL) {
640 if (fgetpos(fds[fd].stream, &pos) < 0) return wasi_errno_io;
641 if (fseek(fds[fd].stream, offset, SEEK_SET) < 0) return wasi_errno_io;
642 }
638643
639644 size_t size = 0;
640645 for (uint32_t i = 0; i < iovs_len; i += 1) {
......@@ -648,7 +653,9 @@ uint32_t wasi_snapshot_preview1_fd_pwrite(uint32_t fd, uint32_t iovs, uint32_t i
648653 if (written_size < len) break;
649654 }
650655
651 if (fsetpos(fds[fd].stream, &pos) < 0) return wasi_errno_io;
656 if (fds[fd].stream != NULL) {
657 if (fsetpos(fds[fd].stream, &pos) < 0) return wasi_errno_io;
658 }
652659
653660 if (size > 0) {
654661 time_t now = time(NULL);
......@@ -964,6 +971,11 @@ uint32_t wasi_snapshot_preview1_fd_pread(uint32_t fd, uint32_t iovs, uint32_t io
964971 default: panic("unimplemented: fd_pread special file");
965972 }
966973
974 if (fds[fd].stream == NULL) {
975 store32_align2(res_size_ptr, 0);
976 return wasi_errno_success;
977 }
978
967979 fpos_t pos;
968980 if (fgetpos(fds[fd].stream, &pos) < 0) return wasi_errno_io;
969981 if (fseek(fds[fd].stream, offset, SEEK_SET) < 0) return wasi_errno_io;