Reviewed-by: Xingtao Yao
> -Original Message-
> From: Gregor Haas
> Sent: Saturday, June 29, 2024 2:27 AM
> To: qemu-devel@nongnu.org
> Cc: berra...@redhat.com; Yao, Xingtao/姚 幸涛 ;
> Gregor Haas
> Subject: [PATCH v4] hw/core/loader: allow loading larger ROMs
>
> The read() syscall is not guaranteed to return all data from a file. The
> default ROM loader implementation currently does not take this into account,
> instead failing if all bytes are not read at once. This change loads the ROM
> using g_file_get_contents() instead, which correctly reads all data using
> multiple calls to read() while also returning the loaded ROM size.
>
> Signed-off-by: Gregor Haas
> ---
> hw/core/loader.c | 30 +-
> 1 file changed, 5 insertions(+), 25 deletions(-)
>
> diff --git a/hw/core/loader.c b/hw/core/loader.c
> index 2f8105d7de..4a5714 100644
> --- a/hw/core/loader.c
> +++ b/hw/core/loader.c
> @@ -1075,8 +1075,7 @@ ssize_t rom_add_file(const char *file, const char
> *fw_dir,
> {
> MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
> Rom *rom;
> -ssize_t rc;
> -int fd = -1;
> +g_autoptr(GError) gerr = NULL;
> char devpath[100];
>
> if (as && mr) {
> @@ -1094,35 +1093,19 @@ ssize_t rom_add_file(const char *file, const char
> *fw_dir,
> rom->path = g_strdup(file);
> }
>
> -fd = open(rom->path, O_RDONLY | O_BINARY);
> -if (fd == -1) {
> -fprintf(stderr, "Could not open option rom '%s': %s\n",
> -rom->path, strerror(errno));
> -goto err;
> -}
> -
> if (fw_dir) {
> rom->fw_dir = g_strdup(fw_dir);
> rom->fw_file = g_strdup(file);
> }
> rom->addr = addr;
> -rom->romsize = lseek(fd, 0, SEEK_END);
> -if (rom->romsize == -1) {
> -fprintf(stderr, "rom: file %-20s: get size error: %s\n",
> -rom->name, strerror(errno));
> +if (!g_file_get_contents(rom->path, (gchar **) >data,
> + >romsize, )) {
> +fprintf(stderr, "rom: file %-20s: error %s\n",
> +rom->name, gerr->message);
> goto err;
> }
>
> rom->datasize = rom->romsize;
> -rom->data = g_malloc0(rom->datasize);
> -lseek(fd, 0, SEEK_SET);
> -rc = read(fd, rom->data, rom->datasize);
> -if (rc != rom->datasize) {
> -fprintf(stderr, "rom: file %-20s: read error: rc=%zd (expected
> %zd)\n",
> -rom->name, rc, rom->datasize);
> -goto err;
> -}
> -close(fd);
> rom_insert(rom);
> if (rom->fw_file && fw_cfg) {
> const char *basename;
> @@ -1159,9 +1142,6 @@ ssize_t rom_add_file(const char *file, const char
> *fw_dir,
> return 0;
>
> err:
> -if (fd != -1)
> -close(fd);
> -
> rom_free(rom);
> return -1;
> }
> --
> 2.45.2
