> -Original Message-
> From: Gregor Haas
> Sent: Friday, June 28, 2024 9:51 AM
> To: qemu-devel@nongnu.org
> Cc: Yao, Xingtao/姚 幸涛 ; Gregor Haas
>
> Subject: [PATCH v3] 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 load_image_size() instead, which correctly reads all data using
> multiple calls to read(). Also, the ROM size is now determined using the
> get_image_size() function rather than using manual lseek().
>
> Signed-off-by: Gregor Haas
> ---
> hw/core/loader.c | 17 ++---
> 1 file changed, 2 insertions(+), 15 deletions(-)
>
> diff --git a/hw/core/loader.c b/hw/core/loader.c
> index 2f8105d7de..c2c61158f1 100644
> --- a/hw/core/loader.c
> +++ b/hw/core/loader.c
> @@ -1076,7 +1076,6 @@ 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;
> char devpath[100];
>
> if (as && mr) {
> @@ -1094,19 +1093,12 @@ 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);
> +rom->romsize = get_image_size(rom->path);
> if (rom->romsize == -1) {
> fprintf(stderr, "rom: file %-20s: get size error: %s\n",
> rom->name, strerror(errno));
> @@ -1115,14 +1107,12 @@ ssize_t rom_add_file(const char *file, const char
> *fw_dir,
>
> rom->datasize = rom->romsize;
> rom->data = g_malloc0(rom->datasize);
> -lseek(fd, 0, SEEK_SET);
> -rc = read(fd, rom->data, rom->datasize);
> +rc = load_image_size(rom->path, 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 +1149,6 @@ 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
Reviewed-by: Xingtao Yao
