Re: [qemu-s390x] [PATCH v3 04/25] chardev: Let qemu_chr_be_can_write() return a size_t types

[Marc-André Lureau]

Hi

On Wed, Feb 20, 2019 at 2:04 AM Philippe Mathieu-Daudé
<address@hidden> wrote:
>
> In the previous commit we added an assert to be sure than
> qemu_chr_be_can_write() will never return a negative value.
> We can now change its prototype to return a size_t.
> Adapt the backends accordingly.

Each variable you change to an unsigned type, we should check it isn't
used with negative values.

>
> Suggested-by: Paolo Bonzini <address@hidden>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> ---
>  chardev/baum.c            | 6 +++---
>  chardev/char-fd.c         | 2 +-
>  chardev/char-pty.c        | 4 ++--
>  chardev/char-socket.c     | 7 ++++---
>  chardev/char-udp.c        | 4 ++--
>  chardev/char-win.c        | 2 +-
>  chardev/char.c            | 2 +-
>  chardev/msmouse.c         | 4 ++--
>  chardev/spice.c           | 2 +-
>  chardev/wctablet.c        | 4 ++--
>  hw/bt/hci-csr.c           | 2 +-
>  include/chardev/char-fd.h | 2 +-
>  include/chardev/char.h    | 2 +-
>  ui/console.c              | 6 +++---
>  14 files changed, 25 insertions(+), 24 deletions(-)
>
> diff --git a/chardev/baum.c b/chardev/baum.c
> index 78b0c87625..1d69d62158 100644
> --- a/chardev/baum.c
> +++ b/chardev/baum.c
> @@ -265,7 +265,7 @@ static int baum_deferred_init(BaumChardev *baum)
>  static void baum_chr_accept_input(struct Chardev *chr)
>  {
>      BaumChardev *baum = BAUM_CHARDEV(chr);
> -    int room, first;
> +    size_t room, first;
>
>      if (!baum->out_buf_used)
>          return;
> @@ -292,7 +292,7 @@ static void baum_write_packet(BaumChardev *baum, const 
> uint8_t *buf, int len)
>  {
>      Chardev *chr = CHARDEV(baum);
>      uint8_t io_buf[1 + 2 * len], *cur = io_buf;
> -    int room;
> +    size_t room;
>      *cur++ = ESC;
>      while (len--)
>          if ((*cur++ = *buf++) == ESC)
> @@ -303,7 +303,7 @@ static void baum_write_packet(BaumChardev *baum, const 
> uint8_t *buf, int len)
>          /* Fits */
>          qemu_chr_be_write(chr, io_buf, len);
>      } else {
> -        int first;
> +        size_t first;
>          uint8_t out;
>          /* Can't fit all, send what can be, and store the rest. */
>          qemu_chr_be_write(chr, io_buf, room);

baum room & first are only used for non-negative capacity values. ack

> diff --git a/chardev/char-fd.c b/chardev/char-fd.c
> index 2421d8e216..0fe2822869 100644
> --- a/chardev/char-fd.c
> +++ b/chardev/char-fd.c
> @@ -43,7 +43,7 @@ static gboolean fd_chr_read(QIOChannel *chan, GIOCondition 
> cond, void *opaque)
>  {
>      Chardev *chr = CHARDEV(opaque);
>      FDChardev *s = FD_CHARDEV(opaque);
> -    int len;
> +    size_t len;
>      uint8_t buf[CHR_READ_BUF_LEN];
>      ssize_t ret;
>

fd len is only used for non-negative buffer size. ack

> diff --git a/chardev/char-pty.c b/chardev/char-pty.c
> index 7777f6ddef..eae25f043b 100644
> --- a/chardev/char-pty.c
> +++ b/chardev/char-pty.c
> @@ -34,7 +34,7 @@
>  typedef struct {
>      Chardev parent;
>      QIOChannel *ioc;
> -    int read_bytes;
> +    size_t read_bytes;
>

Only set with values returned from qemu_chr_be_can_write(), ack

>      int connected;
>      GSource *timer_src;
> @@ -132,7 +132,7 @@ static gboolean pty_chr_read(QIOChannel *chan, 
> GIOCondition cond, void *opaque)
>  {
>      Chardev *chr = CHARDEV(opaque);
>      PtyChardev *s = PTY_CHARDEV(opaque);
> -    gsize len;
> +    size_t len;
>      uint8_t buf[CHR_READ_BUF_LEN];
>      ssize_t ret;

pty len is only used for non-negative buffer size. ack

> diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> index 262a59b64f..4010c343e0 100644
> --- a/chardev/char-socket.c
> +++ b/chardev/char-socket.c
> @@ -60,7 +60,7 @@ typedef struct {
>      GSource *hup_source;
>      QCryptoTLSCreds *tls_creds;
>      TCPChardevState state;
> -    int max_size;
> +    size_t max_size;

Only set with values returned from qemu_chr_be_can_write(), ack

>      int do_telnetopt;
>      int do_nodelay;
>      int *read_msgfds;
> @@ -493,10 +493,11 @@ static gboolean tcp_chr_read(QIOChannel *chan, 
> GIOCondition cond, void *opaque)
>      Chardev *chr = CHARDEV(opaque);
>      SocketChardev *s = SOCKET_CHARDEV(opaque);
>      uint8_t buf[CHR_READ_BUF_LEN];
> -    int len, size;
> +    size_t len;

len is only used for non-negative buffer size. ack

> +    int size;
>
>      if ((s->state != TCP_CHARDEV_STATE_CONNECTED) ||
> -        s->max_size <= 0) {
> +        s->max_size == 0) {
>          return TRUE;
>      }
>      len = sizeof(buf);
> diff --git a/chardev/char-udp.c b/chardev/char-udp.c
> index b6e399e983..d4f40626e4 100644
> --- a/chardev/char-udp.c
> +++ b/chardev/char-udp.c
> @@ -39,7 +39,7 @@ typedef struct {
>      uint8_t buf[CHR_READ_BUF_LEN];
>      int bufcnt;
>      int bufptr;
> -    int max_size;
> +    size_t max_size;

Only set with values returned from qemu_chr_be_can_write(), ack

>  } UdpChardev;
>
>  #define UDP_CHARDEV(obj) OBJECT_CHECK(UdpChardev, (obj), TYPE_CHARDEV_UDP)
> @@ -58,7 +58,7 @@ static void udp_chr_flush_buffer(UdpChardev *s)
>      Chardev *chr = CHARDEV(s);
>
>      while (s->max_size > 0 && s->bufptr < s->bufcnt) {
> -        int n = MIN(s->max_size, s->bufcnt - s->bufptr);
> +        size_t n = MIN(s->max_size, s->bufcnt - s->bufptr);

the while() condition ensures the value will be > 0. ack

>          qemu_chr_be_write(chr, &s->buf[s->bufptr], n);
>          s->bufptr += n;
>          s->max_size = qemu_chr_be_can_write(chr);
> diff --git a/chardev/char-win.c b/chardev/char-win.c
> index 05518e0958..30361e8852 100644
> --- a/chardev/char-win.c
> +++ b/chardev/char-win.c
> @@ -29,7 +29,7 @@
>  static void win_chr_read(Chardev *chr, DWORD len)
>  {
>      WinChardev *s = WIN_CHARDEV(chr);
> -    int max_size = qemu_chr_be_can_write(chr);
> +    size_t max_size = qemu_chr_be_can_write(chr);

unmodified, ack

>      int ret, err;
>      uint8_t buf[CHR_READ_BUF_LEN];
>      DWORD size;
> diff --git a/chardev/char.c b/chardev/char.c
> index 71ecd32b25..3149cd3ba9 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -156,7 +156,7 @@ int qemu_chr_write(Chardev *s, const uint8_t *buf, int 
> len, bool write_all)
>      return offset;
>  }
>
> -int qemu_chr_be_can_write(Chardev *s)
> +size_t qemu_chr_be_can_write(Chardev *s)
>  {
>      CharBackend *be = s->be;
>      int receivable_bytes;
> diff --git a/chardev/msmouse.c b/chardev/msmouse.c
> index 0ffd137ce8..cdb6f86037 100644
> --- a/chardev/msmouse.c
> +++ b/chardev/msmouse.c
> @@ -38,7 +38,7 @@ typedef struct {
>      bool btns[INPUT_BUTTON__MAX];
>      bool btnc[INPUT_BUTTON__MAX];
>      uint8_t outbuf[32];
> -    int outlen;
> +    size_t outlen;

outlen is only used as non-negative buffer size, ack

>  } MouseChardev;
>
>  #define TYPE_CHARDEV_MSMOUSE "chardev-msmouse"
> @@ -48,7 +48,7 @@ typedef struct {
>  static void msmouse_chr_accept_input(Chardev *chr)
>  {
>      MouseChardev *mouse = MOUSE_CHARDEV(chr);
> -    int len;
> +    size_t len;
>
>      len = qemu_chr_be_can_write(chr);

same

>      if (len > mouse->outlen) {
> diff --git a/chardev/spice.c b/chardev/spice.c
> index 173c257949..ad180a8a13 100644
> --- a/chardev/spice.c
> +++ b/chardev/spice.c
> @@ -43,7 +43,7 @@ static int vmc_write(SpiceCharDeviceInstance *sin, const 
> uint8_t *buf, int len)
>      uint8_t* p = (uint8_t*)buf;
>
>      while (len > 0) {
> -        int can_write = qemu_chr_be_can_write(chr);
> +        size_t can_write = qemu_chr_be_can_write(chr);

unmodified value, ack

>          last_out = MIN(len, can_write);
>          if (last_out <= 0) {
>              break;
> diff --git a/chardev/wctablet.c b/chardev/wctablet.c
> index cf7a08a363..daae570bc7 100644
> --- a/chardev/wctablet.c
> +++ b/chardev/wctablet.c
> @@ -74,7 +74,7 @@ typedef struct {
>
>      /* Command to be sent to serial port */
>      uint8_t outbuf[WC_OUTPUT_BUF_MAX_LEN];
> -    int outlen;
> +    size_t outlen;

Used as non-negative buffer size only, ack
>
>      int line_speed;
>      bool send_events;
> @@ -186,7 +186,7 @@ static QemuInputHandler wctablet_handler = {
>  static void wctablet_chr_accept_input(Chardev *chr)
>  {
>      TabletChardev *tablet = WCTABLET_CHARDEV(chr);
> -    int len, canWrite;
> +    size_t len, canWrite;

Used as non-negative buffer size only, ack

>
>      canWrite = qemu_chr_be_can_write(chr);
>      len = canWrite;
> diff --git a/hw/bt/hci-csr.c b/hw/bt/hci-csr.c
> index fa6660a113..e837a3fa1f 100644
> --- a/hw/bt/hci-csr.c
> +++ b/hw/bt/hci-csr.c
> @@ -38,7 +38,7 @@ struct csrhci_s {
>  #define FIFO_LEN       4096
>      int out_start;
>      int out_len;
> -    int out_size;
> +    size_t out_size;

Used as non-negative buffer size only, ack

>      uint8_t outfifo[FIFO_LEN * 2];
>      uint8_t inpkt[FIFO_LEN];
>      enum {
> diff --git a/include/chardev/char-fd.h b/include/chardev/char-fd.h
> index e7c2b176f9..36c6b89cee 100644
> --- a/include/chardev/char-fd.h
> +++ b/include/chardev/char-fd.h
> @@ -31,7 +31,7 @@ typedef struct FDChardev {
>      Chardev parent;
>
>      QIOChannel *ioc_in, *ioc_out;
> -    int max_size;
> +    size_t max_size;

Only set with values returned from qemu_chr_be_can_write(), ack

>  } FDChardev;
>
>  #define TYPE_CHARDEV_FD "chardev-fd"
> diff --git a/include/chardev/char.h b/include/chardev/char.h
> index c0b57f7685..0341dd1ba2 100644
> --- a/include/chardev/char.h
> +++ b/include/chardev/char.h
> @@ -173,7 +173,7 @@ Chardev *qemu_chr_new_noreplay(const char *label, const 
> char *filename,
>   *
>   * Returns: the number of bytes the front end can receive via 
> @qemu_chr_be_write
>   */
> -int qemu_chr_be_can_write(Chardev *s);
> +size_t qemu_chr_be_can_write(Chardev *s);
>
>  /**
>   * qemu_chr_be_write:
> diff --git a/ui/console.c b/ui/console.c
> index 6d2282d3e9..42f04e2b37 100644
> --- a/ui/console.c
> +++ b/ui/console.c
> @@ -61,8 +61,8 @@ enum TTYState {
>
>  typedef struct QEMUFIFO {
>      uint8_t *buf;
> -    int buf_size;
> -    int count, wptr, rptr;
> +    size_t buf_size, count;
> +    int wptr, rptr;

Only used as non-negative buffer size, ack

>  } QEMUFIFO;
>
>  static int qemu_fifo_write(QEMUFIFO *f, const uint8_t *buf, int len1)
> @@ -1110,7 +1110,7 @@ static int vc_chr_write(Chardev *chr, const uint8_t 
> *buf, int len)
>  static void kbd_send_chars(void *opaque)
>  {
>      QemuConsole *s = opaque;
> -    int len;
> +    size_t len;

Only used as non-negative buffer size, ack

>      uint8_t buf[16];
>
>      len = qemu_chr_be_can_write(s->chr);
> --
> 2.20.1
>

That was painful, hopefully I didn't miss something...

Reviewed-by: Marc-André Lureau <address@hidden>