Re: [RFC PATCH 2/2] hw/usb/dev-uas: Report command additional adb length as unsupported

2021-01-20 Thread Eric Blake
On 1/18/21 11:03 AM, Philippe Mathieu-Daudé wrote:
> We are not ready to handle additional CDB data.
> 
> If a guest send a packet with such additional data,

sends

> report the command parameter as not supported.
> 
> We can then explicit there is nothing in this additional

then be explicit that there

> buffer, by fixing its size to zero.
> 
> This fixes an error when building with Clang 11:
> 
>   usb/dev-uas.c:157:31: error: field 'status' with variable sized type 
> 'uas_iu' not at the end of a struct or class is a GNU extension 
> [-Werror,-Wgnu-variable-sized-type-not-at-end]
>   uas_iustatus;
> ^
> 
> Reported-by: Daniele Buono 
> Signed-off-by: Philippe Mathieu-Daudé 
> ---
> Cc: Ed Maste 
> Cc: Han Han 
> Cc: Marc-André Lureau 
> Cc: Paolo Bonzini 
> Cc: Gustavo A. R. Silva 
> ---
>  hw/usb/dev-uas.c | 12 +++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
> index cec071d96c4..b6434ad4b9c 100644
> --- a/hw/usb/dev-uas.c
> +++ b/hw/usb/dev-uas.c
> @@ -16,6 +16,7 @@
>  #include "qemu/error-report.h"
>  #include "qemu/main-loop.h"
>  #include "qemu/module.h"
> +#include "qemu/log.h"
>  
>  #include "hw/usb.h"
>  #include "migration/vmstate.h"
> @@ -70,7 +71,7 @@ typedef struct {
>  uint8_treserved_2;
>  uint64_t   lun;
>  uint8_tcdb[16];
> -uint8_tadd_cdb[];
> +uint8_tadd_cdb[0];  /* not supported by QEMU */
>  } QEMU_PACKED  uas_iu_command;

Technically, a zero-sized array is also a gcc/clang extension, and may
bite us later if that extension starts triggering compiler complaints in
one of the two compilers, just as our current use of an extension is
causing grief in clang 11.  But in the short term, it works, and gets
rid of the more problematic extension of a dynamically-sized type
preventing the determination of a packed union containing that type.

>  
>  typedef struct {
> @@ -700,6 +701,11 @@ static void usb_uas_command(UASDevice *uas, uas_iu *iu)
>  uint32_t len;
>  uint16_t tag = be16_to_cpu(iu->hdr.tag);
>  
> +if (iu->command.add_cdb_length > 0) {
> +qemu_log_mask(LOG_UNIMP, "additional adb length not yet 
> supported\n");
> +goto unsupported_len;
> +}
> +
>  if (uas_using_streams(uas) && tag > UAS_MAX_STREAMS) {
>  goto invalid_tag;
>  }
> @@ -735,6 +741,10 @@ static void usb_uas_command(UASDevice *uas, uas_iu *iu)
>  }
>  return;
>  
> +unsupported_len:
> +usb_uas_queue_fake_sense(uas, tag, sense_code_INVALID_PARAM_VALUE);
> +return;
> +
>  invalid_tag:
>  usb_uas_queue_fake_sense(uas, tag, sense_code_INVALID_TAG);
>  return;
> 

Reviewed-by: Eric Blake 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3226
Virtualization:  qemu.org | libvirt.org




Re: [RFC PATCH 2/2] hw/usb/dev-uas: Report command additional adb length as unsupported

2021-01-19 Thread Philippe Mathieu-Daudé
On 1/18/21 6:03 PM, Philippe Mathieu-Daudé wrote:
> We are not ready to handle additional CDB data.
> 
> If a guest send a packet with such additional data,
> report the command parameter as not supported.
> 
> We can then explicit there is nothing in this additional
> buffer, by fixing its size to zero.
> 
> This fixes an error when building with Clang 11:
> 
>   usb/dev-uas.c:157:31: error: field 'status' with variable sized type 
> 'uas_iu' not at the end of a struct or class is a GNU extension 
> [-Werror,-Wgnu-variable-sized-type-not-at-end]
>   uas_iustatus;
> ^
> 
> Reported-by: Daniele Buono 

TBH this should be (chronological order):
Reported-by: Ed Maste 
Reported-by: Daniele Buono 
Reported-by: Han Han 

> Signed-off-by: Philippe Mathieu-Daudé 
> ---
> Cc: Ed Maste 
> Cc: Han Han 
> Cc: Marc-André Lureau 
> Cc: Paolo Bonzini 
> Cc: Gustavo A. R. Silva 
> ---
>  hw/usb/dev-uas.c | 12 +++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
> index cec071d96c4..b6434ad4b9c 100644
> --- a/hw/usb/dev-uas.c
> +++ b/hw/usb/dev-uas.c
> @@ -16,6 +16,7 @@
>  #include "qemu/error-report.h"
>  #include "qemu/main-loop.h"
>  #include "qemu/module.h"
> +#include "qemu/log.h"
>  
>  #include "hw/usb.h"
>  #include "migration/vmstate.h"
> @@ -70,7 +71,7 @@ typedef struct {
>  uint8_treserved_2;
>  uint64_t   lun;
>  uint8_tcdb[16];
> -uint8_tadd_cdb[];
> +uint8_tadd_cdb[0];  /* not supported by QEMU */
>  } QEMU_PACKED  uas_iu_command;
>  
>  typedef struct {
> @@ -700,6 +701,11 @@ static void usb_uas_command(UASDevice *uas, uas_iu *iu)
>  uint32_t len;
>  uint16_t tag = be16_to_cpu(iu->hdr.tag);
>  
> +if (iu->command.add_cdb_length > 0) {
> +qemu_log_mask(LOG_UNIMP, "additional adb length not yet 
> supported\n");
> +goto unsupported_len;
> +}
> +
>  if (uas_using_streams(uas) && tag > UAS_MAX_STREAMS) {
>  goto invalid_tag;
>  }
> @@ -735,6 +741,10 @@ static void usb_uas_command(UASDevice *uas, uas_iu *iu)
>  }
>  return;
>  
> +unsupported_len:
> +usb_uas_queue_fake_sense(uas, tag, sense_code_INVALID_PARAM_VALUE);
> +return;
> +
>  invalid_tag:
>  usb_uas_queue_fake_sense(uas, tag, sense_code_INVALID_TAG);
>  return;
> 




[RFC PATCH 2/2] hw/usb/dev-uas: Report command additional adb length as unsupported

2021-01-18 Thread Philippe Mathieu-Daudé
We are not ready to handle additional CDB data.

If a guest send a packet with such additional data,
report the command parameter as not supported.

We can then explicit there is nothing in this additional
buffer, by fixing its size to zero.

This fixes an error when building with Clang 11:

  usb/dev-uas.c:157:31: error: field 'status' with variable sized type 'uas_iu' 
not at the end of a struct or class is a GNU extension 
[-Werror,-Wgnu-variable-sized-type-not-at-end]
  uas_iustatus;
^

Reported-by: Daniele Buono 
Signed-off-by: Philippe Mathieu-Daudé 
---
Cc: Ed Maste 
Cc: Han Han 
Cc: Marc-André Lureau 
Cc: Paolo Bonzini 
Cc: Gustavo A. R. Silva 
---
 hw/usb/dev-uas.c | 12 +++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
index cec071d96c4..b6434ad4b9c 100644
--- a/hw/usb/dev-uas.c
+++ b/hw/usb/dev-uas.c
@@ -16,6 +16,7 @@
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/module.h"
+#include "qemu/log.h"
 
 #include "hw/usb.h"
 #include "migration/vmstate.h"
@@ -70,7 +71,7 @@ typedef struct {
 uint8_treserved_2;
 uint64_t   lun;
 uint8_tcdb[16];
-uint8_tadd_cdb[];
+uint8_tadd_cdb[0];  /* not supported by QEMU */
 } QEMU_PACKED  uas_iu_command;
 
 typedef struct {
@@ -700,6 +701,11 @@ static void usb_uas_command(UASDevice *uas, uas_iu *iu)
 uint32_t len;
 uint16_t tag = be16_to_cpu(iu->hdr.tag);
 
+if (iu->command.add_cdb_length > 0) {
+qemu_log_mask(LOG_UNIMP, "additional adb length not yet supported\n");
+goto unsupported_len;
+}
+
 if (uas_using_streams(uas) && tag > UAS_MAX_STREAMS) {
 goto invalid_tag;
 }
@@ -735,6 +741,10 @@ static void usb_uas_command(UASDevice *uas, uas_iu *iu)
 }
 return;
 
+unsupported_len:
+usb_uas_queue_fake_sense(uas, tag, sense_code_INVALID_PARAM_VALUE);
+return;
+
 invalid_tag:
 usb_uas_queue_fake_sense(uas, tag, sense_code_INVALID_TAG);
 return;
-- 
2.26.2