The GCC9 compiler complains about QXL code that takes the address of
members of the 'struct QXLReleaseRing' which is marked packed:
CC hw/display/qxl.o
/home/elmarco/src/qemu/hw/display/qxl.c: In function ‘init_qxl_ram’:
/home/elmarco/src/qemu/hw/display/qxl.c:50:19: warning: taking address of packed member of ‘struct QXLReleaseRing_ring_el’ may result in an unaligned pointer value [-Waddress-of-packed-member]
50 | ret = &(r)->items[prod].el; \
| ^~~~~~~~~~~~~~~~~~~~
/home/elmarco/src/qemu/hw/display/qxl.c:429:5: note: in expansion of macro ‘SPICE_RING_PROD_ITEM’
429 | SPICE_RING_PROD_ITEM(d, &d->ram->release_ring, item);
| ^~~~~~~~~~~~~~~~~~~~
/home/elmarco/src/qemu/hw/display/qxl.c: In function ‘qxl_push_free_res’:
/home/elmarco/src/qemu/hw/display/qxl.c:50:19: warning: taking address of packed member of ‘struct QXLReleaseRing_ring_el’ may result in an unaligned pointer value [-Waddress-of-packed-member]
50 | ret = &(r)->items[prod].el; \
| ^~~~~~~~~~~~~~~~~~~~
/home/elmarco/src/qemu/hw/display/qxl.c:762:5: note: in expansion of macro ‘SPICE_RING_PROD_ITEM’
762 | SPICE_RING_PROD_ITEM(d, ring, item);
| ^~~~~~~~~~~~~~~~~~~~
/home/elmarco/src/qemu/hw/display/qxl.c: In function ‘interface_release_resource’:
/home/elmarco/src/qemu/hw/display/qxl.c:50:19: warning: taking address of packed member of ‘struct QXLReleaseRing_ring_el’ may result in an unaligned pointer value [-Waddress-of-packed-member]
50 | ret = &(r)->items[prod].el; \
| ^~~~~~~~~~~~~~~~~~~~
/home/elmarco/src/qemu/hw/display/qxl.c:795:5: note: in expansion of macro ‘SPICE_RING_PROD_ITEM’
795 | SPICE_RING_PROD_ITEM(qxl, ring, item);
| ^~~~~~~~~~~~~~~~~~~~
Replace pointer usage by direct structure/array access instead.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
hw/display/qxl.c | 83 +++++++++++++++++++++++++++++-------------------
1 file changed, 50 insertions(+), 33 deletions(-)
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index c8ce5781e0..12d83dd6f1 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -39,29 +39,49 @@
* abort we just qxl_set_guest_bug and set the return to NULL. Still
* it may happen as a result of emulator bug as well.
*/
-#undef SPICE_RING_PROD_ITEM
-#define SPICE_RING_PROD_ITEM(qxl, r, ret) { \
- uint32_t prod = (r)->prod & SPICE_RING_INDEX_MASK(r); \
- if (prod >= ARRAY_SIZE((r)->items)) { \
- qxl_set_guest_bug(qxl, "SPICE_RING_PROD_ITEM indices mismatch " \
- "%u >= %zu", prod, ARRAY_SIZE((r)->items)); \
- ret = NULL; \
- } else { \
- ret = &(r)->items[prod].el; \
- } \
+#define SPICE_RING_GET_CHECK(qxl, r, field) ({ \
+ field = (r)->field & SPICE_RING_INDEX_MASK(r); \
+ bool mismatch = field >= ARRAY_SIZE((r)->items); \
+ if (mismatch) { \
+ qxl_set_guest_bug(qxl, "SPICE_RING_GET %s indices mismatch " \
+ "%u >= %zu", stringify(field), field, \
+ ARRAY_SIZE((r)->items)); \
+ } \
+ !mismatch; \
+})
+
+static inline uint64_t
+qxl_release_ring_get_prod(PCIQXLDevice *qxl)
+{
+ struct QXLReleaseRing *ring = &qxl->ram->release_ring;
+ uint32_t prod;
+ bool ok = SPICE_RING_GET_CHECK(qxl, ring, prod);
+ assert(ok);
+
+ return ring->items[prod].el;
+}
+
+static inline bool
+qxl_release_ring_set_prod(PCIQXLDevice *qxl, uint64_t val)
+{
+ struct QXLReleaseRing *ring = &qxl->ram->release_ring;
+ uint32_t prod;
+ bool ok = SPICE_RING_GET_CHECK(qxl, ring, prod);
+ if (ok) {
+ ring->items[prod].el = val;
}
+ return ok;
+}
#undef SPICE_RING_CONS_ITEM
-#define SPICE_RING_CONS_ITEM(qxl, r, ret) { \
- uint32_t cons = (r)->cons & SPICE_RING_INDEX_MASK(r); \
- if (cons >= ARRAY_SIZE((r)->items)) { \
- qxl_set_guest_bug(qxl, "SPICE_RING_CONS_ITEM indices mismatch " \
- "%u >= %zu", cons, ARRAY_SIZE((r)->items)); \
- ret = NULL; \
- } else { \
- ret = &(r)->items[cons].el; \
- } \
- }
+#define SPICE_RING_CONS_ITEM(qxl, r, ret) { \
+ uint32_t cons; \
+ if (!SPICE_RING_GET_CHECK(qxl, r, cons)) { \
+ ret = NULL; \
+ } else { \
+ ret = &(r)->items[cons].el; \
+ } \
+}
#undef ALIGN
#define ALIGN(a, b) (((a) + ((b) - 1)) & ~((b) - 1))
@@ -414,7 +434,6 @@ static void init_qxl_rom(PCIQXLDevice *d)
static void init_qxl_ram(PCIQXLDevice *d)
{
uint8_t *buf;
- uint64_t *item;
buf = d->vga.vram_ptr;
d->ram = (QXLRam *)(buf + le32_to_cpu(d->shadow_rom.ram_header_offset));
@@ -426,9 +445,9 @@ static void init_qxl_ram(PCIQXLDevice *d)
SPICE_RING_INIT(&d->ram->cmd_ring);
SPICE_RING_INIT(&d->ram->cursor_ring);
SPICE_RING_INIT(&d->ram->release_ring);
- SPICE_RING_PROD_ITEM(d, &d->ram->release_ring, item);
- assert(item);
- *item = 0;
+ if (!qxl_release_ring_set_prod(d, 0)) {
+ g_assert_not_reached();
+ }
qxl_ring_set_dirty(d);
}
@@ -732,7 +751,6 @@ static int interface_req_cmd_notification(QXLInstance *sin)
static inline void qxl_push_free_res(PCIQXLDevice *d, int flush)
{
QXLReleaseRing *ring = &d->ram->release_ring;
- uint64_t *item;
int notify;
#define QXL_FREE_BUNCH_SIZE 32
@@ -759,11 +777,9 @@ static inline void qxl_push_free_res(PCIQXLDevice *d, int flush)
if (notify) {
qxl_send_events(d, QXL_INTERRUPT_DISPLAY);
}
- SPICE_RING_PROD_ITEM(d, ring, item);
- if (!item) {
+ if (!qxl_release_ring_set_prod(d, 0)) {
return;
}
- *item = 0;
d->num_free_res = 0;
d->last_release = NULL;
qxl_ring_set_dirty(d);
@@ -775,7 +791,8 @@ static void interface_release_resource(QXLInstance *sin,
{
PCIQXLDevice *qxl = container_of(sin, PCIQXLDevice, ssd.qxl);
QXLReleaseRing *ring;
- uint64_t *item, id;
+ uint32_t prod;
+ uint64_t id;
if (ext.group_id == MEMSLOT_GROUP_HOST) {
/* host group -> vga mode update request */
@@ -792,16 +809,16 @@ static void interface_release_resource(QXLInstance *sin,
* pci bar 0, $command.release_info
*/
ring = &qxl->ram->release_ring;
- SPICE_RING_PROD_ITEM(qxl, ring, item);
- if (!item) {
+
+ if (!SPICE_RING_GET_CHECK(qxl, ring, prod)) {
return;
}
- if (*item == 0) {
+ if (qxl_release_ring_get_prod(qxl) == 0) {
/* stick head into the ring */
id = ext.info->id;
ext.info->next = 0;
qxl_ram_set_dirty(qxl, &ext.info->next);
- *item = id;
+ qxl_release_ring_set_prod(qxl, id);
qxl_ring_set_dirty(qxl);
} else {
/* append item to the list */
--
2.21.0.196.g041f5ea1cf
On 4/8/19 10:12 PM, Marc-André Lureau wrote: > The GCC9 compiler complains about QXL code that takes the address of > members of the 'struct QXLReleaseRing' which is marked packed: > > CC hw/display/qxl.o > /home/elmarco/src/qemu/hw/display/qxl.c: In function ‘init_qxl_ram’: > /home/elmarco/src/qemu/hw/display/qxl.c:50:19: warning: taking address of packed member of ‘struct QXLReleaseRing_ring_el’ may result in an unaligned pointer value [-Waddress-of-packed-member] > 50 | ret = &(r)->items[prod].el; \ > | ^~~~~~~~~~~~~~~~~~~~ > /home/elmarco/src/qemu/hw/display/qxl.c:429:5: note: in expansion of macro ‘SPICE_RING_PROD_ITEM’ > 429 | SPICE_RING_PROD_ITEM(d, &d->ram->release_ring, item); > | ^~~~~~~~~~~~~~~~~~~~ > /home/elmarco/src/qemu/hw/display/qxl.c: In function ‘qxl_push_free_res’: > /home/elmarco/src/qemu/hw/display/qxl.c:50:19: warning: taking address of packed member of ‘struct QXLReleaseRing_ring_el’ may result in an unaligned pointer value [-Waddress-of-packed-member] > 50 | ret = &(r)->items[prod].el; \ > | ^~~~~~~~~~~~~~~~~~~~ > /home/elmarco/src/qemu/hw/display/qxl.c:762:5: note: in expansion of macro ‘SPICE_RING_PROD_ITEM’ > 762 | SPICE_RING_PROD_ITEM(d, ring, item); > | ^~~~~~~~~~~~~~~~~~~~ > /home/elmarco/src/qemu/hw/display/qxl.c: In function ‘interface_release_resource’: > /home/elmarco/src/qemu/hw/display/qxl.c:50:19: warning: taking address of packed member of ‘struct QXLReleaseRing_ring_el’ may result in an unaligned pointer value [-Waddress-of-packed-member] > 50 | ret = &(r)->items[prod].el; \ > | ^~~~~~~~~~~~~~~~~~~~ > /home/elmarco/src/qemu/hw/display/qxl.c:795:5: note: in expansion of macro ‘SPICE_RING_PROD_ITEM’ > 795 | SPICE_RING_PROD_ITEM(qxl, ring, item); > | ^~~~~~~~~~~~~~~~~~~~ > > Replace pointer usage by direct structure/array access instead. > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > hw/display/qxl.c | 83 +++++++++++++++++++++++++++++------------------- > 1 file changed, 50 insertions(+), 33 deletions(-) > > diff --git a/hw/display/qxl.c b/hw/display/qxl.c > index c8ce5781e0..12d83dd6f1 100644 > --- a/hw/display/qxl.c > +++ b/hw/display/qxl.c > @@ -39,29 +39,49 @@ > * abort we just qxl_set_guest_bug and set the return to NULL. Still > * it may happen as a result of emulator bug as well. > */ > -#undef SPICE_RING_PROD_ITEM > -#define SPICE_RING_PROD_ITEM(qxl, r, ret) { \ > - uint32_t prod = (r)->prod & SPICE_RING_INDEX_MASK(r); \ > - if (prod >= ARRAY_SIZE((r)->items)) { \ > - qxl_set_guest_bug(qxl, "SPICE_RING_PROD_ITEM indices mismatch " \ > - "%u >= %zu", prod, ARRAY_SIZE((r)->items)); \ > - ret = NULL; \ > - } else { \ > - ret = &(r)->items[prod].el; \ > - } \ > +#define SPICE_RING_GET_CHECK(qxl, r, field) ({ \ > + field = (r)->field & SPICE_RING_INDEX_MASK(r); \ > + bool mismatch = field >= ARRAY_SIZE((r)->items); \ > + if (mismatch) { \ > + qxl_set_guest_bug(qxl, "SPICE_RING_GET %s indices mismatch " \ > + "%u >= %zu", stringify(field), field, \ > + ARRAY_SIZE((r)->items)); \ > + } \ > + !mismatch; \ > +}) > + > +static inline uint64_t > +qxl_release_ring_get_prod(PCIQXLDevice *qxl) > +{ > + struct QXLReleaseRing *ring = &qxl->ram->release_ring; > + uint32_t prod; > + bool ok = SPICE_RING_GET_CHECK(qxl, ring, prod); > + assert(ok); > + > + return ring->items[prod].el; > +} > + > +static inline bool > +qxl_release_ring_set_prod(PCIQXLDevice *qxl, uint64_t val) > +{ > + struct QXLReleaseRing *ring = &qxl->ram->release_ring; > + uint32_t prod; > + bool ok = SPICE_RING_GET_CHECK(qxl, ring, prod); > + if (ok) { > + ring->items[prod].el = val; > } > + return ok; > +} > > #undef SPICE_RING_CONS_ITEM > -#define SPICE_RING_CONS_ITEM(qxl, r, ret) { \ > - uint32_t cons = (r)->cons & SPICE_RING_INDEX_MASK(r); \ > - if (cons >= ARRAY_SIZE((r)->items)) { \ > - qxl_set_guest_bug(qxl, "SPICE_RING_CONS_ITEM indices mismatch " \ > - "%u >= %zu", cons, ARRAY_SIZE((r)->items)); \ > - ret = NULL; \ > - } else { \ > - ret = &(r)->items[cons].el; \ > - } \ > - } > +#define SPICE_RING_CONS_ITEM(qxl, r, ret) { \ > + uint32_t cons; \ > + if (!SPICE_RING_GET_CHECK(qxl, r, cons)) { \ > + ret = NULL; \ > + } else { \ > + ret = &(r)->items[cons].el; \ > + } \ > +} > > #undef ALIGN > #define ALIGN(a, b) (((a) + ((b) - 1)) & ~((b) - 1)) > @@ -414,7 +434,6 @@ static void init_qxl_rom(PCIQXLDevice *d) > static void init_qxl_ram(PCIQXLDevice *d) > { > uint8_t *buf; > - uint64_t *item; > > buf = d->vga.vram_ptr; > d->ram = (QXLRam *)(buf + le32_to_cpu(d->shadow_rom.ram_header_offset)); > @@ -426,9 +445,9 @@ static void init_qxl_ram(PCIQXLDevice *d) > SPICE_RING_INIT(&d->ram->cmd_ring); > SPICE_RING_INIT(&d->ram->cursor_ring); > SPICE_RING_INIT(&d->ram->release_ring); > - SPICE_RING_PROD_ITEM(d, &d->ram->release_ring, item); > - assert(item); > - *item = 0; > + if (!qxl_release_ring_set_prod(d, 0)) { > + g_assert_not_reached(); > + } > qxl_ring_set_dirty(d); > } > > @@ -732,7 +751,6 @@ static int interface_req_cmd_notification(QXLInstance *sin) > static inline void qxl_push_free_res(PCIQXLDevice *d, int flush) > { > QXLReleaseRing *ring = &d->ram->release_ring; > - uint64_t *item; > int notify; > > #define QXL_FREE_BUNCH_SIZE 32 > @@ -759,11 +777,9 @@ static inline void qxl_push_free_res(PCIQXLDevice *d, int flush) > if (notify) { > qxl_send_events(d, QXL_INTERRUPT_DISPLAY); > } > - SPICE_RING_PROD_ITEM(d, ring, item); > - if (!item) { > + if (!qxl_release_ring_set_prod(d, 0)) { > return; > } > - *item = 0; > d->num_free_res = 0; > d->last_release = NULL; > qxl_ring_set_dirty(d); > @@ -775,7 +791,8 @@ static void interface_release_resource(QXLInstance *sin, > { > PCIQXLDevice *qxl = container_of(sin, PCIQXLDevice, ssd.qxl); > QXLReleaseRing *ring; > - uint64_t *item, id; > + uint32_t prod; > + uint64_t id; > > if (ext.group_id == MEMSLOT_GROUP_HOST) { > /* host group -> vga mode update request */ > @@ -792,16 +809,16 @@ static void interface_release_resource(QXLInstance *sin, > * pci bar 0, $command.release_info > */ > ring = &qxl->ram->release_ring; > - SPICE_RING_PROD_ITEM(qxl, ring, item); > - if (!item) { > + > + if (!SPICE_RING_GET_CHECK(qxl, ring, prod)) { > return; > } > - if (*item == 0) { > + if (qxl_release_ring_get_prod(qxl) == 0) { > /* stick head into the ring */ > id = ext.info->id; > ext.info->next = 0; > qxl_ram_set_dirty(qxl, &ext.info->next); > - *item = id; > + qxl_release_ring_set_prod(qxl, id); > qxl_ring_set_dirty(qxl); > } else { > /* append item to the list */ >
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