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| author | Markus Armbruster <armbru@pond.sub.org> | 2013-01-10 14:24:49 +0100 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2013-01-14 08:59:38 +0100 |
| commit | bc5f92e5db6f303e73387278e32f8669f0abf0e5 (patch) | |
| tree | 006ad6ca4e2bf25ce973c765e9198669faaf8671 | |
| parent | 63fb2590839162afdf14d7c0ee02d460766c0956 (diff) | |
| download | qemu-bc5f92e5db6f303e73387278e32f8669f0abf0e5.zip qemu-bc5f92e5db6f303e73387278e32f8669f0abf0e5.tar.gz qemu-bc5f92e5db6f303e73387278e32f8669f0abf0e5.tar.bz2 | |
qxl: Fix SPICE_RING_PROD_ITEM(), SPICE_RING_CONS_ITEM() sanity check
The pointer arithmetic there is safe, but ugly. Coverity grouses
about it. However, the actual comparison is off by one: <= end
instead of < end. Fix by rewriting the check in a cleaner way.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | hw/qxl.c | 20 |
1 files changed, 6 insertions, 14 deletions
@@ -37,33 +37,25 @@ */ #undef SPICE_RING_PROD_ITEM #define SPICE_RING_PROD_ITEM(qxl, r, ret) { \ - typeof(r) start = r; \ - typeof(r) end = r + 1; \ uint32_t prod = (r)->prod & SPICE_RING_INDEX_MASK(r); \ - typeof(&(r)->items[prod]) m_item = &(r)->items[prod]; \ - if (!((uint8_t*)m_item >= (uint8_t*)(start) && (uint8_t*)(m_item + 1) <= (uint8_t*)(end))) { \ + if (prod >= ARRAY_SIZE((r)->items)) { \ qxl_set_guest_bug(qxl, "SPICE_RING_PROD_ITEM indices mismatch " \ - "! %p <= %p < %p", (uint8_t *)start, \ - (uint8_t *)m_item, (uint8_t *)end); \ + "%u >= %zu", prod, ARRAY_SIZE((r)->items)); \ ret = NULL; \ } else { \ - ret = &m_item->el; \ + ret = &(r)->items[prod].el; \ } \ } #undef SPICE_RING_CONS_ITEM #define SPICE_RING_CONS_ITEM(qxl, r, ret) { \ - typeof(r) start = r; \ - typeof(r) end = r + 1; \ uint32_t cons = (r)->cons & SPICE_RING_INDEX_MASK(r); \ - typeof(&(r)->items[cons]) m_item = &(r)->items[cons]; \ - if (!((uint8_t*)m_item >= (uint8_t*)(start) && (uint8_t*)(m_item + 1) <= (uint8_t*)(end))) { \ + if (cons >= ARRAY_SIZE((r)->items)) { \ qxl_set_guest_bug(qxl, "SPICE_RING_CONS_ITEM indices mismatch " \ - "! %p <= %p < %p", (uint8_t *)start, \ - (uint8_t *)m_item, (uint8_t *)end); \ + "%u >= %zu", cons, ARRAY_SIZE((r)->items)); \ ret = NULL; \ } else { \ - ret = &m_item->el; \ + ret = &(r)->items[cons].el; \ } \ } |