romsize is an uint32_t variable. Specifying -1 as an uint32_t value is obscure way to denote UINT32_MAX.
Worse, if int is wider than 32-bit, it will change the behavior of a construct like the following: romsize = -1; if (romsize != -1) { ... } When -1 is assigned to romsize, -1 will be implicitly casted into uint32_t, resulting in UINT32_MAX. On contrary, when evaluating romsize != -1, romsize will be casted into int, and it will be a comparison of UINT32_MAX and -1, and result in false. Replace -1 with UINT32_MAX for statements involving the variable to clarify the intent and prevent potential breakage. Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com> Reviewed-by: Markus Armbruster <arm...@redhat.com> --- hw/pci/pci.c | 8 ++++---- hw/xen/xen_pt_load_rom.c | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 54b375da2d26..84df07a2789b 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -70,7 +70,7 @@ static bool pcie_has_upstream_port(PCIDevice *dev); static Property pci_props[] = { DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1), DEFINE_PROP_STRING("romfile", PCIDevice, romfile), - DEFINE_PROP_UINT32("romsize", PCIDevice, romsize, -1), + DEFINE_PROP_UINT32("romsize", PCIDevice, romsize, UINT32_MAX), DEFINE_PROP_UINT32("rombar", PCIDevice, rom_bar, 1), DEFINE_PROP_BIT("multifunction", PCIDevice, cap_present, QEMU_PCI_CAP_MULTIFUNCTION_BITNR, false), @@ -2073,7 +2073,7 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp) g_cmp_uint32, NULL); } - if (pci_dev->romsize != -1 && !is_power_of_2(pci_dev->romsize)) { + if (pci_dev->romsize != UINT32_MAX && !is_power_of_2(pci_dev->romsize)) { error_setg(errp, "ROM size %u is not a power of two", pci_dev->romsize); return; } @@ -2359,7 +2359,7 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom, return; } - if (load_file || pdev->romsize == -1) { + if (load_file || pdev->romsize == UINT32_MAX) { path = qemu_find_file(QEMU_FILE_TYPE_BIOS, pdev->romfile); if (path == NULL) { path = g_strdup(pdev->romfile); @@ -2378,7 +2378,7 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom, pdev->romfile); return; } - if (pdev->romsize != -1) { + if (pdev->romsize != UINT_MAX) { if (size > pdev->romsize) { error_setg(errp, "romfile \"%s\" (%u bytes) " "is too large for ROM size %u", diff --git a/hw/xen/xen_pt_load_rom.c b/hw/xen/xen_pt_load_rom.c index 03422a8a7148..6bc64acd3352 100644 --- a/hw/xen/xen_pt_load_rom.c +++ b/hw/xen/xen_pt_load_rom.c @@ -53,7 +53,7 @@ void *pci_assign_dev_load_option_rom(PCIDevice *dev, } fseek(fp, 0, SEEK_SET); - if (dev->romsize != -1) { + if (dev->romsize != UINT_MAX) { if (st.st_size > dev->romsize) { error_report("ROM BAR \"%s\" (%ld bytes) is too large for ROM size %u", rom_file, (long) st.st_size, dev->romsize); -- 2.43.2