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hw/pci: Replace -1 with UINT32_MAX for romsize

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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.odaki@daynix.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20240627-reuse-v10-10-7ca0b8ed3d9f@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Akihiko Odaki 2024-06-27 15:07:59 +09:00 committed by Michael S. Tsirkin
parent 107a64b9a3
commit 6a67577d80
2 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
hw/pci/pci.c
View File

@ -70,7 +70,7 @@ static bool pcie_has_upstream_port(PCIDevice *dev);
static Property pci_props[] = { static Property pci_props[] = {
DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1), DEFINE_PROP_PCI_DEVFN("addr", PCIDevice, devfn, -1),
DEFINE_PROP_STRING("romfile", PCIDevice, romfile), 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_UINT32("rombar", PCIDevice, rom_bar, 1),
DEFINE_PROP_BIT("multifunction", PCIDevice, cap_present, DEFINE_PROP_BIT("multifunction", PCIDevice, cap_present,
QEMU_PCI_CAP_MULTIFUNCTION_BITNR, false), QEMU_PCI_CAP_MULTIFUNCTION_BITNR, false),
@ -2073,7 +2073,7 @@ static void pci_qdev_realize(DeviceState *qdev, Error **errp)
g_cmp_uint32, NULL); 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); error_setg(errp, "ROM size %u is not a power of two", pci_dev->romsize);
return; return;
} }
@ -2359,7 +2359,7 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom,
return; return;
} }
if (load_file || pdev->romsize == -1) { if (load_file || pdev->romsize == UINT32_MAX) {
path = qemu_find_file(QEMU_FILE_TYPE_BIOS, pdev->romfile); path = qemu_find_file(QEMU_FILE_TYPE_BIOS, pdev->romfile);
if (path == NULL) { if (path == NULL) {
path = g_strdup(pdev->romfile); path = g_strdup(pdev->romfile);
@ -2378,7 +2378,7 @@ static void pci_add_option_rom(PCIDevice *pdev, bool is_default_rom,
pdev->romfile); pdev->romfile);
return; return;
} }
if (pdev->romsize != -1) { if (pdev->romsize != UINT_MAX) {
if (size > pdev->romsize) { if (size > pdev->romsize) {
error_setg(errp, "romfile \"%s\" (%u bytes) " error_setg(errp, "romfile \"%s\" (%u bytes) "
"is too large for ROM size %u", "is too large for ROM size %u",

2
hw/xen/xen_pt_load_rom.c
View File

@ -53,7 +53,7 @@ void *pci_assign_dev_load_option_rom(PCIDevice *dev,
} }
fseek(fp, 0, SEEK_SET); fseek(fp, 0, SEEK_SET);
if (dev->romsize != -1) { if (dev->romsize != UINT_MAX) {
if (st.st_size > dev->romsize) { if (st.st_size > dev->romsize) {
error_report("ROM BAR \"%s\" (%ld bytes) is too large for ROM size %u", error_report("ROM BAR \"%s\" (%ld bytes) is too large for ROM size %u",
rom_file, (long) st.st_size, dev->romsize); rom_file, (long) st.st_size, dev->romsize);