From 421b1b27f6e9135ac8f01db219e0d8c0cefd7e71 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 19 Mar 2015 15:14:18 +1100 Subject: [PATCH] spapr_pci: Fix unsafe signed/unsigned comparisons spapr_pci.c contains a number of expressions of the form (uval == -1) or (uval != -1), where 'uval' is an unsigned value. This mostly works in practice, because as long as the width of uval is greater or equal than that of (int), the -1 will be promoted to the unsigned type, which is the expected outcome. However, at least for the cases where uval is uint32_t, this would break on platforms where sizeof(int) > 4 (and a few such do exist), because then the uint32_t value would be promoted to the larger int type, and never be equal to -1. This patch fixes these errors. The fixes for the (uint32_t) cases are necessary as described above. I've made similar fixes to (uint64_t) and (hwaddr) cases. Those are strictly theoretical, since I don't know of any platforms where sizeof(int) > 8, but hey, it's not that hard so we might as well be strictly C standard compliant. Reported-by: Markus Armbruster Signed-off-by: David Gibson Reviewed-by: Markus Armbruster Signed-off-by: Alexander Graf --- hw/ppc/spapr_pci.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index 05f4faca6e..03f6d961d2 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -742,12 +742,12 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) PCIBus *bus; uint64_t msi_window_size = 4096; - if (sphb->index != -1) { + if (sphb->index != (uint32_t)-1) { hwaddr windows_base; - if ((sphb->buid != -1) || (sphb->dma_liobn != -1) - || (sphb->mem_win_addr != -1) - || (sphb->io_win_addr != -1)) { + if ((sphb->buid != (uint64_t)-1) || (sphb->dma_liobn != (uint32_t)-1) + || (sphb->mem_win_addr != (hwaddr)-1) + || (sphb->io_win_addr != (hwaddr)-1)) { error_setg(errp, "Either \"index\" or other parameters must" " be specified for PAPR PHB, not both"); return; @@ -768,22 +768,22 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) sphb->io_win_addr = windows_base + SPAPR_PCI_IO_WIN_OFF; } - if (sphb->buid == -1) { + if (sphb->buid == (uint64_t)-1) { error_setg(errp, "BUID not specified for PHB"); return; } - if (sphb->dma_liobn == -1) { + if (sphb->dma_liobn == (uint32_t)-1) { error_setg(errp, "LIOBN not specified for PHB"); return; } - if (sphb->mem_win_addr == -1) { + if (sphb->mem_win_addr == (hwaddr)-1) { error_setg(errp, "Memory window address not specified for PHB"); return; } - if (sphb->io_win_addr == -1) { + if (sphb->io_win_addr == (hwaddr)-1) { error_setg(errp, "IO window address not specified for PHB"); return; }