| Message ID | 1336392045-31211-1-git-send-email-avi@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, May 07, 2012 at 03:00:45PM +0300, Avi Kivity wrote: > Commit afe0a595356192 added byte reads for TxStatus/TxAddr, but > broke 32-bit reads; the mask generation > > (1 << (8 * size)) - 1 > > is unspecified in C for size >= sizeof(int), and in fact returns 0 > on x86. > > Fix by using a larger type. > > Fixes (at least) Fedora 9 i386 with -machine kernel_irqchip=on. I > didn't see it with the qemu APIC implementation; may be due to timing > or (more likely) a tester error. > > Signed-off-by: Avi Kivity <avi@redhat.com> Applied, thanks > --- > hw/rtl8139.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/rtl8139.c b/hw/rtl8139.c > index 4d0f5ba..eb22d04 100644 > --- a/hw/rtl8139.c > +++ b/hw/rtl8139.c > @@ -2500,7 +2500,7 @@ static uint32_t rtl8139_TxStatus_TxAddr_read(RTL8139State *s, uint32_t regs[], > case 1: /* fall through */ > case 2: /* fall through */ > case 4: > - ret = (regs[reg] >> offset * 8) & ((1 << (size * 8)) - 1); > + ret = (regs[reg] >> offset * 8) & (((uint64_t)1 << (size * 8)) - 1); > DPRINTF("TxStatus/TxAddr[%d] read addr=0x%x size=0x%x val=0x%08x\n", > reg, addr, size, ret); > break; > -- > 1.7.10.1
diff --git a/hw/rtl8139.c b/hw/rtl8139.c index 4d0f5ba..eb22d04 100644 --- a/hw/rtl8139.c +++ b/hw/rtl8139.c @@ -2500,7 +2500,7 @@ static uint32_t rtl8139_TxStatus_TxAddr_read(RTL8139State *s, uint32_t regs[], case 1: /* fall through */ case 2: /* fall through */ case 4: - ret = (regs[reg] >> offset * 8) & ((1 << (size * 8)) - 1); + ret = (regs[reg] >> offset * 8) & (((uint64_t)1 << (size * 8)) - 1); DPRINTF("TxStatus/TxAddr[%d] read addr=0x%x size=0x%x val=0x%08x\n", reg, addr, size, ret); break;
Commit afe0a595356192 added byte reads for TxStatus/TxAddr, but broke 32-bit reads; the mask generation (1 << (8 * size)) - 1 is unspecified in C for size >= sizeof(int), and in fact returns 0 on x86. Fix by using a larger type. Fixes (at least) Fedora 9 i386 with -machine kernel_irqchip=on. I didn't see it with the qemu APIC implementation; may be due to timing or (more likely) a tester error. Signed-off-by: Avi Kivity <avi@redhat.com> --- hw/rtl8139.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)