Messages in this thread | | | Date | Sun, 8 Feb 2009 04:26:51 -0700 | From | Matthew Wilcox <> | Subject | Re: [PATCH] PCI/MSI: fix msi_mask() |
| |
On Thu, Feb 05, 2009 at 11:47:36AM +0900, Hidetoshi Seto wrote: > The commit bffac3c593eba1f9da3efd0199e49ea6558a40ce does: > > - temp = (1 << multi_msi_capable(control)); > - temp = ((temp - 1) & ~temp); > + temp = msi_mask((control & PCI_MSI_FLAGS_QMASK) >> 1); > > and provides msi_mask() to avoid undefined shift by 32. [...] > This patch fix the wrong array in the msi_mask().
Quite correct. While disconnected for a couple of weeks, I also considered this possible fix:
static inline __attribute_const__ u32 msi_mask(unsigned x) { /* Don't shift by >= width of type */ if (x >= 5) return 0xffffffff; return (1 << (1 << x)) - 1; }
which has the added bonus of not running off the end of the array if some device has a bogus value in its config space.
What do you think?
-- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."
| |