Messages in this thread | | | Date | Sun, 26 Jan 2014 17:53:07 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH v3 4/4] x86, mpx: extend siginfo structure to include bound violation information |
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On 01/26/2014 05:34 PM, Ren Qiaowei wrote: >> > I agree with you and we should suppress all the warnings as possible. If > I use (unsgined long) to cast like the following code, what do you think > about it? sizeof(long) will be 4 for 32-bit. > > info->si_lower = (void __user *)(unsigned long) > (xsave_buf->bndregs.bndregs[2*bndregno]); > info->si_upper = (void __user *)(unsigned long) > (~xsave_buf->bndregs.bndregs[2*bndregno+1]); >
That is the way it is usually done, yes. Add a comment saying something like:
/* Note: the upper 32 bits are ignored in 32-bit mode. */
It is worth watching out a bit here, though, because you could be running a 32-bit process on top of a 64-bit kernel.
-hpa
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