Messages in this thread | | | From | mike stump <> | Date | Sun, 6 Jan 2002 10:20:47 -0800 (PST) | Subject | Re: [PATCH] C undefined behavior fix |
| |
> From: dewar@gnat.com > To: dewar@gnat.com, paulus@samba.org > Date: Sun, 6 Jan 2002 08:05:56 -0500 (EST)
> If you have a memory mapped byte, you really want a way of saying > "when I read this byte, do a byte read, it will not work to do a > word read"
> (volatile gets close in C, but is not close enough) will ensure a > byte store in practice, but may not ensure byte reads.
? Do you have an example where this fails? Do you not consider it a bug? Now, I would place a fair amount of buren on the compiler to get it right, though, this isn't absolute. For example, eieieio or whatever it is called on the powerpc. I think the chip/OS/MMU must bear some responsibility for meeting its obligations to the compiler, and if it doesn't, then that chip/OS/MMU fails to provide a reasonable base on which to provide the compiler. Did you have this case in mind? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |