On Mon, Sep 24, 2012 at 01:44:47PM -0700, Eric W. Biederman wrote: > Cyrill Gorcunov <gorcunov@xxxxxxxxxx> writes: > > > On Mon, Sep 24, 2012 at 10:51:19PM +0400, Cyrill Gorcunov wrote: > >> > I expect what you want is a call to access_ok, rather than hard coding > >> > details about task layout here. This test certainly looks wrong > >> > for a 32bit process on a 64bit kernel. If I read your test right it > >> > appears I can set values of say 0x100000000 on a 32bit process... > >> > > >> > As for mmap_min_addr I would expect your find_vma check would make that > >> > test unnecessary, simply by not finding a vma... > >> > >> Good point, Eric, thanks! I'm cooking a new patch now. > > > > Btw, Eric, I somehow miss one bit -- how would you set this 0x100000000 > > if TASK_SIZE is a macro which does check for TIF_ADDR32 and sets limit > > acordingly? What i'm missing? > > How odd. Last time I had looked TASK_SIZE was a simple constant. Ah, I see. > Still I wonder a little if all architectures currently run from 0 to > TASK_SIZE, for address space available. I seem to remember there have > been some exceptions to that rule. But I can't recall what they were. Actually I;ve tuned up the code to use access_ok instead but now I'm trying to fugure out situation if it can somehow affect c/r process (well, i've ran all test cases we use for c/r and all are passed well, but still...). Mark, after some more thinking, I agree that your proposal with min-address should work better than mine explicit CONFIG_MMU. Could you please send your patch for that? As to access_ok -- gimme some more time, i need to double check everything and I'll patch the code on top of your patch a bit later, ok? -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
