Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH] remove duplicate asm/mman.h files | Date | Mon, 21 Sep 2009 11:30:26 +0200 |
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On Monday 21 September 2009, David Rientjes wrote: > > I tried not to change the ABI in any way in my patch, and there is > > a theoretical possibility that some user space program on ia64 currently > > depends on that definition. > > > > I don't buy that as justification, if some userspace program uses it based > on the false belief that it actually does what it says, it's probably > better to break their build than perpetuating the lie that it's different > than ~MAP_GROWSDOWN.
It's more a matter of principle of my patches. I try to strictly separate patches that move code around (like the one I sent) from those that change contents (like yours, or the one before that adds MAP_STACK and MAP_HUGETLB).
Removing a definition from an exported header file either requires specific knowledge about why it is there to start with, or more research on the topic than I wanted to do. For instance, a theoretical program might have a helper function correctly doing
void *xmmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { if (flags & MAP_GROWSUP) { /* MAP_GROWSUP is not supported */ errno = -EINVAL; return MAP_FAILED; }
return mmap(addr, length, prot, flags, fd, offset); }
Of course, such a program would only work on ia64 currently, so it should be safe to make ia64 behave like the other architectures in this regard.
> ia64: remove definition for MAP_GROWSUP > > MAP_GROWSUP is unused. > > Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
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