Messages in this thread | | | Date | Fri, 13 Apr 2018 08:49:17 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH] mmap.2: MAP_FIXED is okay if the address range has been reserved |
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On Fri 13-04-18 08:43:27, Michael Kerrisk wrote: [...] > So, you mean remove this entire paragraph: > > For cases in which the specified memory region has not been > reserved using an existing mapping, newer kernels (Linux > 4.17 and later) provide an option MAP_FIXED_NOREPLACE that > should be used instead; older kernels require the caller to > use addr as a hint (without MAP_FIXED) and take appropriate > action if the kernel places the new mapping at a different > address. > > It seems like some version of the first half of the paragraph is worth > keeping, though, so as to point the reader in the direction of a remedy. > How about replacing that text with the following: > > Since Linux 4.17, the MAP_FIXED_NOREPLACE flag can be used > in a multithreaded program to avoid the hazard described > above.
Yes, that sounds reasonable to me.
-- Michal Hocko SUSE Labs
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