On Wed, Jun 28, 2017 at 04:02:37AM +0000, Konstantin Belousov wrote: > Author: kib > Date: Wed Jun 28 04:02:36 2017 > New Revision: 320430 > URL: https://svnweb.freebsd.org/changeset/base/320430 > > Log: > Treat the addr argument for mmap(2) request without MAP_FIXED flag as > a hint. > > Right now, for non-fixed mmap(2) calls, addr is de-facto interpreted > as the absolute minimal address of the range where the mapping is > created. The VA allocator only allocates in the range [addr, > VM_MAXUSER_ADDRESS]. This is too restrictive, the mmap(2) call might > unduly fail if there is no free addresses above addr but a lot of > usable space below it. > > Lift this implementation limitation by allocating VA in two passes. > First, try to allocate above addr, as before. If that fails, do the > second pass with less restrictive constraints for the start of > allocation by specifying minimal allocation address at the max bss > end, if this limit is less than addr. > > One important case where this change makes a difference is the > allocation of the stacks for new threads in libthr. Under some > configuration conditions, libthr tries to hint kernel to reuse the > main thread stack grow area for the new stacks. This cannot work by > design now after grow area is converted to stack, and there is no > unallocated VA above the main stack. Interpreting requested stack > base address as the hint provides compatibility with old libthr and > with (mis-)configured current libthr. > > Reviewed by: alc > Tested by: dim (previous version) > Sponsored by: The FreeBSD Foundation > MFC after: 1 week > > Modified: > head/sys/vm/vm_map.c > head/sys/vm/vm_map.h > head/sys/vm/vm_mmap.c
Hey Kostik, This commit breaks both xorg and shutting down/rebooting. Reverting this commit makes my laptop happy again. Thanks, -- Shawn Webb Cofounder and Security Engineer HardenedBSD GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE
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