Remainder of fix for PR kern/51135: if there is an entropy source
that can produce arbitrarily much data, as in rump, then nothing
should ever block indefinitely waiting for data.
rumpuser_random is limited to 32 bytes at a time -- which would be
reasonable, except that there are too many buffers in the way between
entropy sources and users of the entropy pool.
Partial fix for PR kern/51135.
of the commit log message, but this is easier for releng to find when
they start collecting info for 8.0
If anyone else wants to edit this entry, please feel free.
When allocating memory, the kernel allocates physical pages and virtual
addresses for these pages. In order to optimize allocations smaller
than PAGE_SIZE, uvm_km_kmem_alloc can allocate a single physical page
and take its virtual address in the direct map in high virtual memory.
This direct map is set up at boot time, its PTEs do not change, and
therefore they don't need to be kentered. These high virtual PTEs being
constant, the permissions of the areas they point to are fixed at boot
time and cannot change.
The problem is that at boot time, they are created with RWX permissions.
Therefore, allocations smaller than PAGE_SIZE in the kernel heap are all
executable: mbufs, pnbufs, small kmem allocations, etc.
Fix this by setting the NOX bit in the direct map pages at boot time. We
also set the NOX bit in the temporary tmpva, since it does not need to
be executable either.
This also makes the U-area non executable on amd64.
don't wake up all the threads being requeued to have them move themselves
from one list to another (thus defeating the purpose), just change the lists
directly in futex_wake().
src/external/mit/xorg/lib/libxcb/xkb.
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=231599
PR debug/67355
* var-tracking.c (reverse_op): Don't add dummy zero to reverse
ops that simplify back to the original value.
* alias.c (refs_newer_value_p): Cut off recursion for
expressions containing the original value.
We are no longer calling UFS_WAPBL_BEGIN/END with vnodes (we are giving
NULL as a parameter in all cases), so we can get rid of this input
parameter and the relevant check.
From coypu.
christos