This commit adds proper cache and shareability attributes to
the TCR register.
Set memory attributes to Normal, outer and inner cacheable WBWA.
Set shareability to inner and outer shareable when SMP is enabled.
Reviewed by: andrew
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3093
Summary:
In a runtime that is purely based on capability-based security, there is
a strong emphasis on how programs start their execution. We need to make
sure that we execute an new program with an exact set of file
descriptors, ensuring that credentials are not leaked into the process
accidentally.
Providing the right file descriptors is just half the problem. There
also needs to be a framework in place that gives meaning to these file
descriptors. How does a CloudABI mail server know which of the file
descriptors corresponds to the socket that receives incoming emails?
Furthermore, how will this mail server acquire its configuration
parameters, as it cannot open a configuration file from a global path on
disk?
CloudABI solves this problem by replacing traditional string command
line arguments by tree-like data structure consisting of scalars,
sequences and mappings (similar to YAML/JSON). In this structure, file
descriptors are treated as a first-class citizen. When calling exec(),
file descriptors are passed on to the new executable if and only if they
are referenced from this tree structure. See the cloudabi-run(1) man
page for more details and examples (sysutils/cloudabi-utils).
Fortunately, the kernel does not need to care about this tree structure
at all. The C library is responsible for serializing and deserializing,
but also for extracting the list of referenced file descriptors. The
system call only receives a copy of the serialized data and a layout of
what the new file descriptor table should look like:
int proc_exec(int execfd, const void *data, size_t datalen, const int *fds,
size_t fdslen);
This change introduces a set of fd*_remapped() functions:
- fdcopy_remapped() pulls a copy of a file descriptor table, remapping
all of the file descriptors according to the provided mapping table.
- fdinstall_remapped() replaces the file descriptor table of the process
by the copy created by fdcopy_remapped().
- fdescfree_remapped() frees the table in case we aborted before
fdinstall_remapped().
We then add a function exec_copyin_data_fds() that builds on top these
functions. It copies in the data and constructs a new remapped file
descriptor. This is used by cloudabi_sys_proc_exec().
Test Plan:
cloudabi-run(1) is capable of spawning processes successfully, providing
it data and file descriptors. procstat -f seems to confirm all is good.
Regular FreeBSD processes also work properly.
Reviewers: kib, mjg
Reviewed By: mjg
Subscribers: imp
Differential Revision: https://reviews.freebsd.org/D3079
It appears that the linker will not handle 64-bit relocations at addresses that
are not aligned to 8-byte boundaries. Prior to this change the line:
.llong generictrap
was aligned to a 4-byte address, and the linker replaced that with an 8-byte
0x0. Aligning that address to 8 bytes caused the linker to generate the proper
relocation. As a follow-through, the dblow from trap_subr33.S used the code
sequence 'lwz %r1, TRAP_GENTRAP(0)', so this reproduces the analogue of that for
64-bit.
polling at device attach time [1].
Add tunables 'debug.uart_force_poll' and 'debug.uart_poll_freq' to control
uart polling.
Submitted by: Aleksey Kuleshov (rndfax@yandex.ru) [1]
strict-aliasing rules.
Declare some variables as statics as well as some functions that are internal
helpers. Update the function broadcast_result() to a post-K&R definition.
Differential Revision: D2690
Reviewed by: rodrigc, dim
because for no mailwrapper case we have:
/usr/sbin/sendmail -> /usr/sbin/mailwrapper
/usr/sbin/mailwrapper -> /usr/libexec/sendmail/sendmail
Add comment explaining it.
architectures. Atomic_cmpset_int(9) is a direct replacement, due to
loop. The change fixes arm, arm64, mips an sparc64, which lack
atomic_swap().
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
current value. It is believed that the change is the real fix for the
issue which was covered over by the r252683.
With the current code, if the interrupt handler sets it_need between
read and consequent reset, the update could be lost and
ithread_execute_handlers() would not be called in response to the lost
update.
The r252683 could have hide the issue since at the moment of commit,
atomic_load_acq_int() did locked cmpxchg on the variable, which puts
the cache line into the exclusive owned state and clears store
buffers. Then the immediate store of zero has very high chance of
reusing the exclusive state of the cache line and make the load and
store sequence operate as atomic swap.
For now, add the acq+rel fence immediately after the swap, to not
disturb current (but excessive) ordering. Acquire is needed for the
ih_need reads after the load, while release does not serve a useful
purpose [*].
Reviewed by: alc
Noted by: alc [*]
Discussed with: bde
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Identify current CPU. This is necessary to setup
affinity registers and to provide support for
runtime chip identification.
Reviewed by: andrew
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3095
We can map these system calls directly to the FreeBSD counterparts. The
other filesystem related system calls will be sent out for review
separately, as they are a bit more complex to get right.
an if_ixv instance can now set at creation time, and the receive ring
tail pointer is correctly initialized (previously, things still worked
because the receive ring tail pointer was being fixed up as a side
effect of other activity).
Differential Revision: https://reviews.freebsd.org/D2922
Reviewed by: erj, gnn
Approved by: jmallett (mentor)
Sponsored by: Norse Corp, Inc.
I performed the commit on a different system as where I wrote the
change. After pulling in the change from Phabricator, I didn't notice
that a single chunk did not apply.
Approved by: secteam (implicit, as intended change was approved)
Pointy hat to: me
