FreeBSD source tree https://cgit-dev.freebsd.org/src/atom?h=release%2F12.3.0 2019-05-15T17:50:17Z 2019-05-15T17:50:17Z Ian Lepore ian@FreeBSD.org 2019-05-15T17:50:17Z urn:sha1:66fdffa429986d1abd3f3c1b07ab6b5e5f94bef9 Allow dcons(4) to be unloaded when loaded as a module. When the module is unloaded, the tty devices are destroyed. That requires implementing the tsw_free callback to avoid a panic. This driver requires no particular cleanup to be done from the callback, but the module itself must remain in memory until the deferred tsw_free callbacks are invoked. These changes implement that by incrementing a reference count variable in the detach routine, and decrementing it in the tsw_free callback. The MOD_UNLOAD event handler doesn't return until the count drops to zero. PR: 237758 2018-04-13T20:30:49Z Konstantin Belousov kib@FreeBSD.org 2018-04-13T20:30:49Z urn:sha1:d86c1f0dc1b17d94a533b4d3e9228dff9cb3fb31 The change makes the user and kernel address spaces on i386 independent, giving each almost the full 4G of usable virtual addresses except for one PDE at top used for trampoline and per-CPU trampoline stacks, and system structures that must be always mapped, namely IDT, GDT, common TSS and LDT, and process-private TSS and LDT if allocated. By using 1:1 mapping for the kernel text and data, it appeared possible to eliminate assembler part of the locore.S which bootstraps initial page table and KPTmap. The code is rewritten in C and moved into the pmap_cold(). The comment in vmparam.h explains the KVA layout. There is no PCID mechanism available in protected mode, so each kernel/user switch forth and back completely flushes the TLB, except for the trampoline PTD region. The TLB invalidations for userspace becomes trivial, because IPI handlers switch page tables. On the other hand, context switches no longer need to reload %cr3. copyout(9) was rewritten to use vm_fault_quick_hold(). An issue for new copyout(9) is compatibility with wiring user buffers around sysctl handlers. This explains two kind of locks for copyout ptes and accounting of the vslock() calls. The vm_fault_quick_hold() AKA slow path, is only tried after the 'fast path' failed, which temporary changes mapping to the userspace and copies the data to/from small per-cpu buffer in the trampoline. If a page fault occurs during the copy, it is short-circuit by exception.s to not even reach C code. The change was motivated by the need to implement the Meltdown mitigation, but instead of KPTI the full split is done. The i386 architecture already shows the sizing problems, in particular, it is impossible to link clang and lld with debugging. I expect that the issues due to the virtual address space limits would only exaggerate and the split gives more liveness to the platform. Tested by: pho Discussed with: bde Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D14633 2017-11-18T14:26:50Z Pedro F. Giffuni pfg@FreeBSD.org 2017-11-18T14:26:50Z urn:sha1:df57947f083046d50552e99b91074927d2458708 The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point. Initially, only tag files that use BSD 4-Clause "Original" license. RelNotes: yes Differential Revision: https://reviews.freebsd.org/D13133 2015-05-22T17:05:21Z Jung-uk Kim jkim@FreeBSD.org 2015-05-22T17:05:21Z urn:sha1:fd90e2ed54a69bb07d14dcd4e805431ccb7d6cb6 years for head. However, it is continuously misused as the mpsafe argument for callout_init(9). Deprecate the flag and clean up callout_init() calls to make them more consistent. Differential Revision: https://reviews.freebsd.org/D2613 Reviewed by: jhb MFC after: 2 weeks 2015-01-21T19:53:52Z Will Andrews will@FreeBSD.org 2015-01-21T19:53:52Z urn:sha1:49f159beefdb052e182816178db93c83abbfb649 Submitted by: gibbs MFC after: 1 week Sponsored by: Spectra Logic MFSpectraBSD: 1110990 on 2015/01/06 2013-02-19T18:22:25Z Alexander Motin mav@FreeBSD.org 2013-02-19T18:22:25Z urn:sha1:fd7e68271969f2a6a2b4a10cbc451c090ac276a3 Make dcons input polling adaptive, reducing poll rate to 1Hz after several minutes of inactivty to reduce global interrupt rate. Most of users never used FireWire debugging, so it is not very useful to consume power by it. 2011-12-17T15:08:43Z Andriy Gapon avg@FreeBSD.org 2011-12-17T15:08:43Z urn:sha1:9976156f12f1be7cb85c90e9ef54be06690bc955 At the moment grab and ungrab methods of all console drivers are no-ops. Current intended meaning of the calls is that the kernel takes control of console input. In the future the semantics may be extended to mean that the calling thread takes full ownership of the console (e.g. console output from other threads could be suspended). Inspired by: bde MFC after: 2 months 2011-11-07T15:43:11Z Ed Schouten ed@FreeBSD.org 2011-11-07T15:43:11Z urn:sha1:6472ac3d8a86336899b6cfb789a4cd9897e3fab5 The SYSCTL_NODE macro defines a list that stores all child-elements of that node. If there's no SYSCTL_DECL macro anywhere else, there's no reason why it shouldn't be static. 2011-08-27T14:24:27Z Robert Watson rwatson@FreeBSD.org 2011-08-27T14:24:27Z urn:sha1:e5a0927394502ac7d7d0383c523490eb35f773dc improvements: (1) Implement new model in previously missed at91 UART driver (2) Move BREAK_TO_DEBUGGER and ALT_BREAK_TO_DEBUGGER from opt_comconsole.h to opt_kdb.h (spotted by np) (3) Garbage collect now-unused opt_comconsole.h MFC after: 3 weeks Approved by: re (bz) 2011-08-26T21:46:36Z Robert Watson rwatson@FreeBSD.org 2011-08-26T21:46:36Z urn:sha1:4cf75455890c103c9a66cb791e88998aafd4f8ce accessible: (1) Always compile in support for breaking into the debugger if options KDB is present in the kernel. (2) Disable both by default, but allow them to be enabled via tunables and sysctls debug.kdb.break_to_debugger and debug.kdb.alt_break_to_debugger. (3) options BREAK_TO_DEBUGGER and options ALT_BREAK_TO_DEBUGGER continue to behave as before -- only now instead of compiling in break-to-debugger support, they change the default values of the above sysctls to enable those features by default. Current kernel configurations should, therefore, continue to behave as expected. (4) Migrate alternative break-to-debugger state machine logic out of individual device drivers into centralised KDB code. This has a number of upsides, but also one downside: it's now tricky to release sio spin locks when entering the debugger, so we don't. However, similar logic does not exist in other device drivers, including uart. (5) dcons requires some special handling; unlike other console types, it allows overriding KDB's own debugger selection, so we need a new interface to KDB to allow that to work. GENERIC kernels in -CURRENT will now support break-to-debugger as long as appropriate boot/run-time options are set, which should improve the debuggability of BETA kernels significantly. MFC after: 3 weeks Reviewed by: kib, nwhitehorn Approved by: re (bz)