kernel.git/arch/openrisc, branch linux-5.13.y

openrisc: don't printk() unconditionally

2021-09-18T11:41:52Z

[ Upstream commit 946e1052cdcc7e585ee5d1e72528ca49fb295243 ] Don't call printk() when CONFIG_PRINTK is not set. Fixes the following build errors: or1k-linux-ld: arch/openrisc/kernel/entry.o: in function `_external_irq_handler': (.text+0x804): undefined reference to `printk' (.text+0x804): relocation truncated to fit: R_OR1K_INSN_REL_26 against undefined symbol `printk' Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Signed-off-by: Randy Dunlap Reported-by: kernel test robot Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: Stafford Horne Cc: openrisc@lists.librecores.org Signed-off-by: Stafford Horne Signed-off-by: Sasha Levin

sched/core: Initialize the idle task with preemption disabled

2021-07-14T15:06:21Z

[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ] As pointed out by commit de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread") init_idle() can and will be invoked more than once on the same idle task. At boot time, it is invoked for the boot CPU thread by sched_init(). Then smp_init() creates the threads for all the secondary CPUs and invokes init_idle() on them. As the hotplug machinery brings the secondaries to life, it will issue calls to idle_thread_get(), which itself invokes init_idle() yet again. In this case it's invoked twice more per secondary: at _cpu_up(), and at bringup_cpu(). Given smp_init() already initializes the idle tasks for all *possible* CPUs, no further initialization should be required. Now, removing init_idle() from idle_thread_get() exposes some interesting expectations with regards to the idle task's preempt_count: the secondary startup always issues a preempt_disable(), requiring some reset of the preempt count to 0 between hot-unplug and hotplug, which is currently served by idle_thread_get() -> idle_init(). Given the idle task is supposed to have preemption disabled once and never see it re-enabled, it seems that what we actually want is to initialize its preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove init_idle() from idle_thread_get(). Secondary startups were patched via coccinelle: @begone@ @@ -preempt_disable(); ... cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); Signed-off-by: Valentin Schneider Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com Signed-off-by: Sasha Levin

Merge tag 'for-linus' of git://github.com/openrisc/linux

2021-05-21T16:06:19Z

Pull OpenRISC fixes from Stafford Horne: "A few fixes that came in around the time of the merge window" * tag 'for-linus' of git://github.com/openrisc/linux: openrisc: Define memory barrier mb openrisc: mm/init.c: remove unused variable 'end' in paging_init() openrisc: mm/init.c: remove unused memblock_region variable in map_ram() openrisc: Fix a memory leak

openrisc: Define memory barrier mb

2021-05-15T07:00:10Z

This came up in the discussion of the requirements of qspinlock on an architecture. OpenRISC uses qspinlock, but it was noticed that the memmory barrier was not defined. Peter defined it in the mail thread writing: As near as I can tell this should do. The arch spec only lists this one instruction and the text makes it sound like a completion barrier. This is correct so applying this patch. Signed-off-by: Peter Zijlstra [shorne@gmail.com:Turned the mail into a patch] Signed-off-by: Stafford Horne

openrisc: mm/init.c: remove unused variable 'end' in paging_init()

2021-05-09T21:22:43Z

A build with W=1 enabled produces the following warning: CC arch/openrisc/mm/init.o arch/openrisc/mm/init.c: In function 'paging_init': arch/openrisc/mm/init.c:131:16: warning: variable 'end' set but not used [-Wunused-but-set-variable] 131 | unsigned long end; | ^~~ Remove the unused variable 'end'. Signed-off-by: Mike Rapoport Signed-off-by: Stafford Horne

openrisc: mm/init.c: remove unused memblock_region variable in map_ram()

2021-05-09T21:22:31Z

Kernel test robot reports: cppcheck possible warnings: (new ones prefixed by >>, may not real problems) >> arch/openrisc/mm/init.c:125:10: warning: Uninitialized variable: region [uninitvar] region->base, region->base + region->size); ^ Replace usage of memblock_region fields with 'start' and 'end' variables that are initialized in for_each_mem_range() and remove the declaration of region. Fixes: b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") Reported-by: kernel test robot Signed-off-by: Mike Rapoport Signed-off-by: Stafford Horne

drivers/char: remove /dev/kmem for good

2021-05-07T07:26:34Z

Patch series "drivers/char: remove /dev/kmem for good". Exploring /dev/kmem and /dev/mem in the context of memory hot(un)plug and memory ballooning, I started questioning the existence of /dev/kmem. Comparing it with the /proc/kcore implementation, it does not seem to be able to deal with things like a) Pages unmapped from the direct mapping (e.g., to be used by secretmem) -> kern_addr_valid(). virt_addr_valid() is not sufficient. b) Special cases like gart aperture memory that is not to be touched -> mem_pfn_is_ram() Unless I am missing something, it's at least broken in some cases and might fault/crash the machine. Looks like its existence has been questioned before in 2005 and 2010 [1], after ~11 additional years, it might make sense to revive the discussion. CONFIG_DEVKMEM is only enabled in a single defconfig (on purpose or by mistake?). All distributions disable it: in Ubuntu it has been disabled for more than 10 years, in Debian since 2.6.31, in Fedora at least starting with FC3, in RHEL starting with RHEL4, in SUSE starting from 15sp2, and OpenSUSE has it disabled as well. 1) /dev/kmem was popular for rootkits [2] before it got disabled basically everywhere. Ubuntu documents [3] "There is no modern user of /dev/kmem any more beyond attackers using it to load kernel rootkits.". RHEL documents in a BZ [5] "it served no practical purpose other than to serve as a potential security problem or to enable binary module drivers to access structures/functions they shouldn't be touching" 2) /proc/kcore is a decent interface to have a controlled way to read kernel memory for debugging puposes. (will need some extensions to deal with memory offlining/unplug, memory ballooning, and poisoned pages, though) 3) It might be useful for corner case debugging [1]. KDB/KGDB might be a better fit, especially, to write random memory; harder to shoot yourself into the foot. 4) "Kernel Memory Editor" [4] hasn't seen any updates since 2000 and seems to be incompatible with 64bit [1]. For educational purposes, /proc/kcore might be used to monitor value updates -- or older kernels can be used. 5) It's broken on arm64, and therefore, completely disabled there. Looks like it's essentially unused and has been replaced by better suited interfaces for individual tasks (/proc/kcore, KDB/KGDB). Let's just remove it. [1] https://lwn.net/Articles/147901/ [2] https://www.linuxjournal.com/article/10505 [3] https://wiki.ubuntu.com/Security/Features#A.2Fdev.2Fkmem_disabled [4] https://sourceforge.net/projects/kme/ [5] https://bugzilla.redhat.com/show_bug.cgi?id=154796 Link: https://lkml.kernel.org/r/20210324102351.6932-1-david@redhat.com Link: https://lkml.kernel.org/r/20210324102351.6932-2-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Michal Hocko Acked-by: Kees Cook Cc: Linus Torvalds Cc: Greg Kroah-Hartman Cc: "Alexander A. Klimov" Cc: Alexander Viro Cc: Alexandre Belloni Cc: Andrew Lunn Cc: Andrey Zhizhikin Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Brian Cain Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Chris Zankel Cc: Corentin Labbe Cc: "David S. Miller" Cc: "Eric W. Biederman" Cc: Geert Uytterhoeven Cc: Gerald Schaefer Cc: Greentime Hu Cc: Gregory Clement Cc: Heiko Carstens Cc: Helge Deller Cc: Hillf Danton Cc: huang ying Cc: Ingo Molnar Cc: Ivan Kokshaysky Cc: "James E.J. Bottomley" Cc: James Troup Cc: Jiaxun Yang Cc: Jonas Bonn Cc: Jonathan Corbet Cc: Kairui Song Cc: Krzysztof Kozlowski Cc: Kuninori Morimoto Cc: Liviu Dudau Cc: Lorenzo Pieralisi Cc: Luc Van Oostenryck Cc: Luis Chamberlain Cc: Matthew Wilcox Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Mike Rapoport Cc: Mikulas Patocka Cc: Minchan Kim Cc: Niklas Schnelle Cc: Oleksiy Avramchenko Cc: openrisc@lists.librecores.org Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: "Pavel Machek (CIP)" Cc: Pavel Machek Cc: "Peter Zijlstra (Intel)" Cc: Pierre Morel Cc: Randy Dunlap Cc: Richard Henderson Cc: Rich Felker Cc: Robert Richter Cc: Rob Herring Cc: Russell King Cc: Sam Ravnborg Cc: Sebastian Andrzej Siewior Cc: Sebastian Hesselbarth Cc: sparclinux@vger.kernel.org Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Steven Rostedt Cc: Sudeep Holla Cc: Theodore Dubois Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Viresh Kumar Cc: William Cohen Cc: Xiaoming Ni Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: move mem_init_print_info() into mm_init()

2021-04-30T18:20:42Z

mem_init_print_info() is called in mem_init() on each architecture, and pass NULL argument, so using void argument and move it into mm_init(). Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: Dave Hansen [x86] Reviewed-by: Christophe Leroy [powerpc] Acked-by: David Hildenbrand Tested-by: Anatoly Pugachev [sparc64] Acked-by: Russell King [arm] Acked-by: Mike Rapoport Cc: Catalin Marinas Cc: Richard Henderson Cc: Guo Ren Cc: Yoshinori Sato Cc: Huacai Chen Cc: Jonas Bonn Cc: Palmer Dabbelt Cc: Heiko Carstens Cc: "David S. Miller" Cc: "Peter Zijlstra" Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

openrisc: Fix a memory leak

2021-04-28T12:40:44Z

'setup_find_cpu_node()' take a reference on the node it returns. This reference must be decremented when not needed anymore, or there will be a leak. Add the missing 'of_node_put(cpu)'. Note that 'setup_cpuinfo()' that also calls this function already has a correct 'of_node_put(cpu)' at its end. Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Signed-off-by: Christophe JAILLET Signed-off-by: Stafford Horne

Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block

2021-02-27T16:29:02Z

Pull io_uring thread rewrite from Jens Axboe: "This converts the io-wq workers to be forked off the tasks in question instead of being kernel threads that assume various bits of the original task identity. This kills > 400 lines of code from io_uring/io-wq, and it's the worst part of the code. We've had several bugs in this area, and the worry is always that we could be missing some pieces for file types doing unusual things (recent /dev/tty example comes to mind, userfaultfd reads installing file descriptors is another fun one... - both of which need special handling, and I bet it's not the last weird oddity we'll find). With these identical workers, we can have full confidence that we're never missing anything. That, in itself, is a huge win. Outside of that, it's also more efficient since we're not wasting space and code on tracking state, or switching between different states. I'm sure we're going to find little things to patch up after this series, but testing has been pretty thorough, from the usual regression suite to production. Any issue that may crop up should be manageable. There's also a nice series of further reductions we can do on top of this, but I wanted to get the meat of it out sooner rather than later. The general worry here isn't that it's fundamentally broken. Most of the little issues we've found over the last week have been related to just changes in how thread startup/exit is done, since that's the main difference between using kthreads and these kinds of threads. In fact, if all goes according to plan, I want to get this into the 5.10 and 5.11 stable branches as well. That said, the changes outside of io_uring/io-wq are: - arch setup, simple one-liner to each arch copy_thread() implementation. - Removal of net and proc restrictions for io_uring, they are no longer needed or useful" * tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits) io-wq: remove now unused IO_WQ_BIT_ERROR io_uring: fix SQPOLL thread handling over exec io-wq: improve manager/worker handling over exec io_uring: ensure SQPOLL startup is triggered before error shutdown io-wq: make buffered file write hashed work map per-ctx io-wq: fix race around io_worker grabbing io-wq: fix races around manager/worker creation and task exit io_uring: ensure io-wq context is always destroyed for tasks arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread() io_uring: cleanup ->user usage io-wq: remove nr_process accounting io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS net: remove cmsg restriction from io_uring based send/recvmsg calls Revert "proc: don't allow async path resolution of /proc/self components" Revert "proc: don't allow async path resolution of /proc/thread-self components" io_uring: move SQPOLL thread io-wq forked worker io-wq: make io_wq_fork_thread() available to other users io-wq: only remove worker from free_list, if it was there io_uring: remove io_identity io_uring: remove any grabbing of context ...