kernel/linux.git/arch/nds32, branch v5.10.257

exit: Add and use make_task_dead.

2023-02-01T07:23:19+00:00

commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream. There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin

arch: setup PF_IO_WORKER threads like PF_KTHREAD

2023-01-04T10:39:22+00:00

[ Upstream commit 4727dc20e0422211a0e0c72b1ace4ed6096df8a6 ] PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the sense that we don't assign ->set_child_tid with our own structure. Just ensure that every arch sets up the PF_IO_WORKER threads like kthreads in the arch implementation of copy_thread(). Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

nds32: add support for TIF_NOTIFY_SIGNAL

2023-01-04T10:39:21+00:00

[ Upstream commit b13e8bf615fe26fb6a6dfe1b5a1c65e1624dfee2 ] Wire up TIF_NOTIFY_SIGNAL handling for nds32. Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

nds32: fix access_ok() checks in get/put_user

2022-03-28T07:57:10+00:00

commit 8926d88ced46700bf6117ceaf391480b943ea9f4 upstream. The get_user()/put_user() functions are meant to check for access_ok(), while the __get_user()/__put_user() functions don't. This broke in 4.19 for nds32, when it gained an extraneous check in __get_user(), but lost the check it needs in __put_user(). Fixes: 487913ab18c2 ("nds32: Extract the checking and getting pointer to a macro") Cc: stable@vger.kernel.org @ v4.19+ Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

perf: Protect perf_guest_cbs with RCU

2022-01-20T08:17:50+00:00

commit ff083a2d972f56bebfd82409ca62e5dfce950961 upstream. Protect perf_guest_cbs with RCU to fix multiple possible errors. Luckily, all paths that read perf_guest_cbs already require RCU protection, e.g. to protect the callback chains, so only the direct perf_guest_cbs touchpoints need to be modified. Bug #1 is a simple lack of WRITE_ONCE/READ_ONCE behavior to ensure perf_guest_cbs isn't reloaded between a !NULL check and a dereference. Fixed via the READ_ONCE() in rcu_dereference(). Bug #2 is that on weakly-ordered architectures, updates to the callbacks themselves are not guaranteed to be visible before the pointer is made visible to readers. Fixed by the smp_store_release() in rcu_assign_pointer() when the new pointer is non-NULL. Bug #3 is that, because the callbacks are global, it's possible for readers to run in parallel with an unregisters, and thus a module implementing the callbacks can be unloaded while readers are in flight, resulting in a use-after-free. Fixed by a synchronize_rcu() call when unregistering callbacks. Bug #1 escaped notice because it's extremely unlikely a compiler will reload perf_guest_cbs in this sequence. perf_guest_cbs does get reloaded for future derefs, e.g. for ->is_user_mode(), but the ->is_in_guest() guard all but guarantees the consumer will win the race, e.g. to nullify perf_guest_cbs, KVM has to completely exit the guest and teardown down all VMs before KVM start its module unload / unregister sequence. This also makes it all but impossible to encounter bug #3. Bug #2 has not been a problem because all architectures that register callbacks are strongly ordered and/or have a static set of callbacks. But with help, unloading kvm_intel can trigger bug #1 e.g. wrapping perf_guest_cbs with READ_ONCE in perf_misc_flags() while spamming kvm_intel module load/unload leads to: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 6 PID: 1825 Comm: stress Not tainted 5.14.0-rc2+ #459 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:perf_misc_flags+0x1c/0x70 Call Trace: perf_prepare_sample+0x53/0x6b0 perf_event_output_forward+0x67/0x160 __perf_event_overflow+0x52/0xf0 handle_pmi_common+0x207/0x300 intel_pmu_handle_irq+0xcf/0x410 perf_event_nmi_handler+0x28/0x50 nmi_handle+0xc7/0x260 default_do_nmi+0x6b/0x170 exc_nmi+0x103/0x130 asm_exc_nmi+0x76/0xbf Fixes: 39447b386c84 ("perf: Enhance perf to allow for guest statistic collection from host") Signed-off-by: Sean Christopherson Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Paolo Bonzini Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211111020738.2512932-2-seanjc@google.com Signed-off-by: Greg Kroah-Hartman

nds32: fix up stack guard gap

2021-07-28T12:35:46+00:00

commit c453db6cd96418c79702eaf38259002755ab23ff upstream. Commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") fixed up all architectures to deal with the stack guard gap. But when nds32 was added to the tree, it forgot to do the same thing. Resolve this by properly fixing up the nsd32's version of arch_get_unmapped_area() Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Cc: Michal Hocko Cc: Hugh Dickins Cc: Qiang Liu Cc: stable Reported-by: iLifetruth Acked-by: Hugh Dickins Link: https://lore.kernel.org/r/20210629104024.2293615-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff

2021-04-14T06:41:58+00:00

commit a3a8833dffb7e7329c2586b8bfc531adb503f123 upstream. Commit cb9f753a3731 ("mm: fix races between swapoff and flush dcache") updated flush_dcache_page implementations on several architectures to use page_mapping_file() in order to avoid races between page_mapping() and swapoff(). This update missed arch/nds32 and there is a possibility of a race there. Replace page_mapping() with page_mapping_file() in nds32 implementation of flush_dcache_page(). Link: https://lkml.kernel.org/r/20210330175126.26500-1-rppt@kernel.org Fixes: cb9f753a3731 ("mm: fix races between swapoff and flush dcache") Signed-off-by: Mike Rapoport Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Greentime Hu Cc: Huang Ying Cc: Nick Hu Cc: Vincent Chen Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

local64.h: make mandatory

2021-01-12T19:18:16+00:00

[ Upstream commit 87dbc209ea04645fd2351981f09eff5d23f8e2e9 ] Make mandatory in include/asm-generic/Kbuild and remove all arch/*/include/asm/local64.h arch-specific files since they only #include . This fixes build errors on arch/c6x/ and arch/nios2/ for block/blk-iocost.c. Build-tested on 21 of 25 arch-es. (tools problems on the others) Yes, we could even rename to and change all #includes to use instead. Link: https://lkml.kernel.org/r/20201227024446.17018-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Suggested-by: Christoph Hellwig Reviewed-by: Masahiro Yamada Cc: Jens Axboe Cc: Ley Foon Tan Cc: Mark Salter Cc: Aurelien Jacquiot Cc: Peter Zijlstra Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

Merge tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block

2020-10-23T17:06:38+00:00

Pull arch task_work cleanups from Jens Axboe: "Two cleanups that don't fit other categories: - Finally get the task_work_add() cleanup done properly, so we don't have random 0/1/false/true/TWA_SIGNAL confusing use cases. Updates all callers, and also fixes up the documentation for task_work_add(). - While working on some TIF related changes for 5.11, this TIF_NOTIFY_RESUME cleanup fell out of that. Remove some arch duplication for how that is handled" * tag 'arch-cleanup-2020-10-22' of git://git.kernel.dk/linux-block: task_work: cleanup notification modes tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()

Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-10-22T20:13:57+00:00

Pull Kbuild updates from Masahiro Yamada: - Support 'make compile_commands.json' to generate the compilation database more easily, avoiding stale entries - Support 'make clang-analyzer' and 'make clang-tidy' for static checks using clang-tidy - Preprocess scripts/modules.lds.S to allow CONFIG options in the module linker script - Drop cc-option tests from compiler flags supported by our minimal GCC/Clang versions - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y - Use sha1 build id for both BFD linker and LLD - Improve deb-pkg for reproducible builds and rootless builds - Remove stale, useless scripts/namespace.pl - Turn -Wreturn-type warning into error - Fix build error of deb-pkg when CONFIG_MODULES=n - Replace 'hostname' command with more portable 'uname -n' - Various Makefile cleanups * tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: Use uname for LINUX_COMPILE_HOST detection kbuild: Only add -fno-var-tracking-assignments for old GCC versions kbuild: remove leftover comment for filechk utility treewide: remove DISABLE_LTO kbuild: deb-pkg: clean up package name variables kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n kbuild: enforce -Werror=return-type scripts: remove namespace.pl builddeb: Add support for all required debian/rules targets builddeb: Enable rootless builds builddeb: Pass -n to gzip for reproducible packages kbuild: split the build log of kallsyms kbuild: explicitly specify the build id style scripts/setlocalversion: make git describe output more reliable kbuild: remove cc-option test of -Werror=date-time kbuild: remove cc-option test of -fno-stack-check kbuild: remove cc-option test of -fno-strict-overflow kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan kbuild: do not create built-in objects for external module builds ...