kernel.git/arch/sparc/kernel, branch linux-4.19.y

sparc64: Fix number of online CPUs

2024-06-16T11:23:44Z

commit 98937707fea8375e8acea0aaa0b68a956dd52719 upstream. Nick Bowler reported: When using newer kernels on my Ultra 60 with dual 450MHz UltraSPARC-II CPUs, I noticed that only CPU 0 comes up, while older kernels (including 4.7) are working fine with both CPUs. I bisected the failure to this commit: 9b2f753ec23710aa32c0d837d2499db92fe9115b is the first bad commit commit 9b2f753ec23710aa32c0d837d2499db92fe9115b Author: Atish Patra Date: Thu Sep 15 14:54:40 2016 -0600 sparc64: Fix cpu_possible_mask if nr_cpus is set This is a small change that reverts very easily on top of 5.18: there is just one trivial conflict. Once reverted, both CPUs work again. Maybe this is related to the fact that the CPUs on this system are numbered CPU0 and CPU2 (there is no CPU1)? The current code that adjust cpu_possible based on nr_cpu_ids do not take into account that CPU's may not come one after each other. Move the chech to the function that setup the cpu_possible mask so there is no need to adjust it later. Signed-off-by: Sam Ravnborg Fixes: 9b2f753ec237 ("sparc64: Fix cpu_possible_mask if nr_cpus is set") Reported-by: Nick Bowler Tested-by: Nick Bowler Link: https://lore.kernel.org/sparclinux/20201009161924.c8f031c079dd852941307870@gmx.de/ Link: https://lore.kernel.org/all/CADyTPEwt=ZNams+1bpMB1F9w_vUdPsGCt92DBQxxq_VtaLoTdw@mail.gmail.com/ Cc: stable@vger.kernel.org # v4.8+ Cc: Andreas Larsson Cc: David S. Miller Cc: Atish Patra Cc: Bob Picco Cc: Vijay Kumar Cc: David S. Miller Reviewed-by: Andreas Larsson Acked-by: Arnd Bergmann Link: https://lore.kernel.org/r/20240330-sparc64-warnings-v1-9-37201023ee2f@ravnborg.org Signed-off-by: Andreas Larsson Signed-off-by: Greg Kroah-Hartman

sparc64: NMI watchdog: fix return value of __setup handler

2024-04-13T10:50:03Z

[ Upstream commit 3ed7c61e49d65dacb96db798c0ab6fcd55a1f20f ] __setup() handlers should return 1 to obsolete_checksetup() in init/main.c to indicate that the boot option has been handled. A return of 0 causes the boot option/value to be listed as an Unknown kernel parameter and added to init's (limited) argument or environment strings. Also, error return codes don't mean anything to obsolete_checksetup() -- only non-zero (usually 1) or zero. So return 1 from setup_nmi_watchdog(). Fixes: e5553a6d0442 ("sparc64: Implement NMI watchdog on capable cpus.") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Cc: "David S. Miller" Cc: sparclinux@vger.kernel.org Cc: Sam Ravnborg Cc: Andrew Morton Cc: stable@vger.kernel.org Cc: Arnd Bergmann Cc: Andreas Larsson Signed-off-by: Andreas Larsson Link: https://lore.kernel.org/r/20240211052802.22612-1-rdunlap@infradead.org Signed-off-by: Sasha Levin

sparc32: Fix section mismatch in leon_pci_grpci

2024-03-26T22:22:41Z

[ Upstream commit 24338a6ae13cb743ced77da1b3a12c83f08a0c96 ] Passing a datastructre marked _initconst to platform_driver_register() is wrong. Drop the __initconst notation. This fixes the following warnings: WARNING: modpost: vmlinux: section mismatch in reference: grpci1_of_driver+0x30 (section: .data) -> grpci1_of_match (section: .init.rodata) WARNING: modpost: vmlinux: section mismatch in reference: grpci2_of_driver+0x30 (section: .data) -> grpci2_of_match (section: .init.rodata) Signed-off-by: Sam Ravnborg Cc: "David S. Miller" Cc: Andreas Larsson Fixes: 4154bb821f0b ("sparc: leon: grpci1: constify of_device_id") Fixes: 03949b1cb9f1 ("sparc: leon: grpci2: constify of_device_id") Tested-by: Randy Dunlap # build-tested Reviewed-by: Andreas Larsson Tested-by: Andreas Larsson Signed-off-by: Andreas Larsson Link: https://lore.kernel.org/r/20240224-sam-fix-sparc32-all-builds-v2-7-1f186603c5c4@ravnborg.org Signed-off-by: Sasha Levin

sparc/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T17:49:17Z

commit 44ade508e3bfac45ae97864587de29eb1a881ec0 upstream check_bugs() is about to be phased out. Switch over to the new arch_cpu_finalize_init() implementation. No functional change. Signed-off-by: Thomas Gleixner Reviewed-by: Sam Ravnborg Link: https://lore.kernel.org/r/20230613224545.431995857@linutronix.de Signed-off-by: Daniel Sneddon Signed-off-by: Greg Kroah-Hartman

exit: Add and use make_task_dead.

2023-02-06T06:49:45Z

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: Greg Kroah-Hartman

sparc: avoid stringop-overread errors

2021-10-06T13:31:17Z

[ Upstream commit fc7c028dcdbfe981bca75d2a7b95f363eb691ef3 ] The sparc mdesc code does pointer games with 'struct mdesc_hdr', but didn't describe to the compiler how that header is then followed by the data that the header describes. As a result, gcc is now unhappy since it does stricter pointer range tracking, and doesn't understand about how these things work. This results in various errors like: arch/sparc/kernel/mdesc.c: In function ‘mdesc_node_by_name’: arch/sparc/kernel/mdesc.c:647:22: error: ‘strcmp’ reading 1 or more bytes from a region of size 0 [-Werror=stringop-overread] 647 | if (!strcmp(names + ep[ret].name_offset, name)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ which are easily avoided by just describing 'struct mdesc_hdr' better, and making the node_block() helper function look into that unsized data[] that follows the header. This makes the sparc64 build happy again at least for my cross-compiler version (gcc version 11.2.1). Link: https://lore.kernel.org/lkml/CAHk-=wi4NW3NC0xWykkw=6LnjQD6D_rtRtxY9g8gQAJXtQMi8A@mail.gmail.com/ Cc: Guenter Roeck Cc: David S. Miller Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

sparc64: Fix opcode filtering in handling of no fault loads

2021-03-30T12:36:58Z

[ Upstream commit e5e8b80d352ec999d2bba3ea584f541c83f4ca3f ] is_no_fault_exception() has two bugs which were discovered via random opcode testing with stress-ng. Both are caused by improper filtering of opcodes. The first bug can be triggered by a floating point store with a no-fault ASI, for instance "sta %f0, [%g0] #ASI_PNF", opcode C1A01040. The code first tests op3[5] (0x1000000), which denotes a floating point instruction, and then tests op3[2] (0x200000), which denotes a store instruction. But these bits are not mutually exclusive, and the above mentioned opcode has both bits set. The intent is to filter out stores, so the test for stores must be done first in order to have any effect. The second bug can be triggered by a floating point load with one of the invalid ASI values 0x8e or 0x8f, which pass this check in is_no_fault_exception(): if ((asi & 0xf2) == ASI_PNF) An example instruction is "ldqa [%l7 + %o7] #ASI 0x8f, %f38", opcode CF95D1EF. Asi values greater than 0x8b (ASI_SNFL) are fatal in handle_ldf_stq(), and is_no_fault_exception() must not allow these invalid asi values to make it that far. In both of these cases, handle_ldf_stq() reacts by calling sun4v_data_access_exception() or spitfire_data_access_exception(), which call is_no_fault_exception() and results in an infinite recursion. Signed-off-by: Rob Gardner Tested-by: Anatoly Pugachev Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

sparc64: remove mm_cpumask clearing to fix kthread_use_mm race

2020-11-05T10:08:38Z

[ Upstream commit bafb056ce27940c9994ea905336aa8f27b4f7275 ] The de facto (and apparently uncommented) standard for using an mm had, thanks to this code in sparc if nothing else, been that you must have a reference on mm_users *and that reference must have been obtained with mmget()*, i.e., from a thread with a reference to mm_users that had used the mm. The introduction of mmget_not_zero() in commit d2005e3f41d4 ("userfaultfd: don't pin the user memory in userfaultfd_file_create()") allowed mm_count holders to aoperate on user mappings asynchronously from the actual threads using the mm, but they were not to load those mappings into their TLB (i.e., walking vmas and page tables is okay, kthread_use_mm() is not). io_uring 2b188cc1bb857 ("Add io_uring IO interface") added code which does a kthread_use_mm() from a mmget_not_zero() refcount. The problem with this is code which previously assumed mm == current->mm and mm->mm_users == 1 implies the mm will remain single-threaded at least until this thread creates another mm_users reference, has now broken. arch/sparc/kernel/smp_64.c: if (atomic_read(&mm->mm_users) == 1) { cpumask_copy(mm_cpumask(mm), cpumask_of(cpu)); goto local_flush_and_out; } vs fs/io_uring.c if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) || !mmget_not_zero(ctx->sqo_mm))) return -EFAULT; kthread_use_mm(ctx->sqo_mm); mmget_not_zero() could come in right after the mm_users == 1 test, then kthread_use_mm() which sets its CPU in the mm_cpumask. That update could be lost if cpumask_copy() occurs afterward. I propose we fix this by allowing mmget_not_zero() to be a first-class reference, and not have this obscure undocumented and unchecked restriction. The basic fix for sparc64 is to remove its mm_cpumask clearing code. The optimisation could be effectively restored by sending IPIs to mm_cpumask members and having them remove themselves from mm_cpumask. This is more tricky so I leave it as an exercise for someone with a sparc64 SMP. powerpc has a (currently similarly broken) example. Signed-off-by: Nicholas Piggin Acked-by: David S. Miller Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200914045219.3736466-4-npiggin@gmail.com Signed-off-by: Sasha Levin

fix a braino in "sparc32: fix register window handling in genregs32_[gs]et()"

2020-07-01T03:17:02Z

[ Upstream commit 9d964e1b82d8182184153b70174f445ea616f053 ] lost npc in PTRACE_SETREGSET, breaking PTRACE_SETREGS as well Fixes: cf51e129b968 "sparc32: fix register window handling in genregs32_[gs]et()" Signed-off-by: Al Viro Signed-off-by: Sasha Levin

sparc64: fix misuses of access_process_vm() in genregs32_[sg]et()

2020-06-22T07:05:28Z

commit 142cd25293f6a7ecbdff4fb0af17de6438d46433 upstream. We do need access_process_vm() to access the target's reg_window. However, access to caller's memory (storing the result in genregs32_get(), fetching the new values in case of genregs32_set()) should be done by normal uaccess primitives. Fixes: ad4f95764040 ([SPARC64]: Fix user accesses in regset code.) Cc: stable@kernel.org Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman