kernel.git/arch/arm/kernel, branch linux-5.18.y

vmcore: convert copy_oldmem_page() to take an iov_iter

2022-06-29T07:04:36Z

[ Upstream commit 5d8de293c224896a4da99763fce4f9794308caf4 ] Patch series "Convert vmcore to use an iov_iter", v5. For some reason several people have been sending bad patches to fix compiler warnings in vmcore recently. Here's how it should be done. Compile-tested only on x86. As noted in the first patch, s390 should take this conversion a bit further, but I'm not inclined to do that work myself. This patch (of 3): Instead of passing in a 'buf' and 'userbuf' argument, pass in an iov_iter. s390 needs more work to pass the iov_iter down further, or refactor, but I'd be more comfortable if someone who can test on s390 did that work. It's more convenient to convert the whole of read_from_oldmem() to take an iov_iter at the same time, so rename it to read_from_oldmem_iter() and add a temporary read_from_oldmem() wrapper that creates an iov_iter. Link: https://lkml.kernel.org/r/20220408090636.560886-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20220408090636.560886-2-bhe@redhat.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Baoquan He Reviewed-by: Christoph Hellwig Cc: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

signal: Deliver SIGTRAP on perf event asynchronously if blocked

2022-06-09T08:30:00Z

[ Upstream commit 78ed93d72ded679e3caf0758357209887bda885f ] With SIGTRAP on perf events, we have encountered termination of processes due to user space attempting to block delivery of SIGTRAP. Consider this case: ... sigset_t s; sigemptyset(&s); sigaddset(&s, SIGTRAP | ); sigprocmask(SIG_BLOCK, &s, ...); ... When the perf event triggers, while SIGTRAP is blocked, force_sig_perf() will force the signal, but revert back to the default handler, thus terminating the task. This makes sense for error conditions, but not so much for explicitly requested monitoring. However, the expectation is still that signals generated by perf events are synchronous, which will no longer be the case if the signal is blocked and delivered later. To give user space the ability to clearly distinguish synchronous from asynchronous signals, introduce siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for flags in case more binary information is required in future). The resolution to the problem is then to (a) no longer force the signal (avoiding the terminations), but (b) tell user space via si_perf_flags if the signal was synchronous or not, so that such signals can be handled differently (e.g. let user space decide to ignore or consider the data imprecise). The alternative of making the kernel ignore SIGTRAP on perf events if the signal is blocked may work for some usecases, but likely causes issues in others that then have to revert back to interception of sigprocmask() (which we want to avoid). [ A concrete example: when using breakpoint perf events to track data-flow, in a region of code where signals are blocked, data-flow can no longer be tracked accurately. When a relevant asynchronous signal is received after unblocking the signal, the data-flow tracking logic needs to know its state is imprecise. ] Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Acked-by: Geert Uytterhoeven Tested-by: Dmitry Vyukov Link: https://lore.kernel.org/r/20220404111204.935357-1-elver@google.com Signed-off-by: Sasha Levin

ARM: 9197/1: spectre-bhb: fix loop8 sequence for Thumb2

2022-05-18T10:38:47Z

In Thumb2, 'b . + 4' produces a branch instruction that uses a narrow encoding, and so it does not jump to the following instruction as expected. So use W(b) instead. Fixes: 6c7cb60bff7a ("ARM: fix Thumb2 regression with Spectre BHB") Signed-off-by: Ard Biesheuvel Signed-off-by: Russell King (Oracle)

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2022-04-03T17:17:48Z

Pull ARM fixes from Russell King: - avoid unnecessary rebuilds for library objects - fix return value of __setup handlers - fix invalid input check for "crashkernel=" kernel option - silence KASAN warnings in unwind_frame * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 9191/1: arm/stacktrace, kasan: Silence KASAN warnings in unwind_frame() ARM: 9190/1: kdump: add invalid input check for 'crashkernel=0' ARM: 9187/1: JIVE: fix return value of __setup handler ARM: 9189/1: decompressor: fix unneeded rebuilds of library objects

Merge branches 'fixes' and 'misc' into for-linus

2022-04-01T15:12:31Z

ARM: 9191/1: arm/stacktrace, kasan: Silence KASAN warnings in unwind_frame()

2022-04-01T11:58:39Z

The following KASAN warning is detected by QEMU. ================================================================== BUG: KASAN: stack-out-of-bounds in unwind_frame+0x508/0x870 Read of size 4 at addr c36bba90 by task cat/163 CPU: 1 PID: 163 Comm: cat Not tainted 5.10.0-rc1 #40 Hardware name: ARM-Versatile Express [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x98/0xb0) [] (dump_stack) from [] (print_address_description.constprop.0+0x58/0x4bc) [] (print_address_description.constprop.0) from [] (kasan_report+0x154/0x170) [] (kasan_report) from [] (unwind_frame+0x508/0x870) [] (unwind_frame) from [] (__save_stack_trace+0x110/0x134) [] (__save_stack_trace) from [] (stack_trace_save+0x8c/0xb4) [] (stack_trace_save) from [] (kasan_set_track+0x38/0x60) [] (kasan_set_track) from [] (kasan_set_free_info+0x20/0x2c) [] (kasan_set_free_info) from [] (__kasan_slab_free+0xec/0x120) [] (__kasan_slab_free) from [] (kmem_cache_free+0x7c/0x334) [] (kmem_cache_free) from [] (rcu_core+0x390/0xccc) [] (rcu_core) from [] (__do_softirq+0x180/0x518) [] (__do_softirq) from [] (irq_exit+0x9c/0xe0) [] (irq_exit) from [] (__handle_domain_irq+0xb0/0x110) [] (__handle_domain_irq) from [] (gic_handle_irq+0xa0/0xb8) [] (gic_handle_irq) from [] (__irq_svc+0x6c/0x94) Exception stack(0xc36bb928 to 0xc36bb970) b920: c36bb9c0 00000000 c0126919 c0101228 c36bb9c0 b76d7730 b940: c36b8000 c36bb9a0 c3335b00 c01ce0d8 00000003 c36bba3c c36bb940 c36bb978 b960: c010e298 c011373c 60000013 ffffffff [] (__irq_svc) from [] (unwind_frame+0x0/0x870) [] (unwind_frame) from [<00000000>] (0x0) The buggy address belongs to the page: page:(ptrval) refcount:0 mapcount:0 mapping:00000000 index:0x0 pfn:0x636bb flags: 0x0() raw: 00000000 00000000 ef867764 00000000 00000000 00000000 ffffffff 00000000 page dumped because: kasan: bad access detected addr c36bba90 is located in stack of task cat/163 at offset 48 in frame: stack_trace_save+0x0/0xb4 this frame has 1 object: [32, 48) 'trace' Memory state around the buggy address: c36bb980: f1 f1 f1 f1 00 04 f2 f2 00 00 f3 f3 00 00 00 00 c36bba00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 >c36bba80: 00 00 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ^ c36bbb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c36bbb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== There is a same issue on x86 and has been resolved by the commit f7d27c35ddff ("x86/mm, kasan: Silence KASAN warnings in get_wchan()"). The solution could be applied to arm architecture too. Signed-off-by: Lin Yujun Reported-by: He Ying Signed-off-by: Russell King (Oracle)

ARM: 9190/1: kdump: add invalid input check for 'crashkernel=0'

2022-04-01T11:58:08Z

Add invalid input check expression when 'crashkernel=0' is specified running kdump. Signed-off-by: Austin Kim Signed-off-by: Russell King (Oracle)

Merge tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2022-03-29T00:29:53Z

Pull ptrace cleanups from Eric Biederman: "This set of changes removes tracehook.h, moves modification of all of the ptrace fields inside of siglock to remove races, adds a missing permission check to ptrace.c The removal of tracehook.h is quite significant as it has been a major source of confusion in recent years. Much of that confusion was around task_work and TIF_NOTIFY_SIGNAL (which I have now decoupled making the semantics clearer). For people who don't know tracehook.h is a vestiage of an attempt to implement uprobes like functionality that was never fully merged, and was later superseeded by uprobes when uprobes was merged. For many years now we have been removing what tracehook functionaly a little bit at a time. To the point where anything left in tracehook.h was some weird strange thing that was difficult to understand" * tag 'ptrace-cleanups-for-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ptrace: Remove duplicated include in ptrace.c ptrace: Check PTRACE_O_SUSPEND_SECCOMP permission on PTRACE_SEIZE ptrace: Return the signal to continue with from ptrace_stop ptrace: Move setting/clearing ptrace_message into ptrace_stop tracehook: Remove tracehook.h resume_user_mode: Move to resume_user_mode.h resume_user_mode: Remove #ifdef TIF_NOTIFY_RESUME in set_notify_resume signal: Move set_notify_signal and clear_notify_signal into sched/signal.h task_work: Decouple TIF_NOTIFY_SIGNAL and task_work task_work: Call tracehook_notify_signal from get_signal on all architectures task_work: Introduce task_work_pending task_work: Remove unnecessary include from posix_timers.h ptrace: Remove tracehook_signal_handler ptrace: Remove arch_syscall_{enter,exit}_tracehook ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h ptrace/arm: Rename tracehook_report_syscall report_syscall ptrace: Move ptrace_report_syscall into ptrace.h

Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2022-03-24T01:03:08Z

Pull asm-generic updates from Arnd Bergmann: "There are three sets of updates for 5.18 in the asm-generic tree: - The set_fs()/get_fs() infrastructure gets removed for good. This was already gone from all major architectures, but now we can finally remove it everywhere, which loses some particularly tricky and error-prone code. There is a small merge conflict against a parisc cleanup, the solution is to use their new version. - The nds32 architecture ends its tenure in the Linux kernel. The hardware is still used and the code is in reasonable shape, but the mainline port is not actively maintained any more, as all remaining users are thought to run vendor kernels that would never be updated to a future release. - A series from Masahiro Yamada cleans up some of the uapi header files to pass the compile-time checks" * tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits) nds32: Remove the architecture uaccess: remove CONFIG_SET_FS ia64: remove CONFIG_SET_FS support sh: remove CONFIG_SET_FS support sparc64: remove CONFIG_SET_FS support lib/test_lockup: fix kernel pointer check for separate address spaces uaccess: generalize access_ok() uaccess: fix type mismatch warnings from access_ok() arm64: simplify access_ok() m68k: fix access_ok for coldfire MIPS: use simpler access_ok() MIPS: Handle address errors for accesses above CPU max virtual user address uaccess: add generic __{get,put}_kernel_nofault nios2: drop access_ok() check from __put_user() x86: use more conventional access_ok() definition x86: remove __range_not_ok() sparc64: add __{get,put}_kernel_nofault() nds32: fix access_ok() checks in get/put_user uaccess: fix nios2 and microblaze get_user_8() sparc64: fix building assembly files ...

Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2022-03-24T00:35:57Z

Pull ARM updates from Russell King: "Updates for IRQ stacks and virtually mapped stack support, and ftrace: - Support for IRQ and vmap'ed stacks This covers all the work related to implementing IRQ stacks and vmap'ed stacks for all 32-bit ARM systems that are currently supported by the Linux kernel, including RiscPC and Footbridge. It has been submitted for review in four different waves: - IRQ stacks support for v7 SMP systems [0] - vmap'ed stacks support for v7 SMP systems[1] - extending support for both IRQ stacks and vmap'ed stacks for all remaining configurations, including v6/v7 SMP multiplatform kernels and uniprocessor configurations including v7-M [2] - fixes and updates in [3] - ftrace fixes and cleanups Make all flavors of ftrace available on all builds, regardless of ISA choice, unwinder choice or compiler [4]: - use ADD not POP where possible - fix a couple of Thumb2 related issues - enable HAVE_FUNCTION_GRAPH_FP_TEST for robustness - enable the graph tracer with the EABI unwinder - avoid clobbering frame pointer registers to make Clang happy - Fixes for the above" [0] https://lore.kernel.org/linux-arm-kernel/20211115084732.3704393-1-ardb@kernel.org/ [1] https://lore.kernel.org/linux-arm-kernel/20211122092816.2865873-1-ardb@kernel.org/ [2] https://lore.kernel.org/linux-arm-kernel/20211206164659.1495084-1-ardb@kernel.org/ [3] https://lore.kernel.org/linux-arm-kernel/20220124174744.1054712-1-ardb@kernel.org/ [4] https://lore.kernel.org/linux-arm-kernel/20220203082204.1176734-1-ardb@kernel.org/ * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (62 commits) ARM: fix building NOMMU ARMv4/v5 kernels ARM: unwind: only permit stack switch when unwinding call_with_stack() ARM: Revert "unwind: dump exception stack from calling frame" ARM: entry: fix unwinder problems caused by IRQ stacks ARM: unwind: set frame.pc correctly for current-thread unwinding ARM: 9184/1: return_address: disable again for CONFIG_ARM_UNWIND=y ARM: 9183/1: unwind: avoid spurious warnings on bogus code addresses Revert "ARM: 9144/1: forbid ftrace with clang and thumb2_kernel" ARM: mach-bcm: disable ftrace in SMC invocation routines ARM: cacheflush: avoid clobbering the frame pointer ARM: kprobes: treat R7 as the frame pointer register in Thumb2 builds ARM: ftrace: enable the graph tracer with the EABI unwinder ARM: unwind: track location of LR value in stack frame ARM: ftrace: enable HAVE_FUNCTION_GRAPH_FP_TEST ARM: ftrace: avoid unnecessary literal loads ARM: ftrace: avoid redundant loads or clobbering IP ARM: ftrace: use trampolines to keep .init.text in branching range ARM: ftrace: use ADD not POP to counter PUSH at entry ARM: ftrace: ensure that ADR takes the Thumb bit into account ARM: make get_current() and __my_cpu_offset() __always_inline ...