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

csky, hexagon: fix broken sys_sync_file_range

2024-07-05T07:12:54+00:00

commit 3339b99ef6fe38dac43b534cba3a8a0e29fb2eff upstream. Both of these architectures require u64 function arguments to be passed in even/odd pairs of registers or stack slots, which in case of sync_file_range would result in a seven-argument system call that is not currently possible. The system call is therefore incompatible with all existing binaries. While it would be possible to implement support for seven arguments like on mips, it seems better to use a six-argument version, either with the normal argument order but misaligned as on most architectures or with the reordered sync_file_range2() calling conventions as on arm and powerpc. Cc: stable@vger.kernel.org Acked-by: Guo Ren Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

csky: Fix function name in csky_alignment() and die()

2023-02-01T07:23:20+00:00

commit 751971af2e3615dc5bd12674080bc795505fefeb upstream. When building ARCH=csky defconfig: arch/csky/kernel/traps.c: In function 'die': arch/csky/kernel/traps.c:112:17: error: implicit declaration of function 'make_dead_task' [-Werror=implicit-function-declaration] 112 | make_dead_task(SIGSEGV); | ^~~~~~~~~~~~~~ The function's name is make_task_dead(), change it so there is no more build error. Fixes: 0e25498f8cd4 ("exit: Add and use make_task_dead.") Signed-off-by: Nathan Chancellor Reviewed-by: Guo Ren Link: https://lkml.kernel.org/r/20211227184851.2297759-4-nathan@kernel.org Signed-off-by: Eric W. Biederman Signed-off-by: Eric Biggers Signed-off-by: Sasha Levin

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

csky: add support for TIF_NOTIFY_SIGNAL

2023-01-04T10:39:20+00:00

[ Upstream commit f3924d763c8af4c5d441b666c01f4de03ac9449e ] Wire up TIF_NOTIFY_SIGNAL handling for csky. Cc: linux-csky@vger.kernel.org Acked-by: Guo Ren Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

csky/kprobe: reclaim insn_slot on kprobe unregistration

2022-08-25T09:38:16+00:00

[ Upstream commit a2310c74d418deca0f1d749c45f1f43162510f51 ] On kprobe registration kernel allocate one insn_slot for new kprobe, but it forget to reclaim the insn_slot on unregistration, leading to a potential leakage. Reported-by: Chen Guokai Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Liao Chang Signed-off-by: Guo Ren Signed-off-by: Sasha Levin

csky: patch_text: Fixup last cpu should be master

2022-06-09T08:21:26+00:00

commit 8c4d16471e2babe9bdfe41d6ef724526629696cb upstream. These patch_text implementations are using stop_machine_cpuslocked infrastructure with atomic cpu_count. The original idea: When the master CPU patch_text, the others should wait for it. But current implementation is using the first CPU as master, which couldn't guarantee the remaining CPUs are waiting. This patch changes the last CPU as the master to solve the potential risk. Fixes: 33e53ae1ce41 ("csky: Add kprobes supported") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Masami Hiramatsu Cc: Signed-off-by: Greg Kroah-Hartman

uaccess: fix type mismatch warnings from access_ok()

2022-04-08T12:40:35+00:00

[ Upstream commit 23fc539e81295b14b50c6ccc5baeb4f3d59d822d ] On some architectures, access_ok() does not do any argument type checking, so replacing the definition with a generic one causes a few warnings for harmless issues that were never caught before. Fix the ones that I found either through my own test builds or that were reported by the 0-day bot. Reported-by: kernel test robot Reviewed-by: Christoph Hellwig Acked-by: Dinh Nguyen Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin

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

csky: fix typo of fpu config macro

2021-12-14T10:32:45+00:00

commit a0793fdad9a11a32bc6d21317c93c83f4aa82ebc upstream. Fix typo which will cause fpe and privilege exception error. Signed-off-by: Kelly Devilliv Cc: stable Signed-off-by: Guo Ren Signed-off-by: Greg Kroah-Hartman