BMC/Intel-BMC/linux.git/arch/csky/kernel, branch dev-5.15-intel

uaccess: fix type mismatch warnings from access_ok()

2022-04-08T12:24:01+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

2022-01-20T08:13:14+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

2021-12-14T09:57:22+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

csky: Fixup regs.sr broken in ptrace

2021-10-15T23:20:12+00:00

gpr_get() return the entire pt_regs (include sr) to userspace, if we don't restore the C bit in gpr_set, it may break the ALU result in that context. So the C flag bit is part of gpr context, that's why riscv totally remove the C bit in the ISA. That makes sr reg clear from userspace to supervisor privilege. Signed-off-by: Guo Ren Cc: Al Viro Cc: stable@vger.kernel.org

csky: don't let sigreturn play with priveleged bits of status register

2021-10-15T23:20:12+00:00

csky restore_sigcontext() blindly overwrites regs->sr with the value it finds in sigcontext. Attacker can store whatever they want in there, which includes things like S-bit. Userland shouldn't be able to set that, or anything other than C flag (bit 0). Do the same thing other architectures with protected bits in flags register do - preserve everything that shouldn't be settable in user mode, picking the rest from the value saved is sigcontext. Signed-off-by: Al Viro Signed-off-by: Guo Ren Cc: stable@vger.kernel.org

entry: rseq: Call rseq_handle_notify_resume() in tracehook_notify_resume()

2021-09-22T14:24:01+00:00

Invoke rseq_handle_notify_resume() from tracehook_notify_resume() now that the two function are always called back-to-back by architectures that have rseq. The rseq helper is stubbed out for architectures that don't support rseq, i.e. this is a nop across the board. Note, tracehook_notify_resume() is horribly named and arguably does not belong in tracehook.h as literally every line of code in it has nothing to do with tracing. But, that's been true since commit a42c6ded827d ("move key_repace_session_keyring() into tracehook_notify_resume()") first usurped tracehook_notify_resume() back in 2012. Punt cleaning that mess up to future patches. No functional change intended. Acked-by: Mathieu Desnoyers Signed-off-by: Sean Christopherson Message-Id: <20210901203030.1292304-3-seanjc@google.com> Signed-off-by: Paolo Bonzini

arch/csky/kernel/probes/kprobes.c: fix bugon.cocci warnings

2021-09-03T16:58:09+00:00

Use BUG_ON instead of a if condition followed by BUG. Generated by: scripts/coccinelle/misc/bugon.cocci Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2107061049150.7197@hadrien Fixes: 7d37cb2c912d ("lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS") Signed-off-by: kernel test robot Signed-off-by: Julia Lawall Reported-by: kernel test robot Cc: Julian Braha Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

csky: convert to setup_initial_init_mm()

2021-07-08T18:48:21+00:00

Use setup_initial_init_mm() helper to simplify code. Link: https://lkml.kernel.org/r/20210608083418.137226-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: Guo Ren Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-06-28T19:14:19+00:00

Pull scheduler udpates from Ingo Molnar: - Changes to core scheduling facilities: - Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables coordinated scheduling across SMT siblings. This is a much requested feature for cloud computing platforms, to allow the flexible utilization of SMT siblings, without exposing untrusted domains to information leaks & side channels, plus to ensure more deterministic computing performance on SMT systems used by heterogenous workloads. There are new prctls to set core scheduling groups, which allows more flexible management of workloads that can share siblings. - Fix task->state access anti-patterns that may result in missed wakeups and rename it to ->__state in the process to catch new abuses. - Load-balancing changes: - Tweak newidle_balance for fair-sched, to improve 'memcache'-like workloads. - "Age" (decay) average idle time, to better track & improve workloads such as 'tbench'. - Fix & improve energy-aware (EAS) balancing logic & metrics. - Fix & improve the uclamp metrics. - Fix task migration (taskset) corner case on !CONFIG_CPUSET. - Fix RT and deadline utilization tracking across policy changes - Introduce a "burstable" CFS controller via cgroups, which allows bursty CPU-bound workloads to borrow a bit against their future quota to improve overall latencies & batching. Can be tweaked via /sys/fs/cgroup/cpu//cpu.cfs_burst_us. - Rework assymetric topology/capacity detection & handling. - Scheduler statistics & tooling: - Disable delayacct by default, but add a sysctl to enable it at runtime if tooling needs it. Use static keys and other optimizations to make it more palatable. - Use sched_clock() in delayacct, instead of ktime_get_ns(). - Misc cleanups and fixes. * tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits) sched/doc: Update the CPU capacity asymmetry bits sched/topology: Rework CPU capacity asymmetry detection sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag psi: Fix race between psi_trigger_create/destroy sched/fair: Introduce the burstable CFS controller sched/uclamp: Fix uclamp_tg_restrict() sched/rt: Fix Deadline utilization tracking during policy change sched/rt: Fix RT utilization tracking during policy change sched: Change task_struct::state sched,arch: Remove unused TASK_STATE offsets sched,timer: Use __set_current_state() sched: Add get_current_state() sched,perf,kvm: Fix preemption condition sched: Introduce task_is_running() sched: Unbreak wakeups sched/fair: Age the average idle time sched/cpufreq: Consider reduced CPU capacity in energy calculation sched/fair: Take thermal pressure into account while estimating energy thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure sched/fair: Return early from update_tg_cfs_load() if delta == 0 ...

sched,arch: Remove unused TASK_STATE offsets

2021-06-18T09:43:09+00:00

All 6 architectures define TASK_STATE in asm-offsets, but then never actually use it. Remove the definitions to make sure they never will. Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210611082838.472811363@infradead.org