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403 Commits
Author | SHA1 | Message | Date | |
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2cfcbe1554 |
x86/iopl: Cure TIF_IO_BITMAP inconsistencies
commit 8b68e978718f14fdcb080c2a7791c52a0d09bc6d upstream.
io_bitmap_exit() is invoked from exit_thread() when a task exists or
when a fork fails. In the latter case the exit_thread() cleans up
resources which were allocated during fork().
io_bitmap_exit() invokes task_update_io_bitmap(), which in turn ends up
in tss_update_io_bitmap(). tss_update_io_bitmap() operates on the
current task. If current has TIF_IO_BITMAP set, but no bitmap installed,
tss_update_io_bitmap() crashes with a NULL pointer dereference.
There are two issues, which lead to that problem:
1) io_bitmap_exit() should not invoke task_update_io_bitmap() when
the task, which is cleaned up, is not the current task. That's a
clear indicator for a cleanup after a failed fork().
2) A task should not have TIF_IO_BITMAP set and neither a bitmap
installed nor IOPL emulation level 3 activated.
This happens when a kernel thread is created in the context of
a user space thread, which has TIF_IO_BITMAP set as the thread
flags are copied and the IO bitmap pointer is cleared.
Other than in the failed fork() case this has no impact because
kernel threads including IO workers never return to user space and
therefore never invoke tss_update_io_bitmap().
Cure this by adding the missing cleanups and checks:
1) Prevent io_bitmap_exit() to invoke task_update_io_bitmap() if
the to be cleaned up task is not the current task.
2) Clear TIF_IO_BITMAP in copy_thread() unconditionally. For user
space forks it is set later, when the IO bitmap is inherited in
io_bitmap_share().
For paranoia sake, add a warning into tss_update_io_bitmap() to catch
the case, when that code is invoked with inconsistent state.
Fixes:
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5dea6398f2 |
x86/idle: Remove MFENCEs for X86_BUG_CLFLUSH_MONITOR in mwait_idle_with_hints() and prefer_mwait_c1_over_halt()
[ Upstream commit 1f13c60d84e880df6698441026e64f84c7110c49 ] The following commit, 12 years ago: |
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29f040d4ef |
x86/tdx: Fix arch_safe_halt() execution for TDX VMs
commit 9f98a4f4e7216dbe366010b4cdcab6b220f229c4 upstream. Direct HLT instruction execution causes #VEs for TDX VMs which is routed to hypervisor via TDCALL. If HLT is executed in STI-shadow, resulting #VE handler will enable interrupts before TDCALL is routed to hypervisor leading to missed wakeup events, as current TDX spec doesn't expose interruptibility state information to allow #VE handler to selectively enable interrupts. Commit |
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2541b0d1ce |
x86/fpu: Avoid copying dynamic FP state from init_task in arch_dup_task_struct()
[ Upstream commit 5d3b81d4d8520efe888536b6906dc10fd1a228a8 ]
The init_task instance of struct task_struct is statically allocated and
may not contain the full FP state for userspace. As such, limit the copy
to the valid area of both init_task and 'dst' and ensure all memory is
initialized.
Note that the FP state is only needed for userspace, and as such it is
entirely reasonable for init_task to not contain parts of it.
Fixes:
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1a45994fb2 |
x86: Increase brk randomness entropy for 64-bit systems
[ Upstream commit |
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748c90c693 |
x86/shstk: Remove useless clone error handling
When clone fails after the shadow stack is allocated, any allocated shadow
stack is cleaned up in exit_thread() in copy_process(). So the logic in
copy_thread() is unneeded, and also will not handle failures that happen
outside of copy_thread().
In addition, since there is a second attempt to unmap the same shadow
stack, there is a race where an newly mapped region could get unmapped.
So remove the logic in copy_thread() and rely on exit_thread() to handle
clone failure.
Fixes:
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df57721f9a |
Add x86 shadow stack support
Convert IBT selftest to asm to fix objtool warning -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmTv1QQACgkQaDWVMHDJ krAUwhAAn6TOwHJK8BSkHeiQhON1nrlP3c5cv0AyZ2NP8RYDrZrSZvhpYBJ6wgKC Cx5CGq5nn9twYsYS3KsktLKDfR3lRdsQ7K9qtyFtYiaeaVKo+7gEKl/K+klwai8/ gninQWHk0zmSCja8Vi77q52WOMkQKapT8+vaON9EVDO8dVEi+CvhAIfPwMafuiwO Rk4X86SzoZu9FP79LcCg9XyGC/XbM2OG9eNUTSCKT40qTTKm5y4gix687NvAlaHR ko5MTsdl0Wfp6Qk0ohT74LnoA2c1g/FluvZIM33ci/2rFpkf9Hw7ip3lUXqn6CPx rKiZ+pVRc0xikVWkraMfIGMJfUd2rhelp8OyoozD7DB7UZw40Q4RW4N5tgq9Fhe9 MQs3p1v9N8xHdRKl365UcOczUxNAmv4u0nV5gY/4FMC6VjldCl2V9fmqYXyzFS4/ Ogg4FSd7c2JyGFKPs+5uXyi+RY2qOX4+nzHOoKD7SY616IYqtgKoz5usxETLwZ6s VtJOmJL0h//z0A7tBliB0zd+SQ5UQQBDC2XouQH2fNX2isJMn0UDmWJGjaHgK6Hh 8jVp6LNqf+CEQS387UxckOyj7fu438hDky1Ggaw4YqowEOhQeqLVO4++x+HITrbp AupXfbJw9h9cMN63Yc0gVxXQ9IMZ+M7UxLtZ3Cd8/PVztNy/clA= =3UUm -----END PGP SIGNATURE----- Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 shadow stack support from Dave Hansen: "This is the long awaited x86 shadow stack support, part of Intel's Control-flow Enforcement Technology (CET). CET consists of two related security features: shadow stacks and indirect branch tracking. This series implements just the shadow stack part of this feature, and just for userspace. The main use case for shadow stack is providing protection against return oriented programming attacks. It works by maintaining a secondary (shadow) stack using a special memory type that has protections against modification. When executing a CALL instruction, the processor pushes the return address to both the normal stack and to the special permission shadow stack. Upon RET, the processor pops the shadow stack copy and compares it to the normal stack copy. For more information, refer to the links below for the earlier versions of this patch set" Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/ Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/ * tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) x86/shstk: Change order of __user in type x86/ibt: Convert IBT selftest to asm x86/shstk: Don't retry vm_munmap() on -EINTR x86/kbuild: Fix Documentation/ reference x86/shstk: Move arch detail comment out of core mm x86/shstk: Add ARCH_SHSTK_STATUS x86/shstk: Add ARCH_SHSTK_UNLOCK x86: Add PTRACE interface for shadow stack selftests/x86: Add shadow stack test x86/cpufeatures: Enable CET CR4 bit for shadow stack x86/shstk: Wire in shadow stack interface x86: Expose thread features in /proc/$PID/status x86/shstk: Support WRSS for userspace x86/shstk: Introduce map_shadow_stack syscall x86/shstk: Check that signal frame is shadow stack mem x86/shstk: Check that SSP is aligned on sigreturn x86/shstk: Handle signals for shadow stack x86/shstk: Introduce routines modifying shstk x86/shstk: Handle thread shadow stack x86/shstk: Add user-mode shadow stack support ... |
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b2926a36b9 |
x86/shstk: Handle thread shadow stack
When a process is duplicated, but the child shares the address space with the parent, there is potential for the threads sharing a single stack to cause conflicts for each other. In the normal non-CET case this is handled in two ways. With regular CLONE_VM a new stack is provided by userspace such that the parent and child have different stacks. For vfork, the parent is suspended until the child exits. So as long as the child doesn't return from the vfork()/CLONE_VFORK calling function and sticks to a limited set of operations, the parent and child can share the same stack. For shadow stack, these scenarios present similar sharing problems. For the CLONE_VM case, the child and the parent must have separate shadow stacks. Instead of changing clone to take a shadow stack, have the kernel just allocate one and switch to it. Use stack_size passed from clone3() syscall for thread shadow stack size. A compat-mode thread shadow stack size is further reduced to 1/4. This allows more threads to run in a 32-bit address space. The clone() does not pass stack_size, which was added to clone3(). In that case, use RLIMIT_STACK size and cap to 4 GB. For shadow stack enabled vfork(), the parent and child can share the same shadow stack, like they can share a normal stack. Since the parent is suspended until the child terminates, the child will not interfere with the parent while executing as long as it doesn't return from the vfork() and overwrite up the shadow stack. The child can safely overwrite down the shadow stack, as the parent can just overwrite this later. So CET does not add any additional limitations for vfork(). Free the shadow stack on thread exit by doing it in mm_release(). Skip this when exiting a vfork() child since the stack is shared in the parent. During this operation, the shadow stack pointer of the new thread needs to be updated to point to the newly allocated shadow stack. Since the ability to do this is confined to the FPU subsystem, change fpu_clone() to take the new shadow stack pointer, and update it internally inside the FPU subsystem. This part was suggested by Thomas Gleixner. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-30-rick.p.edgecombe%40intel.com |
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3aec4ecb3d |
x86: Rewrite ret_from_fork() in C
When kCFI is enabled, special handling is needed for the indirect call to the kernel thread function. Rewrite the ret_from_fork() function in C so that the compiler can properly handle the indirect call. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lkml.kernel.org/r/20230623225529.34590-3-brgerst@gmail.com |
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9b040453d4 |
x86/smp: Dont access non-existing CPUID leaf
stop_this_cpu() tests CPUID leaf 0x8000001f::EAX unconditionally. Intel
CPUs return the content of the highest supported leaf when a non-existing
leaf is read, while AMD CPUs return all zeros for unsupported leafs.
So the result of the test on Intel CPUs is lottery.
While harmless it's incorrect and causes the conditional wbinvd() to be
issued where not required.
Check whether the leaf is supported before reading it.
[ tglx: Adjusted changelog ]
Fixes:
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1f5e7eb786 |
x86/smp: Make stop_other_cpus() more robust
Tony reported intermittent lockups on poweroff. His analysis identified the
wbinvd() in stop_this_cpu() as the culprit. This was added to ensure that
on SME enabled machines a kexec() does not leave any stale data in the
caches when switching from encrypted to non-encrypted mode or vice versa.
That wbinvd() is conditional on the SME feature bit which is read directly
from CPUID. But that readout does not check whether the CPUID leaf is
available or not. If it's not available the CPU will return the value of
the highest supported leaf instead. Depending on the content the "SME" bit
might be set or not.
That's incorrect but harmless. Making the CPUID readout conditional makes
the observed hangs go away, but it does not fix the underlying problem:
CPU0 CPU1
stop_other_cpus()
send_IPIs(REBOOT); stop_this_cpu()
while (num_online_cpus() > 1); set_online(false);
proceed... -> hang
wbinvd()
WBINVD is an expensive operation and if multiple CPUs issue it at the same
time the resulting delays are even larger.
But CPU0 already observed num_online_cpus() going down to 1 and proceeds
which causes the system to hang.
This issue exists independent of WBINVD, but the delays caused by WBINVD
make it more prominent.
Make this more robust by adding a cpumask which is initialized to the
online CPU mask before sending the IPIs and CPUs clear their bit in
stop_this_cpu() after the WBINVD completed. Check for that cpumask to
become empty in stop_other_cpus() instead of watching num_online_cpus().
The cpumask cannot plug all holes either, but it's better than a raw
counter and allows to restrict the NMI fallback IPI to be sent only the
CPUs which have not reported within the timeout window.
Fixes:
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2aff7c706c |
Objtool changes for v6.4:
- Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically. - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it. - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code. - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown/panic functions. - Misc improvements & fixes. Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmRK1x0RHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1ghxQ/+IkCynMYtdF5OG9YwbcGJqsPSfOPMEcEM pUSFYg+gGPBDT/fJfcVSqvUtdnWbLC2kXt9yiswXz3X3J2nmNkBk5YKQftsNDcul TmKeqIIAK51XTncpegKH0EGnOX63oZ9Vxa8CTPdDlb+YF23Km2FoudGRI9F5qbUd LoraXqGYeiaeySkGyWmZVl6Uc8dIxnMkTN3H/oI9aB6TOrsi059hAtFcSaFfyemP c4LqXXCH7k2baiQt+qaLZ8cuZVG/+K5r2N2cmjO5kmJc6ynIaFnfMe4XxZLjp5LT /PulYI15bXkvSARKx5CRh/CDHMOx5Blw+ASO0RhWbdy0WH4ZhhcaVF5AeIpPW86a 1LBcz97rMp72WmvKgrJeVO1r9+ll4SI6/YKGJRsxsCMdP3hgFpqntXyVjTFNdTM1 0gH6H5v55x06vJHvhtTk8SR3PfMTEM2fRU5jXEOrGowoGifx+wNUwORiwj6LE3KQ SKUdT19RNzoW3VkFxhgk65ThK1S7YsJUKRoac3YdhttpqqqtFV//erenrZoR4k/p vzvKy68EQ7RCNyD5wNWNFe0YjeJl5G8gQ8bUm4Xmab7djjgz+pn4WpQB8yYKJLAo x9dqQ+6eUbw3Hcgk6qQ9E+r/svbulnAL0AeALAWK/91DwnZ2mCzKroFkLN7napKi fRho4CqzrtM= =NwEV -----END PGP SIGNATURE----- Merge tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ... |
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2f8794bd08 |
x86/mm: Provide arch_prctl() interface for LAM
Add a few of arch_prctl() handles: - ARCH_ENABLE_TAGGED_ADDR enabled LAM. The argument is required number of tag bits. It is rounded up to the nearest LAM mode that can provide it. For now only LAM_U57 is supported, with 6 tag bits. - ARCH_GET_UNTAG_MASK returns untag mask. It can indicates where tag bits located in the address. - ARCH_GET_MAX_TAG_BITS returns the maximum tag bits user can request. Zero if LAM is not supported. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Alexander Potapenko <glider@google.com> Link: https://lore.kernel.org/all/20230312112612.31869-9-kirill.shutemov%40linux.intel.com |
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74c228d20a |
x86/uaccess: Provide untagged_addr() and remove tags before address check
untagged_addr() is a helper used by the core-mm to strip tag bits and get the address to the canonical shape based on rules of the current thread. It only handles userspace addresses. The untagging mask is stored in per-CPU variable and set on context switching to the task. The tags must not be included into check whether it's okay to access the userspace address. Strip tags in access_ok(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Alexander Potapenko <glider@google.com> Link: https://lore.kernel.org/all/20230312112612.31869-7-kirill.shutemov%40linux.intel.com |
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b4c108d7da |
x86/cpu: Expose arch_cpu_idle_dead()'s prototype definition
Include <linux/cpu.h> to make sure arch_cpu_idle_dead() matches its prototype going forward. Inspired-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Link: https://lore.kernel.org/r/20230214083857.50163-1-philmd@linaro.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> |
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071c44e427 |
sched/idle: Mark arch_cpu_idle_dead() __noreturn
Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead() return"), in Xen, when a previously offlined CPU was brought back online, it unexpectedly resumed execution where it left off in the middle of the idle loop. There were some hacks to make that work, but the behavior was surprising as do_idle() doesn't expect an offlined CPU to return from the dead (in arch_cpu_idle_dead()). Now that Xen has been fixed, and the arch-specific implementations of arch_cpu_idle_dead() also don't return, give it a __noreturn attribute. This will cause the compiler to complain if an arch-specific implementation might return. It also improves code generation for both caller and callee. Also fixes the following warning: vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction Reported-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> |
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eab89405b6 |
x86/cpu: Mark play_dead() __noreturn
play_dead() doesn't return. Annotate it as such. By extension this also makes arch_cpu_idle_dead() noreturn. Link: https://lore.kernel.org/r/f3a069e6869c51ccfdda656b76882363bc9fcfa4.1676358308.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> |
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2504ba8b01 |
Power management updates for 6.3-rc1
- Add EPP support to the AMD P-state cpufreq driver (Perry Yuan, Wyes Karny, Arnd Bergmann, Bagas Sanjaya). - Drop the custom cpufreq driver for loongson1 that is not necessary any more and the corresponding cpufreq platform device (Keguang Zhang). - Remove "select SRCU" from system sleep, cpufreq and OPP Kconfig entries (Paul E. McKenney). - Enable thermal cooling for Tegra194 (Yi-Wei Wang). - Register module device table and add missing compatibles for cpufreq-qcom-hw (Nícolas F. R. A. Prado, Abel Vesa and Luca Weiss). - Various dt binding updates for qcom-cpufreq-nvmem and opp-v2-kryo-cpu (Christian Marangi). - Make kobj_type structure in the cpufreq core constant (Thomas Weißschuh). - Make cpufreq_unregister_driver() return void (Uwe Kleine-König). - Make the TEO cpuidle governor check CPU utilization in order to refine idle state selection (Kajetan Puchalski). - Make Kconfig select the haltpoll cpuidle governor when the haltpoll cpuidle driver is selected and replace a default_idle() call in that driver with arch_cpu_idle() to allow MWAIT to be used (Li RongQing). - Add Emerald Rapids Xeon support to the intel_idle driver (Artem Bityutskiy). - Add ARCH_SUSPEND_POSSIBLE dependencies for ARMv4 cpuidle drivers to avoid randconfig build failures (Arnd Bergmann). - Make kobj_type structures used in the cpuidle sysfs interface constant (Thomas Weißschuh). - Make the cpuidle driver registration code update microsecond values of idle state parameters in accordance with their nanosecond values if they are provided (Rafael Wysocki). - Make the PSCI cpuidle driver prevent topology CPUs from being suspended on PREEMPT_RT (Krzysztof Kozlowski). - Document that pm_runtime_force_suspend() cannot be used with DPM_FLAG_SMART_SUSPEND (Richard Fitzgerald). - Add EXPORT macros for exporting PM functions from drivers (Richard Fitzgerald). - Remove /** from non-kernel-doc comments in hibernation code (Randy Dunlap). - Fix possible name leak in powercap_register_zone() (Yang Yingliang). - Add Meteor Lake and Emerald Rapids support to the intel_rapl power capping driver (Zhang Rui). - Modify the idle_inject power capping facility to support 100% idle injection (Srinivas Pandruvada). - Fix large time windows handling in the intel_rapl power capping driver (Zhang Rui). - Fix memory leaks with using debugfs_lookup() in the generic PM domains and Energy Model code (Greg Kroah-Hartman). - Add missing 'cache-unified' property in the example for kryo OPP bindings (Rob Herring). - Fix error checking in opp_migrate_dentry() (Qi Zheng). - Let qcom,opp-fuse-level be a 2-long array for qcom SoCs (Konrad Dybcio). - Modify some power management utilities to use the canonical ftrace path (Ross Zwisler). - Correct spelling problems for Documentation/power/ as reported by codespell (Randy Dunlap). -----BEGIN PGP SIGNATURE----- iQJGBAABCAAwFiEE4fcc61cGeeHD/fCwgsRv/nhiVHEFAmPuJfMSHHJqd0Byand5 c29ja2kubmV0AAoJEILEb/54YlRx/5kQAJNOVImLEPLerLP8xufw30//LuDU5Gi0 STsyDOMql/I2MpkeqeCcgrSbpy6NlEglOvg16gfpQ3qqTCLF9ypENxs9E5BGGvW0 aEdCzvaoqmvi9PCr/jmj0EPP70/U+rIX5m/k0QdjLh9x0aLoAEe3uRJTfR9QVqXf I7JX0N9kjKi7YxpA5DlkHrS7J7GPPiWlesJ3p4wXuHMo3jf+6fgkoPFt8yRrGWeh AHzGT2BLrsy7aAUjGZB65Qx9q3fnSXMmXOjmn0Xh2njQah+zRZDwrNzwoY2HTLL/ KQ6/Ww16USYRZtCS1fmGwAj9I+ddq6AOvhPCMn0vLXXmKVAMUrVVWnQS/0+vpm9y suUMK9Tndkgxd1vjby2246ThJn27uDd/ERFan4ouQo2j22uICY+SDo3osj2hMXka wq4zthXkY8KgjZ+MuXnZxPhcOvo8KRvfxAU0fy5efQnSkbtwY9UlMvjPBMBHm/RA 21/6kjQNtq5vMmI37oC8DH+oPrRQ7sUKuY7HNqwO9P3QNKWVmNe7cF5UtXXxME7Q ULvP1d+u+TNNdHFLryPwCSzBO34wQEccdRZBjalZ8tBe6JiDWUFHC3giSURZSuzZ GDvzVaNX6PkgToyv4inBTB8lTp6pAuUjaWNvNJzVvUXiEKHB0ihzg5vpJW5NdwlH 15Tn8cjH7pp0 =lZLx -----END PGP SIGNATURE----- Merge tag 'pm-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These add EPP support to the AMD P-state cpufreq driver, add support for new platforms to the Intel RAPL power capping driver, intel_idle and the Qualcomm cpufreq driver, enable thermal cooling for Tegra194, drop the custom cpufreq driver for loongson1 that is not necessary any more (and the corresponding cpufreq platform device), fix assorted issues and clean up code. Specifics: - Add EPP support to the AMD P-state cpufreq driver (Perry Yuan, Wyes Karny, Arnd Bergmann, Bagas Sanjaya) - Drop the custom cpufreq driver for loongson1 that is not necessary any more and the corresponding cpufreq platform device (Keguang Zhang) - Remove "select SRCU" from system sleep, cpufreq and OPP Kconfig entries (Paul E. McKenney) - Enable thermal cooling for Tegra194 (Yi-Wei Wang) - Register module device table and add missing compatibles for cpufreq-qcom-hw (Nícolas F. R. A. Prado, Abel Vesa and Luca Weiss) - Various dt binding updates for qcom-cpufreq-nvmem and opp-v2-kryo-cpu (Christian Marangi) - Make kobj_type structure in the cpufreq core constant (Thomas Weißschuh) - Make cpufreq_unregister_driver() return void (Uwe Kleine-König) - Make the TEO cpuidle governor check CPU utilization in order to refine idle state selection (Kajetan Puchalski) - Make Kconfig select the haltpoll cpuidle governor when the haltpoll cpuidle driver is selected and replace a default_idle() call in that driver with arch_cpu_idle() to allow MWAIT to be used (Li RongQing) - Add Emerald Rapids Xeon support to the intel_idle driver (Artem Bityutskiy) - Add ARCH_SUSPEND_POSSIBLE dependencies for ARMv4 cpuidle drivers to avoid randconfig build failures (Arnd Bergmann) - Make kobj_type structures used in the cpuidle sysfs interface constant (Thomas Weißschuh) - Make the cpuidle driver registration code update microsecond values of idle state parameters in accordance with their nanosecond values if they are provided (Rafael Wysocki) - Make the PSCI cpuidle driver prevent topology CPUs from being suspended on PREEMPT_RT (Krzysztof Kozlowski) - Document that pm_runtime_force_suspend() cannot be used with DPM_FLAG_SMART_SUSPEND (Richard Fitzgerald) - Add EXPORT macros for exporting PM functions from drivers (Richard Fitzgerald) - Remove /** from non-kernel-doc comments in hibernation code (Randy Dunlap) - Fix possible name leak in powercap_register_zone() (Yang Yingliang) - Add Meteor Lake and Emerald Rapids support to the intel_rapl power capping driver (Zhang Rui) - Modify the idle_inject power capping facility to support 100% idle injection (Srinivas Pandruvada) - Fix large time windows handling in the intel_rapl power capping driver (Zhang Rui) - Fix memory leaks with using debugfs_lookup() in the generic PM domains and Energy Model code (Greg Kroah-Hartman) - Add missing 'cache-unified' property in the example for kryo OPP bindings (Rob Herring) - Fix error checking in opp_migrate_dentry() (Qi Zheng) - Let qcom,opp-fuse-level be a 2-long array for qcom SoCs (Konrad Dybcio) - Modify some power management utilities to use the canonical ftrace path (Ross Zwisler) - Correct spelling problems for Documentation/power/ as reported by codespell (Randy Dunlap)" * tag 'pm-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (53 commits) Documentation: amd-pstate: disambiguate user space sections cpufreq: amd-pstate: Fix invalid write to MSR_AMD_CPPC_REQ dt-bindings: opp: opp-v2-kryo-cpu: enlarge opp-supported-hw maximum dt-bindings: cpufreq: qcom-cpufreq-nvmem: make cpr bindings optional dt-bindings: cpufreq: qcom-cpufreq-nvmem: specify supported opp tables PM: Add EXPORT macros for exporting PM functions cpuidle: psci: Do not suspend topology CPUs on PREEMPT_RT MIPS: loongson32: Drop obsolete cpufreq platform device powercap: intel_rapl: Fix handling for large time window cpuidle: driver: Update microsecond values of state parameters as needed cpuidle: sysfs: make kobj_type structures constant cpuidle: add ARCH_SUSPEND_POSSIBLE dependencies PM: EM: fix memory leak with using debugfs_lookup() PM: domains: fix memory leak with using debugfs_lookup() cpufreq: Make kobj_type structure constant cpufreq: davinci: Fix clk use after free cpufreq: amd-pstate: avoid uninitialized variable use cpufreq: Make cpufreq_unregister_driver() return void OPP: fix error checking in opp_migrate_dentry() dt-bindings: cpufreq: cpufreq-qcom-hw: Add SM8550 compatible ... |
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716ff71ae2 |
cpuidle-haltpoll: Replace default_idle() with arch_cpu_idle()
When a KVM guest has MWAIT, mwait_idle() is used as the default idle
function.
However, the cpuidle-haltpoll driver calls default_idle() from
default_enter_idle() directly and that one uses HLT instead of MWAIT,
which may affect performance adversely, because MWAIT is preferred to
HLT as explained by the changelog of commit
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89b3098703 |
arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabled
Current arch_cpu_idle() is called with IRQs disabled, but will return with IRQs enabled. However, the very first thing the generic code does after calling arch_cpu_idle() is raw_local_irq_disable(). This means that architectures that can idle with IRQs disabled end up doing a pointless 'enable-disable' dance. Therefore, push this IRQ disabling into the idle function, meaning that those architectures can avoid the pointless IRQ state flipping. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.618076436@infradead.org |
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aaa3896b96 |
x86/idle: Replace 'x86_idle' function pointer with a static_call
Typical boot time setup; no need to suffer an indirect call for that. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20230112195539.453613251@infradead.org |
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268325bda5 |
Random number generator updates for Linux 6.2-rc1.
-----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEq5lC5tSkz8NBJiCnSfxwEqXeA64FAmOU+U8ACgkQSfxwEqXe A67NnQ//Y5DltmvibyPd7r1TFT2gUYv+Rx3sUV9ZE1NYptd/SWhhcL8c5FZ70Fuw bSKCa1uiWjOxosjXT1kGrWq3de7q7oUpAPSOGxgxzoaNURIt58N/ajItCX/4Au8I RlGAScHy5e5t41/26a498kB6qJ441fBEqCYKQpPLINMBAhe8TQ+NVp0rlpUwNHFX WrUGg4oKWxdBIW3HkDirQjJWDkkAiklRTifQh/Al4b6QDbOnRUGGCeckNOhixsvS waHWTld+Td8jRrA4b82tUb2uVZ2/b8dEvj/A8CuTv4yC0lywoyMgBWmJAGOC+UmT ZVNdGW02Jc2T+Iap8ZdsEmeLHNqbli4+IcbY5xNlov+tHJ2oz41H9TZoYKbudlr6 /ReAUPSn7i50PhbQlEruj3eg+M2gjOeh8OF8UKwwRK8PghvyWQ1ScW0l3kUhPIhI PdIG6j4+D2mJc1FIj2rTVB+Bg933x6S+qx4zDxGlNp62AARUFYf6EgyD6aXFQVuX RxcKb6cjRuFkzFiKc8zkqg5edZH+IJcPNuIBmABqTGBOxbZWURXzIQvK/iULqZa4 CdGAFIs6FuOh8pFHLI3R4YoHBopbHup/xKDEeAO9KZGyeVIuOSERDxxo5f/ITzcq APvT77DFOEuyvanr8RMqqh0yUjzcddXqw9+ieufsAyDwjD9DTuE= =QRhK -----END PGP SIGNATURE----- Merge tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: - Replace prandom_u32_max() and various open-coded variants of it, there is now a new family of functions that uses fast rejection sampling to choose properly uniformly random numbers within an interval: get_random_u32_below(ceil) - [0, ceil) get_random_u32_above(floor) - (floor, U32_MAX] get_random_u32_inclusive(floor, ceil) - [floor, ceil] Coccinelle was used to convert all current users of prandom_u32_max(), as well as many open-coded patterns, resulting in improvements throughout the tree. I'll have a "late" 6.1-rc1 pull for you that removes the now unused prandom_u32_max() function, just in case any other trees add a new use case of it that needs to converted. According to linux-next, there may be two trivial cases of prandom_u32_max() reintroductions that are fixable with a 's/.../.../'. So I'll have for you a final conversion patch doing that alongside the removal patch during the second week. This is a treewide change that touches many files throughout. - More consistent use of get_random_canary(). - Updates to comments, documentation, tests, headers, and simplification in configuration. - The arch_get_random*_early() abstraction was only used by arm64 and wasn't entirely useful, so this has been replaced by code that works in all relevant contexts. - The kernel will use and manage random seeds in non-volatile EFI variables, refreshing a variable with a fresh seed when the RNG is initialized. The RNG GUID namespace is then hidden from efivarfs to prevent accidental leakage. These changes are split into random.c infrastructure code used in the EFI subsystem, in this pull request, and related support inside of EFISTUB, in Ard's EFI tree. These are co-dependent for full functionality, but the order of merging doesn't matter. - Part of the infrastructure added for the EFI support is also used for an improvement to the way vsprintf initializes its siphash key, replacing an sleep loop wart. - The hardware RNG framework now always calls its correct random.c input function, add_hwgenerator_randomness(), rather than sometimes going through helpers better suited for other cases. - The add_latent_entropy() function has long been called from the fork handler, but is a no-op when the latent entropy gcc plugin isn't used, which is fine for the purposes of latent entropy. But it was missing out on the cycle counter that was also being mixed in beside the latent entropy variable. So now, if the latent entropy gcc plugin isn't enabled, add_latent_entropy() will expand to a call to add_device_randomness(NULL, 0), which adds a cycle counter, without the absent latent entropy variable. - The RNG is now reseeded from a delayed worker, rather than on demand when used. Always running from a worker allows it to make use of the CPU RNG on platforms like S390x, whose instructions are too slow to do so from interrupts. It also has the effect of adding in new inputs more frequently with more regularity, amounting to a long term transcript of random values. Plus, it helps a bit with the upcoming vDSO implementation (which isn't yet ready for 6.2). - The jitter entropy algorithm now tries to execute on many different CPUs, round-robining, in hopes of hitting even more memory latencies and other unpredictable effects. It also will mix in a cycle counter when the entropy timer fires, in addition to being mixed in from the main loop, to account more explicitly for fluctuations in that timer firing. And the state it touches is now kept within the same cache line, so that it's assured that the different execution contexts will cause latencies. * tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits) random: include <linux/once.h> in the right header random: align entropy_timer_state to cache line random: mix in cycle counter when jitter timer fires random: spread out jitter callback to different CPUs random: remove extraneous period and add a missing one in comments efi: random: refresh non-volatile random seed when RNG is initialized vsprintf: initialize siphash key using notifier random: add back async readiness notifier random: reseed in delayed work rather than on-demand random: always mix cycle counter in add_latent_entropy() hw_random: use add_hwgenerator_randomness() for early entropy random: modernize documentation comment on get_random_bytes() random: adjust comment to account for removed function random: remove early archrandom abstraction random: use random.trust_{bootloader,cpu} command line option only stackprotector: actually use get_random_canary() stackprotector: move get_random_canary() into stackprotector.h treewide: use get_random_u32_inclusive() when possible treewide: use get_random_u32_{above,below}() instead of manual loop treewide: use get_random_u32_below() instead of deprecated function ... |
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6606515742 |
x86/bugs: Make sure MSR_SPEC_CTRL is updated properly upon resume from S3
The "force" argument to write_spec_ctrl_current() is currently ambiguous
as it does not guarantee the MSR write. This is due to the optimization
that writes to the MSR happen only when the new value differs from the
cached value.
This is fine in most cases, but breaks for S3 resume when the cached MSR
value gets out of sync with the hardware MSR value due to S3 resetting
it.
When x86_spec_ctrl_current is same as x86_spec_ctrl_base, the MSR write
is skipped. Which results in SPEC_CTRL mitigations not getting restored.
Move the MSR write from write_spec_ctrl_current() to a new function that
unconditionally writes to the MSR. Update the callers accordingly and
rename functions.
[ bp: Rework a bit. ]
Fixes:
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8032bf1233 |
treewide: use get_random_u32_below() instead of deprecated function
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
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81895a65ec |
treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: KP Singh <kpsingh@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
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42efa5e3a8 |
- Remove the vendor check when selecting MWAIT as the default idle state
- Respect idle=nomwait when supplied on the kernel cmdline - Two small cleanups -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmLntx0ACgkQEsHwGGHe VUqlRxAAkULobsk6Dx3wrQcYlpA8Mt/ctttTQXWiIQwhK1j7uP0zlGWBqImr5Wsk T04g1s29azulnPs3PydCF2QlLqSyF4v2PyyUwnpKfTP6CPM+MLtz98Gm6Xcbkt+s f28ISYgNP+15tskWdNqB5XIVGkuyBdNne9TiFwtnVrJYF47FSwqEWRyqMH+bIOGT wSZUCfjcw7PtKwfIAmYq4beS2+wbY9bsfVyIz+H0ks2EVFQdjYWb/kH9PgUYEQFe VEOBsPvTHDOJt0QXEXSJjmoSRUS77Wduw56Y3L2T4jWdXXQFWJ79rqNYDBvXGAdh Y8BKM5IYFZpzrmfw2RB6jbDY/JWO5PPFvHTXogQf9+wttSerZEffVQdOeTwjT8VD wc9/ZnNkT7915033VI90V+hdFkwarq8FXuFH8TkzcxP9DQNYG8CRTZBceq0UWBl0 5RpIDwNX9JxGrR+frJi0D24qxz//wLe56UqW9hLp73NP8QtEYEW1nb1q30Q2eM3N iQblgmh63qQ/dy6JV1GFb3aePiWMUNQwcTrj1pd8YDfNlp4IsFsSswnsdAZWtr1A l9qewHkBZbbzyTQkBjExUsaIdiaMywFwnUmcQNL+fHqznZIvMhJC/oCJeS0Pe/RH alTUrYsk6Y87HFpxoXpd85a9+20m8yrA64uY8cSQguGZ9i5Lm8g= =jkpj -----END PGP SIGNATURE----- Merge tag 'x86_cpu_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cpu updates from Borislav Petkov: - Remove the vendor check when selecting MWAIT as the default idle state - Respect idle=nomwait when supplied on the kernel cmdline - Two small cleanups * tag 'x86_cpu_for_v6.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Use MSR_IA32_MISC_ENABLE constants x86: Fix comment for X86_FEATURE_ZEN x86: Remove vendor checks from prefer_mwait_c1_over_halt x86: Handle idle=nomwait cmdline properly for x86_idle |
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c779bc1a90 |
x86/bugs: Optimize SPEC_CTRL MSR writes
When changing SPEC_CTRL for user control, the WRMSR can be delayed until return-to-user when KERNEL_IBRS has been enabled. This avoids an MSR write during context switch. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> |
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caa0ff24d5 |
x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value
Due to TIF_SSBD and TIF_SPEC_IB the actual IA32_SPEC_CTRL value can differ from x86_spec_ctrl_base. As such, keep a per-CPU value reflecting the current task's MSR content. [jpoimboe: rename] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> |
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aebef63cf7 |
x86: Remove vendor checks from prefer_mwait_c1_over_halt
Remove vendor checks from prefer_mwait_c1_over_halt function. Restore the decision tree to support MWAIT C1 as the default idle state based on CPUID checks as done by Thomas Gleixner in commit |
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8bcedb4ce0 |
x86: Handle idle=nomwait cmdline properly for x86_idle
When kernel is booted with idle=nomwait do not use MWAIT as the default idle state. If the user boots the kernel with idle=nomwait, it is a clear direction to not use mwait as the default idle state. However, the current code does not take this into consideration while selecting the default idle state on x86. Fix it by checking for the idle=nomwait boot option in prefer_mwait_c1_over_halt(). Also update the documentation around idle=nomwait appropriately. [ dhansen: tweak commit message ] Signed-off-by: Wyes Karny <wyes.karny@amd.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Zhang Rui <rui.zhang@intel.com> Link: https://lkml.kernel.org/r/fdc2dc2d0a1bc21c2f53d989ea2d2ee3ccbc0dbe.1654538381.git-series.wyes.karny@amd.com |
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1ec6574a3c |
This set of changes updates init and user mode helper tasks to be
ordinary user mode tasks. In commit |
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3e2cbc016b |
- Add Raptor Lake to the set of CPU models which support splitlock
- Make life miserable for apps using split locks by slowing them down considerably while the rest of the system remains responsive. The hope is it will hurt more and people will really fix their misaligned locks apps. As a result, free a TIF bit. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmKL5PQACgkQEsHwGGHe VUrz1Q//QjAKyKsAwCzGSPergtnZp9drimSuNsZAz6/xL8wFnn2nfWJTxugNF5jg n0Hal2oUGC8lg13mliB7NuDNu4RUWpkFzTzcIbPT8K9h7CUBdQPzqS7E3/p4s/eG ZCHp8psBGNp8+/+/LFfu9yhzYsAH9ji5KWmOzTVx9UdP3ovgR8BuCI7FCVJSfRz7 cY690XgvcuKoXKckVNaCcoQXPJxykfk4Y1yt1TpITqivFbs2I0vLgzEhoRcTAhPA nX3pR3uy6oaA6rZAapRt8lbLWOwIEWoI0Tt1v+r5p28+nFiCRfm1XdPYK6CDBlox UuMBK4WyvSKjKHLu3wEdLCvYbs1kw2l9pXvS3hrqsKhbdeXKrxrNZ3zshwFMAYap MY/nSTsKSWUUgMgUbWI084csapGFB+hxwY8OVr6JXbxE8YYD/yCbPGOe1cLI7MMt /H3F6vNqSzdp1N3mAaaKVxiiT21lHIn6oJuSZcDE5sOvBwvpXsOp/w3FxhJCOX49 PXrZLZmSHkDQSbh1XnvT/a+rq3XX1TFXFz71HYZf1yDk+xTijECglNtGnGSdj2Za iOw6M8VduV5Wy3ED9ubonruuHEJn6njpx/MH1B9+mAZsuLBpmuYFBxOn6AHOkXSb MVJD4flHXj0ugYm4Q5Y3yi24iWLsRI9utTOU079VL6i6DmFXeZc= =svvI -----END PGP SIGNATURE----- Merge tag 'x86_splitlock_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 splitlock updates from Borislav Petkov: - Add Raptor Lake to the set of CPU models which support splitlock - Make life miserable for apps using split locks by slowing them down considerably while the rest of the system remains responsive. The hope is it will hurt more and people will really fix their misaligned locks apps. As a result, free a TIF bit. * tag 'x86_splitlock_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/split_lock: Enable the split lock feature on Raptor Lake x86/split-lock: Remove unused TIF_SLD bit x86/split_lock: Make life miserable for split lockers |
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de8ac81747 |
- Remove all the code around GS switching on 32-bit now that it is not
needed anymore - Other misc improvements -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmKLp74ACgkQEsHwGGHe VUpqrhAAgNdNw/vNTTzeOH5ZSNxyIoTQapmrSNev0cXRW4tV2hxuYSa2wPZPJZXx aYhnFxwL7rVy0er7jG/5KaOyzHmrh6PcmqgFdPVo8+yVrfcsPIUqg/4L5peFZh7T ETV2pvFIiB4njkL/pR3mU5uAtTjyO89tD/LclKmc4ndv19vI8maj+k/dCDOnNnEz m4wJMXYWh4bG47/izU5TcTYU7ttTLEiVQ/mC5kEuj7PQeUR0kXKvvLo4rX+lOI2v dQRHgHg/qoNM7uVLd7vV/YdMWwcHchmKG5Y7+a/ogdlwR7a/X9e+lklFSeuxNvyH 8dOHIyzcb6lKTijpqhisZ3o9150ax3Q5FlSWuE3F/9Rcuc1T5eY82kTW2RTOTdV9 xsjob4y+hlpsUfuImupxJLHn685xsYAdqyiG/SPkcnJL++tNBlWiGHX9NqXF5cgw bq4/94Aouxevl0OBxnFBeoQOJvOnf60OY3LHcYR78yEEJyi4iWsC0/TEmD+9IE+r EpC1wz9bHCYbSwZ+yv8u2tNPd/rKxdspPL/6SxT9a+WAVrOZbQAN3VmlOIon6W9O bW5ye6suqBbl/Q1FACVU1xxSNjLTJUTFsB1X3QKGm8E+Kr7/zD1ZtT0WQNvyLMfT p/I4VRcdIxV3eDiYqeTfJ3sTS7IjKHSaZVBnpkZvRh869mMdqCg= =CfX1 -----END PGP SIGNATURE----- Merge tag 'x86_core_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core x86 updates from Borislav Petkov: - Remove all the code around GS switching on 32-bit now that it is not needed anymore - Other misc improvements * tag 'x86_core_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: bug: Use normal relative pointers in 'struct bug_entry' x86/nmi: Make register_nmi_handler() more robust x86/asm: Merge load_gs_index() x86/32: Remove lazy GS macros ELF: Remove elf_core_copy_kernel_regs() x86/32: Simplify ELF_CORE_COPY_REGS |
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a13dc4d409 |
- Serious sanitization and cleanup of the whole APERF/MPERF and
frequency invariance code along with removing the need for unnecessary IPIs - Finally remove a.out support - The usual trivial cleanups and fixes all over x86 -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmKLn48ACgkQEsHwGGHe VUpbkg/+PELrc0y/qxLM/+dyftKYY16Rhk6ZVAXfwqlh5ldyVQcLMUgKwDqYyTn2 XmgdI3cTcFlH2K7j6ANWLu0I9NPaviimUcEdMVcXt7aY5mGWk/q4hIyCYM8d41sV qKx4OjNSdyoofG6MtwFLJDuoeVg99Bqgvm4nP9BuxL0dZJ2hfcUZ7MTxYCx9ZYjK /3trx0NV287Yg/wm91EU0nLQzy9xbGS7WCmMnse6uxiUdm2vXbBt8oNFF4f747Dj 0cArfNrMgYq4Cv5bgt/Ki0NU/n4EOGDpJUSyQwlnjDKeN81ESPy7IWtTQ6cE/rJK BZeUIPiGiYHwtqXv0UTAPGLG8cAqKeab8u0xAOyrFVDkTc0+WlPJRsUAOmRRGIGE M8ZjoxrLeuFgxw6vKpVjaA+mDRj3qEpSH+IrTcekS98PN7gmVzvq03GobgGbT7YB xmtbThJa+514FfUVckkyC0+A56BknUIgVxwFPqrthE2atzYTbH67hW4U0yVWXXr7 2VI7ttozBrYVgHCWhD9eoT0uhyD74Vl6pqHnqzY9ShIfKVUGvMgKHHg04nLLtF7W hm87xV3Q5UEmXhTmDzT1rUZ99mBUxGbWxk227I9raMugIh7pp9wIr57+7O0LRYfX TdnE2+tL8RMi7+XzRH5iLhnwkrvahBESeHSQ7GVI1Y2zMmmFN+0= =Dks/ -----END PGP SIGNATURE----- Merge tag 'x86_cleanups_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Borislav Petkov: - Serious sanitization and cleanup of the whole APERF/MPERF and frequency invariance code along with removing the need for unnecessary IPIs - Finally remove a.out support - The usual trivial cleanups and fixes all over x86 * tag 'x86_cleanups_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits) x86: Remove empty files x86/speculation: Add missing srbds=off to the mitigations= help text x86/prctl: Remove pointless task argument x86/aperfperf: Make it correct on 32bit and UP kernels x86/aperfmperf: Integrate the fallback code from show_cpuinfo() x86/aperfmperf: Replace arch_freq_get_on_cpu() x86/aperfmperf: Replace aperfmperf_get_khz() x86/aperfmperf: Store aperf/mperf data for cpu frequency reads x86/aperfmperf: Make parts of the frequency invariance code unconditional x86/aperfmperf: Restructure arch_scale_freq_tick() x86/aperfmperf: Put frequency invariance aperf/mperf data into a struct x86/aperfmperf: Untangle Intel and AMD frequency invariance init x86/aperfmperf: Separate AP/BP frequency invariance init x86/smp: Move APERF/MPERF code where it belongs x86/aperfmperf: Dont wake idle CPUs in arch_freq_get_on_cpu() x86/process: Fix kernel-doc warning due to a changed function name x86: Remove a.out support x86/mm: Replace nodes_weight() with nodes_empty() where appropriate x86: Replace cpumask_weight() with cpumask_empty() where appropriate x86/pkeys: Remove __arch_set_user_pkey_access() declaration ... |
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f5c0b4f304 |
x86/prctl: Remove pointless task argument
The functions invoked via do_arch_prctl_common() can only operate on the current task and none of these function uses the task argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/87lev7vtxj.ffs@tglx |
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5bd2e97c86 |
fork: Generalize PF_IO_WORKER handling
Add fn and fn_arg members into struct kernel_clone_args and test for them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER). This allows any task that wants to be a user space task that only runs in kernel mode to use this functionality. The code on x86 is an exception and still retains a PF_KTHREAD test because x86 unlikely everything else handles kthreads slightly differently than user space tasks that start with a function. The functions that created tasks that start with a function have been updated to set ".fn" and ".fn_arg" instead of ".stack" and ".stack_size". These functions are fork_idle(), create_io_thread(), kernel_thread(), and user_mode_thread(). Link: https://lkml.kernel.org/r/20220506141512.516114-4-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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c5febea095 |
fork: Pass struct kernel_clone_args into copy_thread
With io_uring we have started supporting tasks that are for most purposes user space tasks that exclusively run code in kernel mode. The kernel task that exec's init and tasks that exec user mode helpers are also user mode tasks that just run kernel code until they call kernel execve. Pass kernel_clone_args into copy_thread so these oddball tasks can be supported more cleanly and easily. v2: Fix spelling of kenrel_clone_args on h8300 Link: https://lkml.kernel.org/r/20220506141512.516114-2-ebiederm@xmission.com Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> |
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ef79970d7c |
x86/split-lock: Remove unused TIF_SLD bit
Changes to the "warn" mode of split lock handling mean that TIF_SLD is never set. Remove the bit, and the functions that use it. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20220310204854.31752-3-tony.luck@intel.com |
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3a24a60854 |
x86/32: Remove lazy GS macros
GS is always a user segment now. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lore.kernel.org/r/20220325153953.162643-4-brgerst@gmail.com |
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dbb5ab6d2c |
x86/process: Fix kernel-doc warning due to a changed function name
Fix the following scripts/kernel-doc warning: arch/x86/kernel/process.c:412: warning: expecting prototype for tss_update_io_bitmap(). Prototype was for native_tss_update_io_bitmap() instead. [ bp: Massage. ] Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220414062110.60343-1-jiapeng.chong@linux.alibaba.com |
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bfe6ed0c67 |
x86/tdx: Add HLT support for TDX guests
The HLT instruction is a privileged instruction, executing it stops instruction execution and places the processor in a HALT state. It is used in kernel for cases like reboot, idle loop and exception fixup handlers. For the idle case, interrupts will be enabled (using STI) before the HLT instruction (this is also called safe_halt()). To support the HLT instruction in TDX guests, it needs to be emulated using TDVMCALL (hypercall to VMM). More details about it can be found in Intel Trust Domain Extensions (Intel TDX) Guest-Host-Communication Interface (GHCI) specification, section TDVMCALL[Instruction.HLT]. In TDX guests, executing HLT instruction will generate a #VE, which is used to emulate the HLT instruction. But #VE based emulation will not work for the safe_halt() flavor, because it requires STI instruction to be executed just before the TDCALL. Since idle loop is the only user of safe_halt() variant, handle it as a special case. To avoid *safe_halt() call in the idle function, define the tdx_guest_idle() and use it to override the "x86_idle" function pointer for a valid TDX guest. Alternative choices like PV ops have been considered for adding safe_halt() support. But it was rejected because HLT paravirt calls only exist under PARAVIRT_XXL, and enabling it in TDX guest just for safe_halt() use case is not worth the cost. Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lkml.kernel.org/r/20220405232939.73860-9-kirill.shutemov@linux.intel.com |
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9cea0d46f5 |
Merge branch 'x86/cpu' into x86/core, to resolve conflicts
Conflicts: arch/x86/include/asm/cpufeatures.h Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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f9cdf7ca57 |
x86: Mark stop_this_cpu() __noreturn
vmlinux.o: warning: objtool: smp_stop_nmi_callback()+0x2b: unreachable instruction 0000 0000000000047cf0 <smp_stop_nmi_callback>: ... 0026 47d16: e8 00 00 00 00 call 47d1b <smp_stop_nmi_callback+0x2b> 47d17: R_X86_64_PLT32 stop_this_cpu-0x4 002b 47d1b: b8 01 00 00 00 mov $0x1,%eax Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.290905453@infradead.org |
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08f253ec37 |
x86/cpu: Clear SME feature flag when not in use
Currently, the SME CPU feature flag is reflective of whether the CPU supports the feature but not whether it has been activated by the kernel. Change this around to clear the SME feature flag if the kernel is not using it so userspace can determine if it is available and in use from /proc/cpuinfo. As the feature flag is cleared on systems where SME isn't active, use CPUID 0x8000001f to confirm SME availability before calling native_wbinvd(). Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20220216034446.2430634-1-mario.limonciello@amd.com |
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79e06c4c49 |
RISCV:
- Use common KVM implementation of MMU memory caches - SBI v0.2 support for Guest - Initial KVM selftests support - Fix to avoid spurious virtual interrupts after clearing hideleg CSR - Update email address for Anup and Atish ARM: - Simplification of the 'vcpu first run' by integrating it into KVM's 'pid change' flow - Refactoring of the FP and SVE state tracking, also leading to a simpler state and less shared data between EL1 and EL2 in the nVHE case - Tidy up the header file usage for the nvhe hyp object - New HYP unsharing mechanism, finally allowing pages to be unmapped from the Stage-1 EL2 page-tables - Various pKVM cleanups around refcounting and sharing - A couple of vgic fixes for bugs that would trigger once the vcpu xarray rework is merged, but not sooner - Add minimal support for ARMv8.7's PMU extension - Rework kvm_pgtable initialisation ahead of the NV work - New selftest for IRQ injection - Teach selftests about the lack of default IPA space and page sizes - Expand sysreg selftest to deal with Pointer Authentication - The usual bunch of cleanups and doc update s390: - fix sigp sense/start/stop/inconsistency - cleanups x86: - Clean up some function prototypes more - improved gfn_to_pfn_cache with proper invalidation, used by Xen emulation - add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery - completely remove potential TOC/TOU races in nested SVM consistency checks - update some PMCs on emulated instructions - Intel AMX support (joint work between Thomas and Intel) - large MMU cleanups - module parameter to disable PMU virtualization - cleanup register cache - first part of halt handling cleanups - Hyper-V enlightened MSR bitmap support for nested hypervisors Generic: - clean up Makefiles - introduce CONFIG_HAVE_KVM_DIRTY_RING - optimize memslot lookup using a tree - optimize vCPU array usage by converting to xarray -----BEGIN PGP SIGNATURE----- iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmHhxvsUHHBib256aW5p QHJlZGhhdC5jb20ACgkQv/vSX3jHroPZkAf+Nz92UL/5nNGcdHtE4m7AToMmitE9 bYkesf9BMQvAe5wjkABLuoHGi6ay4jabo4fiGzbdkiK7lO5YgfsWiMB3/MT5fl4E jRPzaVQabp3YZLM8UYCBmfUVuRj524S967SfSRe0AvYjDEH8y7klPf4+7sCsFT0/ Px9Vf2KGuOlf0eM78yKg4rGaF0jS22eLgXm6FfNMY8/e29ZAo/jyUmqBY+Z2xxZG aWhceDtSheW1jwLHLj3nOlQJvHTn8LVGXBE/R8Gda3ZjrBV2rKaDi4Fh+HD+dz86 2zVXwzQ7uck2CMW73GMoXMTWoKSHMyvlBOs1BdvBm4UsnGcXR+q8IFCeuQ== =s73m -----END PGP SIGNATURE----- Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm Pull kvm updates from Paolo Bonzini: "RISCV: - Use common KVM implementation of MMU memory caches - SBI v0.2 support for Guest - Initial KVM selftests support - Fix to avoid spurious virtual interrupts after clearing hideleg CSR - Update email address for Anup and Atish ARM: - Simplification of the 'vcpu first run' by integrating it into KVM's 'pid change' flow - Refactoring of the FP and SVE state tracking, also leading to a simpler state and less shared data between EL1 and EL2 in the nVHE case - Tidy up the header file usage for the nvhe hyp object - New HYP unsharing mechanism, finally allowing pages to be unmapped from the Stage-1 EL2 page-tables - Various pKVM cleanups around refcounting and sharing - A couple of vgic fixes for bugs that would trigger once the vcpu xarray rework is merged, but not sooner - Add minimal support for ARMv8.7's PMU extension - Rework kvm_pgtable initialisation ahead of the NV work - New selftest for IRQ injection - Teach selftests about the lack of default IPA space and page sizes - Expand sysreg selftest to deal with Pointer Authentication - The usual bunch of cleanups and doc update s390: - fix sigp sense/start/stop/inconsistency - cleanups x86: - Clean up some function prototypes more - improved gfn_to_pfn_cache with proper invalidation, used by Xen emulation - add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery - completely remove potential TOC/TOU races in nested SVM consistency checks - update some PMCs on emulated instructions - Intel AMX support (joint work between Thomas and Intel) - large MMU cleanups - module parameter to disable PMU virtualization - cleanup register cache - first part of halt handling cleanups - Hyper-V enlightened MSR bitmap support for nested hypervisors Generic: - clean up Makefiles - introduce CONFIG_HAVE_KVM_DIRTY_RING - optimize memslot lookup using a tree - optimize vCPU array usage by converting to xarray" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (268 commits) x86/fpu: Fix inline prefix warnings selftest: kvm: Add amx selftest selftest: kvm: Move struct kvm_x86_state to header selftest: kvm: Reorder vcpu_load_state steps for AMX kvm: x86: Disable interception for IA32_XFD on demand x86/fpu: Provide fpu_sync_guest_vmexit_xfd_state() kvm: selftests: Add support for KVM_CAP_XSAVE2 kvm: x86: Add support for getting/setting expanded xstate buffer x86/fpu: Add uabi_size to guest_fpu kvm: x86: Add CPUID support for Intel AMX kvm: x86: Add XCR0 support for Intel AMX kvm: x86: Disable RDMSR interception of IA32_XFD_ERR kvm: x86: Emulate IA32_XFD_ERR for guest kvm: x86: Intercept #NM for saving IA32_XFD_ERR x86/fpu: Prepare xfd_err in struct fpu_guest kvm: x86: Add emulation for IA32_XFD x86/fpu: Provide fpu_update_guest_xfd() for IA32_XFD emulation kvm: x86: Enable dynamic xfeatures at KVM_SET_CPUID2 x86/fpu: Provide fpu_enable_guest_xfd_features() for KVM x86/fpu: Add guest support to xfd_enable_feature() ... |
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980fe2fddc |
x86/fpu: Extend fpu_xstate_prctl() with guest permissions
KVM requires a clear separation of host user space and guest permissions for dynamic XSTATE components. Add a guest permissions member to struct fpu and a separate set of prctl() arguments: ARCH_GET_XCOMP_GUEST_PERM and ARCH_REQ_XCOMP_GUEST_PERM. The semantics are equivalent to the host user space permission control except for the following constraints: 1) Permissions have to be requested before the first vCPU is created 2) Permissions are frozen when the first vCPU is created to ensure consistency. Any attempt to expand permissions via the prctl() after that point is rejected. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jing Liu <jing2.liu@intel.com> Signed-off-by: Yang Zhong <yang.zhong@intel.com> Message-Id: <20220105123532.12586-2-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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dca99fb643 |
x86: Snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are disabled, the flags can change under our feet. Generally this is unlikely to cause a problem in practice, but it is somewhat unsound, and KCSAN will legitimately warn that there is a data race. To avoid such issues, a snapshot of the flags has to be taken prior to using them. Some places already use READ_ONCE() for that, others do not. Convert them all to the new flag accessor helpers. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20211129130653.2037928-12-mark.rutland@arm.com |
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0dc636b3b7 |
x86: Pin task-stack in __get_wchan()
When commit |
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cc0356d6a0 |
- Do not #GP on userspace use of CLI/STI but pretend it was a NOP to
keep old userspace from breaking. Adjust the corresponding iopl selftest to that. - Improve stack overflow warnings to say which stack got overflowed and raise the exception stack sizes to 2 pages since overflowing the single page of exception stack is very easy to do nowadays with all the tracing machinery enabled. With that, rip out the custom mapping of AMD SEV's too. - A bunch of changes in preparation for FGKASLR like supporting more than 64K section headers in the relocs tool, correct ORC lookup table size to cover the whole kernel .text and other adjustments. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmF/uugACgkQEsHwGGHe VUroKw//e8BJ3Aun8bg00FHxfiMGbPYcozjLGDkaoMtMDZ8WlfCUrvtqYICEr8eB UU0eRyygAPI167dre1O9JvAcbilkNTKntaU6qbu/ZVyUwS3+Jkjwsotbqn3xKtkd QDDTDNiCU+beCJ2ZbspbrPgEh13+H0MwMHUfRxZB9Scpmo6aGSEaU3g295f6GX57 VFGJ/LNov5MV1dTD7Pp/h6/Nb+R6WmflKcBzJmQxYuKyKX+g1xsSv0VSga+t+uf3 M9pUkizqTiUxzC2eLgtcEZTqqBHu810E8M76FmhKBUMilsFJT5YAJTiqyahwHXds HYarOFRgcnFuJPd29vn8UHjqeeoi6ru8GtcZYzccEc7U3ku/gXPaDJ9ffmvhs7vU pJX5Um3GiiFm0w/ZZOKDqh78wRAsCKLN+jIoyszuhkkNchZSj/jKfOgdd3EmcZst 6L6rxBA4oRHwNOgM7uVMp+jFeRe1/prR280OWWH0D4QmmuqybThOdO23Iuh/Deth W3qPUH3UQtfSWxGy2yODzJ1ciuGAr/AzJZ9zjg04e3Vl0DkEpyWtLKJiG3ClXZag Nj+3xc4xYH2Aw+M0HRaONk5XVKLpqVjuAfgU5iLQa0YSUbtrR+wCWvY8KgQNbAqK xZmzYzQ89stwVCuGKx10gPsL3jSJ3VCylMfqdHD2Ajmld1yApr0= =DOZU -----END PGP SIGNATURE----- Merge tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to keep old userspace from breaking. Adjust the corresponding iopl selftest to that. - Improve stack overflow warnings to say which stack got overflowed and raise the exception stack sizes to 2 pages since overflowing the single page of exception stack is very easy to do nowadays with all the tracing machinery enabled. With that, rip out the custom mapping of AMD SEV's too. - A bunch of changes in preparation for FGKASLR like supporting more than 64K section headers in the relocs tool, correct ORC lookup table size to cover the whole kernel .text and other adjustments. * tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext x86/boot/compressed: Avoid duplicate malloc() implementations x86/boot: Allow a "silent" kaslr random byte fetch x86/tools/relocs: Support >64K section headers x86/sev: Make the #VC exception stacks part of the default stacks storage x86: Increase exception stack sizes x86/mm/64: Improve stack overflow warnings x86/iopl: Fake iopl(3) CLI/STI usage |
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8cb1ae19bf |
x86/fpu updates:
- Cleanup of extable fixup handling to be more robust, which in turn allows to make the FPU exception fixups more robust as well. - Change the return code for signal frame related failures from explicit error codes to a boolean fail/success as that's all what the calling code evaluates. - A large refactoring of the FPU code to prepare for adding AMX support: - Distangle the public header maze and remove especially the misnomed kitchen sink internal.h which is despite it's name included all over the place. - Add a proper abstraction for the register buffer storage (struct fpstate) which allows to dynamically size the buffer at runtime by flipping the pointer to the buffer container from the default container which is embedded in task_struct::tread::fpu to a dynamically allocated container with a larger register buffer. - Convert the code over to the new fpstate mechanism. - Consolidate the KVM FPU handling by moving the FPU related code into the FPU core which removes the number of exports and avoids adding even more export when AMX has to be supported in KVM. This also removes duplicated code which was of course unnecessary different and incomplete in the KVM copy. - Simplify the KVM FPU buffer handling by utilizing the new fpstate container and just switching the buffer pointer from the user space buffer to the KVM guest buffer when entering vcpu_run() and flipping it back when leaving the function. This cuts the memory requirements of a vCPU for FPU buffers in half and avoids pointless memory copy operations. This also solves the so far unresolved problem of adding AMX support because the current FPU buffer handling of KVM inflicted a circular dependency between adding AMX support to the core and to KVM. With the new scheme of switching fpstate AMX support can be added to the core code without affecting KVM. - Replace various variables with proper data structures so the extra information required for adding dynamically enabled FPU features (AMX) can be added in one place - Add AMX (Advanved Matrix eXtensions) support (finally): AMX is a large XSTATE component which is going to be available with Saphire Rapids XEON CPUs. The feature comes with an extra MSR (MSR_XFD) which allows to trap the (first) use of an AMX related instruction, which has two benefits: 1) It allows the kernel to control access to the feature 2) It allows the kernel to dynamically allocate the large register state buffer instead of burdening every task with the the extra 8K or larger state storage. It would have been great to gain this kind of control already with AVX512. The support comes with the following infrastructure components: 1) arch_prctl() to - read the supported features (equivalent to XGETBV(0)) - read the permitted features for a task - request permission for a dynamically enabled feature Permission is granted per process, inherited on fork() and cleared on exec(). The permission policy of the kernel is restricted to sigaltstack size validation, but the syscall obviously allows further restrictions via seccomp etc. 2) A stronger sigaltstack size validation for sys_sigaltstack(2) which takes granted permissions and the potentially resulting larger signal frame into account. This mechanism can also be used to enforce factual sigaltstack validation independent of dynamic features to help with finding potential victims of the 2K sigaltstack size constant which is broken since AVX512 support was added. 3) Exception handling for #NM traps to catch first use of a extended feature via a new cause MSR. If the exception was caused by the use of such a feature, the handler checks permission for that feature. If permission has not been granted, the handler sends a SIGILL like the #UD handler would do if the feature would have been disabled in XCR0. If permission has been granted, then a new fpstate which fits the larger buffer requirement is allocated. In the unlikely case that this allocation fails, the handler sends SIGSEGV to the task. That's not elegant, but unavoidable as the other discussed options of preallocation or full per task permissions come with their own set of horrors for kernel and/or userspace. So this is the lesser of the evils and SIGSEGV caused by unexpected memory allocation failures is not a fundamentally new concept either. When allocation succeeds, the fpstate properties are filled in to reflect the extended feature set and the resulting sizes, the fpu::fpstate pointer is updated accordingly and the trap is disarmed for this task permanently. 4) Enumeration and size calculations 5) Trap switching via MSR_XFD The XFD (eXtended Feature Disable) MSR is context switched with the same life time rules as the FPU register state itself. The mechanism is keyed off with a static key which is default disabled so !AMX equipped CPUs have zero overhead. On AMX enabled CPUs the overhead is limited by comparing the tasks XFD value with a per CPU shadow variable to avoid redundant MSR writes. In case of switching from a AMX using task to a non AMX using task or vice versa, the extra MSR write is obviously inevitable. All other places which need to be aware of the variable feature sets and resulting variable sizes are not affected at all because they retrieve the information (feature set, sizes) unconditonally from the fpstate properties. 6) Enable the new AMX states Note, this is relatively new code despite the fact that AMX support is in the works for more than a year now. The big refactoring of the FPU code, which allowed to do a proper integration has been started exactly 3 weeks ago. Refactoring of the existing FPU code and of the original AMX patches took a week and has been subject to extensive review and testing. The only fallout which has not been caught in review and testing right away was restricted to AMX enabled systems, which is completely irrelevant for anyone outside Intel and their early access program. There might be dragons lurking as usual, but so far the fine grained refactoring has held up and eventual yet undetected fallout is bisectable and should be easily addressable before the 5.16 release. Famous last words... Many thanks to Chang Bae and Dave Hansen for working hard on this and also to the various test teams at Intel who reserved extra capacity to follow the rapid development of this closely which provides the confidence level required to offer this rather large update for inclusion into 5.16-rc1. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmF/NkITHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYodDkEADH4+/nN/QoSUHIuuha5Zptj3g2b16a /3TxT9fhwPen/kzMGsUk70s3iWJMA+I5dCfkSZexJ2hfhcRe9cBzZIa1HCawKwf3 YCISTsO/M+LpeORuZ+TpfFLJKnxNr1SEOl+EYffGhq0AkCjifb9Cnr0JZuoMUzGU jpfJZ2bj28ri5lG812DtzSMBM9E3SAwgJv+GNjmZbxZKb9mAfhbAMdBUXHirX7Ej jmx6koQjYOKwYIW8w1BrdC270lUKQUyJTbQgdRkN9Mh/HnKyFixQ18JqGlgaV2cT EtYePUfTEdaHdAhUINLIlEug1MfOslHU+HyGsdywnoChNB4GHPQuePC5Tz60VeFN RbQ9aKcBUu8r95rjlnKtAtBijNMA4bjGwllVxNwJ/ZoA9RPv1SbDZ07RX3qTaLVY YhVQl8+shD33/W24jUTJv1kMMexpHXIlv0gyfMryzpwI7uzzmGHRPAokJdbYKctC dyMPfdE90rxTiMUdL/1IQGhnh3awjbyfArzUhHyQ++HyUyzCFh0slsO0CD18vUy8 FofhCugGBhjuKw3XwLNQ+KsWURz5qHctSzBc3qMOSyqFHbAJCVRANkhsFvWJo2qL 75+Z7OTRebtsyOUZIdq26r4roSxHrps3dupWTtN70HWx2NhQG1nLEw986QYiQu1T hcKvDmehQLrUvg== =x3WL -----END PGP SIGNATURE----- Merge tag 'x86-fpu-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu updates from Thomas Gleixner: - Cleanup of extable fixup handling to be more robust, which in turn allows to make the FPU exception fixups more robust as well. - Change the return code for signal frame related failures from explicit error codes to a boolean fail/success as that's all what the calling code evaluates. - A large refactoring of the FPU code to prepare for adding AMX support: - Distangle the public header maze and remove especially the misnomed kitchen sink internal.h which is despite it's name included all over the place. - Add a proper abstraction for the register buffer storage (struct fpstate) which allows to dynamically size the buffer at runtime by flipping the pointer to the buffer container from the default container which is embedded in task_struct::tread::fpu to a dynamically allocated container with a larger register buffer. - Convert the code over to the new fpstate mechanism. - Consolidate the KVM FPU handling by moving the FPU related code into the FPU core which removes the number of exports and avoids adding even more export when AMX has to be supported in KVM. This also removes duplicated code which was of course unnecessary different and incomplete in the KVM copy. - Simplify the KVM FPU buffer handling by utilizing the new fpstate container and just switching the buffer pointer from the user space buffer to the KVM guest buffer when entering vcpu_run() and flipping it back when leaving the function. This cuts the memory requirements of a vCPU for FPU buffers in half and avoids pointless memory copy operations. This also solves the so far unresolved problem of adding AMX support because the current FPU buffer handling of KVM inflicted a circular dependency between adding AMX support to the core and to KVM. With the new scheme of switching fpstate AMX support can be added to the core code without affecting KVM. - Replace various variables with proper data structures so the extra information required for adding dynamically enabled FPU features (AMX) can be added in one place - Add AMX (Advanced Matrix eXtensions) support (finally): AMX is a large XSTATE component which is going to be available with Saphire Rapids XEON CPUs. The feature comes with an extra MSR (MSR_XFD) which allows to trap the (first) use of an AMX related instruction, which has two benefits: 1) It allows the kernel to control access to the feature 2) It allows the kernel to dynamically allocate the large register state buffer instead of burdening every task with the the extra 8K or larger state storage. It would have been great to gain this kind of control already with AVX512. The support comes with the following infrastructure components: 1) arch_prctl() to - read the supported features (equivalent to XGETBV(0)) - read the permitted features for a task - request permission for a dynamically enabled feature Permission is granted per process, inherited on fork() and cleared on exec(). The permission policy of the kernel is restricted to sigaltstack size validation, but the syscall obviously allows further restrictions via seccomp etc. 2) A stronger sigaltstack size validation for sys_sigaltstack(2) which takes granted permissions and the potentially resulting larger signal frame into account. This mechanism can also be used to enforce factual sigaltstack validation independent of dynamic features to help with finding potential victims of the 2K sigaltstack size constant which is broken since AVX512 support was added. 3) Exception handling for #NM traps to catch first use of a extended feature via a new cause MSR. If the exception was caused by the use of such a feature, the handler checks permission for that feature. If permission has not been granted, the handler sends a SIGILL like the #UD handler would do if the feature would have been disabled in XCR0. If permission has been granted, then a new fpstate which fits the larger buffer requirement is allocated. In the unlikely case that this allocation fails, the handler sends SIGSEGV to the task. That's not elegant, but unavoidable as the other discussed options of preallocation or full per task permissions come with their own set of horrors for kernel and/or userspace. So this is the lesser of the evils and SIGSEGV caused by unexpected memory allocation failures is not a fundamentally new concept either. When allocation succeeds, the fpstate properties are filled in to reflect the extended feature set and the resulting sizes, the fpu::fpstate pointer is updated accordingly and the trap is disarmed for this task permanently. 4) Enumeration and size calculations 5) Trap switching via MSR_XFD The XFD (eXtended Feature Disable) MSR is context switched with the same life time rules as the FPU register state itself. The mechanism is keyed off with a static key which is default disabled so !AMX equipped CPUs have zero overhead. On AMX enabled CPUs the overhead is limited by comparing the tasks XFD value with a per CPU shadow variable to avoid redundant MSR writes. In case of switching from a AMX using task to a non AMX using task or vice versa, the extra MSR write is obviously inevitable. All other places which need to be aware of the variable feature sets and resulting variable sizes are not affected at all because they retrieve the information (feature set, sizes) unconditonally from the fpstate properties. 6) Enable the new AMX states Note, this is relatively new code despite the fact that AMX support is in the works for more than a year now. The big refactoring of the FPU code, which allowed to do a proper integration has been started exactly 3 weeks ago. Refactoring of the existing FPU code and of the original AMX patches took a week and has been subject to extensive review and testing. The only fallout which has not been caught in review and testing right away was restricted to AMX enabled systems, which is completely irrelevant for anyone outside Intel and their early access program. There might be dragons lurking as usual, but so far the fine grained refactoring has held up and eventual yet undetected fallout is bisectable and should be easily addressable before the 5.16 release. Famous last words... Many thanks to Chang Bae and Dave Hansen for working hard on this and also to the various test teams at Intel who reserved extra capacity to follow the rapid development of this closely which provides the confidence level required to offer this rather large update for inclusion into 5.16-rc1 * tag 'x86-fpu-2021-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits) Documentation/x86: Add documentation for using dynamic XSTATE features x86/fpu: Include vmalloc.h for vzalloc() selftests/x86/amx: Add context switch test selftests/x86/amx: Add test cases for AMX state management x86/fpu/amx: Enable the AMX feature in 64-bit mode x86/fpu: Add XFD handling for dynamic states x86/fpu: Calculate the default sizes independently x86/fpu/amx: Define AMX state components and have it used for boot-time checks x86/fpu/xstate: Prepare XSAVE feature table for gaps in state component numbers x86/fpu/xstate: Add fpstate_realloc()/free() x86/fpu/xstate: Add XFD #NM handler x86/fpu: Update XFD state where required x86/fpu: Add sanity checks for XFD x86/fpu: Add XFD state to fpstate x86/msr-index: Add MSRs for XFD x86/cpufeatures: Add eXtended Feature Disabling (XFD) feature bit x86/fpu: Reset permission and fpstate on exec() x86/fpu: Prepare fpu_clone() for dynamically enabled features x86/fpu/signal: Prepare for variable sigframe length x86/signal: Use fpu::__state_user_size for sigalt stack validation ... |