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2024-07-05x86: stop playing stack games in profile_pc()Linus Torvalds
[ Upstream commit 093d9603b60093a9aaae942db56107f6432a5dca ] The 'profile_pc()' function is used for timer-based profiling, which isn't really all that relevant any more to begin with, but it also ends up making assumptions based on the stack layout that aren't necessarily valid. Basically, the code tries to account the time spent in spinlocks to the caller rather than the spinlock, and while I support that as a concept, it's not worth the code complexity or the KASAN warnings when no serious profiling is done using timers anyway these days. And the code really does depend on stack layout that is only true in the simplest of cases. We've lost the comment at some point (I think when the 32-bit and 64-bit code was unified), but it used to say: Assume the lock function has either no stack frame or a copy of eflags from PUSHF. which explains why it just blindly loads a word or two straight off the stack pointer and then takes a minimal look at the values to just check if they might be eflags or the return pc: Eflags always has bits 22 and up cleared unlike kernel addresses but that basic stack layout assumption assumes that there isn't any lock debugging etc going on that would complicate the code and cause a stack frame. It causes KASAN unhappiness reported for years by syzkaller [1] and others [2]. With no real practical reason for this any more, just remove the code. Just for historical interest, here's some background commits relating to this code from 2006: 0cb91a229364 ("i386: Account spinlocks to the caller during profiling for !FP kernels") 31679f38d886 ("Simplify profile_pc on x86-64") and a code unification from 2009: ef4512882dbe ("x86: time_32/64.c unify profile_pc") but the basics of this thing actually goes back to before the git tree. Link: https://syzkaller.appspot.com/bug?extid=84fe685c02cd112a2ac3 [1] Link: https://lore.kernel.org/all/CAK55_s7Xyq=nh97=K=G1sxueOFrJDAvPOJAL4TPTCAYvmxO9_A@mail.gmail.com/ [2] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05x86/fpu: Fix AMD X86_BUG_FXSAVE_LEAK fixupUros Bizjak
[ Upstream commit 5d31174f3c8c465d9dbe88f6b9d1fe5716f44981 ] The assembly snippet in restore_fpregs_from_fpstate() that implements X86_BUG_FXSAVE_LEAK fixup loads the value from a random variable, preferably the one that is already in the L1 cache. However, the access to fpinit_state via *fpstate pointer is not implemented correctly. The "m" asm constraint requires dereferenced pointer variable, otherwise the compiler just reloads the value via temporary stack slot. The current asm code reflects this: mov %rdi,(%rsp) ... fildl (%rsp) With dereferenced pointer variable, the code does what the comment above the asm snippet says: fildl (%rdi) Also, remove the pointless %P operand modifier. The modifier is ineffective on non-symbolic references - it was used to prevent %rip-relative addresses in .altinstr sections, but FILDL in the .text section can use %rip-relative addresses without problems. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240315081849.5187-1-ubizjak@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27x86/cpu: Fix x86_match_cpu() to match just X86_VENDOR_INTELTony Luck
[ Upstream commit 93022482b2948a9a7e9b5a2bb685f2e1cb4c3348 ] Code in v6.9 arch/x86/kernel/smpboot.c was changed by commit 4db64279bc2b ("x86/cpu: Switch to new Intel CPU model defines") from: static const struct x86_cpu_id intel_cod_cpu[] = { X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X, 0), /* COD */ X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X, 0), /* COD */ X86_MATCH_INTEL_FAM6_MODEL(ANY, 1), /* SNC */ <--- 443 {} }; static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu); to: static const struct x86_cpu_id intel_cod_cpu[] = { X86_MATCH_VFM(INTEL_HASWELL_X, 0), /* COD */ X86_MATCH_VFM(INTEL_BROADWELL_X, 0), /* COD */ X86_MATCH_VFM(INTEL_ANY, 1), /* SNC */ {} }; static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu); On an Intel CPU with SNC enabled this code previously matched the rule on line 443 to avoid printing messages about insane cache configuration. The new code did not match any rules. Expanding the macros for the intel_cod_cpu[] array shows that the old is equivalent to: static const struct x86_cpu_id intel_cod_cpu[] = { [0] = { .vendor = 0, .family = 6, .model = 0x3F, .steppings = 0, .feature = 0, .driver_data = 0 }, [1] = { .vendor = 0, .family = 6, .model = 0x4F, .steppings = 0, .feature = 0, .driver_data = 0 }, [2] = { .vendor = 0, .family = 6, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 1 }, [3] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 0 } } while the new code expands to: static const struct x86_cpu_id intel_cod_cpu[] = { [0] = { .vendor = 0, .family = 6, .model = 0x3F, .steppings = 0, .feature = 0, .driver_data = 0 }, [1] = { .vendor = 0, .family = 6, .model = 0x4F, .steppings = 0, .feature = 0, .driver_data = 0 }, [2] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 1 }, [3] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 0 } } Looking at the code for x86_match_cpu(): const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match) { const struct x86_cpu_id *m; struct cpuinfo_x86 *c = &boot_cpu_data; for (m = match; m->vendor | m->family | m->model | m->steppings | m->feature; m++) { ... } return NULL; it is clear that there was no match because the ANY entry in the table (array index 2) is now the loop termination condition (all of vendor, family, model, steppings, and feature are zero). So this code was working before because the "ANY" check was looking for any Intel CPU in family 6. But fails now because the family is a wild card. So the root cause is that x86_match_cpu() has never been able to match on a rule with just X86_VENDOR_INTEL and all other fields set to wildcards. Add a new flags field to struct x86_cpu_id that has a bit set to indicate that this entry in the array is valid. Update X86_MATCH*() macros to set that bit. Change the end-marker check in x86_match_cpu() to just check the flags field for this bit. Backporter notes: The commit in Fixes is really the one that is broken: you can't have m->vendor as part of the loop termination conditional in x86_match_cpu() because it can happen - as it has happened above - that that whole conditional is 0 albeit vendor == 0 is a valid case - X86_VENDOR_INTEL is 0. However, the only case where the above happens is the SNC check added by 4db64279bc2b1 so you only need this fix if you have backported that other commit 4db64279bc2b ("x86/cpu: Switch to new Intel CPU model defines") Fixes: 644e9cbbe3fc ("Add driver auto probing for x86 features v4") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable+noautosel@kernel.org> # see above Link: https://lore.kernel.org/r/20240517144312.GBZkdtAOuJZCvxhFbJ@fat_crate.local Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27x86/resctrl: Don't try to free nonexistent RMIDsDave Martin
[ Upstream commit 739c9765793e5794578a64aab293c58607f1826a ] Commit 6791e0ea3071 ("x86/resctrl: Access per-rmid structures by index") adds logic to map individual monitoring groups into a global index space used for tracking allocated RMIDs. Attempts to free the default RMID are ignored in free_rmid(), and this works fine on x86. With arm64 MPAM, there is a latent bug here however: on platforms with no monitors exposed through resctrl, each control group still gets a different monitoring group ID as seen by the hardware, since the CLOSID always forms part of the monitoring group ID. This means that when removing a control group, the code may try to free this group's default monitoring group RMID for real. If there are no monitors however, the RMID tracking table rmid_ptrs[] would be a waste of memory and is never allocated, leading to a splat when free_rmid() tries to dereference the table. One option would be to treat RMID 0 as special for every CLOSID, but this would be ugly since bookkeeping still needs to be done for these monitoring group IDs when there are monitors present in the hardware. Instead, add a gating check of resctrl_arch_mon_capable() in free_rmid(), and just do nothing if the hardware doesn't have monitors. This fix mirrors the gating checks already present in mkdir_rdt_prepare_rmid_alloc() and elsewhere. No functional change on x86. [ bp: Massage commit message. ] Fixes: 6791e0ea3071 ("x86/resctrl: Access per-rmid structures by index") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Link: https://lore.kernel.org/r/20240618140152.83154-1-Dave.Martin@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27kprobe/ftrace: bail out if ftrace was killedStephen Brennan
[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ] If an error happens in ftrace, ftrace_kill() will prevent disarming kprobes. Eventually, the ftrace_ops associated with the kprobes will be freed, yet the kprobes will still be active, and when triggered, they will use the freed memory, likely resulting in a page fault and panic. This behavior can be reproduced quite easily, by creating a kprobe and then triggering a ftrace_kill(). For simplicity, we can simulate an ftrace error with a kernel module like [1]: [1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer sudo perf probe --add commit_creds sudo perf trace -e probe:commit_creds # In another terminal make sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug # Back to perf terminal # ctrl-c sudo perf probe --del commit_creds After a short period, a page fault and panic would occur as the kprobe continues to execute and uses the freed ftrace_ops. While ftrace_kill() is supposed to be used only in extreme circumstances, it is invoked in FTRACE_WARN_ON() and so there are many places where an unexpected bug could be triggered, yet the system may continue operating, possibly without the administrator noticing. If ftrace_kill() does not panic the system, then we should do everything we can to continue operating, rather than leave a ticking time bomb. Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/ Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21x86/amd_nb: Check for invalid SMN readsYazen Ghannam
commit c625dabbf1c4a8e77e4734014f2fde7aa9071a1f upstream. AMD Zen-based systems use a System Management Network (SMN) that provides access to implementation-specific registers. SMN accesses are done indirectly through an index/data pair in PCI config space. The PCI config access may fail and return an error code. This would prevent the "read" value from being updated. However, the PCI config access may succeed, but the return value may be invalid. This is in similar fashion to PCI bad reads, i.e. return all bits set. Most systems will return 0 for SMN addresses that are not accessible. This is in line with AMD convention that unavailable registers are Read-as-Zero/Writes-Ignored. However, some systems will return a "PCI Error Response" instead. This value, along with an error code of 0 from the PCI config access, will confuse callers of the amd_smn_read() function. Check for this condition, clear the return value, and set a proper error code. Fixes: ddfe43cdc0da ("x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h") Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230403164244.471141-1-yazen.ghannam@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-21x86/kexec: Fix bug with call depth trackingDavid Kaplan
commit 93c1800b3799f17375989b0daf76497dd3e80922 upstream. The call to cc_platform_has() triggers a fault and system crash if call depth tracking is active because the GS segment has been reset by load_segments() and GS_BASE is now 0 but call depth tracking uses per-CPU variables to operate. Call cc_platform_has() earlier in the function when GS is still valid. [ bp: Massage. ] Fixes: 5d8213864ade ("x86/retbleed: Add SKL return thunk") Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/20240603083036.637-1-bp@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-21x86/cpu: Provide default cache line size if not enumeratedDave Hansen
[ Upstream commit 2a38e4ca302280fdcce370ba2bee79bac16c4587 ] tl;dr: CPUs with CPUID.80000008H but without CPUID.01H:EDX[CLFSH] will end up reporting cache_line_size()==0 and bad things happen. Fill in a default on those to avoid the problem. Long Story: The kernel dies a horrible death if c->x86_cache_alignment (aka. cache_line_size() is 0. Normally, this value is populated from c->x86_clflush_size. Right now the code is set up to get c->x86_clflush_size from two places. First, modern CPUs get it from CPUID. Old CPUs that don't have leaf 0x80000008 (or CPUID at all) just get some sane defaults from the kernel in get_cpu_address_sizes(). The vast majority of CPUs that have leaf 0x80000008 also get ->x86_clflush_size from CPUID. But there are oddballs. Intel Quark CPUs[1] and others[2] have leaf 0x80000008 but don't set CPUID.01H:EDX[CLFSH], so they skip over filling in ->x86_clflush_size: cpuid(0x00000001, &tfms, &misc, &junk, &cap0); if (cap0 & (1<<19)) c->x86_clflush_size = ((misc >> 8) & 0xff) * 8; So they: land in get_cpu_address_sizes() and see that CPUID has level 0x80000008 and jump into the side of the if() that does not fill in c->x86_clflush_size. That assigns a 0 to c->x86_cache_alignment, and hilarity ensues in code like: buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()), GFP_KERNEL); To fix this, always provide a sane value for ->x86_clflush_size. Big thanks to Andy Shevchenko for finding and reporting this and also providing a first pass at a fix. But his fix was only partial and only worked on the Quark CPUs. It would not, for instance, have worked on the QEMU config. 1. https://raw.githubusercontent.com/InstLatx64/InstLatx64/master/GenuineIntel/GenuineIntel0000590_Clanton_03_CPUID.txt 2. You can also get this behavior if you use "-cpu 486,+clzero" in QEMU. [ dhansen: remove 'vp_bits_from_cpuid' reference in changelog because bpetkov brutally murdered it recently. ] Fixes: fbf6449f84bf ("x86/sev-es: Set x86_virt_bits to the correct value straight away, instead of a two-phase approach") Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Tested-by: Jörn Heusipp <osmanx@heusipp.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240516173928.3960193-1-andriy.shevchenko@linux.intel.com/ Link: https://lore.kernel.org/lkml/5e31cad3-ad4d-493e-ab07-724cfbfaba44@heusipp.de/ Link: https://lore.kernel.org/all/20240517200534.8EC5F33E%40davehans-spike.ostc.intel.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21x86/cpu: Get rid of an unnecessary local variable in get_cpu_address_sizes()Borislav Petkov (AMD)
[ Upstream commit 95bfb35269b2e85cff0dd2c957b2d42ebf95ae5f ] Drop 'vp_bits_from_cpuid' as it is not really needed. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240316120706.4352-1-bp@alien8.de Stable-dep-of: 2a38e4ca3022 ("x86/cpu: Provide default cache line size if not enumerated") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16x86/topology/amd: Evaluate SMT in CPUID leaf 0x8000001e only on family 0x17 ↵Thomas Gleixner
and greater commit 34bf6bae3286a58762711cfbce2cf74ecd42e1b5 upstream. The new AMD/HYGON topology parser evaluates the SMT information in CPUID leaf 0x8000001e unconditionally while the original code restricted it to CPUs with family 0x17 and greater. This breaks family 0x15 CPUs which advertise that leaf and have a non-zero value in the SMT section. The machine boots, but the scheduler complains loudly about the mismatch of the core IDs: WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:6482 sched_cpu_starting+0x183/0x250 WARNING: CPU: 0 PID: 1 at kernel/sched/topology.c:2408 build_sched_domains+0x76b/0x12b0 Add the condition back to cure it. [ bp: Make it actually build because grandpa is not concerned with trivial stuff. :-P ] Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Closes: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/56 Reported-by: Tim Teichmann <teichmanntim@outlook.de> Reported-by: Christian Heusel <christian@heusel.eu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tim Teichmann <teichmanntim@outlook.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/7skhx6mwe4hxiul64v6azhlxnokheorksqsdbp7qw6g2jduf6c@7b5pvomauugk Signed-off-by: Christian Heusel <christian@heusel.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-12genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offlineDongli Zhang
commit a6c11c0a5235fb144a65e0cb2ffd360ddc1f6c32 upstream. The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of interrupt affinity reconfiguration via procfs. Instead, the change is deferred until the next instance of the interrupt being triggered on the original CPU. When the interrupt next triggers on the original CPU, the new affinity is enforced within __irq_move_irq(). A vector is allocated from the new CPU, but the old vector on the original CPU remains and is not immediately reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming process is delayed until the next trigger of the interrupt on the new CPU. Upon the subsequent triggering of the interrupt on the new CPU, irq_complete_move() adds a task to the old CPU's vector_cleanup list if it remains online. Subsequently, the timer on the old CPU iterates over its vector_cleanup list, reclaiming old vectors. However, a rare scenario arises if the old CPU is outgoing before the interrupt triggers again on the new CPU. In that case irq_force_complete_move() is not invoked on the outgoing CPU to reclaim the old apicd->prev_vector because the interrupt isn't currently affine to the outgoing CPU, and irq_needs_fixup() returns false. Even though __vector_schedule_cleanup() is later called on the new CPU, it doesn't reclaim apicd->prev_vector; instead, it simply resets both apicd->move_in_progress and apicd->prev_vector to 0. As a result, the vector remains unreclaimed in vector_matrix, leading to a CPU vector leak. To address this issue, move the invocation of irq_force_complete_move() before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the interrupt is currently or used to be affine to the outgoing CPU. Additionally, reclaim the vector in __vector_schedule_cleanup() as well, following a warning message, although theoretically it should never see apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU. Fixes: f0383c24b485 ("genirq/cpuhotplug: Add support for cleaning up move in progress") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240522220218.162423-1-dongli.zhang@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-12x86/topology/intel: Unlock CPUID before evaluating anythingThomas Gleixner
commit 0c2f6d04619ec2b53ad4b0b591eafc9389786e86 upstream. Intel CPUs have a MSR bit to limit CPUID enumeration to leaf two. If this bit is set by the BIOS then CPUID evaluation including topology enumeration does not work correctly as the evaluation code does not try to analyze any leaf greater than two. This went unnoticed before because the original topology code just repeated evaluation several times and managed to overwrite the initial limited information with the correct one later. The new evaluation code does it once and therefore ends up with the limited and wrong information. Cure this by unlocking CPUID right before evaluating anything which depends on the maximum CPUID leaf being greater than two instead of rereading stuff after unlock. Fixes: 22d63660c35e ("x86/cpu: Use common topology code for Intel") Reported-by: Peter Schneider <pschneider1968@googlemail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/fd3f73dc-a86f-4bcf-9c60-43556a21eb42@googlemail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-12x86/topology: Handle bogus ACPI tables correctlyThomas Gleixner
commit 9d22c96316ac59ed38e80920c698fed38717b91b upstream. The ACPI specification clearly states how the processors should be enumerated in the MADT: "To ensure that the boot processor is supported post initialization, two guidelines should be followed. The first is that OSPM should initialize processors in the order that they appear in the MADT. The second is that platform firmware should list the boot processor as the first processor entry in the MADT. ... Failure of OSPM implementations and platform firmware to abide by these guidelines can result in both unpredictable and non optimal platform operation." The kernel relies on that ordering to detect the real BSP on crash kernels which is important to avoid sending a INIT IPI to it as that would cause a full machine reset. On a Dell XPS 16 9640 the BIOS ignores this rule and enumerates the CPUs in the wrong order. As a consequence the kernel falsely detects a crash kernel and disables the corresponding CPU. Prevent this by checking the IA32_APICBASE MSR for the BSP bit on the boot CPU. If that bit is set, then the MADT based BSP detection can be safely ignored. If the kernel detects a mismatch between the BSP bit and the first enumerated MADT entry then emit a firmware bug message. This obviously also has to be taken into account when the boot APIC ID and the first enumerated APIC ID match. If the boot CPU does not have the BSP bit set in the APICBASE MSR then there is no way for the boot CPU to determine which of the CPUs is the real BSP. Sending an INIT to the real BSP would reset the machine so the only sane way to deal with that is to limit the number of CPUs to one and emit a corresponding warning message. Fixes: 5c5682b9f87a ("x86/cpu: Detect real BSP on crash kernels") Reported-by: Carsten Tolkmit <ctolkmit@ennit.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Carsten Tolkmit <ctolkmit@ennit.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87le48jycb.ffs@tglx Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218837 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-30x86/microcode/AMD: Avoid -Wformat warning with clang-15Arnd Bergmann
[ Upstream commit 9e11fc78e2df7a2649764413029441a0c897fb11 ] Older versions of clang show a warning for amd.c after a fix for a gcc warning: arch/x86/kernel/cpu/microcode/amd.c:478:47: error: format specifies type \ 'unsigned char' but the argument has type 'u16' (aka 'unsigned short') [-Werror,-Wformat] "amd-ucode/microcode_amd_fam%02hhxh.bin", family); ~~~~~~ ^~~~~~ %02hx In clang-16 and higher, this warning is disabled by default, but clang-15 is still supported, and it's trivial to avoid by adapting the types according to the range of the passed data and the format string. [ bp: Massage commit message. ] Fixes: 2e9064faccd1 ("x86/microcode/amd: Fix snprintf() format string warning in W=1 build") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240405204919.1003409-1-arnd@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-30x86/tsc: Trust initial offset in architectural TSC-adjust MSRsDaniel J Blueman
commit 455f9075f14484f358b3c1d6845b4a438de198a7 upstream. When the BIOS configures the architectural TSC-adjust MSRs on secondary sockets to correct a constant inter-chassis offset, after Linux brings the cores online, the TSC sync check later resets the core-local MSR to 0, triggering HPET fallback and leading to performance loss. Fix this by unconditionally using the initial adjust values read from the MSRs. Trusting the initial offsets in this architectural mechanism is a better approach than special-casing workarounds for specific platforms. Signed-off-by: Daniel J Blueman <daniel@quora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steffen Persvold <sp@numascale.com> Reviewed-by: James Cleverdon <james.cleverdon.external@eviden.com> Reviewed-by: Dimitri Sivanich <sivanich@hpe.com> Reviewed-by: Prarit Bhargava <prarit@redhat.com> Link: https://lore.kernel.org/r/20240419085146.175665-1-daniel@quora.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-10x86/topology/amd: Ensure that LLC ID is initializedThomas Gleixner
The original topology evaluation code initialized cpu_data::topo::llc_id with the die ID initialy and then eventually overwrite it with information gathered from a CPUID leaf. The conversion analysis failed to spot that particular detail and omitted this initial assignment under the assumption that each topology evaluation path will set it up. That assumption is mostly correct, but turns out to be wrong in case that the CPUID leaf 0x80000006 does not provide a LLC ID. In that case, LLC ID is invalid and as a consequence the setup of the scheduling domain CPU masks is incorrect which subsequently causes the scheduler core to complain about it during CPU hotplug: BUG: arch topology borken the CLS domain not a subset of the MC domain Cure it by reusing legacy_set_llc() and assigning the die ID if the LLC ID is invalid after all possible parsers have been tried. Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Reported-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Link: https://lore.kernel.org/r/PUZPR04MB63168AC442C12627E827368581292@PUZPR04MB6316.apcprd04.prod.outlook.com
2024-05-10x86/amd_nb: Add new PCI IDs for AMD family 0x1aShyam Sundar S K
Add the new PCI Device IDs to the MISC IDs list to support new generation of AMD 1Ah family 70h Models of processors. [ bp: Massage commit message. ] Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240510111829.969501-1-Shyam-sundar.S-k@amd.com
2024-04-30x86/apic: Don't access the APIC when disabling x2APICThomas Gleixner
With 'iommu=off' on the kernel command line and x2APIC enabled by the BIOS the code which disables the x2APIC triggers an unchecked MSR access error: RDMSR from 0x802 at rIP: 0xffffffff94079992 (native_apic_msr_read+0x12/0x50) This is happens because default_acpi_madt_oem_check() selects an x2APIC driver before the x2APIC is disabled. When the x2APIC is disabled because interrupt remapping cannot be enabled due to 'iommu=off' on the command line, x2apic_disable() invokes apic_set_fixmap() which in turn tries to read the APIC ID. This triggers the MSR warning because x2APIC is disabled, but the APIC driver is still x2APIC based. Prevent that by adding an argument to apic_set_fixmap() which makes the APIC ID read out conditional and set it to false from the x2APIC disable path. That's correct as the APIC ID has already been read out during early discovery. Fixes: d10a904435fa ("x86/apic: Consolidate boot_cpu_physical_apicid initialization sites") Reported-by: Adrian Huang <ahuang12@lenovo.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Adrian Huang <ahuang12@lenovo.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/875xw5t6r7.ffs@tglx
2024-04-29x86/e820: Add a new e820 table update helperAshish Kalra
Add a new API helper e820__range_update_table() with which to update an arbitrary e820 table. Move all current users of e820__range_update_kexec() to this new helper. [ bp: Massage. ] Signed-off-by: Ashish Kalra <ashish.kalra@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/b726af213ad55053f8a7a1e793b01bb3f1ca9dd5.1714090302.git.ashish.kalra@amd.com
2024-04-24x86/cpu: Fix check for RDPKRU in __show_regs()David Kaplan
cpu_feature_enabled(X86_FEATURE_OSPKE) does not necessarily reflect whether CR4.PKE is set on the CPU. In particular, they may differ on non-BSP CPUs before setup_pku() is executed. In this scenario, RDPKRU will #UD causing the system to hang. Fix by checking CR4 for PKE enablement which is always correct for the current CPU. The scenario happens by inserting a WARN* before setup_pku() in identiy_cpu() or some other diagnostic which would lead to calling __show_regs(). [ bp: Massage commit message. ] Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240421191728.32239-1-bp@kernel.org
2024-04-24x86/CPU/AMD: Add models 0x10-0x1f to the Zen5 rangeWenkuan Wang
Add some more Zen5 models. Fixes: 3e4147f33f8b ("x86/CPU/AMD: Add X86_FEATURE_ZEN5") Signed-off-by: Wenkuan Wang <Wenkuan.Wang@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240423144111.1362-1-bp@kernel.org
2024-04-22x86/sev: Check for MWAITX and MONITORX opcodes in the #VC handlerTom Lendacky
The MWAITX and MONITORX instructions generate the same #VC error code as the MWAIT and MONITOR instructions, respectively. Update the #VC handler opcode checking to also support the MWAITX and MONITORX opcodes. Fixes: e3ef461af35a ("x86/sev: Harden #VC instruction emulation somewhat") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/453d5a7cfb4b9fe818b6fb67f93ae25468bc9e23.1713793161.git.thomas.lendacky@amd.com
2024-04-18x86/cpufeatures: Fix dependencies for GFNI, VAES, and VPCLMULQDQEric Biggers
Fix cpuid_deps[] to list the correct dependencies for GFNI, VAES, and VPCLMULQDQ. These features don't depend on AVX512, and there exist CPUs that support these features but not AVX512. GFNI actually doesn't even depend on AVX. This prevents GFNI from being unnecessarily disabled if AVX is disabled to mitigate the GDS vulnerability. This also prevents all three features from being unnecessarily disabled if AVX512VL (or its dependency AVX512F) were to be disabled, but it looks like there isn't any case where this happens anyway. Fixes: c128dbfa0f87 ("x86/cpufeatures: Enable new SSE/AVX/AVX512 CPU features") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20240417060434.47101-1-ebiggers@kernel.org
2024-04-14x86/bugs: Fix BHI retpoline checkJosh Poimboeuf
Confusingly, X86_FEATURE_RETPOLINE doesn't mean retpolines are enabled, as it also includes the original "AMD retpoline" which isn't a retpoline at all. Also replace cpu_feature_enabled() with boot_cpu_has() because this is before alternatives are patched and cpu_feature_enabled()'s fallback path is slower than plain old boot_cpu_has(). Fixes: ec9404e40e8f ("x86/bhi: Add BHI mitigation knob") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/ad3807424a3953f0323c011a643405619f2a4927.1712944776.git.jpoimboe@kernel.org
2024-04-12x86/cpu/amd: Move TOPOEXT enablement into the topology parserThomas Gleixner
The topology rework missed that early_init_amd() tries to re-enable the Topology Extensions when the BIOS disabled them. The new parser is invoked before early_init_amd() so the re-enable attempt happens too late. Move it into the AMD specific topology parser code where it belongs. Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/878r1j260l.ffs@tglx
2024-04-12x86/cpu/amd: Make the NODEID_MSR union actually workThomas Gleixner
A system with NODEID_MSR was reported to crash during early boot without any output. The reason is that the union which is used for accessing the bitfields in the MSR is written wrongly and the resulting executable code accesses the wrong part of the MSR data. As a consequence a later division by that value results in 0 and that result is used for another division as divisor, which obviously does not work well. The magic world of C, unions and bitfields: union { u64 bita : 3, bitb : 3; u64 all; } x; x.all = foo(); a = x.bita; b = x.bitb; results in the effective executable code of: a = b = x.bita; because bita and bitb are treated as union members and therefore both end up at bit offset 0. Wrapping the bitfield into an anonymous struct: union { struct { u64 bita : 3, bitb : 3; }; u64 all; } x; works like expected. Rework the NODEID_MSR union in exactly that way to cure the problem. Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Reported-by: "kernelci.org bot" <bot@kernelci.org> Reported-by: Laura Nao <laura.nao@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Laura Nao <laura.nao@collabora.com> Link: https://lore.kernel.org/r/20240410194311.596282919@linutronix.de Closes: https://lore.kernel.org/all/20240322175210.124416-1-laura.nao@collabora.com/
2024-04-12x86/cpu/amd: Make the CPUID 0x80000008 parser correctThomas Gleixner
CPUID 0x80000008 ECX.cpu_nthreads describes the number of threads in the package. The parser uses this value to initialize the SMT domain level. That's wrong because cpu_nthreads does not describe the number of threads per physical core. So this needs to set the CORE domain level and let the later parsers set the SMT shift if available. Preset the SMT domain level with the assumption of one thread per core, which is correct ifrt here are no other CPUID leafs to parse, and propagate cpu_nthreads and the core level APIC bitwidth into the CORE domain. Fixes: f7fb3b2dd92c ("x86/cpu: Provide an AMD/HYGON specific topology parser") Reported-by: "kernelci.org bot" <bot@kernelci.org> Reported-by: Laura Nao <laura.nao@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Laura Nao <laura.nao@collabora.com> Link: https://lore.kernel.org/r/20240410194311.535206450@linutronix.de
2024-04-12x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHIJosh Poimboeuf
For consistency with the other CONFIG_MITIGATION_* options, replace the CONFIG_SPECTRE_BHI_{ON,OFF} options with a single CONFIG_MITIGATION_SPECTRE_BHI option. [ mingo: Fix ] Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nikolay Borisov <nik.borisov@suse.com> Link: https://lore.kernel.org/r/3833812ea63e7fdbe36bf8b932e63f70d18e2a2a.1712813475.git.jpoimboe@kernel.org
2024-04-12x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=autoJosh Poimboeuf
Unlike most other mitigations' "auto" options, spectre_bhi=auto only mitigates newer systems, which is confusing and not particularly useful. Remove it. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/412e9dc87971b622bbbaf64740ebc1f140bff343.1712813475.git.jpoimboe@kernel.org
2024-04-11x86/bugs: Clarify that syscall hardening isn't a BHI mitigationJosh Poimboeuf
While syscall hardening helps prevent some BHI attacks, there's still other low-hanging fruit remaining. Don't classify it as a mitigation and make it clear that the system may still be vulnerable if it doesn't have a HW or SW mitigation enabled. Fixes: ec9404e40e8f ("x86/bhi: Add BHI mitigation knob") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/b5951dae3fdee7f1520d5136a27be3bdfe95f88b.1712813475.git.jpoimboe@kernel.org
2024-04-11x86/bugs: Fix BHI handling of RRSBAJosh Poimboeuf
The ARCH_CAP_RRSBA check isn't correct: RRSBA may have already been disabled by the Spectre v2 mitigation (or can otherwise be disabled by the BHI mitigation itself if needed). In that case retpolines are fine. Fixes: ec9404e40e8f ("x86/bhi: Add BHI mitigation knob") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/6f56f13da34a0834b69163467449be7f58f253dc.1712813475.git.jpoimboe@kernel.org
2024-04-11x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'Ingo Molnar
So we are using the 'ia32_cap' value in a number of places, which got its name from MSR_IA32_ARCH_CAPABILITIES MSR register. But there's very little 'IA32' about it - this isn't 32-bit only code, nor does it originate from there, it's just a historic quirk that many Intel MSR names are prefixed with IA32_. This is already clear from the helper method around the MSR: x86_read_arch_cap_msr(), which doesn't have the IA32 prefix. So rename 'ia32_cap' to 'x86_arch_cap_msr' to be consistent with its role and with the naming of the helper function. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nikolay Borisov <nik.borisov@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
2024-04-11x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIESJosh Poimboeuf
There's no need to keep reading MSR_IA32_ARCH_CAPABILITIES over and over. It's even read in the BHI sysfs function which is a big no-no. Just read it once and cache it. Fixes: ec9404e40e8f ("x86/bhi: Add BHI mitigation knob") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Nikolay Borisov <nik.borisov@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/9592a18a814368e75f8f4b9d74d3883aa4fd1eaf.1712813475.git.jpoimboe@kernel.org
2024-04-10x86/topology: Don't update cpu_possible_map in topo_set_cpuids()Thomas Gleixner
topo_set_cpuids() updates cpu_present_map and cpu_possible map. It is invoked during enumeration and "physical hotplug" operations. In the latter case this results in a kernel crash because cpu_possible_map is marked read only after init completes. There is no reason to update cpu_possible_map in that function. During enumeration cpu_possible_map is not relevant and gets fully initialized after enumeration completed. On "physical hotplug" the bit is already set because the kernel allows only CPUs to be plugged which have been enumerated and associated to a CPU number during early boot. Remove the bogus update of cpu_possible_map. Fixes: 0e53e7b656cf ("x86/cpu/topology: Sanitize the APIC admission logic") Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/87ttkc6kwx.ffs@tglx
2024-04-10x86/bugs: Fix return type of spectre_bhi_state()Daniel Sneddon
The definition of spectre_bhi_state() incorrectly returns a const char * const. This causes the a compiler warning when building with W=1: warning: type qualifiers ignored on function return type [-Wignored-qualifiers] 2812 | static const char * const spectre_bhi_state(void) Remove the const qualifier from the pointer. Fixes: ec9404e40e8f ("x86/bhi: Add BHI mitigation knob") Reported-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240409230806.1545822-1-daniel.sneddon@linux.intel.com
2024-04-08Merge tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds
Pull x86 mitigations from Thomas Gleixner: "Mitigations for the native BHI hardware vulnerabilty: Branch History Injection (BHI) attacks may allow a malicious application to influence indirect branch prediction in kernel by poisoning the branch history. eIBRS isolates indirect branch targets in ring0. The BHB can still influence the choice of indirect branch predictor entry, and although branch predictor entries are isolated between modes when eIBRS is enabled, the BHB itself is not isolated between modes. Add mitigations against it either with the help of microcode or with software sequences for the affected CPUs" [ This also ends up enabling the full mitigation by default despite the system call hardening, because apparently there are other indirect calls that are still sufficiently reachable, and the 'auto' case just isn't hardened enough. We'll have some more inevitable tweaking in the future - Linus ] * tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: KVM: x86: Add BHI_NO x86/bhi: Mitigate KVM by default x86/bhi: Add BHI mitigation knob x86/bhi: Enumerate Branch History Injection (BHI) bug x86/bhi: Define SPEC_CTRL_BHI_DIS_S x86/bhi: Add support for clearing branch history at syscall entry x86/syscall: Don't force use of indirect calls for system calls x86/bugs: Change commas to semicolons in 'spectre_v2' sysfs file
2024-04-08x86/bhi: Mitigate KVM by defaultPawan Gupta
BHI mitigation mode spectre_bhi=auto does not deploy the software mitigation by default. In a cloud environment, it is a likely scenario where userspace is trusted but the guests are not trusted. Deploying system wide mitigation in such cases is not desirable. Update the auto mode to unconditionally mitigate against malicious guests. Deploy the software sequence at VMexit in auto mode also, when hardware mitigation is not available. Unlike the force =on mode, software sequence is not deployed at syscalls in auto mode. Suggested-by: Alexandre Chartre <alexandre.chartre@oracle.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08x86/bhi: Add BHI mitigation knobPawan Gupta
Branch history clearing software sequences and hardware control BHI_DIS_S were defined to mitigate Branch History Injection (BHI). Add cmdline spectre_bhi={on|off|auto} to control BHI mitigation: auto - Deploy the hardware mitigation BHI_DIS_S, if available. on - Deploy the hardware mitigation BHI_DIS_S, if available, otherwise deploy the software sequence at syscall entry and VMexit. off - Turn off BHI mitigation. The default is auto mode which does not deploy the software sequence mitigation. This is because of the hardening done in the syscall dispatch path, which is the likely target of BHI. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08x86/bhi: Enumerate Branch History Injection (BHI) bugPawan Gupta
Mitigation for BHI is selected based on the bug enumeration. Add bits needed to enumerate BHI bug. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08x86/bhi: Define SPEC_CTRL_BHI_DIS_SDaniel Sneddon
Newer processors supports a hardware control BHI_DIS_S to mitigate Branch History Injection (BHI). Setting BHI_DIS_S protects the kernel from userspace BHI attacks without having to manually overwrite the branch history. Define MSR_SPEC_CTRL bit BHI_DIS_S and its enumeration CPUID.BHI_CTRL. Mitigation is enabled later. Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
2024-04-08x86/bugs: Change commas to semicolons in 'spectre_v2' sysfs fileJosh Poimboeuf
Change the format of the 'spectre_v2' vulnerabilities sysfs file slightly by converting the commas to semicolons, so that mitigations for future variants can be grouped together and separated by commas. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2024-04-06Merge branch 'linus' into x86/urgent, to pick up dependent commitIngo Molnar
We want to fix: 0e110732473e ("x86/retpoline: Do the necessary fixup to the Zen3/4 srso return thunk for !SRSO") So merge in Linus's latest into x86/urgent to have it available. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-04Merge tag 'net-6.9-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from netfilter, bluetooth and bpf. Fairly usual collection of driver and core fixes. The large selftest accompanying one of the fixes is also becoming a common occurrence. Current release - regressions: - ipv6: fix infinite recursion in fib6_dump_done() - net/rds: fix possible null-deref in newly added error path Current release - new code bugs: - net: do not consume a full cacheline for system_page_pool - bpf: fix bpf_arena-related file descriptor leaks in the verifier - drv: ice: fix freeing uninitialized pointers, fixing misuse of the newfangled __free() auto-cleanup Previous releases - regressions: - x86/bpf: fixes the BPF JIT with retbleed=stuff - xen-netfront: add missing skb_mark_for_recycle, fix page pool accounting leaks, revealed by recently added explicit warning - tcp: fix bind() regression for v6-only wildcard and v4-mapped-v6 non-wildcard addresses - Bluetooth: - replace "hci_qca: Set BDA quirk bit if fwnode exists in DT" with better workarounds to un-break some buggy Qualcomm devices - set conn encrypted before conn establishes, fix re-connecting to some headsets which use slightly unusual sequence of msgs - mptcp: - prevent BPF accessing lowat from a subflow socket - don't account accept() of non-MPC client as fallback to TCP - drv: mana: fix Rx DMA datasize and skb_over_panic - drv: i40e: fix VF MAC filter removal Previous releases - always broken: - gro: various fixes related to UDP tunnels - netns crossing problems, incorrect checksum conversions, and incorrect packet transformations which may lead to panics - bpf: support deferring bpf_link dealloc to after RCU grace period - nf_tables: - release batch on table validation from abort path - release mutex after nft_gc_seq_end from abort path - flush pending destroy work before exit_net release - drv: r8169: skip DASH fw status checks when DASH is disabled" * tag 'net-6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits) netfilter: validate user input for expected length net/sched: act_skbmod: prevent kernel-infoleak net: usb: ax88179_178a: avoid the interface always configured as random address net: dsa: sja1105: Fix parameters order in sja1110_pcs_mdio_write_c45() net: ravb: Always update error counters net: ravb: Always process TX descriptor ring netfilter: nf_tables: discard table flag update with pending basechain deletion netfilter: nf_tables: Fix potential data-race in __nft_flowtable_type_get() netfilter: nf_tables: reject new basechain after table flag update netfilter: nf_tables: flush pending destroy work before exit_net release netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path netfilter: nf_tables: release batch on table validation from abort path Revert "tg3: Remove residual error handling in tg3_suspend" tg3: Remove residual error handling in tg3_suspend net: mana: Fix Rx DMA datasize and skb_over_panic net/sched: fix lockdep splat in qdisc_tree_reduce_backlog() net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping net: stmmac: fix rx queue priority assignment net: txgbe: fix i2c dev name cannot match clkdev net: fec: Set mac_managed_pm during probe ...
2024-04-04x86/mce: Make sure to grab mce_sysfs_mutex in set_bank()Borislav Petkov (AMD)
Modifying a MCA bank's MCA_CTL bits which control which error types to be reported is done over /sys/devices/system/machinecheck/ ├── machinecheck0 │   ├── bank0 │   ├── bank1 │   ├── bank10 │   ├── bank11 ... sysfs nodes by writing the new bit mask of events to enable. When the write is accepted, the kernel deletes all current timers and reinits all banks. Doing that in parallel can lead to initializing a timer which is already armed and in the timer wheel, i.e., in use already: ODEBUG: init active (active state 0) object: ffff888063a28000 object type: timer_list hint: mce_timer_fn+0x0/0x240 arch/x86/kernel/cpu/mce/core.c:2642 WARNING: CPU: 0 PID: 8120 at lib/debugobjects.c:514 debug_print_object+0x1a0/0x2a0 lib/debugobjects.c:514 Fix that by grabbing the sysfs mutex as the rest of the MCA sysfs code does. Reported by: Yue Sun <samsun1006219@gmail.com> Reported by: xingwei lee <xrivendell7@gmail.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/CAEkJfYNiENwQY8yV1LYJ9LjJs%2Bx_-PqMv98gKig55=2vbzffRw@mail.gmail.com
2024-04-04x86/CPU/AMD: Track SNP host status with cc_platform_*()Borislav Petkov (AMD)
The host SNP worthiness can determined later, after alternatives have been patched, in snp_rmptable_init() depending on cmdline options like iommu=pt which is incompatible with SNP, for example. Which means that one cannot use X86_FEATURE_SEV_SNP and will need to have a special flag for that control. Use that newly added CC_ATTR_HOST_SEV_SNP in the appropriate places. Move kdump_sev_callback() to its rightful place, while at it. Fixes: 216d106c7ff7 ("x86/sev: Add SEV-SNP host initialization support") Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com> Tested-by: Srikanth Aithal <sraithal@amd.com> Link: https://lore.kernel.org/r/20240327154317.29909-6-bp@alien8.de
2024-04-04x86/coco: Require seeding RNG with RDRAND on CoCo systemsJason A. Donenfeld
There are few uses of CoCo that don't rely on working cryptography and hence a working RNG. Unfortunately, the CoCo threat model means that the VM host cannot be trusted and may actively work against guests to extract secrets or manipulate computation. Since a malicious host can modify or observe nearly all inputs to guests, the only remaining source of entropy for CoCo guests is RDRAND. If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole is meant to gracefully continue on gathering entropy from other sources, but since there aren't other sources on CoCo, this is catastrophic. This is mostly a concern at boot time when initially seeding the RNG, as after that the consequences of a broken RDRAND are much more theoretical. So, try at boot to seed the RNG using 256 bits of RDRAND output. If this fails, panic(). This will also trigger if the system is booted without RDRAND, as RDRAND is essential for a safe CoCo boot. Add this deliberately to be "just a CoCo x86 driver feature" and not part of the RNG itself. Many device drivers and platforms have some desire to contribute something to the RNG, and add_device_randomness() is specifically meant for this purpose. Any driver can call it with seed data of any quality, or even garbage quality, and it can only possibly make the quality of the RNG better or have no effect, but can never make it worse. Rather than trying to build something into the core of the RNG, consider the particular CoCo issue just a CoCo issue, and therefore separate it all out into driver (well, arch/platform) code. [ bp: Massage commit message. ] Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Elena Reshetova <elena.reshetova@intel.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240326160735.73531-1-Jason@zx2c4.com
2024-04-03Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "ARM: - Ensure perf events programmed to count during guest execution are actually enabled before entering the guest in the nVHE configuration - Restore out-of-range handler for stage-2 translation faults - Several fixes to stage-2 TLB invalidations to avoid stale translations, possibly including partial walk caches - Fix early handling of architectural VHE-only systems to ensure E2H is appropriately set - Correct a format specifier warning in the arch_timer selftest - Make the KVM banner message correctly handle all of the possible configurations RISC-V: - Remove redundant semicolon in num_isa_ext_regs() - Fix APLIC setipnum_le/be write emulation - Fix APLIC in_clrip[x] read emulation x86: - Fix a bug in KVM_SET_CPUID{2,} where KVM looks at the wrong CPUID entries (old vs. new) and ultimately neglects to clear PV_UNHALT from vCPUs with HLT-exiting disabled - Documentation fixes for SEV - Fix compat ABI for KVM_MEMORY_ENCRYPT_OP - Fix a 14-year-old goof in a declaration shared by host and guest; the enabled field used by Linux when running as a guest pushes the size of "struct kvm_vcpu_pv_apf_data" from 64 to 68 bytes. This is really unconsequential because KVM never consumes anything beyond the first 64 bytes, but the resulting struct does not match the documentation Selftests: - Fix spelling mistake in arch_timer selftest" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits) KVM: arm64: Rationalise KVM banner output arm64: Fix early handling of FEAT_E2H0 not being implemented KVM: arm64: Ensure target address is granule-aligned for range TLBI KVM: arm64: Use TLBI_TTL_UNKNOWN in __kvm_tlb_flush_vmid_range() KVM: arm64: Don't pass a TLBI level hint when zapping table entries KVM: arm64: Don't defer TLB invalidation when zapping table entries KVM: selftests: Fix __GUEST_ASSERT() format warnings in ARM's arch timer test KVM: arm64: Fix out-of-IPA space translation fault handling KVM: arm64: Fix host-programmed guest events in nVHE RISC-V: KVM: Fix APLIC in_clrip[x] read emulation RISC-V: KVM: Fix APLIC setipnum_le/be write emulation RISC-V: KVM: Remove second semicolon KVM: selftests: Fix spelling mistake "trigged" -> "triggered" Documentation: kvm/sev: clarify usage of KVM_MEMORY_ENCRYPT_OP Documentation: kvm/sev: separate description of firmware KVM: SEV: fix compat ABI for KVM_MEMORY_ENCRYPT_OP KVM: selftests: Check that PV_UNHALT is cleared when HLT exiting is disabled KVM: x86: Use actual kvm_cpuid.base for clearing KVM_FEATURE_PV_UNHALT KVM: x86: Introduce __kvm_get_hypervisor_cpuid() helper KVM: SVM: Return -EINVAL instead of -EBUSY on attempt to re-init SEV/SEV-ES ...
2024-04-03x86/resctrl: Fix uninitialized memory read when last CPU of domain goes offlineReinette Chatre
Tony encountered this OOPS when the last CPU of a domain goes offline while running a kernel built with CONFIG_NO_HZ_FULL: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 Oops: 0000 [#1] PREEMPT SMP NOPTI ... RIP: 0010:__find_nth_andnot_bit+0x66/0x110 ... Call Trace: <TASK> ? __die() ? page_fault_oops() ? exc_page_fault() ? asm_exc_page_fault() cpumask_any_housekeeping() mbm_setup_overflow_handler() resctrl_offline_cpu() resctrl_arch_offline_cpu() cpuhp_invoke_callback() cpuhp_thread_fun() smpboot_thread_fn() kthread() ret_from_fork() ret_from_fork_asm() </TASK> The NULL pointer dereference is encountered while searching for another online CPU in the domain (of which there are none) that can be used to run the MBM overflow handler. Because the kernel is configured with CONFIG_NO_HZ_FULL the search for another CPU (in its effort to prefer those CPUs that aren't marked nohz_full) consults the mask representing the nohz_full CPUs, tick_nohz_full_mask. On a kernel with CONFIG_CPUMASK_OFFSTACK=y tick_nohz_full_mask is not allocated unless the kernel is booted with the "nohz_full=" parameter and because of that any access to tick_nohz_full_mask needs to be guarded with tick_nohz_full_enabled(). Replace the IS_ENABLED(CONFIG_NO_HZ_FULL) with tick_nohz_full_enabled(). The latter ensures tick_nohz_full_mask can be accessed safely and can be used whether kernel is built with CONFIG_NO_HZ_FULL enabled or not. [ Use Ingo's suggestion that combines the two NO_HZ checks into one. ] Fixes: a4846aaf3945 ("x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow") Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Babu Moger <babu.moger@amd.com> Link: https://lore.kernel.org/r/ff8dfc8d3dcb04b236d523d1e0de13d2ef585223.1711993956.git.reinette.chatre@intel.com Closes: https://lore.kernel.org/lkml/ZgIFT5gZgIQ9A9G7@agluck-desk3/
2024-04-02Merge tag 'kvmarm-fixes-6.9-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.9, part #1 - Ensure perf events programmed to count during guest execution are actually enabled before entering the guest in the nVHE configuration. - Restore out-of-range handler for stage-2 translation faults. - Several fixes to stage-2 TLB invalidations to avoid stale translations, possibly including partial walk caches. - Fix early handling of architectural VHE-only systems to ensure E2H is appropriately set. - Correct a format specifier warning in the arch_timer selftest. - Make the KVM banner message correctly handle all of the possible configurations.
2024-04-01x86/bpf: Fix IP for relocating call depth accountingJoan Bruguera Micó
The commit: 59bec00ace28 ("x86/percpu: Introduce %rip-relative addressing to PER_CPU_VAR()") made PER_CPU_VAR() to use rip-relative addressing, hence INCREMENT_CALL_DEPTH macro and skl_call_thunk_template got rip-relative asm code inside of it. A follow up commit: 17bce3b2ae2d ("x86/callthunks: Handle %rip-relative relocations in call thunk template") changed x86_call_depth_emit_accounting() to use apply_relocation(), but mistakenly assumed that the code is being patched in-place (where the destination of the relocation matches the address of the code), using *pprog as the destination ip. This is not true for the call depth accounting, emitted by the BPF JIT, so the calculated address was wrong, JIT-ed BPF progs on kernels with call depth tracking got broken and usually caused a page fault. Pass the destination IP when the BPF JIT emits call depth accounting. Fixes: 17bce3b2ae2d ("x86/callthunks: Handle %rip-relative relocations in call thunk template") Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com> Reviewed-by: Uros Bizjak <ubizjak@gmail.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/r/20240401185821.224068-3-ubizjak@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>