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The previous patch ("function_graph: Support recording and printing
the return value of function") has laid the groundwork for the for
the funcgraph-retval, and this modification makes it available on
the x86 platform.
We introduce a new structure called fgraph_ret_regs for the x86
platform to hold return registers and the frame pointer. We then
fill its content in the return_to_handler and pass its address
to the function ftrace_return_to_handler to record the return
value.
Link: https://lkml.kernel.org/r/53a506f0f18ff4b7aeb0feb762f1c9a5e9b83ee9.1680954589.git.pengdonglin@sangfor.com.cn
Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Parking CPUs in a HLT loop is not completely safe vs. kexec() as HLT can
resume execution due to NMI, SMI and MCE, which has the same issue as the
MWAIT loop.
Kicking the secondary CPUs into INIT makes this safe against NMI and SMI.
A broadcast MCE will take the machine down, but a broadcast MCE which makes
HLT resume and execute overwritten text, pagetables or data will end up in
a disaster too.
So chose the lesser of two evils and kick the secondary CPUs into INIT
unless the system has installed special wakeup mechanisms which are not
using INIT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230615193330.608657211@linutronix.de
Putting CPUs into INIT is a safer place during kexec() to park CPUs.
Split the INIT assert/deassert sequence out so it can be reused.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Link: https://lore.kernel.org/r/20230615193330.551157083@linutronix.de
TLDR: It's a mess.
When kexec() is executed on a system with offline CPUs, which are parked in
mwait_play_dead() it can end up in a triple fault during the bootup of the
kexec kernel or cause hard to diagnose data corruption.
The reason is that kexec() eventually overwrites the previous kernel's text,
page tables, data and stack. If it writes to the cache line which is
monitored by a previously offlined CPU, MWAIT resumes execution and ends
up executing the wrong text, dereferencing overwritten page tables or
corrupting the kexec kernels data.
Cure this by bringing the offlined CPUs out of MWAIT into HLT.
Write to the monitored cache line of each offline CPU, which makes MWAIT
resume execution. The written control word tells the offlined CPUs to issue
HLT, which does not have the MWAIT problem.
That does not help, if a stray NMI, MCE or SMI hits the offlined CPUs as
those make it come out of HLT.
A follow up change will put them into INIT, which protects at least against
NMI and SMI.
Fixes: ea53069231f9 ("x86, hotplug: Use mwait to offline a processor, fix the legacy case")
Reported-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615193330.492257119@linutronix.de
Monitoring idletask::thread_info::flags in mwait_play_dead() has been an
obvious choice as all what is needed is a cache line which is not written
by other CPUs.
But there is a use case where a "dead" CPU needs to be brought out of
MWAIT: kexec().
This is required as kexec() can overwrite text, pagetables, stacks and the
monitored cacheline of the original kernel. The latter causes MWAIT to
resume execution which obviously causes havoc on the kexec kernel which
results usually in triple faults.
Use a dedicated per CPU storage to prepare for that.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615193330.434553750@linutronix.de
The wmb()s before sending the IPIs are not synchronizing anything.
If at all then the apic IPI functions have to provide or act as appropriate
barriers.
Remove these cargo cult barriers which have no explanation of what they are
synchronizing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615193330.378358382@linutronix.de
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: 08f253ec3767 ("x86/cpu: Clear SME feature flag when not in use")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/3817d810-e0f1-8ef8-0bbd-663b919ca49b@cybernetics.com
Link: https://lore.kernel.org/r/20230615193330.322186388@linutronix.de
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: 08f253ec3767 ("x86/cpu: Clear SME feature flag when not in use")
Reported-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/3817d810-e0f1-8ef8-0bbd-663b919ca49b@cybernetics.com
Link: https://lore.kernel.org/r/87h6r770bv.ffs@tglx
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Merge tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv fixes from Wei Liu:
- Fix races in Hyper-V PCI controller (Dexuan Cui)
- Fix handling of hyperv_pcpu_input_arg (Michael Kelley)
- Fix vmbus_wait_for_unload to scan present CPUs (Michael Kelley)
- Call hv_synic_free in the failure path of hv_synic_alloc (Dexuan Cui)
- Add noop for real mode handlers for virtual trust level code (Saurabh
Sengar)
* tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
PCI: hv: Add a per-bus mutex state_lock
Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally"
PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev
PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic
PCI: hv: Fix a race condition bug in hv_pci_query_relations()
arm64/hyperv: Use CPUHP_AP_HYPERV_ONLINE state to fix CPU online sequencing
x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline
Drivers: hv: vmbus: Fix vmbus_wait_for_unload() to scan present CPUs
Drivers: hv: vmbus: Call hv_synic_free() if hv_synic_alloc() fails
x86/hyperv/vtl: Add noop for realmode pointers
sme_populate_pgd() is an __init function for sme_encrypt_kernel():
it should use pte_offset_kernel() instead of pte_offset_map(), to avoid
the question of whether a pte_unmap() will be needed to balance.
Link: https://lkml.kernel.org/r/497d7777-736e-85f2-c37-aa6bcf155e4@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: John David Anglin <dave.anglin@bell.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When booting with "intremap=off" and "x2apic_phys" on the kernel command
line, the physical x2APIC driver ends up being used even when x2APIC
mode is disabled ("intremap=off" disables x2APIC mode). This happens
because the first compound condition check in x2apic_phys_probe() is
false due to x2apic_mode == 0 and so the following one returns true
after default_acpi_madt_oem_check() having already selected the physical
x2APIC driver.
This results in the following panic:
kernel BUG at arch/x86/kernel/apic/io_apic.c:2409!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc2-ver4.1rc2 #2
Hardware name: Dell Inc. PowerEdge R6515/07PXPY, BIOS 2.3.6 07/06/2021
RIP: 0010:setup_IO_APIC+0x9c/0xaf0
Call Trace:
<TASK>
? native_read_msr
apic_intr_mode_init
x86_late_time_init
start_kernel
x86_64_start_reservations
x86_64_start_kernel
secondary_startup_64_no_verify
</TASK>
which is:
setup_IO_APIC:
apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
for_each_ioapic(ioapic)
BUG_ON(mp_irqdomain_create(ioapic));
Return 0 to denote that x2APIC has not been enabled when probing the
physical x2APIC driver.
[ bp: Massage commit message heavily. ]
Fixes: 9ebd680bd029 ("x86, apic: Use probe routines to simplify apic selection")
Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230616212236.1389-1-dheerajkumar.srivastava@amd.com
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Backmerge tag 'v6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next
Linux 6.4-rc7
Need this to pull in the msm work.
Signed-off-by: Dave Airlie <airlied@redhat.com>
These commits
a494aef23dfc ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg")
2c6ba4216844 ("PCI: hv: Enable PCI pass-thru devices in Confidential VMs")
update the Hyper-V virtual PCI driver to use the hyperv_pcpu_input_arg
because that memory will be correctly marked as decrypted or encrypted
for all VM types (CoCo or normal). But problems ensue when CPUs in the
VM go online or offline after virtual PCI devices have been configured.
When a CPU is brought online, the hyperv_pcpu_input_arg for that CPU is
initialized by hv_cpu_init() running under state CPUHP_AP_ONLINE_DYN.
But this state occurs after state CPUHP_AP_IRQ_AFFINITY_ONLINE, which
may call the virtual PCI driver and fault trying to use the as yet
uninitialized hyperv_pcpu_input_arg. A similar problem occurs in a CoCo
VM if the MMIO read and write hypercalls are used from state
CPUHP_AP_IRQ_AFFINITY_ONLINE.
When a CPU is taken offline, IRQs may be reassigned in state
CPUHP_TEARDOWN_CPU. Again, the virtual PCI driver may fault trying to
use the hyperv_pcpu_input_arg that has already been freed by a
higher state.
Fix the onlining problem by adding state CPUHP_AP_HYPERV_ONLINE
immediately after CPUHP_AP_ONLINE_IDLE (similar to CPUHP_AP_KVM_ONLINE)
and before CPUHP_AP_IRQ_AFFINITY_ONLINE. Use this new state for
Hyper-V initialization so that hyperv_pcpu_input_arg is allocated
early enough.
Fix the offlining problem by not freeing hyperv_pcpu_input_arg when
a CPU goes offline. Retain the allocated memory, and reuse it if
the CPU comes back online later.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1684862062-51576-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Moving mem_encrypt_init() broke the AMD_MEM_ENCRYPT=n because the
declaration of that function was under #ifdef CONFIG_AMD_MEM_ENCRYPT and
the obvious placement for the inline stub was the #else path.
This is a leftover of commit 20f07a044a76 ("x86/sev: Move common memory
encryption code to mem_encrypt.c") which made mem_encrypt_init() depend on
X86_MEM_ENCRYPT without moving the prototype. That did not fail back then
because there was no stub inline as the core init code had a weak function.
Move both the declaration and the stub out of the CONFIG_AMD_MEM_ENCRYPT
section and guard it with CONFIG_X86_MEM_ENCRYPT.
Fixes: 439e17576eb4 ("init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Closes: https://lore.kernel.org/oe-kbuild-all/202306170247.eQtCJPE8-lkp@intel.com/
KPTI keeps around two PGDs: one for userspace and another for the
kernel. Among other things, set_pgd() contains infrastructure to
ensure that updates to the kernel PGD are reflected in the user PGD
as well.
One side-effect of this is that set_pgd() expects to be passed whole
pages. Unfortunately, init_trampoline_kaslr() passes in a single entry:
'trampoline_pgd_entry'.
When KPTI is on, set_pgd() will update 'trampoline_pgd_entry' (an
8-Byte globally stored [.bss] variable) and will then proceed to
replicate that value into the non-existent neighboring user page
(located +4k away), leading to the corruption of other global [.bss]
stored variables.
Fix it by directly assigning 'trampoline_pgd_entry' and avoiding
set_pgd().
[ dhansen: tweak subject and changelog ]
Fixes: 0925dda5962e ("x86/mm/KASLR: Use only one PUD entry for real mode trampoline")
Suggested-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/all/20230614163859.924309-1-lee@kernel.org/g
Commits ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC
metadata") and fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in
two") changed the ORC format. Although ORC is internal to the kernel,
it's the only way for external tools to get reliable kernel stack traces
on x86-64. In particular, the drgn debugger [1] uses ORC for stack
unwinding, and these format changes broke it [2]. As the drgn
maintainer, I don't care how often or how much the kernel changes the
ORC format as long as I have a way to detect the change.
It suffices to store a version identifier in the vmlinux and kernel
module ELF files (to use when parsing ORC sections from ELF), and in
kernel memory (to use when parsing ORC from a core dump+symbol table).
Rather than hard-coding a version number that needs to be manually
bumped, Peterz suggested hashing the definitions from orc_types.h. If
there is a format change that isn't caught by this, the hashing script
can be updated.
This patch adds an .orc_header allocated ELF section containing the
20-byte hash to vmlinux and kernel modules, along with the corresponding
__start_orc_header and __stop_orc_header symbols in vmlinux.
1: https://github.com/osandov/drgn
2: https://github.com/osandov/drgn/issues/303
Fixes: ffb1b4a41016 ("x86/unwind/orc: Add 'signal' field to ORC metadata")
Fixes: fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com
When counting a FRONTEND event, the MSR_PEBS_FRONTEND is not correctly
set on GNR and MTL p-core.
The umask value for the FRONTEND events is changed on GNR and MTL. The
new umask is missing in the extra_regs[] table.
Add a dedicated intel_gnr_extra_regs[] for GNR and MTL p-core.
Fixes: bc4000fdb009 ("perf/x86/intel: Add Granite Rapids")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20230615173242.3726364-1-kan.liang@linux.intel.com
When running as an unprivileged PV guest under Xen (not dom0), the
default MTRR memory type should be write-back.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20230615123959.12298-1-jgross@suse.com
e0bddc19ba95 ("x86/mm: Reduce untagged_addr() overhead for systems without LAM")
removed its only usage site so drop it.
Move the tlbstate_untag_mask up in the header and drop the ugly
ifdeffery as the unused declaration should be properly discarded.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/r/20230614174148.5439-1-bp@alien8.de
Initializing the FPU during the early boot process is a pointless
exercise. Early boot is convoluted and fragile enough.
Nothing requires that the FPU is set up early. It has to be initialized
before fork_init() because the task_struct size depends on the FPU register
buffer size.
Move the initialization to arch_cpu_finalize_init() which is the perfect
place to do so.
No functional change.
This allows to remove quite some of the custom early command line parsing,
but that's subject to the next installment.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.902376621@linutronix.de
No point in doing this during really early boot. Move it to an early
initcall so that it is set up before possible user mode helpers are started
during device initialization.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.727330699@linutronix.de
Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and
remove the weak fallback from the core code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de
check_bugs() is a dumping ground for finalizing the CPU bringup. Only parts of
it has to do with actual CPU bugs.
Split it apart into arch_cpu_finalize_init() and cpu_select_mitigations().
Fixup the bogus 32bit comments while at it.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230613224545.019583869@linutronix.de
The Linux build process on x86 roughly consists of compiling all input
files, statically linking them into a vmlinux ELF file, and then taking
and turning this file into an actual bzImage bootable file.
vmlinux has in this process two main purposes:
1) It is an intermediate build target on the way to produce the final
bootable image.
2) It is a file that is expected to be used by debuggers and standard
ELF tooling to work with the built kernel.
For the second purpose, a vmlinux file is typically collected by various
package build recipes, such as distribution spec files, including the
kernel's own tar-pkg target.
When building a kernel supporting KASLR with CONFIG_X86_NEED_RELOCS,
vmlinux contains also relocation information produced by using the
--emit-relocs linker option. This is utilized by subsequent build steps
to create vmlinux.relocs and produce a relocatable image. However, the
information is not needed by debuggers and other standard ELF tooling.
The issue is then that the collected vmlinux file and hence distribution
packages end up unnecessarily large because of this extra data. The
following is a size comparison of vmlinux v6.0 with and without the
relocation information:
| Configuration | With relocs | Stripped relocs |
| x86_64_defconfig | 70 MB | 43 MB |
| +CONFIG_DEBUG_INFO | 818 MB | 367 MB |
Optimize a resulting vmlinux by adding a postlink step that splits the
relocation information into vmlinux.relocs and then strips it from the
vmlinux binary.
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220927084632.14531-1-petr.pavlu@suse.com
While chasing ghosts, I did notice that optimize_nops() was replacing
'REP NOP' aka 'PAUSE' with NOP2. This is clearly not right.
Fixes: 6c480f222128 ("x86/alternative: Rewrite optimize_nops() some")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/linux-next/20230524130104.GR83892@hirez.programming.kicks-ass.net/
Debugging in the kernel has started slowing down the kernel by a
noticeable amount. The ftrace start up tests are triggering the softlockup
watchdog on some boxes. This is caused by the start up tests that enable
function and function graph tracing several times. Sprinkling
cond_resched() just in the start up test code was not enough to stop the
softlockup from triggering. It would sometimes trigger in the
text_poke_bp_batch() code.
When function tracing enables all functions, it will call
text_poke_queue() to queue the places that need to be patched. Every
256 entries will do a "flush" that calls text_poke_bp_batch() to do the
update of the 256 locations. As this is in a scheduleable context,
calling cond_resched() at the start of text_poke_bp_batch() will ensure
that other tasks could get a chance to run while the patching is
happening. This keeps the softlockup from triggering in the start up
tests.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230531092419.4d051374@rorschach.local.home
WARN and continue if misc_cg_set_capacity() fails, as the only scenario
in which it can fail is if the specified resource is invalid, which should
never happen when CONFIG_KVM_AMD_SEV=y. Deliberately not bailing "fixes"
a theoretical bug where KVM would leak the ASID bitmaps on failure, which
again can't happen.
If the impossible should happen, the end result is effectively the same
with respect to SEV and SEV-ES (they are unusable), while continuing on
has the advantage of letting KVM load, i.e. userspace can still run
non-SEV guests.
Reported-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Link: https://lore.kernel.org/r/20230607004449.1421131-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add a "never" option to the nx_huge_pages module param to allow userspace
to do a one-way hard disabling of the mitigation, and don't create the
per-VM recovery threads when the mitigation is hard disabled. Letting
userspace pinky swear that userspace doesn't want to enable NX mitigation
(without reloading KVM) allows certain use cases to avoid the latency
problems associated with spawning a kthread for each VM.
E.g. in FaaS use cases, the guest kernel is trusted and the host may
create 100+ VMs per logical CPU, which can result in 100ms+ latencies when
a burst of VMs is created.
Reported-by: Li RongQing <lirongqing@baidu.com>
Closes: https://lore.kernel.org/all/1679555884-32544-1-git-send-email-lirongqing@baidu.com
Cc: Yong He <zhuangel570@gmail.com>
Cc: Robert Hoo <robert.hoo.linux@gmail.com>
Cc: Kai Huang <kai.huang@intel.com>
Reviewed-by: Robert Hoo <robert.hoo.linux@gmail.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Tested-by: Luiz Capitulino <luizcap@amazon.com>
Reviewed-by: Li RongQing <lirongqing@baidu.com>
Link: https://lore.kernel.org/r/20230602005859.784190-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Refresh comments about msrs_to_save, emulated_msrs, and msr_based_features
to remove stale references left behind by commit 2374b7310b66 (KVM:
x86/pmu: Use separate array for defining "PMU MSRs to save"), and to
better reflect the current reality, e.g. emulated_msrs is no longer just
for MSRs that are "kvm-specific".
Reported-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20230607004636.1421424-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
If &encl_mm->encl->mm_list does not contain the searched 'encl_mm',
'tmp' will not point to a valid sgx_encl_mm struct.
Linus proposed to avoid any use of the list iterator variable after the
loop, in the attempt to move the list iterator variable declaration into
the macro to avoid any potential misuse after the loop. Using it in
a pointer comparison after the loop is undefined behavior and should be
omitted if possible, see Link tag.
Instead, just use a 'found' boolean to indicate if an element was found.
[ bp: Massage, fix typos. ]
Signed-off-by: Jakob Koschel <jkl820.git@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Link: https://lore.kernel.org/r/20230206-sgx-use-after-iter-v2-1-736ca621adc3@gmail.com
introduced during this -rc cycle or which were considered inappropriate
for a backport.
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Merge tag 'mm-hotfixes-stable-2023-06-12-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"19 hotfixes. 14 are cc:stable and the remainder address issues which
were introduced during this development cycle or which were considered
inappropriate for a backport"
* tag 'mm-hotfixes-stable-2023-06-12-12-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
zswap: do not shrink if cgroup may not zswap
page cache: fix page_cache_next/prev_miss off by one
ocfs2: check new file size on fallocate call
mailmap: add entry for John Keeping
mm/damon/core: fix divide error in damon_nr_accesses_to_accesses_bp()
epoll: ep_autoremove_wake_function should use list_del_init_careful
mm/gup_test: fix ioctl fail for compat task
nilfs2: reject devices with insufficient block count
ocfs2: fix use-after-free when unmounting read-only filesystem
lib/test_vmalloc.c: avoid garbage in page array
nilfs2: fix possible out-of-bounds segment allocation in resize ioctl
riscv/purgatory: remove PGO flags
powerpc/purgatory: remove PGO flags
x86/purgatory: remove PGO flags
kexec: support purgatories with .text.hot sections
mm/uffd: allow vma to merge as much as possible
mm/uffd: fix vma operation where start addr cuts part of vma
radix-tree: move declarations to header
nilfs2: fix incomplete buffer cleanup in nilfs_btnode_abort_change_key()
If profile-guided optimization is enabled, the purgatory ends up with
multiple .text sections. This is not supported by kexec and crashes the
system.
Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-2-b05c520b7296@chromium.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Cc: <stable@vger.kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The sysctl net/core/bpf_jit_enable does not work now due to commit
1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc"). The
commit saved the jitted insns into 'rw_image' instead of 'image'
which caused bpf_jit_dump not dumping proper content.
With 'echo 2 > /proc/sys/net/core/bpf_jit_enable', run
'./test_progs -t fentry_test'. Without this patch, one of jitted
image for one particular prog is:
flen=17 proglen=92 pass=4 image=0000000014c64883 from=test_progs pid=1807
00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000010: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000020: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000030: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000040: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
00000050: cc cc cc cc cc cc cc cc cc cc cc cc
With this patch, the jitte image for the same prog is:
flen=17 proglen=92 pass=4 image=00000000b90254b7 from=test_progs pid=1809
00000000: f3 0f 1e fa 0f 1f 44 00 00 66 90 55 48 89 e5 f3
00000010: 0f 1e fa 31 f6 48 8b 57 00 48 83 fa 07 75 2b 48
00000020: 8b 57 10 83 fa 09 75 22 48 8b 57 08 48 81 e2 ff
00000030: 00 00 00 48 83 fa 08 75 11 48 8b 7f 18 be 01 00
00000040: 00 00 48 83 ff 0a 74 02 31 f6 48 bf 18 d0 14 00
00000050: 00 c9 ff ff 48 89 77 00 31 c0 c9 c3
Fixes: 1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20230609005439.3173569-1-yhs@fb.com
kernel after bypassing the decompressor and the CS descriptor used
ends up being the EFI one which is not mapped in the identity page
table, leading to early SEV/SNP guest communication exceptions
resulting in the guest crashing
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Merge tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Borislav Petkov:
- Set up the kernel CS earlier in the boot process in case EFI boots
the kernel after bypassing the decompressor and the CS descriptor
used ends up being the EFI one which is not mapped in the identity
page table, leading to early SEV/SNP guest communication exceptions
resulting in the guest crashing
* tag 'x86_urgent_for_v6.4_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/head/64: Switch to KERNEL_CS as soon as new GDT is installed
There are a few __weak functions in kernel/fork.c, which architectures
can override. If there is no prototype, the compiler warns about them:
kernel/fork.c:164:13: error: no previous prototype for 'arch_release_task_struct' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]
kernel/fork.c:1086:12: error: no previous prototype for 'arch_dup_task_struct' [-Werror=missing-prototypes]
There are already prototypes in a number of architecture specific headers
that have addressed those warnings before, but it's much better to have
these in a single place so the warning no longer shows up anywhere.
Link: https://lkml.kernel.org/r/20230517131102.934196-14-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The init/main.c file contains some extern declarations for functions
defined in architecture code, and it defines some other functions that are
called from architecture code with a custom prototype. Both of those
result in warnings with 'make W=1':
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
init/main.c:790:20: error: no previous prototype for 'mem_encrypt_init' [-Werror=missing-prototypes]
init/main.c:792:20: error: no previous prototype for 'poking_init' [-Werror=missing-prototypes]
arch/arm64/kernel/irq.c:122:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes]
arch/arm64/kernel/time.c:55:13: error: no previous prototype for 'time_init' [-Werror=missing-prototypes]
arch/x86/kernel/process.c:935:13: error: no previous prototype for 'arch_post_acpi_subsys_init' [-Werror=missing-prototypes]
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]
Add prototypes for all of these in include/linux/init.h or another
appropriate header, and remove the duplicate declarations from
architecture specific code.
[sfr@canb.auug.org.au: declare time_init_early()]
Link: https://lkml.kernel.org/r/20230519124311.5167221c@canb.auug.org.au
Link: https://lkml.kernel.org/r/20230517131102.934196-12-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "remove the vmas parameter from GUP APIs", v6.
(pin_/get)_user_pages[_remote]() each provide an optional output parameter
for an array of VMA objects associated with each page in the input range.
These provide the means for VMAs to be returned, as long as mm->mmap_lock
is never released during the GUP operation (i.e. the internal flag
FOLL_UNLOCKABLE is not specified).
In addition, these VMAs can only be accessed with the mmap_lock held and
become invalidated the moment it is released.
The vast majority of invocations do not use this functionality and of
those that do, all but one case retrieve a single VMA to perform checks
upon.
It is not egregious in the single VMA cases to simply replace the
operation with a vma_lookup(). In these cases we duplicate the (fast)
lookup on a slow path already under the mmap_lock, abstracted to a new
get_user_page_vma_remote() inline helper function which also performs
error checking and reference count maintenance.
The special case is io_uring, where io_pin_pages() specifically needs to
assert that the VMAs underlying the range do not result in broken
long-term GUP file-backed mappings.
As GUP now internally asserts that FOLL_LONGTERM mappings are not
file-backed in a broken fashion (i.e. requiring dirty tracking) - as
implemented in "mm/gup: disallow FOLL_LONGTERM GUP-nonfast writing to
file-backed mappings" - this logic is no longer required and so we can
simply remove it altogether from io_uring.
Eliminating the vmas parameter eliminates an entire class of danging
pointer errors that might have occured should the lock have been
incorrectly released.
In addition, the API is simplified and now clearly expresses what it is
intended for - applying the specified GUP flags and (if pinning) returning
pinned pages.
This change additionally opens the door to further potential improvements
in GUP and the possible marrying of disparate code paths.
I have run this series against gup_test with no issues.
Thanks to Matthew Wilcox for suggesting this refactoring!
This patch (of 6):
No invocation of get_user_pages() use the vmas parameter, so remove it.
The GUP API is confusing and caveated. Recent changes have done much to
improve that, however there is more we can do. Exporting vmas is a prime
target as the caller has to be extremely careful to preclude their use
after the mmap_lock has expired or otherwise be left with dangling
pointers.
Removing the vmas parameter focuses the GUP functions upon their primary
purpose - pinning (and outputting) pages as well as performing the actions
implied by the input flags.
This is part of a patch series aiming to remove the vmas parameter
altogether.
Link: https://lkml.kernel.org/r/cover.1684350871.git.lstoakes@gmail.com
Link: https://lkml.kernel.org/r/589e0c64794668ffc799651e8d85e703262b1e9d.1684350871.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Christian König <christian.koenig@amd.com> (for radeon parts)
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sean Christopherson <seanjc@google.com> (KVM)
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is currently no good way to query the page cache state of large file
sets and directory trees. There is mincore(), but it scales poorly: the
kernel writes out a lot of bitmap data that userspace has to aggregate,
when the user really doesn not care about per-page information in that
case. The user also needs to mmap and unmap each file as it goes along,
which can be quite slow as well.
Some use cases where this information could come in handy:
* Allowing database to decide whether to perform an index scan or
direct table queries based on the in-memory cache state of the
index.
* Visibility into the writeback algorithm, for performance issues
diagnostic.
* Workload-aware writeback pacing: estimating IO fulfilled by page
cache (and IO to be done) within a range of a file, allowing for
more frequent syncing when and where there is IO capacity, and
batching when there is not.
* Computing memory usage of large files/directory trees, analogous to
the du tool for disk usage.
More information about these use cases could be found in the following
thread:
https://lore.kernel.org/lkml/20230315170934.GA97793@cmpxchg.org/
This patch implements a new syscall that queries cache state of a file and
summarizes the number of cached pages, number of dirty pages, number of
pages marked for writeback, number of (recently) evicted pages, etc. in a
given range. Currently, the syscall is only wired in for x86
architecture.
NAME
cachestat - query the page cache statistics of a file.
SYNOPSIS
#include <sys/mman.h>
struct cachestat_range {
__u64 off;
__u64 len;
};
struct cachestat {
__u64 nr_cache;
__u64 nr_dirty;
__u64 nr_writeback;
__u64 nr_evicted;
__u64 nr_recently_evicted;
};
int cachestat(unsigned int fd, struct cachestat_range *cstat_range,
struct cachestat *cstat, unsigned int flags);
DESCRIPTION
cachestat() queries the number of cached pages, number of dirty
pages, number of pages marked for writeback, number of evicted
pages, number of recently evicted pages, in the bytes range given by
`off` and `len`.
An evicted page is a page that is previously in the page cache but
has been evicted since. A page is recently evicted if its last
eviction was recent enough that its reentry to the cache would
indicate that it is actively being used by the system, and that
there is memory pressure on the system.
These values are returned in a cachestat struct, whose address is
given by the `cstat` argument.
The `off` and `len` arguments must be non-negative integers. If
`len` > 0, the queried range is [`off`, `off` + `len`]. If `len` ==
0, we will query in the range from `off` to the end of the file.
The `flags` argument is unused for now, but is included for future
extensibility. User should pass 0 (i.e no flag specified).
Currently, hugetlbfs is not supported.
Because the status of a page can change after cachestat() checks it
but before it returns to the application, the returned values may
contain stale information.
RETURN VALUE
On success, cachestat returns 0. On error, -1 is returned, and errno
is set to indicate the error.
ERRORS
EFAULT cstat or cstat_args points to an invalid address.
EINVAL invalid flags.
EBADF invalid file descriptor.
EOPNOTSUPP file descriptor is of a hugetlbfs file
[nphamcs@gmail.com: replace rounddown logic with the existing helper]
Link: https://lkml.kernel.org/r/20230504022044.3675469-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20230503013608.2431726-3-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Recent commit:
020126239b8f Revert "x86/orc: Make it callthunk aware"
Made the only user of is_callthunk() depend on CONFIG_BPF_JIT=y, while
the definition of the helper function is unconditional.
Move is_callthunk() inside the #ifdef block.
Addresses this build failure:
arch/x86/kernel/callthunks.c:296:13: error: ‘is_callthunk’ defined but not used [-Werror=unused-function]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Some hypervisor interrupts (such as for Hyper-V VMbus and Hyper-V timers)
have hardcoded interrupt vectors on x86 and don't have Linux IRQs assigned.
These interrupts are shown in /proc/interrupts, but are not reported in
the first field of the "intr" line in /proc/stat because the x86 version
of arch_irq_stat_cpu() doesn't include them.
Fix this by adding code to arch_irq_stat_cpu() to include these interrupts,
similar to existing interrupts that don't have Linux IRQs.
Use #if IS_ENABLED() because unlike all the other nearby #ifdefs,
CONFIG_HYPERV can be built as a module.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/1677523568-50263-1-git-send-email-mikelley%40microsoft.com
VMware high-bandwidth hypercalls take the RBP register as input. This
breaks basic frame pointer convention, as RBP should never be clobbered.
So frame pointer unwinding is broken for the instructions surrounding
the hypercalls. Fortunately this doesn't break live patching with
CONFIG_FRAME_POINTER, as it only unwinds from blocking tasks, and stack
traces from preempted tasks are already marked unreliable anyway.
However, for live patching with ORC, this could actually be a
theoretical problem if vmw_port_hb_{in,out}() were still compiled with a
frame pointer due to having an aligned stack. In practice that hasn't
seemed to be an issue since the objtool warnings have only been seen
with CONFIG_FRAME_POINTER.
Add unwind hint annotations to tell the ORC unwinder to mark stack
traces as unreliable.
Fixes the following warnings:
vmlinux.o: warning: objtool: vmw_port_hb_in+0x1df: return with modified stack frame
vmlinux.o: warning: objtool: vmw_port_hb_out+0x1dd: return with modified stack frame
Fixes: 89da76fde68d ("drm/vmwgfx: Add VMWare host messaging capability")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305160135.97q0Elax-lkp@intel.com/
Link: https://lore.kernel.org/r/4c795f2d87bc0391cf6543bcb224fa540b55ce4b.1685981486.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
There's no need for both thunk functions to jump to the same shared
thunk restore code which lives outside the thunk function boundaries.
It disrupts i-cache locality and confuses objtool. Keep it simple by
keeping each thunk's restore code self-contained within the function.
Fixes a bunch of false positive "missing __noreturn" warnings like:
vmlinux.o: warning: objtool: do_arch_prctl_common+0xf4: preempt_schedule_thunk() is missing a __noreturn annotation
Fixes: fedb724c3db5 ("objtool: Detect missing __noreturn annotations")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202305281037.3PaI3tW4-lkp@intel.com/
Link: https://lore.kernel.org/r/46aa8aeb716f302e22e1673ae15ee6fe050b41f4.1685488050.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Commit 396e0b8e09e8 ("x86/orc: Make it callthunk aware") attempted to
deal with the fact that function prefix code didn't have ORC coverage.
However, it didn't work as advertised. Use of the "null" ORC entry just
caused affected unwinds to end early.
The root cause has now been fixed with commit 5743654f5e2e ("objtool:
Generate ORC data for __pfx code").
Revert most of commit 396e0b8e09e8 ("x86/orc: Make it callthunk aware").
The is_callthunk() function remains as it's now used by other code.
Link: https://lore.kernel.org/r/a05b916ef941da872cbece1ab3593eceabd05a79.1684245404.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
