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Step 9/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Step 8/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Step 7/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Step 6/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.
[ mingo: Converted a few more uses in comments/messages as well. ]
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Ariel Miculas <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
Step 4/10 of the namespace unification of CPU mitigations related Kconfig options.
[ mingo: Converted new uses that got added since the series was posted. ]
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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CONFIG_MITIGATION_CALL_DEPTH_TRACKING
Step 3/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Step 2/10 of the namespace unification of CPU mitigations related Kconfig options.
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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So the CPU mitigations Kconfig entries - there's 10 meanwhile - are named
in a historically idiosyncratic and hence rather inconsistent fashion
and have become hard to relate with each other over the years:
https://lore.kernel.org/lkml/20231011044252.42bplzjsam3qsasz@treble/
When they were introduced we never expected that we'd eventually have
about a dozen of them, and that more organization would be useful,
especially for Linux distributions that want to enable them in an
informed fashion, and want to make sure all mitigations are configured
as expected.
For example, the current CONFIG_SPECULATION_MITIGATIONS namespace is only
halfway populated, where some mitigations have entries in Kconfig, and
they could be modified, while others mitigations do not have Kconfig entries,
and can not be controlled at build time.
Fine-grained control over these Kconfig entries can help in a number of ways:
1) Users can choose and pick only mitigations that are important for
their workloads.
2) Users and developers can choose to disable mitigations that mangle
the assembly code generation, making it hard to read.
3) Separate Kconfigs for just source code readability,
so that we see *which* butt-ugly piece of crap code is for what
reason...
In most cases, if a mitigation is disabled at compilation time, it
can still be enabled at runtime using kernel command line arguments.
This is the first patch of an initial series that renames various
mitigation related Kconfig options, unifying them under a single
CONFIG_MITIGATION_* namespace:
CONFIG_GDS_FORCE_MITIGATION => CONFIG_MITIGATION_GDS_FORCE
CONFIG_CPU_IBPB_ENTRY => CONFIG_MITIGATION_IBPB_ENTRY
CONFIG_CALL_DEPTH_TRACKING => CONFIG_MITIGATION_CALL_DEPTH_TRACKING
CONFIG_PAGE_TABLE_ISOLATION => CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINE
CONFIG_SLS => CONFIG_MITIGATION_SLS
CONFIG_CPU_UNRET_ENTRY => CONFIG_MITIGATION_UNRET_ENTRY
CONFIG_CPU_IBRS_ENTRY => CONFIG_MITIGATION_IBRS_ENTRY
CONFIG_CPU_SRSO => CONFIG_MITIGATION_SRSO
CONFIG_RETHUNK => CONFIG_MITIGATION_RETHUNK
Implement step 1/10 of the namespace unification of CPU mitigations related
Kconfig options and rename CONFIG_GDS_FORCE_MITIGATION to
CONFIG_MITIGATION_GDS_FORCE.
[ mingo: Rewrote changelog for clarity. ]
Suggested-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"Quite a lot of kexec work this time around. Many singleton patches in
many places. The notable patch series are:
- nilfs2 folio conversion from Matthew Wilcox in 'nilfs2: Folio
conversions for file paths'.
- Additional nilfs2 folio conversion from Ryusuke Konishi in 'nilfs2:
Folio conversions for directory paths'.
- IA64 remnant removal in Heiko Carstens's 'Remove unused code after
IA-64 removal'.
- Arnd Bergmann has enabled the -Wmissing-prototypes warning
everywhere in 'Treewide: enable -Wmissing-prototypes'. This had
some followup fixes:
- Nathan Chancellor has cleaned up the hexagon build in the series
'hexagon: Fix up instances of -Wmissing-prototypes'.
- Nathan also addressed some s390 warnings in 's390: A couple of
fixes for -Wmissing-prototypes'.
- Arnd Bergmann addresses the same warnings for MIPS in his series
'mips: address -Wmissing-prototypes warnings'.
- Baoquan He has made kexec_file operate in a top-down-fitting manner
similar to kexec_load in the series 'kexec_file: Load kernel at top
of system RAM if required'
- Baoquan He has also added the self-explanatory 'kexec_file: print
out debugging message if required'.
- Some checkstack maintenance work from Tiezhu Yang in the series
'Modify some code about checkstack'.
- Douglas Anderson has disentangled the watchdog code's logging when
multiple reports are occurring simultaneously. The series is
'watchdog: Better handling of concurrent lockups'.
- Yuntao Wang has contributed some maintenance work on the crash code
in 'crash: Some cleanups and fixes'"
* tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (157 commits)
crash_core: fix and simplify the logic of crash_exclude_mem_range()
x86/crash: use SZ_1M macro instead of hardcoded value
x86/crash: remove the unused image parameter from prepare_elf_headers()
kdump: remove redundant DEFAULT_CRASH_KERNEL_LOW_SIZE
scripts/decode_stacktrace.sh: strip unexpected CR from lines
watchdog: if panicking and we dumped everything, don't re-enable dumping
watchdog/hardlockup: use printk_cpu_sync_get_irqsave() to serialize reporting
watchdog/softlockup: use printk_cpu_sync_get_irqsave() to serialize reporting
watchdog/hardlockup: adopt softlockup logic avoiding double-dumps
kexec_core: fix the assignment to kimage->control_page
x86/kexec: fix incorrect end address passed to kernel_ident_mapping_init()
lib/trace_readwrite.c:: replace asm-generic/io with linux/io
nilfs2: cpfile: fix some kernel-doc warnings
stacktrace: fix kernel-doc typo
scripts/checkstack.pl: fix no space expression between sp and offset
x86/kexec: fix incorrect argument passed to kexec_dprintk()
x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs
nilfs2: add missing set_freezable() for freezable kthread
kernel: relay: remove relay_file_splice_read dead code, doesn't work
docs: submit-checklist: remove all of "make namespacecheck"
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
- Add branch stack counters ABI extension to better capture the growing
amount of information the PMU exposes via branch stack sampling.
There's matching tooling support.
- Fix race when creating the nr_addr_filters sysfs file
- Add Intel Sierra Forest and Grand Ridge intel/cstate PMU support
- Add Intel Granite Rapids, Sierra Forest and Grand Ridge uncore PMU
support
- Misc cleanups & fixes
* tag 'perf-core-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Factor out topology_gidnid_map()
perf/x86/intel/uncore: Fix NULL pointer dereference issue in upi_fill_topology()
perf/x86/amd: Reject branch stack for IBS events
perf/x86/intel/uncore: Support Sierra Forest and Grand Ridge
perf/x86/intel/uncore: Support IIO free-running counters on GNR
perf/x86/intel/uncore: Support Granite Rapids
perf/x86/uncore: Use u64 to replace unsigned for the uncore offsets array
perf/x86/intel/uncore: Generic uncore_get_uncores and MMIO format of SPR
perf: Fix the nr_addr_filters fix
perf/x86/intel/cstate: Add Grand Ridge support
perf/x86/intel/cstate: Add Sierra Forest support
x86/smp: Export symbol cpu_clustergroup_mask()
perf/x86/intel/cstate: Cleanup duplicate attr_groups
perf/core: Fix narrow startup race when creating the perf nr_addr_filters sysfs file
perf/x86/intel: Support branch counters logging
perf/x86/intel: Reorganize attrs and is_visible
perf: Add branch_sample_call_stack
perf/x86: Add PERF_X86_EVENT_NEEDS_BRANCH_STACK flag
perf: Add branch stack counters
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
- Change global variables to local
- Add missing kernel-doc function parameter descriptions
- Remove unused parameter from a macro
- Remove obsolete Kconfig entry
- Fix comments
- Fix typos, mostly scripted, manually reviewed
and a micro-optimization got misplaced as a cleanup:
- Micro-optimize the asm code in secondary_startup_64_no_verify()
* tag 'x86-cleanups-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arch/x86: Fix typos
x86/head_64: Use TESTB instead of TESTL in secondary_startup_64_no_verify()
x86/docs: Remove reference to syscall trampoline in PTI
x86/Kconfig: Remove obsolete config X86_32_SMP
x86/io: Remove the unused 'bw' parameter from the BUILDIO() macro
x86/mtrr: Document missing function parameters in kernel-doc
x86/setup: Make relocated_ramdisk a local variable of relocate_initrd()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
"Replace magic numbers in GDT descriptor definitions & handling:
- Introduce symbolic names via macros for descriptor
types/fields/flags, and then use these symbolic names.
- Clean up definitions a bit, such as GDT_ENTRY_INIT()
- Fix/clean up details that became visibly inconsistent after the
symbol-based code was introduced:
- Unify accessed flag handling
- Set the D/B size flag consistently & according to the HW
specification"
* tag 'x86-asm-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Add DB flag to 32-bit percpu GDT entry
x86/asm: Always set A (accessed) flag in GDT descriptors
x86/asm: Replace magic numbers in GDT descriptors, script-generated change
x86/asm: Replace magic numbers in GDT descriptors, preparations
x86/asm: Provide new infrastructure for GDT descriptors
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 apic updates from Ingo Molnar:
- Clean up 'struct apic':
- Drop ::delivery_mode
- Drop 'enum apic_delivery_modes'
- Drop 'struct local_apic'
- Fix comments
* tag 'x86-apic-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioapic: Remove unfinished sentence from comment
x86/apic: Drop struct local_apic
x86/apic: Drop enum apic_delivery_modes
x86/apic: Drop apic::delivery_mode
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS updates from Borislav Petkov:
- Convert the hw error storm handling into a finer-grained, per-bank
solution which allows for more timely detection and reporting of
errors
- Start a documentation section which will hold down relevant RAS
features description and how they should be used
- Add new AMD error bank types
- Slim down and remove error type descriptions from the kernel side of
error decoding to rasdaemon which can be used from now on to decode
hw errors on AMD
- Mark pages containing uncorrectable errors as poison so that kdump
can avoid them and thus not cause another panic
- The usual cleanups and fixlets
* tag 'ras_core_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Handle Intel threshold interrupt storms
x86/mce: Add per-bank CMCI storm mitigation
x86/mce: Remove old CMCI storm mitigation code
Documentation: Begin a RAS section
x86/MCE/AMD: Add new MA_LLC, USR_DP, and USR_CP bank types
EDAC/mce_amd: Remove SMCA Extended Error code descriptions
x86/mce/amd, EDAC/mce_amd: Move long names to decoder module
x86/mce/inject: Clear test status value
x86/mce: Remove redundant check from mce_device_create()
x86/mce: Mark fatal MCE's page as poison to avoid panic in the kdump kernel
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu feature updates from Borislav Petkov:
- Add synthetic X86_FEATURE flags for the different AMD Zen generations
and use them everywhere instead of ad-hoc family/model checks. Drop
an ancient AMD errata checking facility as a result
- Fix a fragile initcall ordering in intel_epb
- Do not issue the MFENCE+LFENCE barrier for the TSC deadline and
X2APIC MSRs on AMD as it is not needed there
* tag 'x86_cpu_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/CPU/AMD: Add X86_FEATURE_ZEN1
x86/CPU/AMD: Drop now unused CPU erratum checking function
x86/CPU/AMD: Get rid of amd_erratum_1485[]
x86/CPU/AMD: Get rid of amd_erratum_400[]
x86/CPU/AMD: Get rid of amd_erratum_383[]
x86/CPU/AMD: Get rid of amd_erratum_1054[]
x86/CPU/AMD: Move the DIV0 bug detection to the Zen1 init function
x86/CPU/AMD: Move Zenbleed check to the Zen2 init function
x86/CPU/AMD: Rename init_amd_zn() to init_amd_zen_common()
x86/CPU/AMD: Call the spectral chicken in the Zen2 init function
x86/CPU/AMD: Move erratum 1076 fix into the Zen1 init function
x86/CPU/AMD: Move the Zen3 BTC_NO detection to the Zen3 init function
x86/CPU/AMD: Carve out the erratum 1386 fix
x86/CPU/AMD: Add ZenX generations flags
x86/cpu/intel_epb: Don't rely on link order
x86/barrier: Do not serialize MSR accesses on AMD
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV updates from Borislav Petkov:
- Convert the sev-guest plaform ->remove callback to return void
- Move the SEV C-bit verification to the BSP as it needs to happen only
once and not on every AP
* tag 'x86_sev_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt: sev-guest: Convert to platform remove callback returning void
x86/sev: Do the C-bit verification only on the BSP
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 paravirt updates from Borislav Petkov:
- Replace the paravirt patching functionality using the alternatives
infrastructure and remove the former
- Misc other improvements
* tag 'x86_paravirt_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/alternative: Correct feature bit debug output
x86/paravirt: Remove no longer needed paravirt patching code
x86/paravirt: Switch mixed paravirt/alternative calls to alternatives
x86/alternative: Add indirect call patching
x86/paravirt: Move some functions and defines to alternative.c
x86/paravirt: Introduce ALT_NOT_XEN
x86/paravirt: Make the struct paravirt_patch_site packed
x86/paravirt: Use relative reference for the original instruction offset
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode updates from Borislav Petkov:
- Correct minor issues after the microcode revision reporting
sanitization
* tag 'x86_microcode_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode/intel: Set new revision only after a successful update
x86/microcode/intel: Remove redundant microcode late updated message
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kvm_guest_cpu_offline() tries to disable kvmclock regardless if it is
present in the VM. It leads to write to a MSR that doesn't exist on some
configurations, namely in TDX guest:
unchecked MSR access error: WRMSR to 0x12 (tried to write 0x0000000000000000)
at rIP: 0xffffffff8110687c (kvmclock_disable+0x1c/0x30)
kvmclock enabling is gated by CLOCKSOURCE and CLOCKSOURCE2 KVM paravirt
features.
Do not disable kvmclock if it was not enabled.
Signed-off-by: Kirill A. Shutemov <[email protected]>
Fixes: c02027b5742b ("x86/kvm: Disable kvmclock on all CPUs on shutdown")
Reviewed-by: Sean Christopherson <[email protected]>
Reviewed-by: Vitaly Kuznetsov <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Wanpeng Li <[email protected]>
Cc: [email protected]
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
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Use SZ_1M macro instead of hardcoded 1<<20 to make code more readable.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yuntao Wang <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Hari Bathini <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Sourabh Jain <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vivek Goyal <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Patch series "crash: Some cleanups and fixes", v2.
This patchset includes two cleanups and one fix.
This patch (of 3):
The image parameter is no longer in use, remove it. Also, tidy up the
code formatting.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yuntao Wang <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dave Young <[email protected]>
Cc: Hari Bathini <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Sourabh Jain <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vivek Goyal <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/ethernet/broadcom/bnxt/bnxt.c
e009b2efb7a8 ("bnxt_en: Remove mis-applied code from bnxt_cfg_ntp_filters()")
0f2b21477988 ("bnxt_en: Fix compile error without CONFIG_RFS_ACCEL")
https://lore.kernel.org/all/[email protected]/
Signed-off-by: Jakub Kicinski <[email protected]>
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kprobe_emulate_call_indirect
kprobe_emulate_call_indirect currently uses int3_emulate_call to emulate
indirect calls. However, int3_emulate_call always assumes the size of
the call to be 5 bytes when calculating the return address. This is
incorrect for register-based indirect calls in x86, which can be either
2 or 3 bytes depending on whether REX prefix is used. At kprobe runtime,
the incorrect return address causes control flow to land onto the wrong
place after return -- possibly not a valid instruction boundary. This
can lead to a panic like the following:
[ 7.308204][ C1] BUG: unable to handle page fault for address: 000000000002b4d8
[ 7.308883][ C1] #PF: supervisor read access in kernel mode
[ 7.309168][ C1] #PF: error_code(0x0000) - not-present page
[ 7.309461][ C1] PGD 0 P4D 0
[ 7.309652][ C1] Oops: 0000 [#1] SMP
[ 7.309929][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.7.0-rc5-trace-for-next #6
[ 7.310397][ C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-20220807_005459-localhost 04/01/2014
[ 7.311068][ C1] RIP: 0010:__common_interrupt+0x52/0xc0
[ 7.311349][ C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[ 7.312512][ C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[ 7.312899][ C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[ 7.313334][ C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[ 7.313702][ C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[ 7.314146][ C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[ 7.314509][ C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[ 7.314951][ C1] FS: 0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[ 7.315396][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.315691][ C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[ 7.316153][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7.316508][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7.316948][ C1] Call Trace:
[ 7.317123][ C1] <IRQ>
[ 7.317279][ C1] ? __die_body+0x64/0xb0
[ 7.317482][ C1] ? page_fault_oops+0x248/0x370
[ 7.317712][ C1] ? __wake_up+0x96/0xb0
[ 7.317964][ C1] ? exc_page_fault+0x62/0x130
[ 7.318211][ C1] ? asm_exc_page_fault+0x22/0x30
[ 7.318444][ C1] ? __cfi_native_send_call_func_single_ipi+0x10/0x10
[ 7.318860][ C1] ? default_idle+0xb/0x10
[ 7.319063][ C1] ? __common_interrupt+0x52/0xc0
[ 7.319330][ C1] common_interrupt+0x78/0x90
[ 7.319546][ C1] </IRQ>
[ 7.319679][ C1] <TASK>
[ 7.319854][ C1] asm_common_interrupt+0x22/0x40
[ 7.320082][ C1] RIP: 0010:default_idle+0xb/0x10
[ 7.320309][ C1] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 66 90 0f 00 2d 09 b9 3b 00 fb f4 <fa> c3 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 b8 0c 67 40 a5 e9
[ 7.321449][ C1] RSP: 0018:ffffc9000009bee8 EFLAGS: 00000256
[ 7.321808][ C1] RAX: ffff88813bca8b68 RBX: 0000000000000001 RCX: 000000000001ef0c
[ 7.322227][ C1] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000001ef0c
[ 7.322656][ C1] RBP: ffffc9000009bef8 R08: 8000000000000000 R09: 00000000000008c2
[ 7.323083][ C1] R10: 0000000000000000 R11: ffffffff81058e70 R12: 0000000000000000
[ 7.323530][ C1] R13: ffff8881002b30c0 R14: 0000000000000000 R15: 0000000000000000
[ 7.323948][ C1] ? __cfi_lapic_next_deadline+0x10/0x10
[ 7.324239][ C1] default_idle_call+0x31/0x50
[ 7.324464][ C1] do_idle+0xd3/0x240
[ 7.324690][ C1] cpu_startup_entry+0x25/0x30
[ 7.324983][ C1] start_secondary+0xb4/0xc0
[ 7.325217][ C1] secondary_startup_64_no_verify+0x179/0x17b
[ 7.325498][ C1] </TASK>
[ 7.325641][ C1] Modules linked in:
[ 7.325906][ C1] CR2: 000000000002b4d8
[ 7.326104][ C1] ---[ end trace 0000000000000000 ]---
[ 7.326354][ C1] RIP: 0010:__common_interrupt+0x52/0xc0
[ 7.326614][ C1] Code: 01 00 4d 85 f6 74 39 49 81 fe 00 f0 ff ff 77 30 4c 89 f7 4d 8b 5e 68 41 ba 91 76 d8 42 45 03 53 fc 74 02 0f 0b cc ff d3 65 48 <8b> 05 30 c7 ff 7e 65 4c 89 3d 28 c7 ff 7e 5b 41 5c 41 5e 41 5f c3
[ 7.327570][ C1] RSP: 0018:ffffc900000e0fd0 EFLAGS: 00010046
[ 7.327910][ C1] RAX: 0000000000000001 RBX: 0000000000000023 RCX: 0000000000000001
[ 7.328273][ C1] RDX: 00000000000003cd RSI: 0000000000000001 RDI: ffff888100d302a4
[ 7.328632][ C1] RBP: 0000000000000001 R08: 0ef439818636191f R09: b1621ff338a3b482
[ 7.329223][ C1] R10: ffffffff81e5127b R11: ffffffff81059810 R12: 0000000000000023
[ 7.329780][ C1] R13: 0000000000000000 R14: ffff888100d30200 R15: 0000000000000000
[ 7.330193][ C1] FS: 0000000000000000(0000) GS:ffff88813bc80000(0000) knlGS:0000000000000000
[ 7.330632][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.331050][ C1] CR2: 000000000002b4d8 CR3: 0000000003028003 CR4: 0000000000370ef0
[ 7.331454][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7.331854][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7.332236][ C1] Kernel panic - not syncing: Fatal exception in interrupt
[ 7.332730][ C1] Kernel Offset: disabled
[ 7.333044][ C1] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
The relevant assembly code is (from objdump, faulting address
highlighted):
ffffffff8102ed9d: 41 ff d3 call *%r11
ffffffff8102eda0: 65 48 <8b> 05 30 c7 ff mov %gs:0x7effc730(%rip),%rax
The emulation incorrectly sets the return address to be ffffffff8102ed9d
+ 0x5 = ffffffff8102eda2, which is the 8b byte in the middle of the next
mov. This in turn causes incorrect subsequent instruction decoding and
eventually triggers the page fault above.
Instead of invoking int3_emulate_call, perform push and jmp emulation
directly in kprobe_emulate_call_indirect. At this point we can obtain
the instruction size from p->ainsn.size so that we can calculate the
correct return address.
Link: https://lore.kernel.org/all/[email protected]/
Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Cc: [email protected]
Signed-off-by: Jinghao Jia <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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Fix typos, most reported by "codespell arch/x86". Only touches comments,
no code changes.
Signed-off-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Randy Dunlap <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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'x86/vt-d', 'x86/amd' and 'core' into next
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In
https://lore.kernel.org/r/20231206110636.GBZXBVvCWj2IDjVk4c@fat_crate.local
I wanted to adjust the alternative patching debug output to the new
changes introduced by
da0fe6e68e10 ("x86/alternative: Add indirect call patching")
but removed the '*' which denotes the ->x86_capability word. The correct
output should be, for example:
[ 0.230071] SMP alternatives: feat: 11*32+15, old: (entry_SYSCALL_64_after_hwframe+0x5a/0x77 (ffffffff81c000c2) len: 16), repl: (ffffffff89ae896a, len: 5) flags: 0x0
while the incorrect one says "... 1132+15" currently.
Add back the '*'.
Fixes: da0fe6e68e10 ("x86/alternative: Add indirect call patching")
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Link: https://lore.kernel.org/r/20231206110636.GBZXBVvCWj2IDjVk4c@fat_crate.local
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kernel_ident_mapping_init() takes an exclusive memory range [pstart, pend)
where pend is not included in the range, while res represents an inclusive
memory range [start, end] where end is considered part of the range.
Passing [start, end] rather than [start, end+1) to
kernel_ident_mapping_init() may result in the identity mapping for the
end address not being set up.
For example, when res->start is equal to res->end,
kernel_ident_mapping_init() will not establish any identity mapping.
Similarly, when the value of res->end is a multiple of 2M and the page
table maps 2M pages, kernel_ident_mapping_init() will also not set up
identity mapping for res->end.
Therefore, passing res->end directly to kernel_ident_mapping_init() is
incorrect, the correct end address should be `res->end + 1`.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yuntao Wang <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Simon Horman <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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kexec_dprintk() expects the last argument to be kbuf.memsz, but the actual
argument being passed is kbuf.bufsz.
Although these two values are currently equal, it is better to pass the
correct one, in case these two values become different in the future.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yuntao Wang <[email protected]>
Cc: Baoquan He <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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When detecting an error, the current code uses kexec_dprintk() to output
log message. This is not quite appropriate as kexec_dprintk() is mainly
used for outputting debugging messages, rather than error messages.
Replace kexec_dprintk() with pr_err(). This also makes the output method
for this error log align with the output method for other error logs in
this function.
Additionally, the last return statement in set_page_address() is
unnecessary, remove it.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yuntao Wang <[email protected]>
Cc: Baoquan He <[email protected]>
Cc: Borislav Petkov (AMD) <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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We're trying to get sched.h down to more or less just types only, not
code - rseq can live in its own header.
This helps us kill the dependency on preempt.h in sched.h.
Signed-off-by: Kent Overstreet <[email protected]>
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The expression `mstart + resource_size(res) - 1` is actually equivalent to
`res->end`, simplify the logic of this function to improve readability.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yuntao Wang <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Simon Horman <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Then when specifying '-d' for kexec_file_load interface, loaded locations
of kernel/initrd/cmdline etc can be printed out to help debug.
Here replace pr_debug() with the newly added kexec_dprintk() in kexec_file
loading related codes.
And also print out e820 memmap passed to 2nd kernel just as kexec_load
interface has been doing.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Baoquan He <[email protected]>
Cc: Conor Dooley <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Signed-off-by: Kent Overstreet <[email protected]>
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The D/B size flag for the 32-bit percpu GDT entry was not set.
The Intel manual (vol 3, section 3.4.5) only specifies the meaning of
this flag for three cases:
1) code segments used for %cs -- doesn't apply here
2) stack segments used for %ss -- doesn't apply
3) expand-down data segments -- but we don't have the expand-down flag
set, so it also doesn't apply here
The flag likely doesn't do anything here, although the manual does also
say: "This flag should always be set to 1 for 32-bit code and data
segments [...]" so we should probably do it anyway.
Signed-off-by: Vegard Nossum <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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We have no known use for having the CPU track whether GDT descriptors
have been accessed or not.
Simplify the code by adding the flag to the common flags and removing
it everywhere else.
Signed-off-by: Vegard Nossum <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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Actually replace the numeric values by the new symbolic values.
I used this to find all the existing users of the GDT_ENTRY*() macros:
$ git grep -P 'GDT_ENTRY(_INIT)?\('
Some of the lines will exceed 80 characters, but some of them will be
shorter again in the next couple of patches.
Signed-off-by: Vegard Nossum <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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We'd like to replace all the magic numbers in various GDT descriptors
with new, semantically meaningful, symbolic values.
In order to be able to verify that the change doesn't cause any actual
changes to the compiled binary code, I've split the change into two
patches:
- Part 1 (this commit): everything _but_ actually replacing the numbers
- Part 2 (the following commit): _only_ replacing the numbers
The reason we need this split for verification is that including new
headers causes some spurious changes to the object files, mostly line
number changes in the debug info but occasionally other subtle codegen
changes.
Signed-off-by: Vegard Nossum <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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This function is now called from a few places that are no __init_or_module,
resulting a link time warning:
WARNING: modpost: vmlinux: section mismatch in reference: patch_dest+0x8a (section: .text) -> apply_relocation (section: .init.text)
Remove the annotation here.
[ mingo: Also sync up add_nop() with these changes. ]
Fixes: 17bce3b2ae2d ("x86/callthunks: Handle %rip-relative relocations in call thunk template")
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Uros Bizjak <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:
====================
pull-request: bpf-next 2023-12-18
This PR is larger than usual and contains changes in various parts
of the kernel.
The main changes are:
1) Fix kCFI bugs in BPF, from Peter Zijlstra.
End result: all forms of indirect calls from BPF into kernel
and from kernel into BPF work with CFI enabled. This allows BPF
to work with CONFIG_FINEIBT=y.
2) Introduce BPF token object, from Andrii Nakryiko.
It adds an ability to delegate a subset of BPF features from privileged
daemon (e.g., systemd) through special mount options for userns-bound
BPF FS to a trusted unprivileged application. The design accommodates
suggestions from Christian Brauner and Paul Moore.
Example:
$ sudo mkdir -p /sys/fs/bpf/token
$ sudo mount -t bpf bpffs /sys/fs/bpf/token \
-o delegate_cmds=prog_load:MAP_CREATE \
-o delegate_progs=kprobe \
-o delegate_attachs=xdp
3) Various verifier improvements and fixes, from Andrii Nakryiko, Andrei Matei.
- Complete precision tracking support for register spills
- Fix verification of possibly-zero-sized stack accesses
- Fix access to uninit stack slots
- Track aligned STACK_ZERO cases as imprecise spilled registers.
It improves the verifier "instructions processed" metric from single
digit to 50-60% for some programs.
- Fix verifier retval logic
4) Support for VLAN tag in XDP hints, from Larysa Zaremba.
5) Allocate BPF trampoline via bpf_prog_pack mechanism, from Song Liu.
End result: better memory utilization and lower I$ miss for calls to BPF
via BPF trampoline.
6) Fix race between BPF prog accessing inner map and parallel delete,
from Hou Tao.
7) Add bpf_xdp_get_xfrm_state() kfunc, from Daniel Xu.
It allows BPF interact with IPSEC infra. The intent is to support
software RSS (via XDP) for the upcoming ipsec pcpu work.
Experiments on AWS demonstrate single tunnel pcpu ipsec reaching
line rate on 100G ENA nics.
8) Expand bpf_cgrp_storage to support cgroup1 non-attach, from Yafang Shao.
9) BPF file verification via fsverity, from Song Liu.
It allows BPF progs get fsverity digest.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (164 commits)
bpf: Ensure precise is reset to false in __mark_reg_const_zero()
selftests/bpf: Add more uprobe multi fail tests
bpf: Fail uprobe multi link with negative offset
selftests/bpf: Test the release of map btf
s390/bpf: Fix indirect trampoline generation
selftests/bpf: Temporarily disable dummy_struct_ops test on s390
x86/cfi,bpf: Fix bpf_exception_cb() signature
bpf: Fix dtor CFI
cfi: Add CFI_NOSEAL()
x86/cfi,bpf: Fix bpf_struct_ops CFI
x86/cfi,bpf: Fix bpf_callback_t CFI
x86/cfi,bpf: Fix BPF JIT call
cfi: Flip headers
selftests/bpf: Add test for abnormal cnt during multi-kprobe attachment
selftests/bpf: Don't use libbpf_get_error() in kprobe_multi_test
selftests/bpf: Add test for abnormal cnt during multi-uprobe attachment
bpf: Limit the number of kprobes when attaching program to multiple kprobes
bpf: Limit the number of uprobes when attaching program to multiple uprobes
bpf: xdp: Register generic_kfunc_set with XDP programs
selftests/bpf: utilize string values for delegate_xxx mount options
...
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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The recent fix to ignore invalid x2APIC entries inadvertently broke
systems with creative MADT APIC tables. The affected systems have APIC
MADT tables where all entries have invalid APIC IDs (0xFF), which means
they register exactly zero CPUs.
But the condition to ignore the entries of APIC IDs < 255 in the X2APIC
MADT table is solely based on the count of MADT APIC table entries.
As a consequence, the affected machines enumerate no secondary CPUs at
all because the APIC table has entries and therefore the X2APIC table
entries with APIC IDs < 255 are ignored.
Change the condition so that the APIC table preference for APIC IDs <
255 only becomes effective when the APIC table has valid APIC ID
entries.
IOW, an APIC table full of invalid APIC IDs is considered to be empty
which in consequence enables the X2APIC table entries with a APIC ID
< 255 and restores the expected behaviour.
Fixes: ec9aedb2aa1a ("x86/acpi: Ignore invalid x2APIC entries")
Reported-by: John Sperbeck <[email protected]>
Reported-by: Andres Freund <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Link: https://lore.kernel.org/r/169953729188.3135.6804572126118798018.tip-bot2@tip-bot2
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Specs don't say anything about UIP being cleared within 10ms. They
only say that UIP won't occur for another 244uS. If a long NMI occurs
while UIP is still updating it might not be possible to get valid
data in 10ms.
This has been observed in the wild that around s2idle some calls can
take up to 480ms before UIP is clear.
Adjust callers from outside an interrupt context to wait for up to a
1s instead of 10ms.
Cc: <[email protected]> # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Reported-by: Carsten Hatger <[email protected]>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217626
Tested-by: Mateusz Jończyk <[email protected]>
Reviewed-by: Mateusz Jończyk <[email protected]>
Acked-by: Mateusz Jończyk <[email protected]>
Signed-off-by: Mario Limonciello <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>
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The UIP timeout is hardcoded to 10ms for all RTC reads, but in some
contexts this might not be enough time. Add a timeout parameter to
mc146818_get_time() and mc146818_get_time_callback().
If UIP timeout is configured by caller to be >=100 ms and a call
takes this long, log a warning.
Make all callers use 10ms to ensure no functional changes.
Cc: <[email protected]> # 6.1.y
Fixes: ec5895c0f2d8 ("rtc: mc146818-lib: extract mc146818_avoid_UIP")
Signed-off-by: Mario Limonciello <[email protected]>
Tested-by: Mateusz Jończyk <[email protected]>
Reviewed-by: Mateusz Jończyk <[email protected]>
Acked-by: Mateusz Jończyk <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexandre Belloni <[email protected]>
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BPF struct_ops uses __arch_prepare_bpf_trampoline() to write
trampolines for indirect function calls. These tramplines much have
matching CFI.
In order to obtain the correct CFI hash for the various methods, add a
matching structure that contains stub functions, the compiler will
generate correct CFI which we can pilfer for the trampolines.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Where the main BPF program is expected to match bpf_func_t,
sub-programs are expected to match bpf_callback_t.
This fixes things like:
tools/testing/selftests/bpf/progs/bloom_filter_bench.c:
bpf_for_each_map_elem(&array_map, bloom_callback, &data, 0);
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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The current BPF call convention is __nocfi, except when it calls !JIT things,
then it calls regular C functions.
It so happens that with FineIBT the __nocfi and C calling conventions are
incompatible. Specifically __nocfi will call at func+0, while FineIBT will have
endbr-poison there, which is not a valid indirect target. Causing #CP.
Notably this only triggers on IBT enabled hardware, which is probably why this
hasn't been reported (also, most people will have JIT on anyway).
Implement proper CFI prologues for the BPF JIT codegen and drop __nocfi for
x86.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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Normal include order is that linux/foo.h should include asm/foo.h, CFI has it
the wrong way around.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Sami Tolvanen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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apply_alternatives() treats alternatives with the ALT_FLAG_NOT flag set
special as it optimizes the existing NOPs in place.
Unfortunately, this happens with interrupts enabled and does not provide any
form of core synchronization.
So an interrupt hitting in the middle of the update and using the affected code
path will observe a half updated NOP and crash and burn. The following
3 NOP sequence was observed to expose this crash halfway reliably under QEMU
32bit:
0x90 0x90 0x90
which is replaced by the optimized 3 byte NOP:
0x8d 0x76 0x00
So an interrupt can observe:
1) 0x90 0x90 0x90 nop nop nop
2) 0x8d 0x90 0x90 undefined
3) 0x8d 0x76 0x90 lea -0x70(%esi),%esi
4) 0x8d 0x76 0x00 lea 0x0(%esi),%esi
Where only #1 and #4 are true NOPs. The same problem exists for 64bit obviously.
Disable interrupts around this NOP optimization and invoke sync_core()
before re-enabling them.
Fixes: 270a69c4485d ("x86/alternative: Support relocations in alternatives")
Reported-by: Paul Gortmaker <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/ZT6narvE%2BLxX%[email protected]
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text_poke_early() does:
local_irq_save(flags);
memcpy(addr, opcode, len);
local_irq_restore(flags);
sync_core();
That's not really correct because the synchronization should happen before
interrupts are re-enabled to ensure that a pending interrupt observes the
complete update of the opcodes.
It's not entirely clear whether the interrupt entry provides enough
serialization already, but moving the sync_core() invocation into interrupt
disabled region does no harm and is obviously correct.
Fixes: 6fffacb30349 ("x86/alternatives, jumplabel: Use text_poke_early() before mm_init()")
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: <[email protected]>
Link: https://lore.kernel.org/r/ZT6narvE%2BLxX%[email protected]
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Chris reported that a Dell PowerEdge T340 system stopped to boot when upgrading
to a kernel which contains the parallel hotplug changes. Disabling parallel
hotplug on the kernel command line makes it boot again.
It turns out that the Dell BIOS has x2APIC enabled and the boot CPU comes up in
X2APIC mode, but the APs come up inconsistently in xAPIC mode.
Parallel hotplug requires that the upcoming CPU reads out its APIC ID from the
local APIC in order to map it to the Linux CPU number.
In this particular case the readout on the APs uses the MMIO mapped registers
because the BIOS failed to enable x2APIC mode. That readout results in a page
fault because the kernel does not have the APIC MMIO space mapped when X2APIC
mode was enabled by the BIOS on the boot CPU and the kernel switched to X2APIC
mode early. That page fault can't be handled on the upcoming CPU that early and
results in a silent boot failure.
If parallel hotplug is disabled the system boots because in that case the APIC
ID read is not required as the Linux CPU number is provided to the AP in the
smpboot control word. When the kernel uses x2APIC mode then the APs are
switched to x2APIC mode too slightly later in the bringup process, but there is
no reason to do it that late.
Cure the BIOS bogosity by checking in the parallel bootup path whether the
kernel uses x2APIC mode and if so switching over the APs to x2APIC mode before
the APIC ID readout.
Fixes: 0c7ffa32dbd6 ("x86/smpboot/64: Implement arch_cpuhp_init_parallel_bringup() and enable it")
Reported-by: Chris Lindee <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Ashok Raj <[email protected]>
Tested-by: Chris Lindee <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/CA%2B2tU59853R49EaU_tyvOZuOTDdcU0RshGyydccp9R1NX9bEeQ@mail.gmail.com
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