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Linux kernel
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Pull x86 cpu fix from Thomas Gleixner:
"A single fix for x86:
- Prevent a bogus setting for the number of HT siblings, which is
caused by the CPUID evaluation trainwreck of X86. That recomputes
the value for each CPU, so the last CPU "wins". That can cause
completely bogus sibling values"
* tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms
Pull perf fixes from Thomas Gleixner:
"A small set of perf fixes:
- Make the MSR-readout based CHA discovery work around broken
discovery tables in some SPR firmwares.
- Prevent saving PEBS configuration which has software bits set that
cause a crash when restored into the relevant MSR"
* tag 'perf-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/uncore: Correct the number of CHAs on SPR
perf/x86/intel: Save/restore cpuc->active_pebs_data_cfg when using guest PEBS
Traditionally, all CPUs in a system have identical numbers of SMT
siblings. That changes with hybrid processors where some logical CPUs
have a sibling and others have none.
Today, the CPU boot code sets the global variable smp_num_siblings when
every CPU thread is brought up. The last thread to boot will overwrite
it with the number of siblings of *that* thread. That last thread to
boot will "win". If the thread is a Pcore, smp_num_siblings == 2. If it
is an Ecore, smp_num_siblings == 1.
smp_num_siblings describes if the *system* supports SMT. It should
specify the maximum number of SMT threads among all cores.
Ensure that smp_num_siblings represents the system-wide maximum number
of siblings by always increasing its value. Never allow it to decrease.
On MeteorLake-P platform, this fixes a problem that the Ecore CPUs are
not updated in any cpu sibling map because the system is treated as an
UP system when probing Ecore CPUs.
Below shows part of the CPU topology information before and after the
fix, for both Pcore and Ecore CPU (cpu0 is Pcore, cpu 12 is Ecore).
...
-/sys/devices/system/cpu/cpu0/topology/package_cpus:000fff
-/sys/devices/system/cpu/cpu0/topology/package_cpus_list:0-11
+/sys/devices/system/cpu/cpu0/topology/package_cpus:3fffff
+/sys/devices/system/cpu/cpu0/topology/package_cpus_list:0-21
...
-/sys/devices/system/cpu/cpu12/topology/package_cpus:001000
-/sys/devices/system/cpu/cpu12/topology/package_cpus_list:12
+/sys/devices/system/cpu/cpu12/topology/package_cpus:3fffff
+/sys/devices/system/cpu/cpu12/topology/package_cpus_list:0-21
Notice that the "before" 'package_cpus_list' has only one CPU. This
means that userspace tools like lscpu will see a little laptop like
an 11-socket system:
-Core(s) per socket: 1
-Socket(s): 11
+Core(s) per socket: 16
+Socket(s): 1
This is also expected to make the scheduler do rather wonky things
too.
[ dhansen: remove CPUID detail from changelog, add end user effects ]
CC: stable@kernel.org
Fixes: bbb65d2d365e ("x86: use cpuid vector 0xb when available for detecting cpu topology")
Fixes: 95f3d39ccf7a ("x86/cpu/topology: Provide detect_extended_topology_early()")
Suggested-by: Len Brown <len.brown@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20230323015640.27906-1-rui.zhang%40intel.com
Pull unwinder fixes from Thomas Gleixner:
"A set of unwinder and tooling fixes:
- Ensure that the stack pointer on x86 is aligned again so that the
unwinder does not read past the end of the stack
- Discard .note.gnu.property section which has a pointlessly
different alignment than the other note sections. That confuses
tooling of all sorts including readelf, libbpf and pahole"
* tag 'objtool-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/show_trace_log_lvl: Ensure stack pointer is aligned, again
vmlinux.lds.h: Discard .note.gnu.property section
The number of CHAs from the discovery table on some SPR variants is
incorrect, because of a firmware issue. An accurate number can be read
from the MSR UNC_CBO_CONFIG.
Fixes: 949b11381f81 ("perf/x86/intel/uncore: Add Sapphire Rapids server CHA support")
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230508140206.283708-1-kan.liang@linux.intel.com
The INVLPG instruction is used to invalidate TLB entries for a
specified virtual address. When PCIDs are enabled, INVLPG is supposed
to invalidate TLB entries for the specified address for both the
current PCID *and* Global entries. (Note: Only kernel mappings set
Global=1.)
Unfortunately, some INVLPG implementations can leave Global
translations unflushed when PCIDs are enabled.
As a workaround, never enable PCIDs on affected processors.
I expect there to eventually be microcode mitigations to replace this
software workaround. However, the exact version numbers where that
will happen are not known today. Once the version numbers are set in
stone, the processor list can be tweaked to only disable PCIDs on
affected processors with affected microcode.
Note: if anyone wants a quick fix that doesn't require patching, just
stick 'nopcid' on your kernel command-line.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Pull debugobjects fixes from Thomas Gleixner:
"Two fixes for debugobjects:
- Prevent the allocation path from waking up kswapd.
That's a long standing issue due to the GFP_ATOMIC allocation flag.
As debug objects can be invoked from pretty much any context waking
kswapd can end up in arbitrary lock chains versus the waitqueue
lock
- Correct the explicit lockdep wait-type violation in
debug_object_fill_pool()"
* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Don't wake up kswapd from fill_pool()
debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
The commit e335bb51cc15 ("x86/unwind: Ensure stack pointer is aligned")
tried to align the stack pointer in show_trace_log_lvl(), otherwise the
"stack < stack_info.end" check can't guarantee that the last read does
not go past the end of the stack.
However, we have the same problem with the initial value of the stack
pointer, it can also be unaligned. So without this patch this trivial
kernel module
#include <linux/module.h>
static int init(void)
{
asm volatile("sub $0x4,%rsp");
dump_stack();
asm volatile("add $0x4,%rsp");
return -EAGAIN;
}
module_init(init);
MODULE_LICENSE("GPL");
crashes the kernel.
Fixes: e335bb51cc15 ("x86/unwind: Ensure stack pointer is aligned")
Signed-off-by: Vernon Lovejoy <vlovejoy@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20230512104232.GA10227@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
After commit b752ea0c28e3 ("perf/x86/intel/ds: Flush PEBS DS when changing
PEBS_DATA_CFG"), the cpuc->pebs_data_cfg may save some bits that are not
supported by real hardware, such as PEBS_UPDATE_DS_SW. This would cause
the VMX hardware MSR switching mechanism to save/restore invalid values
for PEBS_DATA_CFG MSR, thus crashing the host when PEBS is used for guest.
Fix it by using the active host value from cpuc->active_pebs_data_cfg.
Fixes: b752ea0c28e3 ("perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG")
Signed-off-by: Like Xu <likexu@tencent.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230517133808.67885-1-likexu@tencent.com
Enable k10temp on this system.
[ bp: Massage. ]
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230427053338.16653-3-mario.limonciello@amd.com
Pull irq fixes from Thomas Gleixner:
"A set of fixes for interrupt chip drivers:
- Prevent loss of state in the MIPS GIC interrupt controller
- Disable pseudo NMIs on Mediatek based Chromebooks as they have
firmware issues which cause instantenous chrashes and freezes wen
pseudo NMIs are used
- Fix the error handling path in the MBIGEN driver and a defined but
not used warning in the meson-gpio interrupt chip driver"
* tag 'irq-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/mbigen: Unify the error handling in mbigen_of_create_domain()
irqchip/meson-gpio: Mark OF related data as maybe unused
irqchip/mips-gic: Use raw spinlock for gic_lock
irqchip/mips-gic: Don't touch vl_map if a local interrupt is not routable
irqchip/gic-v3: Disable pseudo NMIs on Mediatek devices w/ firmware issues
dt-bindings: interrupt-controller: arm,gic-v3: Add quirk for Mediatek SoCs w/ broken FW
syzbot is reporting a lockdep warning in fill_pool() because the allocation
from debugobjects is using GFP_ATOMIC, which is (__GFP_HIGH | __GFP_KSWAPD_RECLAIM)
and therefore tries to wake up kswapd, which acquires kswapd_wait::lock.
Since fill_pool() might be called with arbitrary locks held, fill_pool()
should not assume that acquiring kswapd_wait::lock is safe.
Use __GFP_HIGH instead and remove __GFP_NORETRY as it is pointless for
!__GFP_DIRECT_RECLAIM allocation.
Fixes: 3ac7fe5a4aab ("infrastructure to debug (dynamic) objects")
Reported-by: syzbot <syzbot+fe0c72f0ccbb93786380@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/6577e1fa-b6ee-f2be-2414-a2b51b1c5e30@I-love.SAKURA.ne.jp
Closes: https://syzkaller.appspot.com/bug?extid=fe0c72f0ccbb93786380
When tooling reads ELF notes, it assumes each note entry is aligned to
the value listed in the .note section header's sh_addralign field.
The kernel-created ELF notes in the .note.Linux and .note.Xen sections
are aligned to 4 bytes. This causes the toolchain to set those
sections' sh_addralign values to 4.
On the other hand, the GCC-created .note.gnu.property section has an
sh_addralign value of 8 for some reason, despite being based on struct
Elf32_Nhdr which only needs 4-byte alignment.
When the mismatched input sections get linked together into the vmlinux
.notes output section, the higher alignment "wins", resulting in an
sh_addralign of 8, which confuses tooling. For example:
$ readelf -n .tmp_vmlinux.btf
...
readelf: .tmp_vmlinux.btf: Warning: note with invalid namesz and/or descsz found at offset 0x170
readelf: .tmp_vmlinux.btf: Warning: type: 0x4, namesize: 0x006e6558, descsize: 0x00008801, alignment: 8
In this case readelf thinks there's alignment padding where there is
none, so it starts reading an ELF note in the middle.
With newer toolchains (e.g., latest Fedora Rawhide), a similar mismatch
triggers a build failure when combined with CONFIG_X86_KERNEL_IBT:
btf_encoder__encode: btf__dedup failed!
Failed to encode BTF
libbpf: failed to find '.BTF' ELF section in vmlinux
FAILED: load BTF from vmlinux: No data available
make[1]: *** [scripts/Makefile.vmlinux:35: vmlinux] Error 255
This latter error was caused by pahole crashing when it encountered the
corrupt .notes section. This crash has been fixed in dwarves version
1.25. As Tianyi Liu describes:
"Pahole reads .notes to look for LINUX_ELFNOTE_BUILD_LTO. When LTO is
enabled, pahole needs to call cus__merge_and_process_cu to merge
compile units, at which point there should only be one unspecified
type (used to represent some compilation information) in the global
context.
However, when the kernel is compiled without LTO, if pahole calls
cus__merge_and_process_cu due to alignment issues with notes,
multiple unspecified types may appear after merging the cus, and
older versions of pahole only support up to one. This is why pahole
1.24 crashes, while newer versions support multiple. However, the
latest version of pahole still does not solve the problem of
incorrect LTO recognition, so compiling the kernel may be slower
than normal."
Even with the newer pahole, the note section misaligment issue still
exists and pahole is misinterpreting the LTO note. Fix it by discarding
the .note.gnu.property section. While GNU properties are important for
user space (and VDSO), they don't seem to have any use for vmlinux.
(In fact, they're already getting (inadvertently) stripped from vmlinux
when CONFIG_DEBUG_INFO_BTF is enabled. The BTF data is extracted from
vmlinux.o with "objcopy --only-section=.BTF" into .btf.vmlinux.bin.o.
That file doesn't have .note.gnu.property, so when it gets modified and
linked back into the main object, the linker automatically strips it
(see "How GNU properties are merged" in the ld man page).)
Reported-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lkml.kernel.org/bpf/57830c30-cd77-40cf-9cd1-3bb608aa602e@app.fastmail.com
Debugged-by: Tianyi Liu <i.pear@outlook.com>
Suggested-by: Joan Bruguera Micó <joanbrugueram@gmail.com>
Link: https://lore.kernel.org/r/20230418214925.ay3jpf2zhw75kgmd@treble
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Commit
310e782a99c7 ("platform/x86/amd: pmc: Utilize SMN index 0 for driver probe")
switched to using amd_smn_read() which relies upon the misc PCI ID used
by DF function 3 being included in a table. The ID for model 78h is
missing in that table, so amd_smn_read() doesn't work.
Add the missing ID into amd_nb, restoring s2idle on this system.
[ bp: Simplify commit message. ]
Fixes: 310e782a99c7 ("platform/x86/amd: pmc: Utilize SMN index 0 for driver probe")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci_ids.h
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230427053338.16653-2-mario.limonciello@amd.com
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