Xin Li (Intel) dc81e556f2 x86/fred: Clear WFE in missing-ENDBRANCH #CPs ... An indirect branch instruction sets the CPU indirect branch tracker (IBT) into WAIT_FOR_ENDBRANCH (WFE) state and WFE stays asserted across the instruction boundary. When the decoder finds an inappropriate instruction while WFE is set ENDBR, the CPU raises a #CP fault. For the "kernel IBT no ENDBR" selftest where #CPs are deliberately triggered, the WFE state of the interrupted context needs to be cleared to let execution continue. Otherwise when the CPU resumes from the instruction that just caused the previous #CP, another missing-ENDBRANCH #CP is raised and the CPU enters a dead loop. This is not a problem with IDT because it doesn't preserve WFE and IRET doesn't set WFE. But FRED provides space on the entry stack (in an expanded CS area) to save and restore the WFE state, thus the WFE state is no longer clobbered, so software must clear it. Clear WFE to avoid dead looping in ibt_clear_fred_wfe() and the !ibt_fatal code path when execution is allowed to continue. Clobbering WFE in any other circumstance is a security-relevant bug. [ dhansen: changelog rewording ] Fixes: a5f6c2ace9 ("x86/shstk: Add user control-protection fault handler") Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241113175934.3897541-1-xin%40zytor.com		2024-12-29 10:18:10 +01:00
..
acpi	A set of updates for the interrupt subsystem:	2024-11-19 15:54:19 -08:00
apic	A set of updates for the interrupt subsystem:	2024-11-19 15:54:19 -08:00
cpu	hyperv-fixes for v6.13-rc4	2024-12-18 09:55:55 -08:00
fpu	x86/pkeys: Ensure updated PKRU value is XRSTOR'd	2024-12-02 15:25:29 -08:00
kprobes	x86/kprobes: Cleanup kprobes on ftrace code	2024-11-07 01:16:59 +09:00
.gitignore
alternative.c	x86/module: prepare module loading for ROX allocations of text	2024-11-07 14:25:16 -08:00
amd_gart_64.c	change alloc_pages name in dma_map_ops to avoid name conflicts	2024-04-25 20:55:53 -07:00
amd_nb.c	x86/amd_nb: Add new PCI ID for AMD family 1Ah model 20h	2024-10-07 21:04:28 +02:00
aperture_64.c	x86/pci: Use PCI_HEADER_TYPE_* instead of literals	2023-12-01 15:00:43 -06:00
apm_32.c	x86/apm_32: Remove dead function apm_get_battery_status()	2024-02-21 19:38:03 +01:00
asm-offsets_32.c
asm-offsets_64.c
asm-offsets.c	x86/bugs: Rename CONFIG_CALL_DEPTH_TRACKING => CONFIG_MITIGATION_CALL_DEPTH_TRACKING	2024-01-10 10:52:28 +01:00
audit_64.c	x86/audit: Fix -Wmissing-variable-declarations warning for ia32_xyz_class	2023-08-30 10:11:16 +02:00
bootflag.c
callthunks.c	x86/xen: remove hypercall page	2024-12-17 08:23:42 +01:00
cet.c	x86/fred: Clear WFE in missing-ENDBRANCH #CPs	2024-12-29 10:18:10 +01:00
cfi.c	cfi: Flip headers	2023-12-15 16:25:55 -08:00
check.c
cpuid.c	x86/cpuid: make cpuid_class a static const structure	2023-08-05 08:31:41 +02:00
crash_dump_32.c
crash_dump_64.c
crash.c	x86/mm: Add callbacks to prepare encrypted memory for kexec	2024-06-17 17:46:02 +02:00
devicetree.c	of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify	2024-10-29 15:32:45 -05:00
doublefault_32.c	x86: Avoid missing-prototype warnings for doublefault code	2023-05-18 11:56:18 -07:00
dumpstack_32.c
dumpstack_64.c
dumpstack.c	x86/dumpstack: Use uniform "Oops: " prefix for die() messages	2024-03-27 08:45:19 +01:00
e820.c	x86/mm: Make e820__end_ram_pfn() cover E820_TYPE_ACPI ranges	2024-06-17 17:46:08 +02:00
early_printk.c
early-quirks.c	drm/intel/pciids: rename i915_pciids.h to just pciids.h	2024-10-29 16:14:04 +02:00
ebda.c
eisa.c	x86/EISA: Dereference memory directly instead of using readl()	2024-08-29 15:57:09 +02:00
espfix_64.c	x86/fred: No ESPFIX needed when FRED is enabled	2024-01-31 22:01:51 +01:00
fred.c	x86/entry: Set FRED RSP0 on return to userspace instead of context switch	2024-08-25 19:23:00 +02:00
ftrace_32.S	x86/headers: Replace #include <asm/export.h> with #include <linux/export.h>	2023-10-03 10:38:07 +02:00
ftrace_64.S	x86/headers: Replace #include <asm/export.h> with #include <linux/export.h>	2023-10-03 10:38:07 +02:00
ftrace.c	- The series "zram: optimal post-processing target selection" from	2024-11-23 09:58:07 -08:00
head32.c	x86/microcode/32: Move early loading after paging enable	2023-10-18 22:15:01 +02:00
head64.c	x86/boot/64: Strip percpu address space when setting up GDT descriptors	2024-08-25 16:07:51 +02:00
head_32.S	x86/cleanups changes for v6.10:	2024-05-13 18:21:24 -07:00
head_64.S	objtool: Detect non-relocated text references	2024-10-17 15:13:06 -07:00
hpet.c	x86/apic/msi: Use DOMAIN_BUS_GENERIC_MSI for HPET/IO-APIC domain search	2024-02-25 18:53:08 +01:00
hw_breakpoint.c	x86/amd: Cache debug register values in percpu variables	2023-01-31 20:09:26 +01:00
i8237.c
i8253.c	x86/i8253: Disable PIT timer 0 when not in use	2024-08-02 18:27:05 +02:00
i8259.c	x86/i8259: Skip probing when ACPI/MADT advertises PCAT compatibility	2023-10-27 20:36:49 +02:00
ibt_selftest.S	x86/ibt: Convert IBT selftest to asm	2023-08-17 17:07:09 +02:00
idt.c	x86/irq: Install posted MSI notification handler	2024-04-30 00:54:42 +02:00
io_delay.c
ioport.c
irq_32.c
irq_64.c	fix missing vmalloc.h includes	2024-04-25 20:55:49 -07:00
irq_work.c	x86/apic: Wrap IPI calls into helper functions	2023-08-09 12:00:55 -07:00
irq.c	x86/irq: Factor out common code for checking pending interrupts	2024-04-30 00:54:43 +02:00
irqflags.S	x86/headers: Replace #include <asm/export.h> with #include <linux/export.h>	2023-10-03 10:38:07 +02:00
irqinit.c	x86/fred: Invoke FRED initialization code to enable FRED	2024-01-31 22:03:36 +01:00
itmt.c	sysctl: treewide: constify the ctl_table argument of proc_handlers	2024-07-24 20:59:29 +02:00
jailhouse.c	xen: allow mapping ACPI data using a different physical address	2024-09-12 08:25:07 +02:00
jump_label.c
kdebugfs.c
kexec-bzimage64.c	- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames	2024-03-14 17:43:30 -07:00
kgdb.c	x86/kgdb: Fix a kerneldoc warning when build with W=1	2023-09-24 11:00:13 +02:00
ksysfs.c
kvm.c	x86/kvm: Override default caching mode for SEV-SNP and TDX	2024-10-20 07:07:02 -04:00
kvmclock.c	kvmclock: Unexport kvmclock clocksource	2024-02-07 17:05:21 +01:00
ldt.c	x86/bugs: Rename CONFIG_PAGE_TABLE_ISOLATION => CONFIG_MITIGATION_PAGE_TABLE_ISOLATION	2024-01-10 10:52:28 +01:00
machine_kexec_32.c
machine_kexec_64.c	x86/kexec: Add EFI config table identity mapping for kexec kernel	2024-08-05 16:09:31 +02:00
Makefile	x86: Ignore stack unwinding in KCOV	2024-08-08 17:36:35 +02:00
mmconf-fam10h_64.c	xen: allow mapping ACPI data using a different physical address	2024-09-12 08:25:07 +02:00
module.c	x86/module: prepare module loading for ROX allocations of text	2024-11-07 14:25:16 -08:00
mpparse.c	x86/mpparse: Cleanup apic_printk()s	2024-08-07 18:13:28 +02:00
msr.c	x86/MSR: make msr_class a static const structure	2023-08-05 08:31:42 +02:00
nmi_selftest.c	x86/apic: Wrap IPI calls into helper functions	2023-08-09 12:00:55 -07:00
nmi.c	x86/nmi: Upgrade NMI backtrace stall checks & messages	2024-03-26 10:07:59 +01:00
paravirt-spinlocks.c
paravirt.c	x86/paravirt: Fix incorrect virt spinlock setting on bare metal	2024-08-07 20:04:38 +02:00
pci-dma.c	x86: always initialize xen-swiotlb when xen-pcifront is enabling	2023-07-31 17:54:27 +02:00
pcspeaker.c
perf_regs.c
platform-quirks.c	x86/quirks: Include linux/pnp.h for arch_pnpbios_disabled()	2023-05-18 11:56:18 -07:00
pmem.c
probe_roms.c	x86/sev: Skip ROM range scans and validation for SEV-SNP guests	2024-03-26 15:22:35 +01:00
process_32.c	x86/fpu: Clean up FPU switching in the middle of task switching	2023-10-20 11:24:22 +02:00
process_64.c	x86/mm: Cleanup prctl_enable_tagged_addr() nr_bits error checking	2024-07-02 11:33:44 -07:00
process.c	x86/smp: Add smp_ops.stop_this_cpu() callback	2024-06-17 17:46:20 +02:00
process.h
ptrace.c	x86: Add PTRACE interface for shadow stack	2023-08-02 15:01:51 -07:00
pvclock.c	locking/atomic: treewide: use raw_atomic*_<op>()	2023-06-05 09:57:20 +02:00
quirks.c
reboot_fixups_32.c
reboot.c	x86/reboot: emergency callbacks are now registered by common KVM code	2024-10-06 03:55:37 -04:00
relocate_kernel_32.S
relocate_kernel_64.S	x86: Fix build regression with CONFIG_KEXEC_JUMP enabled	2024-12-09 10:13:28 -08:00
resource.c
rethook.c
rtc.c	x86/rtc: Remove unused intel-mid.h	2024-04-03 08:24:48 -07:00
setup_percpu.c	x86/asm: Add DB flag to 32-bit percpu GDT entry	2023-12-20 10:57:51 +01:00
setup.c	x86/fred: Enable FRED right after init_mem_mapping()	2024-08-13 21:59:21 +02:00
sev_verify_cbit.S	x86/boot: Use 32-bit XOR to clear registers	2024-03-01 12:47:37 +01:00
shstk.c	uprobe: Add uretprobe syscall to speed up return probe	2024-06-12 08:44:28 +09:00
signal_32.c	x86/syscall/compat: Remove ia32_unistd.h	2024-03-22 09:37:09 +01:00
signal_64.c	x86/pkeys: Restore altstack access in sigreturn()	2024-08-02 14:12:21 +02:00
signal.c	x86/pkeys: Update PKRU to enable all pkeys before XSAVE	2024-08-02 14:12:21 +02:00
smp.c	- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames	2024-03-14 17:43:30 -07:00
smpboot.c	x86/cpu: Enable SD_ASYM_PACKING for PKG domain on AMD	2024-10-25 20:43:22 +02:00
stacktrace.c
static_call.c	x86/static-call: provide a way to do very early static-call updates	2024-12-13 09:28:32 +01:00
step.c	x86/msr: Prepare for including <linux/percpu.h> into <asm/msr.h>	2024-03-04 12:01:39 +01:00
sys_ia32.c
sys_x86_64.c	arch/x86: teach arch_get_unmapped_area_vmflags to handle hugetlb mappings	2024-11-06 20:11:10 -08:00
tboot.c
time.c	x86: stop playing stack games in profile_pc()	2024-06-28 14:27:22 -07:00
tls.c	x86/gsseg: Move load_gs_index() to its own new header file	2023-01-12 13:06:36 +01:00
tls.h
trace_clock.c
trace.c
tracepoint.c
traps.c	x86/traps: move kmsan check after instrumentation_begin	2024-10-28 21:40:39 -07:00
tsc_msr.c	x86/tsc_msr: Switch to new Intel CPU model defines	2024-04-29 10:31:34 +02:00
tsc_sync.c	x86/tsc: Trust initial offset in architectural TSC-adjust MSRs	2024-04-29 23:27:16 +02:00
tsc.c	seqlock, treewide: Switch to non-raw seqcount_latch interface	2024-11-05 12:55:35 +01:00
umip.c
unwind_frame.c
unwind_guess.c
unwind_orc.c	x86/unwind/orc: Fix unwind for newly forked tasks	2024-10-17 15:13:07 -07:00
uprobes.c	uprobe: Add uretprobe syscall to speed up return probe	2024-06-12 08:44:28 +09:00
verify_cpu.S
vm86_32.c
vmcore_info_32.c	crash: split vmcoreinfo exporting code out from crash_core.c	2024-02-23 17:48:22 -08:00
vmcore_info_64.c	crash: split vmcoreinfo exporting code out from crash_core.c	2024-02-23 17:48:22 -08:00
vmlinux.lds.S	x86/xen: remove hypercall page	2024-12-17 08:23:42 +01:00
vsmp_64.c	x86/apic: Remove unused phys_pkg_id() callback	2024-02-15 22:07:38 +01:00
x86_init.c	xen: allow mapping ACPI data using a different physical address	2024-09-12 08:25:07 +02:00