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linux/arch/x86/kernel
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Li RongQing d4932a1b14 x86/bugs: Fix GDS mitigation selecting when mitigation is off 
The current GDS mitigation logic incorrectly returns early when the
attack vector mitigation is turned off, which leads to two problems:

1. CPUs without ARCH_CAP_GDS_CTRL support are incorrectly marked with
   GDS_MITIGATION_OFF when they should be marked as
   GDS_MITIGATION_UCODE_NEEDED.

2. The mitigation state checks and locking verification that follow are
   skipped, which means:
   - fail to detect if the mitigation was locked
   - miss the warning when trying to disable a locked mitigation

Remove the early return to ensure proper mitigation state handling. This
allows:
- Proper mitigation classification for non-ARCH_CAP_GDS_CTRL CPUs
- Complete mitigation state verification

This also addresses the failed MSR 0x123 write attempt at boot on
non-ARCH_CAP_GDS_CTRL CPUs:

  unchecked MSR access error: WRMSR to 0x123 (tried to write 0x0000000000000010) at rIP: ... (update_gds_msr)
  Call Trace:
   identify_secondary_cpu
   start_secondary
   common_startup_64
   WARNING: CPU: 1 PID: 0 at arch/x86/kernel/cpu/bugs.c:1053 update_gds_msr

  [ bp: Massage, zap superfluous braces. ]

Fixes: 8c7261abcb ("x86/bugs: Add attack vector controls for GDS")
Suggested-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Link: https://lore.kernel.org/20250819023356.2012-1-lirongqing@baidu.com
 		2025-08-19 10:38:04 +02:00
..
acpi hyperv-next for v6.16 2025-06-03 08:39:20 -07:00
apic x86/apic: Move apic_update_irq_cfg() call to apic_update_vector() 2025-07-15 11:54:09 +02:00
cpu x86/bugs: Fix GDS mitigation selecting when mitigation is off 2025-08-19 10:38:04 +02:00
fpu x86/fpu: Fix NULL dereference in avx512_status() 2025-08-11 13:28:07 -07:00
kprobes x86/kprobes: enable EXECMEM_ROX_CACHE for kprobes allocations 2025-08-02 12:06:12 -07:00
.gitignore
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Makefile Kbuild updates for v6.16 2025-06-07 10:05:35 -07:00
alternative.c Significant patch series in this pull request: 2025-08-05 16:02:07 +03:00
amd_gart_64.c x86/platform/amd: Move the <asm/amd_nb.h> header to <asm/amd/nb.h> 2025-04-14 09:34:14 +02:00
amd_nb.c x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID header 2025-05-15 18:23:55 +02:00
amd_node.c x86/platform/amd: Move the <asm/amd_node.h> header to <asm/amd/node.h> 2025-04-14 09:34:17 +02:00
aperture_64.c x86/platform/amd: Move the <asm/amd_nb.h> header to <asm/amd/nb.h> 2025-04-14 09:34:14 +02:00
apm_32.c
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asm-offsets.c x86/asm-offsets: Export certain 'struct cpuinfo_x86' fields for 64-bit asm use too 2025-05-15 09:12:07 +02:00
asm-offsets_32.c x86/asm-offsets: Export certain 'struct cpuinfo_x86' fields for 64-bit asm use too 2025-05-15 09:12:07 +02:00
asm-offsets_64.c
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audit_64.c
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bootflag.c
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callthunks.c x86/alternatives: Rename 'apply_relocation()' to 'text_poke_apply_relocation()' 2025-04-11 11:01:35 +02:00
cet.c x86/msr: Add explicit includes of <asm/msr.h> 2025-05-02 10:23:47 +02:00
cfi.c
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check.c
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cpuid.c
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crash.c x86: implement crashkernel cma reservation 2025-07-19 19:08:23 -07:00
crash_dump_32.c
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crash_dump_64.c
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devicetree.c
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doublefault_32.c
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dumpstack.c x86/nmi: Consolidate NMI panic variables 2025-04-01 22:25:56 +02:00
dumpstack_32.c
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dumpstack_64.c
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e820.c x86/e820: temporarily enable KHO scratch for memory below 1M 2025-05-12 23:50:41 -07:00
early-quirks.c
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early_printk.c Linux 6.15-rc4 2025-05-06 12:03:03 +02:00
ebda.c
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eisa.c
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espfix_64.c
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fred.c x86/msr: Add explicit includes of <asm/msr.h> 2025-05-02 10:23:47 +02:00
ftrace.c x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations 2025-08-02 12:06:12 -07:00
ftrace_32.S
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ftrace_64.S
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head32.c x86/microcode: Consolidate the loader enablement checking 2025-05-05 10:51:00 +02:00
head64.c x86/mm/64: Make 5-level paging support unconditional 2025-05-17 10:38:16 +02:00
head_32.S x86/asm: Remove semicolon from "rep" prefixes 2025-04-18 09:33:33 +02:00
head_64.S x86/mm/64: Make 5-level paging support unconditional 2025-05-17 10:38:16 +02:00
hpet.c x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID header 2025-05-15 18:23:55 +02:00
hw_breakpoint.c
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i8237.c
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i8253.c x86/i8253: Call clockevent_i8253_disable() with interrupts disabled 2025-04-11 07:28:20 +02:00
i8259.c
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ibt_selftest.S
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idt.c
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io_delay.c
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ioport.c x86/iopl: Cure TIF_IO_BITMAP inconsistencies 2025-06-03 15:56:39 +02:00
irq.c x86/irq: Plug vector setup race 2025-08-04 23:34:03 +02:00
irq_32.c
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irq_64.c
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irq_work.c
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irqflags.S
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irqinit.c
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itmt.c x86/itmt: Add debugfs file to show core priorities 2025-07-07 22:35:51 +02:00
jailhouse.c x86/cpuid: Rename hypervisor_cpuid_base()/for_each_possible_hypervisor_cpuid_base() to cpuid_base_hypervisor()/for_each_possible_cpuid_base_hypervisor() 2025-05-16 10:54:47 +02:00
jump_label.c x86/alternatives: Rename 'text_poke_queue()' to 'smp_text_poke_batch_add()' 2025-04-11 11:01:33 +02:00
kdebugfs.c
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kexec-bzimage64.c - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
kgdb.c x86/traps: Initialize DR7 by writing its architectural reset value 2025-06-24 13:15:52 -07:00
ksysfs.c sysfs: treewide: switch back to attribute_group::bin_attrs 2025-06-17 10:44:15 +02:00
kvm.c x86: Handle KCOV __init vs inline mismatches 2025-07-24 16:55:11 -07:00
kvmclock.c x86/pvops/msr: Refactor pv_cpu_ops.write_msr{,_safe}() 2025-05-02 10:36:36 +02:00
ldt.c
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machine_kexec_32.c x86/mm: Fix _pgd_alloc() for Xen PV mode 2025-04-23 07:49:14 -07:00
machine_kexec_64.c - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
mmconf-fam10h_64.c x86/msr: Rename 'wrmsrl()' to 'wrmsrq()' 2025-04-10 11:58:33 +02:00
module.c Merge commit 'its-for-linus-20250509-merge' into x86/core, to resolve conflicts 2025-05-13 10:47:10 +02:00
mpparse.c
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msr.c
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nmi.c x86/nmi: Improve NMI duration console printouts 2025-04-01 22:26:38 +02:00
nmi_selftest.c x86/nmi: Clean up NMI selftest 2025-04-01 22:26:32 +02:00
paravirt-spinlocks.c
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paravirt.c x86/paravirt: Restrict PARAVIRT_XXL to 64-bit only 2025-05-17 10:38:29 +02:00
pci-dma.c
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pcspeaker.c
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perf_regs.c
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platform-quirks.c
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pmem.c
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probe_roms.c
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process.c Linux 6.16 2025-07-28 07:17:38 +02:00
process.h
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process_32.c x86/traps: Initialize DR7 by writing its architectural reset value 2025-06-24 13:15:52 -07:00
process_64.c x86/process: Clear hardware feedback history for AMD processors 2025-07-07 22:30:36 +02:00
ptrace.c x86/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names 2025-07-14 22:27:48 -07:00
pvclock.c
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quirks.c
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reboot.c
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reboot_fixups_32.c x86/msr: Rename 'wrmsrl()' to 'wrmsrq()' 2025-04-10 11:58:33 +02:00
relocate_kernel_32.S x86/asm: Remove semicolon from "rep" prefixes 2025-04-18 09:33:33 +02:00
relocate_kernel_64.S x86/asm: Replace "REP; NOP" with PAUSE mnemonic 2025-04-18 10:19:25 +02:00
resource.c
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rethook.c
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rtc.c
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setup.c Significant patch series in this pull request: 2025-08-03 16:23:09 -07:00
setup_percpu.c
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sev_verify_cbit.S
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shstk.c x86/msr: Rename 'wrmsrl()' to 'wrmsrq()' 2025-04-10 11:58:33 +02:00
signal.c x86/fpu: Convert task_struct::thread.fpu accesses to use x86_task_fpu() 2025-04-14 08:18:29 +02:00
signal_32.c x86/fred/signal: Prevent immediate repeat of single step trap on return from SIGTRAP handler 2025-06-09 08:50:58 -07:00
signal_64.c x86/fred/signal: Prevent immediate repeat of single step trap on return from SIGTRAP handler 2025-06-09 08:50:58 -07:00
smp.c x86/smp: PM/hibernate: Split arch_resume_nosmt() 2025-06-07 14:22:56 +02:00
smpboot.c Merge branch 'tip/sched/urgent' 2025-07-14 17:16:28 +02:00
stacktrace.c
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static_call.c Merge commit 'its-for-linus-20250509-merge' into x86/core, to resolve conflicts 2025-05-13 10:47:10 +02:00
step.c
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sys_ia32.c
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sys_x86_64.c
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tboot.c
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time.c
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tls.c
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tls.h
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trace.c
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trace_clock.c x86/msr: Add explicit includes of <asm/msr.h> 2025-05-02 10:23:47 +02:00
traps.c x86/traps: Initialize DR6 by writing its architectural reset value 2025-06-24 13:15:51 -07:00
tsc.c x86/cpuid: Set <asm/cpuid/api.h> as the main CPUID header 2025-05-15 18:23:55 +02:00
tsc_msr.c
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tsc_sync.c x86/msr: Add explicit includes of <asm/msr.h> 2025-05-02 10:23:47 +02:00
umip.c
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unwind_frame.c
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unwind_guess.c
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unwind_orc.c
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uprobes.c uprobes/x86: Add support to emulate NOP instructions 2025-04-18 09:03:05 +02:00
verify_cpu.S x86/cpufeatures: Generate the <asm/cpufeaturemasks.h> header based on build config 2025-03-19 11:15:11 +01:00
vm86_32.c
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vmcore_info_32.c
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vmcore_info_64.c
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vmlinux.lds.S Merge commit 'its-for-linus-20250509-merge' into x86/core, to resolve conflicts 2025-05-13 10:47:10 +02:00
vsmp_64.c
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x86_init.c
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