pm24.git/arch/x86/kernel, branch master

x86: Fix build regression with CONFIG_KEXEC_JUMP enabled

2024-12-09T18:13:28Z

Build 6.13-rc12 for x86_64 with gcc 14.2.1 fails with the error: ld: vmlinux.o: in function `virtual_mapped': linux/arch/x86/kernel/relocate_kernel_64.S:249:(.text+0x5915b): undefined reference to `saved_context_gdt_desc' when CONFIG_KEXEC_JUMP is enabled. This was introduced by commit 07fa619f2a40 ("x86/kexec: Restore GDT on return from ::preserve_context kexec") which introduced a use of saved_context_gdt_desc without a declaration for it. Fix that by including asm/asm-offsets.h where saved_context_gdt_desc is defined (indirectly in include/generated/asm-offsets.h which asm/asm-offsets.h includes). Fixes: 07fa619f2a40 ("x86/kexec: Restore GDT on return from ::preserve_context kexec") Signed-off-by: Damien Le Moal Acked-by: Borislav Petkov (AMD) Acked-by: David Woodhouse Closes: https://lore.kernel.org/oe-kbuild-all/202411270006.ZyyzpYf8-lkp@intel.com/ Signed-off-by: Linus Torvalds

x86/CPU/AMD: WARN when setting EFER.AUTOIBRS if and only if the WRMSR fails

2024-12-06T18:57:05Z

When ensuring EFER.AUTOIBRS is set, WARN only on a negative return code from msr_set_bit(), as '1' is used to indicate the WRMSR was successful ('0' indicates the MSR bit was already set). Fixes: 8cc68c9c9e92 ("x86/CPU/AMD: Make sure EFER[AIBRSE] is set") Reported-by: Nathan Chancellor Signed-off-by: Sean Christopherson Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/Z1MkNofJjt7Oq0G6@google.com Closes: https://lore.kernel.org/all/20241205220604.GA2054199@thelio-3990X

x86/cacheinfo: Delete global num_cache_leaves

2024-12-06T12:13:36Z

Linux remembers cpu_cachinfo::num_leaves per CPU, but x86 initializes all CPUs from the same global "num_cache_leaves". This is erroneous on systems such as Meteor Lake, where each CPU has a distinct num_leaves value. Delete the global "num_cache_leaves" and initialize num_leaves on each CPU. init_cache_level() no longer needs to set num_leaves. Also, it never had to set num_levels as it is unnecessary in x86. Keep checking for zero cache leaves. Such condition indicates a bug. [ bp: Cleanup. ] Signed-off-by: Ricardo Neri Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org # 6.3+ Link: https://lore.kernel.org/r/20241128002247.26726-3-ricardo.neri-calderon@linux.intel.com

x86/kexec: Restore GDT on return from ::preserve_context kexec

2024-12-06T09:35:49Z

The restore_processor_state() function explicitly states that "the asm code that gets us here will have restored a usable GDT". That wasn't true in the case of returning from a ::preserve_context kexec. Make it so. Without this, the kernel was depending on the called function to reload a GDT which is appropriate for the kernel before returning. Test program: #include #include #include #include #include #include #include #include int main (void) { struct kexec_segment segment = {}; unsigned char purgatory[] = { 0x66, 0xba, 0xf8, 0x03, // mov $0x3f8, %dx 0xb0, 0x42, // mov $0x42, %al 0xee, // outb %al, (%dx) 0xc3, // ret }; int ret; segment.buf = &purgatory; segment.bufsz = sizeof(purgatory); segment.mem = (void *)0x400000; segment.memsz = 0x1000; ret = syscall(__NR_kexec_load, 0x400000, 1, &segment, KEXEC_PRESERVE_CONTEXT); if (ret) { perror("kexec_load"); exit(1); } ret = syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, LINUX_REBOOT_CMD_KEXEC); if (ret) { perror("kexec reboot"); exit(1); } printf("Success\n"); return 0; } Signed-off-by: David Woodhouse Signed-off-by: Ingo Molnar Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20241205153343.3275139-2-dwmw2@infradead.org

x86/cpu/topology: Remove limit of CPUs due to disabled IO/APIC

2024-12-05T13:43:32Z

The rework of possible CPUs management erroneously disabled SMP when the IO/APIC is disabled either by the 'noapic' command line parameter or during IO/APIC setup. SMP is possible without IO/APIC. Remove the ioapic_is_disabled conditions from the relevant possible CPU management code paths to restore the orgininal behaviour. Fixes: 7c0edad3643f ("x86/cpu/topology: Rework possible CPU management") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241202145905.1482-1-ffmancera@riseup.net

x86/cpu: Add Lunar Lake to list of CPUs with a broken MONITOR implementation

2024-12-04T20:30:14Z

Under some conditions, MONITOR wakeups on Lunar Lake processors can be lost, resulting in significant user-visible delays. Add Lunar Lake to X86_BUG_MONITOR so that wake_up_idle_cpu() always sends an IPI, avoiding this potential delay. Reported originally here: https://bugzilla.kernel.org/show_bug.cgi?id=219364 [ dhansen: tweak subject ] Signed-off-by: Len Brown Signed-off-by: Dave Hansen Reviewed-by: Rafael J. Wysocki Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/a4aa8842a3c3bfdb7fe9807710eef159cbf0e705.1731463305.git.len.brown%40intel.com

x86/pkeys: Ensure updated PKRU value is XRSTOR'd

2024-12-02T23:25:29Z

When XSTATE_BV[i] is 0, and XRSTOR attempts to restore state component 'i' it ignores any value in the XSAVE buffer and instead restores the state component's init value. This means that if XSAVE writes XSTATE_BV[PKRU]=0 then XRSTOR will ignore the value that update_pkru_in_sigframe() writes to the XSAVE buffer. XSTATE_BV[PKRU] only gets written as 0 if PKRU is in its init state. On Intel CPUs, basically never happens because the kernel usually overwrites the init value (aside: this is why we didn't notice this bug until now). But on AMD, the init tracker is more aggressive and will track PKRU as being in its init state upon any wrpkru(0x0). Unfortunately, sig_prepare_pkru() does just that: wrpkru(0x0). This writes XSTATE_BV[PKRU]=0 which makes XRSTOR ignore the PKRU value in the sigframe. To fix this, always overwrite the sigframe XSTATE_BV with a value that has XSTATE_BV[PKRU]==1. This ensures that XRSTOR will not ignore what update_pkru_in_sigframe() wrote. The problematic sequence of events is something like this: Userspace does: * wrpkru(0xffff0000) (or whatever) * Hardware sets: XINUSE[PKRU]=1 Signal happens, kernel is entered: * sig_prepare_pkru() => wrpkru(0x00000000) * Hardware sets: XINUSE[PKRU]=0 (aggressive AMD init tracker) * XSAVE writes most of XSAVE buffer, including XSTATE_BV[PKRU]=XINUSE[PKRU]=0 * update_pkru_in_sigframe() overwrites PKRU in XSAVE buffer ... signal handling * XRSTOR sees XSTATE_BV[PKRU]==0, ignores just-written value from update_pkru_in_sigframe() Fixes: 70044df250d0 ("x86/pkeys: Update PKRU to enable all pkeys before XSAVE") Suggested-by: Rudi Horn Signed-off-by: Aruna Ramakrishna Signed-off-by: Dave Hansen Acked-by: Dave Hansen Link: https://lore.kernel.org/all/20241119174520.3987538-3-aruna.ramakrishna%40oracle.com

x86/pkeys: Change caller of update_pkru_in_sigframe()

2024-12-02T23:25:21Z

update_pkru_in_sigframe() will shortly need some information which is only available inside xsave_to_user_sigframe(). Move update_pkru_in_sigframe() inside the other function to make it easier to provide it that information. No functional changes. Signed-off-by: Aruna Ramakrishna Signed-off-by: Dave Hansen Link: https://lore.kernel.org/all/20241119174520.3987538-2-aruna.ramakrishna%40oracle.com

Merge tag 'x86_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2024-12-01T20:35:37Z

Pull x86 fixes from Borislav Petkov: - Add a terminating zero end-element to the array describing AMD CPUs affected by erratum 1386 so that the matching loop actually terminates instead of going off into the weeds - Update the boot protocol documentation to mention the fact that the preferred address to load the kernel to is considered in the relocatable kernel case too - Flush the memory buffer containing the microcode patch after applying microcode on AMD Zen1 and Zen2, to avoid unnecessary slowdowns - Make sure the PPIN CPU feature flag is cleared on all CPUs if PPIN has been disabled * tag 'x86_urgent_for_v6.13_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/CPU/AMD: Terminate the erratum_1386_microcode array x86/Documentation: Update algo in init_size description of boot protocol x86/microcode/AMD: Flush patch buffer mapping after application x86/mm: Carve out INVLPG inline asm for use by others x86/cpu: Fix PPIN initialization

Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2024-11-30T21:41:50Z

Pull Kbuild updates from Masahiro Yamada: - Add generic support for built-in boot DTB files - Enable TAB cycling for dialog buttons in nconfig - Fix issues in streamline_config.pl - Refactor Kconfig - Add support for Clang's AutoFDO (Automatic Feedback-Directed Optimization) - Add support for Clang's Propeller, a profile-guided optimization. - Change the working directory to the external module directory for M= builds - Support building external modules in a separate output directory - Enable objtool for *.mod.o and additional kernel objects - Use lz4 instead of deprecated lz4c - Work around a performance issue with "git describe" - Refactor modpost * tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits) kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms gitignore: Don't ignore 'tags' directory kbuild: add dependency from vmlinux to resolve_btfids modpost: replace tdb_hash() with hash_str() kbuild: deb-pkg: add python3:native to build dependency genksyms: reduce indentation in export_symbol() modpost: improve error messages in device_id_check() modpost: rename alias symbol for MODULE_DEVICE_TABLE() modpost: rename variables in handle_moddevtable() modpost: move strstarts() to modpost.h modpost: convert do_usb_table() to a generic handler modpost: convert do_of_table() to a generic handler modpost: convert do_pnp_device_entry() to a generic handler modpost: convert do_pnp_card_entries() to a generic handler modpost: call module_alias_printf() from all do_*_entry() functions modpost: pass (struct module *) to do_*_entry() functions modpost: remove DEF_FIELD_ADDR_VAR() macro modpost: deduplicate MODULE_ALIAS() for all drivers modpost: introduce module_alias_printf() helper modpost: remove unnecessary check in do_acpi_entry() ...