linux/arch/x86/kernel, branch master

Merge tag 'x86-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-05-17T18:40:18Z

Pull x86 fix from Ingo Molnar: - Fix x86 boot crash for non-kjump kexecs (David Woodhouse) * tag 'x86-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kexec: Push kjump return address even for non-kjump kexec

Merge tag 'ras-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-05-17T17:50:13Z

Pull MCE fix from Ingo Molnar: - Fix an MCE polling interval adjustment regression (Borislav Petkov) * tag 'ras-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Restore MCA polling interval halving

Merge tag 'acpi-7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2026-05-14T21:06:31Z

Pull ACPI support fixes from Rafael Wysocki: "These fix several platform drivers that use the ACPI companion of the given platform device without checking its presence, which may lead to a NULL pointer dereference or other kind of malfunction if the driver is forced to match a device without an ACPI companion via driver override, and restore debug log level for some messages in the ACPI CPPC library: - Check ACPI_COMPANION() against NULL during probe in several core ACPI device drivers (Rafael Wysocki) - Restore log level of messages in amd_set_max_freq_ratio() (Mario Limonciello)" * tag 'acpi-7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: PAD: xen: Check ACPI_COMPANION() against NULL ACPI: driver: Check ACPI_COMPANION() against NULL during probe Revert "ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"

Merge branch 'acpi-cppc'

2026-05-14T20:46:33Z

Merge a revert of an ACPI CPPC commit that increased the log level of some debug messages which turned out to be a bad idea: - Restore log level of messages in amd_set_max_freq_ratio() (Mario Limonciello) * acpi-cppc: Revert "ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"

x86/mce: Restore MCA polling interval halving

2026-05-13T15:38:35Z

RongQing reported that the MCA polling interval doesn't halve when an error gets logged. It was traced down to the commit in Fixes:, because: mce_timer_fn() |-> mce_poll_banks() |-> machine_check_poll() |-> mce_log() which will queue the work and return. Now, back in mce_timer_fn(): /* * Alert userspace if needed. If we logged an MCE, reduce the polling * interval, otherwise increase the polling interval. */ if (mce_notify_irq()) <--- here we haven't ran the notifier chain yet so mce_need_notify is not set yet so this won't hit and we won't halve the interval iv. Now the notifier chain runs. mce_early_notifier() sets the bit, does mce_notify_irq(), that clears the bit and then the notifier chain a little later logs the error. So this is a silly timing issue. But, that's all unnecessary. All it needs to happen here is, the "should we notify of a logged MCE" mce_notify_irq() asks, should be simply a question to the mce gen pool: "Are you empty?" And that then turns into a simple yes or no answer and it all JustWorks(tm). So do that and also distribute the functionality where it belongs: - Print that MCE events have been logged in mce_log() - Trigger the mcelog tool specific work in the first notifier As a result, mce_notify_irq() can go now. Fixes: 011d82611172 ("RAS: Add a Corrected Errors Collector") Reported-by: Li RongQing Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Qiuxu Zhuo Tested-by: Qiuxu Zhuo Link: https://lore.kernel.org/r/20260112082747.2842-1-lirongqing@baidu.com

x86/CPU/AMD: Prevent improper isolation of shared resources in Zen2's op cache

2026-05-12T03:06:36Z

Make sure resources are not improperly shared in the op cache and cause instruction corruption this way. Signed-off-by: Prathyushi Nangia Co-developed-by: Borislav Petkov (AMD) Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds

Revert "ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"

2026-05-08T19:14:19Z

Some older systems don't support CPPC in the firmware and this just makes noise for them when booting. Drop back to debug. This reverts commit 21fb59ab4b9767085f4fe1edbdbe3177fbb9ec97. Fixes: 21fb59ab4b976 ("ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn") Suggested-by: Kim Phillips Signed-off-by: Mario Limonciello Tested-by: Kim Phillips Cc: All applicable Link: https://patch.msgid.link/20260504230141.484743-2-mario.limonciello@amd.com Signed-off-by: Rafael J. Wysocki

x86/kexec: Push kjump return address even for non-kjump kexec

2026-05-08T15:00:12Z

The version of purgatory code shipped by kexec-tools attempts to look above the top of its stack to find a return address for a kjump, even in a non-kjump kexec. After the commit in Fixes: the word above the stack might not be there, leading to a fault (which is at least now caught by my exception-handling code in kexec). That commit fixed things for the actual kjump path, but no longer "gratuitously" pushes the unused return address to the stack in the non-kjump path. Put that *back* in the non-kjump path, to prevent purgatory from crashing when trying to access it. Fixes: 2cacf7f23a02 ("x86/kexec: Fix stack and handling of re-entry point for ::preserve_context") Reported-by: Rohan Kakulawaram Signed-off-by: David Woodhouse Signed-off-by: Borislav Petkov (AMD) Acked-by: Dave Hansen Tested-by: Rohan Kakulawaram Cc: Link: https://patch.msgid.link/32d627134143ffd957891cb697138e839c623211.camel@infradead.org

x86/boot/e820: Re-enable BIOS fallback if e820 table is empty

2026-05-07T08:04:54Z

In commit: 157266edcc56 ("x86/boot/e820: Simplify append_e820_table() and remove restriction on single-entry tables") the check on the number of entries in the e820 table was removed. The intention was to support single-entry maps, but by removing the check entirely, we also skip the fallback (to, e.g., the BIOS 88h function). This means that if no E820 map is passed in from the bootloader (which is the case on some bootloaders, like linld), we end up with an empty memory map, and the kernel fails to boot (either by deadlocking on OOM, or by failing to allocate the real mode trampoline, or similar). Re-instate the check in append_e820_table(), but only check that nr_entries is non-zero. This allows e820__memory_setup_default() to fall back to other memory size sources, and doesn't affect e820__memory_setup_extended(), as the latter ignores the return value from append_e820_table(). In doing so, we also update the return values to be proper error codes, with -ENOENT for this case (there are no entries), and -EINVAL for the case where an entry appears invalid. Given none of the callers check the actual value -- just whether it's nonzero -- this is largely aesthetic in practice. Tested against linld, and the kernel boots again fine. [ mingo: Readability edits to the comment and the changelog. ] Fixes: 157266edcc56 ("x86/boot/e820: Simplify append_e820_table() and remove restriction on single-entry tables") Signed-off-by: David Gow Signed-off-by: Ingo Molnar Reviewed-by: Andy Shevchenko Cc: stable@vger.kernel.org Cc: Arnd Bergmann Cc: "H. Peter Anvin" Link: https://patch.msgid.link/20260416065746.1896647-1-david@davidgow.net

Merge tag 'x86-urgent-2026-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-04-24T17:05:42Z

Pull x86 fixes from Ingo Molnar: - Prevent deadlock during shstk sigreturn (Rick Edgecombe) - Disable FRED when PTI is forced on (Dave Hansen) - Revert a CPA INVLPGB optimization that did not properly handle discontiguous virtual addresses (Dave Hansen) * tag 'x86-urgent-2026-04-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Revert INVLPGB optimization for set_memory code x86/cpu: Disable FRED when PTI is forced on x86/shstk: Prevent deadlock during shstk sigreturn