Commit c23719ab authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-urgent-2026-03-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 fixes from Ingo Molnar:

 - Fix SEV guest boot failures in certain circumstances, due to
   very early code relying on a BSS-zeroed variable that isn't
   actually zeroed yet an may contain non-zero bootup values

   Move the variable into the .data section go gain even earlier
   zeroing

 - Expose & allow the IBPB-on-Entry feature on SNP guests, which
   was not properly exposed to guests due to initial implementational
   caution

 - Fix O= build failure when CONFIG_EFI_SBAT_FILE is using relative
   file paths

 - Fix the various SNC (Sub-NUMA Clustering) topology enumeration
   bugs/artifacts (sched-domain build errors mostly).

   SNC enumeration data got more complicated with Granite Rapids X
   (GNR) and Clearwater Forest X (CWF), which exposed these bugs
   and made their effects more serious

 - Also use the now sane(r) SNC code to fix resctrl SNC detection bugs

 - Work around a historic libgcc unwinder bug in the vdso32 sigreturn
   code (again), which regressed during an overly aggressive recent
   cleanup of DWARF annotations

* tag 'x86-urgent-2026-03-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/vdso32: Work around libgcc unwinder bug
  x86/resctrl: Fix SNC detection
  x86/topo: Fix SNC topology mess
  x86/topo: Replace x86_has_numa_in_package
  x86/topo: Add topology_num_nodes_per_package()
  x86/numa: Store extra copy of numa_nodes_parsed
  x86/boot: Handle relative CONFIG_EFI_SBAT_FILE file paths
  x86/sev: Allow IBPB-on-Entry feature for SNP guests
  x86/boot/sev: Move SEV decompressor variables into the .data section
parents 6ff1020c b5ef09a7

arch/x86/boot/compressed/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -113,6 +113,7 @@ vmlinux-objs-$(CONFIG_EFI_SBAT) += $(obj)/sbat.o 


ifdef CONFIG_EFI_SBAT

$(obj)/sbat.o: $(CONFIG_EFI_SBAT_FILE)

AFLAGS_sbat.o += -I $(srctree)

endif



$(obj)/vmlinux: $(vmlinux-objs-y) $(vmlinux-libs-y) FORCE

arch/x86/boot/compressed/sev.c

+5 −4
Original line number Diff line number Diff line
@@ -28,17 +28,17 @@ 
#include "sev.h"



static struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);

struct ghcb *boot_ghcb;

struct ghcb *boot_ghcb __section(".data");



#undef __init

#define __init



#define __BOOT_COMPRESSED



u8 snp_vmpl;

u16 ghcb_version;

u8 snp_vmpl __section(".data");

u16 ghcb_version __section(".data");



u64 boot_svsm_caa_pa;

u64 boot_svsm_caa_pa __section(".data");



/* Include code for early handlers */

#include "../../boot/startup/sev-shared.c"
@@ -188,6 +188,7 @@ bool sev_es_check_ghcb_fault(unsigned long address) 
				 MSR_AMD64_SNP_RESERVED_BIT13 |		\

				 MSR_AMD64_SNP_RESERVED_BIT15 |		\

				 MSR_AMD64_SNP_SECURE_AVIC |		\

				 MSR_AMD64_SNP_RESERVED_BITS19_22 |	\

				 MSR_AMD64_SNP_RESERVED_MASK)



#ifdef CONFIG_AMD_SECURE_AVIC

arch/x86/boot/startup/sev-shared.c

+1 −1
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ static u32 cpuid_std_range_max __ro_after_init; 
static u32 cpuid_hyp_range_max __ro_after_init;

static u32 cpuid_ext_range_max __ro_after_init;



bool sev_snp_needs_sfw;

bool sev_snp_needs_sfw __section(".data");



void __noreturn

sev_es_terminate(unsigned int set, unsigned int reason)

arch/x86/coco/sev/core.c

+1 −0
Original line number Diff line number Diff line
@@ -89,6 +89,7 @@ static const char * const sev_status_feat_names[] = { 
	[MSR_AMD64_SNP_VMSA_REG_PROT_BIT]	= "VMSARegProt",

	[MSR_AMD64_SNP_SMT_PROT_BIT]		= "SMTProt",

	[MSR_AMD64_SNP_SECURE_AVIC_BIT]		= "SecureAVIC",

	[MSR_AMD64_SNP_IBPB_ON_ENTRY_BIT]	= "IBPBOnEntry",

};



/*

arch/x86/entry/vdso/vdso32/sigreturn.S

+30 −0
Original line number Diff line number Diff line
@@ -35,9 +35,38 @@ 
#endif

.endm



/*

 * WARNING:

 *

 * A bug in the libgcc unwinder as of at least gcc 15.2 (2026) means that

 * the unwinder fails to recognize the signal frame flag.

 *

 * There is a hacky legacy fallback path in libgcc which ends up

 * getting invoked instead. It happens to work as long as BOTH of the

 * following conditions are true:

 *

 * 1. There is at least one byte before the each of the sigreturn

 *    functions which falls outside any function. This is enforced by

 *    an explicit nop instruction before the ALIGN.

 * 2. The code sequences between the entry point up to and including

 *    the int $0x80 below need to match EXACTLY. Do not change them

 *    in any way. The exact byte sequences are:

 *

 *    __kernel_sigreturn:

 *        0:   58                      pop    %eax

 *        1:   b8 77 00 00 00          mov    $0x77,%eax

 *        6:   cd 80                   int    $0x80

 *

 *    __kernel_rt_sigreturn:

 *        0:   b8 ad 00 00 00          mov    $0xad,%eax

 *        5:   cd 80                   int    $0x80

 *

 * For details, see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124050

 */

	.text

	.globl __kernel_sigreturn

	.type __kernel_sigreturn,@function

	nop			/* libgcc hack: see comment above */

	ALIGN

__kernel_sigreturn:

	STARTPROC_SIGNAL_FRAME IA32_SIGFRAME_sigcontext
@@ -52,6 +81,7 @@ SYM_INNER_LABEL(vdso32_sigreturn_landing_pad, SYM_L_GLOBAL) 


	.globl __kernel_rt_sigreturn

	.type __kernel_rt_sigreturn,@function

	nop			/* libgcc hack: see comment above */

	ALIGN

__kernel_rt_sigreturn:

	STARTPROC_SIGNAL_FRAME IA32_RT_SIGFRAME_sigcontext