Commit 06b31bdb authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull misc x86 fixes from Ingo Molnar:

 - Fix 32-bit kernel boot crash if passed physical memory with more than
   32 address bits

 - Fix Xen PV crash

 - Work around build bug in certain limited build environments

 - Fix CTEST instruction decoding in insn_decoder_test

* tag 'x86-urgent-2025-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/insn: Fix CTEST instruction decoding
  x86/boot: Work around broken busybox 'truncate' tool
  x86/mm: Fix _pgd_alloc() for Xen PV mode
  x86/e820: Discard high memory that can't be addressed by 32-bit systems
parents 3d23ef05 85fd85bc

arch/x86/boot/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -59,7 +59,7 @@ KBUILD_CFLAGS += $(CONFIG_CC_IMPLICIT_FALLTHROUGH) 
$(obj)/bzImage: asflags-y  := $(SVGA_MODE)



quiet_cmd_image = BUILD   $@

      cmd_image = cp $< $@; truncate -s %4K $@; cat $(obj)/vmlinux.bin >>$@

      cmd_image = (dd if=$< bs=4k conv=sync status=none; cat $(filter-out $<,$(real-prereqs))) >$@



$(obj)/bzImage: $(obj)/setup.bin $(obj)/vmlinux.bin FORCE

	$(call if_changed,image)

arch/x86/include/asm/pgalloc.h

+11 −8
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 
#include <linux/mm.h>		/* for struct page */

#include <linux/pagemap.h>



#include <asm/cpufeature.h>



#define __HAVE_ARCH_PTE_ALLOC_ONE

#define __HAVE_ARCH_PGD_FREE

#include <asm-generic/pgalloc.h>
@@ -29,16 +31,17 @@ static inline void paravirt_release_pud(unsigned long pfn) {} 
static inline void paravirt_release_p4d(unsigned long pfn) {}

#endif



#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION

/*

 * Instead of one PGD, we acquire two PGDs.  Being order-1, it is

 * both 8k in size and 8k-aligned.  That lets us just flip bit 12

 * in a pointer to swap between the two 4k halves.

 * In case of Page Table Isolation active, we acquire two PGDs instead of one.

 * Being order-1, it is both 8k in size and 8k-aligned.  That lets us just

 * flip bit 12 in a pointer to swap between the two 4k halves.

 */

#define PGD_ALLOCATION_ORDER 1

#else

#define PGD_ALLOCATION_ORDER 0

#endif

static inline unsigned int pgd_allocation_order(void)

{

	if (cpu_feature_enabled(X86_FEATURE_PTI))

		return 1;

	return 0;

}



/*

 * Allocate and free page tables.

arch/x86/kernel/e820.c

+8 −0
Original line number Diff line number Diff line
@@ -1299,6 +1299,14 @@ void __init e820__memblock_setup(void) 
		memblock_add(entry->addr, entry->size);

	}



	/*

	 * 32-bit systems are limited to 4BG of memory even with HIGHMEM and

	 * to even less without it.

	 * Discard memory after max_pfn - the actual limit detected at runtime.

	 */

	if (IS_ENABLED(CONFIG_X86_32))

		memblock_remove(PFN_PHYS(max_pfn), -1);



	/* Throw away partial pages: */

	memblock_trim_memory(PAGE_SIZE);

arch/x86/kernel/machine_kexec_32.c

+2 −2
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static void load_segments(void) 


static void machine_kexec_free_page_tables(struct kimage *image)

{

	free_pages((unsigned long)image->arch.pgd, PGD_ALLOCATION_ORDER);

	free_pages((unsigned long)image->arch.pgd, pgd_allocation_order());

	image->arch.pgd = NULL;

#ifdef CONFIG_X86_PAE

	free_page((unsigned long)image->arch.pmd0);
@@ -59,7 +59,7 @@ static void machine_kexec_free_page_tables(struct kimage *image) 
static int machine_kexec_alloc_page_tables(struct kimage *image)

{

	image->arch.pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,

						    PGD_ALLOCATION_ORDER);

						    pgd_allocation_order());

#ifdef CONFIG_X86_PAE

	image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL);

	image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL);

arch/x86/lib/x86-opcode-map.txt

+2 −2
Original line number Diff line number Diff line
@@ -996,8 +996,8 @@ AVXcode: 4 
83: Grp1 Ev,Ib (1A),(es)

# CTESTSCC instructions are: CTESTB, CTESTBE, CTESTF, CTESTL, CTESTLE, CTESTNB, CTESTNBE, CTESTNL,

#			     CTESTNLE, CTESTNO, CTESTNS, CTESTNZ, CTESTO, CTESTS, CTESTT, CTESTZ

84: CTESTSCC (ev)

85: CTESTSCC (es) | CTESTSCC (66),(es)

84: CTESTSCC Eb,Gb (ev)

85: CTESTSCC Ev,Gv (es) | CTESTSCC Ev,Gv (66),(es)

88: POPCNT Gv,Ev (es) | POPCNT Gv,Ev (66),(es)

8f: POP2 Bq,Rq (000),(11B),(ev)

a5: SHLD Ev,Gv,CL (es) | SHLD Ev,Gv,CL (66),(es)