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Commit f3e48e54 authored by Joerg Roedel's avatar Joerg Roedel Committed by Thomas Gleixner
Browse files

x86/ldt: Reserve address-space range on 32 bit for the LDT 



Reserve 2MB/4MB of address-space for mapping the LDT to user-space on 32
bit PTI kernels.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarPavel Machek <pavel@ucw.cz>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1531906876-13451-34-git-send-email-joro@8bytes.org
parent f59dbe9c

arch/x86/include/asm/pgtable_32_types.h

+5 −2
Original line number Diff line number Diff line
@@ -50,13 +50,16 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */ 
	((FIXADDR_TOT_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1))   \

	 & PMD_MASK)



#define PKMAP_BASE		\

#define LDT_BASE_ADDR		\

	((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK)



#define PKMAP_BASE		\

	((LDT_BASE_ADDR - PAGE_SIZE) & PMD_MASK)



#ifdef CONFIG_HIGHMEM

# define VMALLOC_END	(PKMAP_BASE - 2 * PAGE_SIZE)

#else

# define VMALLOC_END	(CPU_ENTRY_AREA_BASE - 2 * PAGE_SIZE)

# define VMALLOC_END	(LDT_BASE_ADDR - 2 * PAGE_SIZE)

#endif



#define MODULES_VADDR	VMALLOC_START

arch/x86/mm/dump_pagetables.c

+9 −0
Original line number Diff line number Diff line
@@ -122,6 +122,9 @@ enum address_markers_idx { 
	VMALLOC_END_NR,

#ifdef CONFIG_HIGHMEM

	PKMAP_BASE_NR,

#endif

#ifdef CONFIG_MODIFY_LDT_SYSCALL

	LDT_NR,

#endif

	CPU_ENTRY_AREA_NR,

	FIXADDR_START_NR,
@@ -135,6 +138,9 @@ static struct addr_marker address_markers[] = { 
	[VMALLOC_END_NR]	= { 0UL,		"vmalloc() End" },

#ifdef CONFIG_HIGHMEM

	[PKMAP_BASE_NR]		= { 0UL,		"Persistent kmap() Area" },

#endif

#ifdef CONFIG_MODIFY_LDT_SYSCALL

	[LDT_NR]		= { 0UL,		"LDT remap" },

#endif

	[CPU_ENTRY_AREA_NR]	= { 0UL,		"CPU entry area" },

	[FIXADDR_START_NR]	= { 0UL,		"Fixmap area" },
@@ -609,6 +615,9 @@ static int __init pt_dump_init(void) 
# endif

	address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;

	address_markers[CPU_ENTRY_AREA_NR].start_address = CPU_ENTRY_AREA_BASE;

# ifdef CONFIG_MODIFY_LDT_SYSCALL

	address_markers[LDT_NR].start_address = LDT_BASE_ADDR;

# endif

#endif

	return 0;

}