Commit a02d8dfd authored by Russell King's avatar Russell King
Browse files

ARM: domains: keep vectors in separate domain 



Keep the machine vectors in its own domain to avoid software based
user access control from making the vector code inaccessible, and
thereby deadlocking the machine.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 3c2aed5b

arch/arm/include/asm/domain.h

+3 −1
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#define DOMAIN_USER	1

#define DOMAIN_IO	0

#endif

#define DOMAIN_VECTORS	3



/*

 * Domain types
@@ -62,7 +63,8 @@ 
	(domain_val(DOMAIN_USER, DOMAIN_CLIENT) | \

	 domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \

	 domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \

	 domain_val(DOMAIN_IO, DOMAIN_CLIENT))

	 domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \

	 domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT))



#ifndef __ASSEMBLY__

arch/arm/include/asm/pgtable-2level-hwdef.h

+1 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#define PMD_PXNTABLE		(_AT(pmdval_t, 1) << 2)     /* v7 */

#define PMD_BIT4		(_AT(pmdval_t, 1) << 4)

#define PMD_DOMAIN(x)		(_AT(pmdval_t, (x)) << 5)

#define PMD_DOMAIN_MASK		PMD_DOMAIN(0x0f)

#define PMD_PROTECTION		(_AT(pmdval_t, 1) << 9)		/* v5 */

/*

 *   - section

arch/arm/mm/mmu.c

+2 −2
Original line number Diff line number Diff line
@@ -291,13 +291,13 @@ static struct mem_type mem_types[] = { 
		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |

				L_PTE_RDONLY,

		.prot_l1   = PMD_TYPE_TABLE,

		.domain    = DOMAIN_USER,

		.domain    = DOMAIN_VECTORS,

	},

	[MT_HIGH_VECTORS] = {

		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |

				L_PTE_USER | L_PTE_RDONLY,

		.prot_l1   = PMD_TYPE_TABLE,

		.domain    = DOMAIN_USER,

		.domain    = DOMAIN_VECTORS,

	},

	[MT_MEMORY_RWX] = {

		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,

arch/arm/mm/pgd.c

+10 −0
Original line number Diff line number Diff line
@@ -84,6 +84,16 @@ pgd_t *pgd_alloc(struct mm_struct *mm) 
		if (!new_pte)

			goto no_pte;



#ifndef CONFIG_ARM_LPAE

		/*

		 * Modify the PTE pointer to have the correct domain.  This

		 * needs to be the vectors domain to avoid the low vectors

		 * being unmapped.

		 */

		pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK;

		pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);

#endif



		init_pud = pud_offset(init_pgd, 0);

		init_pmd = pmd_offset(init_pud, 0);

		init_pte = pte_offset_map(init_pmd, 0);