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authorLinus Torvalds2016-03-10 10:36:07 -0800
committerLinus Torvalds2016-03-10 10:36:07 -0800
commit2da33f9f96dabd62d6c7780cbce15818c2a6ce24 (patch)
tree156ba6512cd0a07f1a3c1dcc99991d153e19bb56 /arch
parent8e0f93cda48ed054e1216bab5c60017e1a5fc1e8 (diff)
parent3446c13b268af86391d06611327006b059b8bab1 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky: "Three bug fixes: - The fix for the page table corruption (CVE-2016-2143) - The diagnose statistics introduced a regression for the dasd diag driver - Boot crash on systems without the set-program-parameters facility" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/mm: four page table levels vs. fork s390/cpumf: Fix lpp detection s390/dasd: fix diag 0x250 inline assembly
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/include/asm/mmu_context.h16
-rw-r--r--arch/s390/include/asm/pgalloc.h24
-rw-r--r--arch/s390/kernel/head64.S2
3 files changed, 31 insertions, 11 deletions
diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index fb1b93ea3e3f..e485817f7b1a 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -15,17 +15,25 @@
static inline int init_new_context(struct task_struct *tsk,
struct mm_struct *mm)
{
+ spin_lock_init(&mm->context.list_lock);
+ INIT_LIST_HEAD(&mm->context.pgtable_list);
+ INIT_LIST_HEAD(&mm->context.gmap_list);
cpumask_clear(&mm->context.cpu_attach_mask);
atomic_set(&mm->context.attach_count, 0);
mm->context.flush_mm = 0;
- mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
- mm->context.asce_bits |= _ASCE_TYPE_REGION3;
#ifdef CONFIG_PGSTE
mm->context.alloc_pgste = page_table_allocate_pgste;
mm->context.has_pgste = 0;
mm->context.use_skey = 0;
#endif
- mm->context.asce_limit = STACK_TOP_MAX;
+ if (mm->context.asce_limit == 0) {
+ /* context created by exec, set asce limit to 4TB */
+ mm->context.asce_bits = _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS | _ASCE_TYPE_REGION3;
+ mm->context.asce_limit = STACK_TOP_MAX;
+ } else if (mm->context.asce_limit == (1UL << 31)) {
+ mm_inc_nr_pmds(mm);
+ }
crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
return 0;
}
@@ -111,8 +119,6 @@ static inline void activate_mm(struct mm_struct *prev,
static inline void arch_dup_mmap(struct mm_struct *oldmm,
struct mm_struct *mm)
{
- if (oldmm->context.asce_limit < mm->context.asce_limit)
- crst_table_downgrade(mm, oldmm->context.asce_limit);
}
static inline void arch_exit_mmap(struct mm_struct *mm)
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 7b7858f158b4..d7cc79fb6191 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -100,12 +100,26 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
- spin_lock_init(&mm->context.list_lock);
- INIT_LIST_HEAD(&mm->context.pgtable_list);
- INIT_LIST_HEAD(&mm->context.gmap_list);
- return (pgd_t *) crst_table_alloc(mm);
+ unsigned long *table = crst_table_alloc(mm);
+
+ if (!table)
+ return NULL;
+ if (mm->context.asce_limit == (1UL << 31)) {
+ /* Forking a compat process with 2 page table levels */
+ if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
+ crst_table_free(mm, table);
+ return NULL;
+ }
+ }
+ return (pgd_t *) table;
+}
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ if (mm->context.asce_limit == (1UL << 31))
+ pgtable_pmd_page_dtor(virt_to_page(pgd));
+ crst_table_free(mm, (unsigned long *) pgd);
}
-#define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd)
static inline void pmd_populate(struct mm_struct *mm,
pmd_t *pmd, pgtable_t pte)
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index c5febe84eba6..03c2b469c472 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -16,7 +16,7 @@
__HEAD
ENTRY(startup_continue)
- tm __LC_STFLE_FAC_LIST+6,0x80 # LPP available ?
+ tm __LC_STFLE_FAC_LIST+5,0x80 # LPP available ?
jz 0f
xc __LC_LPP+1(7,0),__LC_LPP+1 # clear lpp and current_pid
mvi __LC_LPP,0x80 # and set LPP_MAGIC