1 files changed, 83 insertions, 85 deletions

diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 2e10d2b8ad35..2a222a7e14f4 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -1,24 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  flexible mmap layout support
  *
  * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
  * All Rights Reserved.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
- *
  * Started by Ingo Molnar <mingo@elte.hu>
  */
 
@@ -29,40 +15,29 @@
 #include <linux/sched/signal.h>
 #include <linux/sched/mm.h>
 #include <linux/random.h>
-#include <linux/compat.h>
 #include <linux/security.h>
-#include <asm/pgalloc.h>
+#include <linux/hugetlb.h>
 #include <asm/elf.h>
 
 static unsigned long stack_maxrandom_size(void)
 {
 	if (!(current->flags & PF_RANDOMIZE))
 		return 0;
-	if (current->personality & ADDR_NO_RANDOMIZE)
-		return 0;
 	return STACK_RND_MASK << PAGE_SHIFT;
 }
 
-/*
- * Top of mmap area (just below the process stack).
- *
- * Leave at least a ~32 MB hole.
- */
-#define MIN_GAP (32*1024*1024)
-#define MAX_GAP (STACK_TOP/6*5)
-
-static inline int mmap_is_legacy(void)
+static inline int mmap_is_legacy(const struct rlimit *rlim_stack)
 {
 	if (current->personality & ADDR_COMPAT_LAYOUT)
 		return 1;
-	if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
+	if (rlim_stack->rlim_cur == RLIM_INFINITY)
 		return 1;
 	return sysctl_legacy_va_layout;
 }
 
 unsigned long arch_mmap_rnd(void)
 {
-	return (get_random_int() & MMAP_RND_MASK) << PAGE_SHIFT;
+	return (get_random_u32() & MMAP_RND_MASK) << PAGE_SHIFT;
 }
 
 static unsigned long mmap_base_legacy(unsigned long rnd)
@@ -70,26 +45,43 @@ static unsigned long mmap_base_legacy(unsigned long rnd)
 	return TASK_UNMAPPED_BASE + rnd;
 }
 
-static inline unsigned long mmap_base(unsigned long rnd)
+static inline unsigned long mmap_base(unsigned long rnd,
+				      const struct rlimit *rlim_stack)
 {
-	unsigned long gap = rlimit(RLIMIT_STACK);
-
-	if (gap < MIN_GAP)
-		gap = MIN_GAP;
-	else if (gap > MAX_GAP)
-		gap = MAX_GAP;
-	gap &= PAGE_MASK;
-	return STACK_TOP - stack_maxrandom_size() - rnd - gap;
+	unsigned long gap = rlim_stack->rlim_cur;
+	unsigned long pad = stack_maxrandom_size() + stack_guard_gap;
+
+	/* Values close to RLIM_INFINITY can overflow. */
+	if (gap + pad > gap)
+		gap += pad;
+
+	/*
+	 * Top of mmap area (just below the process stack).
+	 * Leave at least a ~128 MB hole.
+	 */
+	gap = clamp(gap, SZ_128M, (STACK_TOP / 6) * 5);
+
+	return PAGE_ALIGN(STACK_TOP - gap - rnd);
 }
 
-unsigned long
-arch_get_unmapped_area(struct file *filp, unsigned long addr,
-		unsigned long len, unsigned long pgoff, unsigned long flags)
+static int get_align_mask(struct file *filp, unsigned long flags)
+{
+	if (filp && is_file_hugepages(filp))
+		return huge_page_mask_align(filp);
+	if (!(current->flags & PF_RANDOMIZE))
+		return 0;
+	if (filp || (flags & MAP_SHARED))
+		return MMAP_ALIGN_MASK << PAGE_SHIFT;
+	return 0;
+}
+
+unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
+				     unsigned long len, unsigned long pgoff,
+				     unsigned long flags, vm_flags_t vm_flags)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
-	struct vm_unmapped_area_info info;
-	int rc;
+	struct vm_unmapped_area_info info = {};
 
 	if (len > TASK_SIZE - mmap_min_addr)
 		return -ENOMEM;
@@ -105,39 +97,27 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 			goto check_asce_limit;
 	}
 
-	info.flags = 0;
 	info.length = len;
 	info.low_limit = mm->mmap_base;
 	info.high_limit = TASK_SIZE;
-	if (filp || (flags & MAP_SHARED))
-		info.align_mask = MMAP_ALIGN_MASK << PAGE_SHIFT;
-	else
-		info.align_mask = 0;
-	info.align_offset = pgoff << PAGE_SHIFT;
+	info.align_mask = get_align_mask(filp, flags);
+	if (!(filp && is_file_hugepages(filp)))
+		info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);
-	if (addr & ~PAGE_MASK)
+	if (offset_in_page(addr))
 		return addr;
 
 check_asce_limit:
-	if (addr + len > current->mm->context.asce_limit) {
-		rc = crst_table_upgrade(mm, addr + len);
-		if (rc)
-			return (unsigned long) rc;
-	}
-
-	return addr;
+	return check_asce_limit(mm, addr, len);
 }
 
-unsigned long
-arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
-			  const unsigned long len, const unsigned long pgoff,
-			  const unsigned long flags)
+unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
+					     unsigned long len, unsigned long pgoff,
+					     unsigned long flags, vm_flags_t vm_flags)
 {
 	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
-	unsigned long addr = addr0;
-	struct vm_unmapped_area_info info;
-	int rc;
+	struct vm_unmapped_area_info info = {};
 
 	/* requested length too big for entire address space */
 	if (len > TASK_SIZE - mmap_min_addr)
@@ -157,13 +137,11 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 
 	info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 	info.length = len;
-	info.low_limit = max(PAGE_SIZE, mmap_min_addr);
+	info.low_limit = PAGE_SIZE;
 	info.high_limit = mm->mmap_base;
-	if (filp || (flags & MAP_SHARED))
-		info.align_mask = MMAP_ALIGN_MASK << PAGE_SHIFT;
-	else
-		info.align_mask = 0;
-	info.align_offset = pgoff << PAGE_SHIFT;
+	info.align_mask = get_align_mask(filp, flags);
+	if (!(filp && is_file_hugepages(filp)))
+		info.align_offset = pgoff << PAGE_SHIFT;
 	addr = vm_unmapped_area(&info);
 
 	/*
@@ -172,31 +150,25 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 	 * can happen with large stack limits and large mmap()
 	 * allocations.
 	 */
-	if (addr & ~PAGE_MASK) {
+	if (offset_in_page(addr)) {
 		VM_BUG_ON(addr != -ENOMEM);
 		info.flags = 0;
 		info.low_limit = TASK_UNMAPPED_BASE;
 		info.high_limit = TASK_SIZE;
 		addr = vm_unmapped_area(&info);
-		if (addr & ~PAGE_MASK)
+		if (offset_in_page(addr))
 			return addr;
 	}
 
 check_asce_limit:
-	if (addr + len > current->mm->context.asce_limit) {
-		rc = crst_table_upgrade(mm, addr + len);
-		if (rc)
-			return (unsigned long) rc;
-	}
-
-	return addr;
+	return check_asce_limit(mm, addr, len);
 }
 
 /*
  * This function, called very early during the creation of a new
  * process VM image, sets up which VM layout function to use:
  */
-void arch_pick_mmap_layout(struct mm_struct *mm)
+void arch_pick_mmap_layout(struct mm_struct *mm, const struct rlimit *rlim_stack)
 {
 	unsigned long random_factor = 0UL;
 
@@ -207,11 +179,37 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
 	 * Fall back to the standard layout if the personality
 	 * bit is set, or if the expected stack growth is unlimited:
 	 */
-	if (mmap_is_legacy()) {
+	if (mmap_is_legacy(rlim_stack)) {
 		mm->mmap_base = mmap_base_legacy(random_factor);
-		mm->get_unmapped_area = arch_get_unmapped_area;
+		mm_flags_clear(MMF_TOPDOWN, mm);
 	} else {
-		mm->mmap_base = mmap_base(random_factor);
-		mm->get_unmapped_area = arch_get_unmapped_area_topdown;
+		mm->mmap_base = mmap_base(random_factor, rlim_stack);
+		mm_flags_set(MMF_TOPDOWN, mm);
 	}
 }
+
+static pgprot_t protection_map[16] __ro_after_init;
+
+void __init setup_protection_map(void)
+{
+	pgprot_t *pm = protection_map;
+
+	pm[VM_NONE]					= PAGE_NONE;
+	pm[VM_READ]					= PAGE_RO;
+	pm[VM_WRITE]					= PAGE_RO;
+	pm[VM_WRITE | VM_READ]				= PAGE_RO;
+	pm[VM_EXEC]					= PAGE_RX;
+	pm[VM_EXEC | VM_READ]				= PAGE_RX;
+	pm[VM_EXEC | VM_WRITE]				= PAGE_RX;
+	pm[VM_EXEC | VM_WRITE | VM_READ]		= PAGE_RX;
+	pm[VM_SHARED]					= PAGE_NONE;
+	pm[VM_SHARED | VM_READ]				= PAGE_RO;
+	pm[VM_SHARED | VM_WRITE]			= PAGE_RW;
+	pm[VM_SHARED | VM_WRITE | VM_READ]		= PAGE_RW;
+	pm[VM_SHARED | VM_EXEC]				= PAGE_RX;
+	pm[VM_SHARED | VM_EXEC | VM_READ]		= PAGE_RX;
+	pm[VM_SHARED | VM_EXEC | VM_WRITE]		= PAGE_RWX;
+	pm[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]	= PAGE_RWX;
+}
+
+DECLARE_VM_GET_PAGE_PROT