From: Ravi Kumar Reddy <bnrkreddy@xxxxxxxxxxx>
- WARNING: Missing a blank line after declarations
- WARNING: Use #include <linux/cacheflush.h> instead of
<asm/cacheflush.h>
- WARNING: externs should be avoided in .c files
extern void mt_dump(const struct maple_tree *mt);
- WARNING: braces {} are not necessary for single statement
blocks
- WARNING: Block comments use a trailing */ on a separate line
- WARNING: function definition argument 'struct file *' should
also
have an identifier
- WARNING: EXPORT_SYMBOL(foo); should immediately follow its
function/variable
- WARNING: simple_strtoul is obsolete, use kstrtoul instead
- WARNING: Comparisons should place the constant on the right
side of the test
Testing:
kernel cmdline included with:
stack_guard_gap=-1
kernel log:
[ 0.018025] mmap: Invalid page count '-1' for stack
gap protection
Signed-off-by: Ravi Kumar Reddy <bnrkreddy@xxxxxxxxxxx>
---
mm/mmap.c | 45 ++++++++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 19 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index 87d929316d57..5d4b0d625607 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -48,9 +48,9 @@
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
+#include <linux/cacheflush.h>
#include <asm/tlb.h>
-#include <asm/mmu_context.h>
+#include <linux/mmu_context.h>
#define CREATE_TRACE_POINTS
#include <trace/events/mmap.h>
@@ -124,6 +124,7 @@ void unlink_file_vma(struct vm_area_struct *vma)
if (file) {
struct address_space *mapping = file->f_mapping;
+
i_mmap_lock_write(mapping);
__remove_shared_vm_struct(vma, file, mapping);
i_mmap_unlock_write(mapping);
@@ -281,9 +282,6 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
}
#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
-extern void mt_validate(struct maple_tree *mt);
-extern void mt_dump(const struct maple_tree *mt);
-
/* Validate the maple tree */
static void validate_mm_mt(struct mm_struct *mm)
{
@@ -572,9 +570,8 @@ inline int vma_expand(struct ma_state *mas, struct vm_area_struct *vma,
}
/* Expanding over the next vma */
- if (remove_next && file) {
+ if (remove_next && file)
__remove_shared_vm_struct(next, file, mapping);
- }
if (anon_vma) {
anon_vma_interval_tree_post_update_vma(vma);
@@ -946,6 +943,7 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
+
vm_pglen = vma_pages(vma);
if (vma->vm_pgoff + vm_pglen == vm_pgoff)
return 1;
@@ -1511,8 +1509,10 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
if (vm_ops && (vm_ops->page_mkwrite || vm_ops->pfn_mkwrite))
return 1;
- /* The open routine did something to the protections that pgprot_modify
- * won't preserve? */
+ /*
+ * The open routine did something to the protections that pgprot_modify
+ * won't preserve?
+ */
if (pgprot_val(vm_page_prot) !=
pgprot_val(vm_pgprot_modify(vm_page_prot, vm_flags)))
return 0;
@@ -1755,10 +1755,12 @@ unsigned long
get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long pgoff, unsigned long flags)
{
- unsigned long (*get_area)(struct file *, unsigned long,
- unsigned long, unsigned long, unsigned long);
+ unsigned long (*get_area)(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long pgoff,
+ unsigned long flags);
unsigned long error = arch_mmap_check(addr, len, flags);
+
if (error)
return error;
@@ -1792,7 +1794,6 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
error = security_mmap_addr(addr);
return error ? error : addr;
}
-
EXPORT_SYMBOL(get_unmapped_area);
/**
@@ -2079,11 +2080,16 @@ unsigned long stack_guard_gap = 256UL<<PAGE_SHIFT;
static int __init cmdline_parse_stack_guard_gap(char *p)
{
unsigned long val;
- char *endptr;
+ int ret;
+
+ ret = kstrtoul(p, 10, &val);
+ if (ret) {
+ pr_warn("Invalid page count '%s' for stack gap protection\n",
+ p);
+ return 1;
+ }
- val = simple_strtoul(p, &endptr, 10);
- if (!*endptr)
- stack_guard_gap = val << PAGE_SHIFT;
+ stack_guard_gap = val << PAGE_SHIFT;
return 1;
}
@@ -2138,7 +2144,6 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr)
return vma;
}
#endif
-
EXPORT_SYMBOL_GPL(find_extend_vma);
/*
@@ -2196,6 +2201,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
{
struct vm_area_struct *new;
int err;
+
validate_mm_mt(mm);
if (vma->vm_ops && vma->vm_ops->may_split) {
@@ -3365,6 +3371,7 @@ static vm_fault_t special_mapping_fault(struct vm_fault *vmf)
if (*pages) {
struct page *page = *pages;
+
get_page(page);
vmf->page = page;
return 0;
@@ -3714,12 +3721,12 @@ static int reserve_mem_notifier(struct notifier_block *nb,
case MEM_ONLINE:
/* Default max is 128MB. Leave alone if modified by operator. */
tmp = sysctl_user_reserve_kbytes;
- if (0 < tmp && tmp < (1UL << 17))
+ if (tmp > 0 && tmp < (1UL << 17))
init_user_reserve();
/* Default max is 8MB. Leave alone if modified by operator. */
tmp = sysctl_admin_reserve_kbytes;
- if (0 < tmp && tmp < (1UL << 13))
+ if (tmp > 0 && tmp < (1UL << 13))
init_admin_reserve();
break;
--
2.31.1
