2015-05-22 16:14:34

by Leon Romanovsky

[permalink] [raw]
Subject: [PATCH v2] mm: nommu: refactor debug and warning prints

kenter/kleave/kdebug are wrapper macros to print functions flow and debug
information. This set was written before pr_devel() was introduced, so
it was controlled by "#if 0" construction. It is questionable if anyone
is using them [1] now.

This patch removes these macros, converts numerous
printk(KERN_WARNING, ...) to use general pr_warn(...) and
removes debug print line from validate_mmap_request() function.

--
Changelog since v1
* Remove kenter/kleave/kdebug macros as was suggested by Andrew Morton [2]
* Convert warning prints to be pr_warn(..)
* Fix checkpatch warnings in legacy prints code
* Change title to reflect new changes. It was "[PATCH] mm: nommu: convert
kenter/kleave/kdebug macros to use pr_devel()" [3].

[1] https://lkml.org/lkml/2015/5/16/279
[2] https://lkml.org/lkml/2015/5/18/903
[3] https://lkml.org/lkml/2015/5/18/682

Signed-off-by: Leon Romanovsky <[email protected]>
---
mm/nommu.c | 112 +++++++++++-------------------------------------------------
1 file changed, 20 insertions(+), 92 deletions(-)

diff --git a/mm/nommu.c b/mm/nommu.c
index e544508..05e7447 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -42,22 +42,6 @@
#include <asm/mmu_context.h>
#include "internal.h"

-#if 0
-#define kenter(FMT, ...) \
- printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
-#define kleave(FMT, ...) \
- printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
-#define kdebug(FMT, ...) \
- printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
-#else
-#define kenter(FMT, ...) \
- no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
-#define kleave(FMT, ...) \
- no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
-#define kdebug(FMT, ...) \
- no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
-#endif
-
void *high_memory;
EXPORT_SYMBOL(high_memory);
struct page *mem_map;
@@ -665,11 +649,7 @@ static void free_page_series(unsigned long from, unsigned long to)
for (; from < to; from += PAGE_SIZE) {
struct page *page = virt_to_page(from);

- kdebug("- free %lx", from);
atomic_long_dec(&mmap_pages_allocated);
- if (page_count(page) != 1)
- kdebug("free page %p: refcount not one: %d",
- page, page_count(page));
put_page(page);
}
}
@@ -683,8 +663,6 @@ static void free_page_series(unsigned long from, unsigned long to)
static void __put_nommu_region(struct vm_region *region)
__releases(nommu_region_sem)
{
- kenter("%p{%d}", region, region->vm_usage);
-
BUG_ON(!nommu_region_tree.rb_node);

if (--region->vm_usage == 0) {
@@ -697,10 +675,8 @@ static void __put_nommu_region(struct vm_region *region)

/* IO memory and memory shared directly out of the pagecache
* from ramfs/tmpfs mustn't be released here */
- if (region->vm_flags & VM_MAPPED_COPY) {
- kdebug("free series");
+ if (region->vm_flags & VM_MAPPED_COPY)
free_page_series(region->vm_start, region->vm_top);
- }
kmem_cache_free(vm_region_jar, region);
} else {
up_write(&nommu_region_sem);
@@ -744,8 +720,6 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
struct address_space *mapping;
struct rb_node **p, *parent, *rb_prev;

- kenter(",%p", vma);
-
BUG_ON(!vma->vm_region);

mm->map_count++;
@@ -813,8 +787,6 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
struct mm_struct *mm = vma->vm_mm;
struct task_struct *curr = current;

- kenter("%p", vma);
-
protect_vma(vma, 0);

mm->map_count--;
@@ -854,7 +826,6 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
*/
static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
{
- kenter("%p", vma);
if (vma->vm_ops && vma->vm_ops->close)
vma->vm_ops->close(vma);
if (vma->vm_file)
@@ -957,12 +928,8 @@ static int validate_mmap_request(struct file *file,
int ret;

/* do the simple checks first */
- if (flags & MAP_FIXED) {
- printk(KERN_DEBUG
- "%d: Can't do fixed-address/overlay mmap of RAM\n",
- current->pid);
+ if (flags & MAP_FIXED)
return -EINVAL;
- }

if ((flags & MAP_TYPE) != MAP_PRIVATE &&
(flags & MAP_TYPE) != MAP_SHARED)
@@ -1060,8 +1027,7 @@ static int validate_mmap_request(struct file *file,
) {
capabilities &= ~NOMMU_MAP_DIRECT;
if (flags & MAP_SHARED) {
- printk(KERN_WARNING
- "MAP_SHARED not completely supported on !MMU\n");
+ pr_warn("MAP_SHARED not completely supported on !MMU\n");
return -EINVAL;
}
}
@@ -1205,16 +1171,12 @@ static int do_mmap_private(struct vm_area_struct *vma,
* we're allocating is smaller than a page
*/
order = get_order(len);
- kdebug("alloc order %d for %lx", order, len);
-
total = 1 << order;
point = len >> PAGE_SHIFT;

/* we don't want to allocate a power-of-2 sized page set */
- if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) {
+ if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages)
total = point;
- kdebug("try to alloc exact %lu pages", total);
- }

base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL);
if (!base)
@@ -1285,18 +1247,14 @@ unsigned long do_mmap_pgoff(struct file *file,
unsigned long capabilities, vm_flags, result;
int ret;

- kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff);
-
*populate = 0;

/* decide whether we should attempt the mapping, and if so what sort of
* mapping */
ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
&capabilities);
- if (ret < 0) {
- kleave(" = %d [val]", ret);
+ if (ret < 0)
return ret;
- }

/* we ignore the address hint */
addr = 0;
@@ -1383,11 +1341,9 @@ unsigned long do_mmap_pgoff(struct file *file,
vma->vm_start = start;
vma->vm_end = start + len;

- if (pregion->vm_flags & VM_MAPPED_COPY) {
- kdebug("share copy");
+ if (pregion->vm_flags & VM_MAPPED_COPY)
vma->vm_flags |= VM_MAPPED_COPY;
- } else {
- kdebug("share mmap");
+ else {
ret = do_mmap_shared_file(vma);
if (ret < 0) {
vma->vm_region = NULL;
@@ -1467,7 +1423,6 @@ share:

up_write(&nommu_region_sem);

- kleave(" = %lx", result);
return result;

error_just_free:
@@ -1479,27 +1434,24 @@ error:
if (vma->vm_file)
fput(vma->vm_file);
kmem_cache_free(vm_area_cachep, vma);
- kleave(" = %d", ret);
return ret;

sharing_violation:
up_write(&nommu_region_sem);
- printk(KERN_WARNING "Attempt to share mismatched mappings\n");
+ pr_warn("Attempt to share mismatched mappings\n");
ret = -EINVAL;
goto error;

error_getting_vma:
kmem_cache_free(vm_region_jar, region);
- printk(KERN_WARNING "Allocation of vma for %lu byte allocation"
- " from process %d failed\n",
- len, current->pid);
+ pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n",
+ len, current->pid);
show_free_areas(0);
return -ENOMEM;

error_getting_region:
- printk(KERN_WARNING "Allocation of vm region for %lu byte allocation"
- " from process %d failed\n",
- len, current->pid);
+ pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n",
+ len, current->pid);
show_free_areas(0);
return -ENOMEM;
}
@@ -1563,8 +1515,6 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_region *region;
unsigned long npages;

- kenter("");
-
/* we're only permitted to split anonymous regions (these should have
* only a single usage on the region) */
if (vma->vm_file)
@@ -1628,8 +1578,6 @@ static int shrink_vma(struct mm_struct *mm,
{
struct vm_region *region;

- kenter("");
-
/* adjust the VMA's pointers, which may reposition it in the MM's tree
* and list */
delete_vma_from_mm(vma);
@@ -1669,8 +1617,6 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
unsigned long end;
int ret;

- kenter(",%lx,%zx", start, len);
-
len = PAGE_ALIGN(len);
if (len == 0)
return -EINVAL;
@@ -1682,11 +1628,9 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
if (!vma) {
static int limit;
if (limit < 5) {
- printk(KERN_WARNING
- "munmap of memory not mmapped by process %d"
- " (%s): 0x%lx-0x%lx\n",
- current->pid, current->comm,
- start, start + len - 1);
+ pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n",
+ current->pid, current->comm,
+ start, start + len - 1);
limit++;
}
return -EINVAL;
@@ -1695,38 +1639,27 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
/* we're allowed to split an anonymous VMA but not a file-backed one */
if (vma->vm_file) {
do {
- if (start > vma->vm_start) {
- kleave(" = -EINVAL [miss]");
+ if (start > vma->vm_start)
return -EINVAL;
- }
if (end == vma->vm_end)
goto erase_whole_vma;
vma = vma->vm_next;
} while (vma);
- kleave(" = -EINVAL [split file]");
return -EINVAL;
} else {
/* the chunk must be a subset of the VMA found */
if (start == vma->vm_start && end == vma->vm_end)
goto erase_whole_vma;
- if (start < vma->vm_start || end > vma->vm_end) {
- kleave(" = -EINVAL [superset]");
+ if (start < vma->vm_start || end > vma->vm_end)
return -EINVAL;
- }
- if (start & ~PAGE_MASK) {
- kleave(" = -EINVAL [unaligned start]");
+ if (start & ~PAGE_MASK)
return -EINVAL;
- }
- if (end != vma->vm_end && end & ~PAGE_MASK) {
- kleave(" = -EINVAL [unaligned split]");
+ if (end != vma->vm_end && end & ~PAGE_MASK)
return -EINVAL;
- }
if (start != vma->vm_start && end != vma->vm_end) {
ret = split_vma(mm, vma, start, 1);
- if (ret < 0) {
- kleave(" = %d [split]", ret);
+ if (ret < 0)
return ret;
- }
}
return shrink_vma(mm, vma, start, end);
}
@@ -1734,7 +1667,6 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
erase_whole_vma:
delete_vma_from_mm(vma);
delete_vma(mm, vma);
- kleave(" = 0");
return 0;
}
EXPORT_SYMBOL(do_munmap);
@@ -1766,8 +1698,6 @@ void exit_mmap(struct mm_struct *mm)
if (!mm)
return;

- kenter("");
-
mm->total_vm = 0;

while ((vma = mm->mmap)) {
@@ -1776,8 +1706,6 @@ void exit_mmap(struct mm_struct *mm)
delete_vma(mm, vma);
cond_resched();
}
-
- kleave("");
}

unsigned long vm_brk(unsigned long addr, unsigned long len)
--
1.7.9.5