#include <linux/mm.h>#include <linux/slab.h>#include <linux/string.h>#include <linux/export.h>#include <linux/err.h>#include <linux/sched.h>#include <linux/security.h>#include <linux/swap.h>#include <linux/swapops.h>#include <linux/mman.h>#include <linux/hugetlb.h> #include <asm/uaccess.h> #include "internal.h" #define CREATE_TRACE_POINTS#include <trace/events/kmem.h> /** * kstrdup - allocate space for and copy an existing string * @s: the string to duplicate * @gfp: the GFP mask used in the kmalloc() call when allocating memory */char *kstrdup(const char *s, gfp_t gfp){ size_t len; char *buf; if (!s) return NULL; len = strlen(s) + 1; buf = kmalloc_track_caller(len, gfp); if (buf) memcpy(buf, s, len); return buf;}EXPORT_SYMBOL(kstrdup); /** * kstrndup - allocate space for and copy an existing string * @s: the string to duplicate * @max: read at most @max chars from @s * @gfp: the GFP mask used in the kmalloc() call when allocating memory */char *kstrndup(const char *s, size_t max, gfp_t gfp){ size_t len; char *buf; if (!s) return NULL; len = strnlen(s, max); buf = kmalloc_track_caller(len+1, gfp); if (buf) { memcpy(buf, s, len); buf[len] = '\0'; } return buf;}EXPORT_SYMBOL(kstrndup); /** * kmemdup - duplicate region of memory * * @src: memory region to duplicate * @len: memory region length * @gfp: GFP mask to use */void *kmemdup(const void *src, size_t len, gfp_t gfp){ void *p; p = kmalloc_track_caller(len, gfp); if (p) memcpy(p, src, len); return p;}EXPORT_SYMBOL(kmemdup); /** * memdup_user - duplicate memory region from user space * * @src: source address in user space * @len: number of bytes to copy * * Returns an ERR_PTR() on failure. */void *memdup_user(const void __user *src, size_t len){ void *p; /* * Always use GFP_KERNEL, since copy_from_user() can sleep and * cause pagefault, which makes it pointless to use GFP_NOFS * or GFP_ATOMIC. */ p = kmalloc_track_caller(len, GFP_KERNEL); if (!p) return ERR_PTR(-ENOMEM); if (copy_from_user(p, src, len)) { kfree(p); return ERR_PTR(-EFAULT); } return p;}EXPORT_SYMBOL(memdup_user); static __always_inline void *__do_krealloc(const void *p, size_t new_size, gfp_t flags){ void *ret; size_t ks = 0; if (p) ks = ksize(p); if (ks >= new_size) return (void *)p; ret = kmalloc_track_caller(new_size, flags); if (ret && p) memcpy(ret, p, ks); return ret;} /** * __krealloc - like krealloc() but don't free @p. * @p: object to reallocate memory for. * @new_size: how many bytes of memory are required. * @flags: the type of memory to allocate. * * This function is like krealloc() except it never frees the originally * allocated buffer. Use this if you don't want to free the buffer immediately * like, for example, with RCU. */void *__krealloc(const void *p, size_t new_size, gfp_t flags){ if (unlikely(!new_size)) return ZERO_SIZE_PTR; return __do_krealloc(p, new_size, flags); }EXPORT_SYMBOL(__krealloc); /** * krealloc - reallocate memory. The contents will remain unchanged. * @p: object to reallocate memory for. * @new_size: how many bytes of memory are required. * @flags: the type of memory to allocate. * * The contents of the object pointed to are preserved up to the * lesser of the new and old sizes. If @p is %NULL, krealloc() * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a * %NULL pointer, the object pointed to is freed. */void *krealloc(const void *p, size_t new_size, gfp_t flags){ void *ret; if (unlikely(!new_size)) { kfree(p); return ZERO_SIZE_PTR; } ret = __do_krealloc(p, new_size, flags); if (ret && p != ret) kfree(p); return ret;}EXPORT_SYMBOL(krealloc); /** * kzfree - like kfree but zero memory * @p: object to free memory of * * The memory of the object @p points to is zeroed before freed. * If @p is %NULL, kzfree() does nothing. * * Note: this function zeroes the whole allocated buffer which can be a good * deal bigger than the requested buffer size passed to kmalloc(). So be * careful when using this function in performance sensitive code. */void kzfree(const void *p){ size_t ks; void *mem = (void *)p; if (unlikely(ZERO_OR_NULL_PTR(mem))) return; ks = ksize(mem); memset(mem, 0, ks); kfree(mem);}EXPORT_SYMBOL(kzfree); /* * strndup_user - duplicate an existing string from user space * @s: The string to duplicate * @n: Maximum number of bytes to copy, including the trailing NUL. */char *strndup_user(const char __user *s, long n){ char *p; long length; length = strnlen_user(s, n); if (!length) return ERR_PTR(-EFAULT); if (length > n) return ERR_PTR(-EINVAL); p = memdup_user(s, length); if (IS_ERR(p)) return p; p[length - 1] = '\0'; return p;}EXPORT_SYMBOL(strndup_user); void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, struct rb_node *rb_parent){ struct vm_area_struct *next; vma->vm_prev = prev; if (prev) { next = prev->vm_next; prev->vm_next = vma; } else { mm->mmap = vma; if (rb_parent) next = rb_entry(rb_parent, struct vm_area_struct, vm_rb); else next = NULL; } vma->vm_next = next; if (next) next->vm_prev = vma;} /* Check if the vma is being used as a stack by this task */static int vm_is_stack_for_task(struct task_struct *t, struct vm_area_struct *vma){ return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));} /* * Check if the vma is being used as a stack. * If is_group is non-zero, check in the entire thread group or else * just check in the current task. Returns the pid of the task that * the vma is stack for. */pid_t vm_is_stack(struct task_struct *task, struct vm_area_struct *vma, int in_group){ pid_t ret = 0; if (vm_is_stack_for_task(task, vma)) return task->pid; if (in_group) { struct task_struct *t; rcu_read_lock(); if (!pid_alive(task)) goto done; t = task; do { if (vm_is_stack_for_task(t, vma)) { ret = t->pid; goto done; } } while_each_thread(task, t);done: rcu_read_unlock(); } return ret;} #if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)void arch_pick_mmap_layout(struct mm_struct *mm){ mm->mmap_base = TASK_UNMAPPED_BASE; mm->get_unmapped_area = arch_get_unmapped_area;}#endif /* * Like get_user_pages_fast() except its IRQ-safe in that it won't fall * back to the regular GUP. * If the architecture not support this function, simply return with no * page pinned */int __attribute__((weak)) __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages){ return 0;}EXPORT_SYMBOL_GPL(__get_user_pages_fast); /** * get_user_pages_fast() - pin user pages in memory * @start: starting user address * @nr_pages: number of pages from start to pin * @write: whether pages will be written to * @pages: array that receives pointers to the pages pinned. * Should be at least nr_pages long. * * Returns number of pages pinned. This may be fewer than the number * requested. If nr_pages is 0 or negative, returns 0. If no pages * were pinned, returns -errno. * * get_user_pages_fast provides equivalent functionality to get_user_pages, * operating on current and current->mm, with force=0 and vma=NULL. However * unlike get_user_pages, it must be called without mmap_sem held. * * get_user_pages_fast may take mmap_sem and page table locks, so no * assumptions can be made about lack of locking. get_user_pages_fast is to be * implemented in a way that is advantageous (vs get_user_pages()) when the * user memory area is already faulted in and present in ptes. However if the * pages have to be faulted in, it may turn out to be slightly slower so * callers need to carefully consider what to use. On many architectures, * get_user_pages_fast simply falls back to get_user_pages. */int __attribute__((weak)) get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages){ struct mm_struct *mm = current->mm; int ret; down_read(&mm->mmap_sem); ret = get_user_pages(current, mm, start, nr_pages, write, 0, pages, NULL); up_read(&mm->mmap_sem); return ret;}EXPORT_SYMBOL_GPL(get_user_pages_fast); unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flag, unsigned long pgoff){ unsigned long ret; struct mm_struct *mm = current->mm; unsigned long populate; ret = security_mmap_file(file, prot, flag); if (!ret) { down_write(&mm->mmap_sem); ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff, &populate); up_write(&mm->mmap_sem); if (populate) mm_populate(ret, populate); } return ret;} unsigned long vm_mmap(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flag, unsigned long offset){ if (unlikely(offset + PAGE_ALIGN(len) < offset)) return -EINVAL; if (unlikely(offset & ~PAGE_MASK)) return -EINVAL; return vm_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);}EXPORT_SYMBOL(vm_mmap); struct address_space *page_mapping(struct page *page){ struct address_space *mapping = page->mapping; /* This happens if someone calls flush_dcache_page on slab page */ if (unlikely(PageSlab(page))) return NULL; if (unlikely(PageSwapCache(page))) { swp_entry_t entry; entry.val = page_private(page); mapping = swap_address_space(entry); } else if ((unsigned long)mapping & PAGE_MAPPING_ANON) mapping = NULL; return mapping;} /* * Committed memory limit enforced when OVERCOMMIT_NEVER policy is used */unsigned long vm_commit_limit(void){ return ((totalram_pages - hugetlb_total_pages()) * sysctl_overcommit_ratio / 100) + total_swap_pages;} /* Tracepoints definitions. */EXPORT_TRACEPOINT_SYMBOL(kmalloc);EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);EXPORT_TRACEPOINT_SYMBOL(kfree);EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/mman.h>
#include <linux/hugetlb.h>
#include <asm/uaccess.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/kmem.h>
/**
* kstrdup - allocate space for and copy an existing string
* @s: the string to duplicate
* @gfp: the GFP mask used in the kmalloc() call when allocating memory
*/
char *kstrdup(const char *s, gfp_t gfp)
{
size_t len;
char *buf;
if (!s)
return NULL;
len = strlen(s) + 1;
buf = kmalloc_track_caller(len, gfp);
if (buf)
memcpy(buf, s, len);
return buf;
}
EXPORT_SYMBOL(kstrdup);
/**
* kstrndup - allocate space for and copy an existing string
* @s: the string to duplicate
* @max: read at most @max chars from @s
* @gfp: the GFP mask used in the kmalloc() call when allocating memory
*/
char *kstrndup(const char *s, size_t max, gfp_t gfp)
{
size_t len;
char *buf;
if (!s)
return NULL;
len = strnlen(s, max);
buf = kmalloc_track_caller(len+1, gfp);
if (buf) {
memcpy(buf, s, len);
buf[len] = '\0';
}
return buf;
}
EXPORT_SYMBOL(kstrndup);
/**
* kmemdup - duplicate region of memory
*
* @src: memory region to duplicate
* @len: memory region length
* @gfp: GFP mask to use
*/
void *kmemdup(const void *src, size_t len, gfp_t gfp)
{
void *p;
p = kmalloc_track_caller(len, gfp);
if (p)
memcpy(p, src, len);
return p;
}
EXPORT_SYMBOL(kmemdup);
/**
* memdup_user - duplicate memory region from user space
*
* @src: source address in user space
* @len: number of bytes to copy
*
* Returns an ERR_PTR() on failure.
*/
void *memdup_user(const void __user *src, size_t len)
{
void *p;
/*
* Always use GFP_KERNEL, since copy_from_user() can sleep and
* cause pagefault, which makes it pointless to use GFP_NOFS
* or GFP_ATOMIC.
*/
p = kmalloc_track_caller(len, GFP_KERNEL);
if (!p)
return ERR_PTR(-ENOMEM);
if (copy_from_user(p, src, len)) {
kfree(p);
return ERR_PTR(-EFAULT);
}
return p;
}
EXPORT_SYMBOL(memdup_user);
static __always_inline void *__do_krealloc(const void *p, size_t new_size,
gfp_t flags)
{
void *ret;
size_t ks = 0;
if (p)
ks = ksize(p);
if (ks >= new_size)
return (void *)p;
ret = kmalloc_track_caller(new_size, flags);
if (ret && p)
memcpy(ret, p, ks);
return ret;
}
/**
* __krealloc - like krealloc() but don't free @p.
* @p: object to reallocate memory for.
* @new_size: how many bytes of memory are required.
* @flags: the type of memory to allocate.
*
* This function is like krealloc() except it never frees the originally
* allocated buffer. Use this if you don't want to free the buffer immediately
* like, for example, with RCU.
*/
void *__krealloc(const void *p, size_t new_size, gfp_t flags)
{
if (unlikely(!new_size))
return ZERO_SIZE_PTR;
return __do_krealloc(p, new_size, flags);
}
EXPORT_SYMBOL(__krealloc);
/**
* krealloc - reallocate memory. The contents will remain unchanged.
* @p: object to reallocate memory for.
* @new_size: how many bytes of memory are required.
* @flags: the type of memory to allocate.
*
* The contents of the object pointed to are preserved up to the
* lesser of the new and old sizes. If @p is %NULL, krealloc()
* behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
* %NULL pointer, the object pointed to is freed.
*/
void *krealloc(const void *p, size_t new_size, gfp_t flags)
{
void *ret;
if (unlikely(!new_size)) {
kfree(p);
return ZERO_SIZE_PTR;
}
ret = __do_krealloc(p, new_size, flags);
if (ret && p != ret)
kfree(p);
return ret;
}
EXPORT_SYMBOL(krealloc);
/**
* kzfree - like kfree but zero memory
* @p: object to free memory of
*
* The memory of the object @p points to is zeroed before freed.
* If @p is %NULL, kzfree() does nothing.
*
* Note: this function zeroes the whole allocated buffer which can be a good
* deal bigger than the requested buffer size passed to kmalloc(). So be
* careful when using this function in performance sensitive code.
*/
void kzfree(const void *p)
{
size_t ks;
void *mem = (void *)p;
if (unlikely(ZERO_OR_NULL_PTR(mem)))
return;
ks = ksize(mem);
memset(mem, 0, ks);
kfree(mem);
}
EXPORT_SYMBOL(kzfree);
/*
* strndup_user - duplicate an existing string from user space
* @s: The string to duplicate
* @n: Maximum number of bytes to copy, including the trailing NUL.
*/
char *strndup_user(const char __user *s, long n)
{
char *p;
long length;
length = strnlen_user(s, n);
if (!length)
return ERR_PTR(-EFAULT);
if (length > n)
return ERR_PTR(-EINVAL);
p = memdup_user(s, length);
if (IS_ERR(p))
return p;
p[length - 1] = '\0';
return p;
}
EXPORT_SYMBOL(strndup_user);
void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node *rb_parent)
{
struct vm_area_struct *next;
vma->vm_prev = prev;
if (prev) {
next = prev->vm_next;
prev->vm_next = vma;
} else {
mm->mmap = vma;
if (rb_parent)
next = rb_entry(rb_parent,
struct vm_area_struct, vm_rb);
else
next = NULL;
}
vma->vm_next = next;
if (next)
next->vm_prev = vma;
}
/* Check if the vma is being used as a stack by this task */
static int vm_is_stack_for_task(struct task_struct *t,
struct vm_area_struct *vma)
{
return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));
}
/*
* Check if the vma is being used as a stack.
* If is_group is non-zero, check in the entire thread group or else
* just check in the current task. Returns the pid of the task that
* the vma is stack for.
*/
pid_t vm_is_stack(struct task_struct *task,
struct vm_area_struct *vma, int in_group)
{
pid_t ret = 0;
if (vm_is_stack_for_task(task, vma))
return task->pid;
if (in_group) {
struct task_struct *t;
rcu_read_lock();
if (!pid_alive(task))
goto done;
t = task;
do {
if (vm_is_stack_for_task(t, vma)) {
ret = t->pid;
goto done;
}
} while_each_thread(task, t);
done:
rcu_read_unlock();
}
return ret;
}
#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)
void arch_pick_mmap_layout(struct mm_struct *mm)
{
mm->mmap_base = TASK_UNMAPPED_BASE;
mm->get_unmapped_area = arch_get_unmapped_area;
}
#endif
/*
* Like get_user_pages_fast() except its IRQ-safe in that it won't fall
* back to the regular GUP.
* If the architecture not support this function, simply return with no
* page pinned
*/
int __attribute__((weak)) __get_user_pages_fast(unsigned long start,
int nr_pages, int write, struct page **pages)
{
return 0;
}
EXPORT_SYMBOL_GPL(__get_user_pages_fast);
/**
* get_user_pages_fast() - pin user pages in memory
* @start: starting user address
* @nr_pages: number of pages from start to pin
* @write: whether pages will be written to
* @pages: array that receives pointers to the pages pinned.
* Should be at least nr_pages long.
*
* Returns number of pages pinned. This may be fewer than the number
* requested. If nr_pages is 0 or negative, returns 0. If no pages
* were pinned, returns -errno.
*
* get_user_pages_fast provides equivalent functionality to get_user_pages,
* operating on current and current->mm, with force=0 and vma=NULL. However
* unlike get_user_pages, it must be called without mmap_sem held.
*
* get_user_pages_fast may take mmap_sem and page table locks, so no
* assumptions can be made about lack of locking. get_user_pages_fast is to be
* implemented in a way that is advantageous (vs get_user_pages()) when the
* user memory area is already faulted in and present in ptes. However if the
* pages have to be faulted in, it may turn out to be slightly slower so
* callers need to carefully consider what to use. On many architectures,
* get_user_pages_fast simply falls back to get_user_pages.
*/
int __attribute__((weak)) get_user_pages_fast(unsigned long start,
int nr_pages, int write, struct page **pages)
{
struct mm_struct *mm = current->mm;
int ret;
down_read(&mm->mmap_sem);
ret = get_user_pages(current, mm, start, nr_pages,
write, 0, pages, NULL);
up_read(&mm->mmap_sem);
return ret;
}
EXPORT_SYMBOL_GPL(get_user_pages_fast);
unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long pgoff)
{
unsigned long ret;
struct mm_struct *mm = current->mm;
unsigned long populate;
ret = security_mmap_file(file, prot, flag);
if (!ret) {
down_write(&mm->mmap_sem);
ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
&populate);
up_write(&mm->mmap_sem);
if (populate)
mm_populate(ret, populate);
}
return ret;
}
unsigned long vm_mmap(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long offset)
{
if (unlikely(offset + PAGE_ALIGN(len) < offset))
return -EINVAL;
if (unlikely(offset & ~PAGE_MASK))
return -EINVAL;
return vm_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
}
EXPORT_SYMBOL(vm_mmap);
struct address_space *page_mapping(struct page *page)
{
struct address_space *mapping = page->mapping;
/* This happens if someone calls flush_dcache_page on slab page */
if (unlikely(PageSlab(page)))
return NULL;
if (unlikely(PageSwapCache(page))) {
swp_entry_t entry;
entry.val = page_private(page);
mapping = swap_address_space(entry);
} else if ((unsigned long)mapping & PAGE_MAPPING_ANON)
mapping = NULL;
return mapping;
}
/*
* Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
*/
unsigned long vm_commit_limit(void)
{
return ((totalram_pages - hugetlb_total_pages())
* sysctl_overcommit_ratio / 100) + total_swap_pages;
}
/* Tracepoints definitions. */
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
EXPORT_TRACEPOINT_SYMBOL(kfree);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);