mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 03:10:12 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
Pull audit updates from Eric Paris. * git://git.infradead.org/users/eparis/audit: (28 commits) AUDIT: make audit_is_compat depend on CONFIG_AUDIT_COMPAT_GENERIC audit: renumber AUDIT_FEATURE_CHANGE into the 1300 range audit: do not cast audit_rule_data pointers pointlesly AUDIT: Allow login in non-init namespaces audit: define audit_is_compat in kernel internal header kernel: Use RCU_INIT_POINTER(x, NULL) in audit.c sched: declare pid_alive as inline audit: use uapi/linux/audit.h for AUDIT_ARCH declarations syscall_get_arch: remove useless function arguments audit: remove stray newline from audit_log_execve_info() audit_panic() call audit: remove stray newlines from audit_log_lost messages audit: include subject in login records audit: remove superfluous new- prefix in AUDIT_LOGIN messages audit: allow user processes to log from another PID namespace audit: anchor all pid references in the initial pid namespace audit: convert PPIDs to the inital PID namespace. pid: get pid_t ppid of task in init_pid_ns audit: rename the misleading audit_get_context() to audit_take_context() audit: Add generic compat syscall support audit: Add CONFIG_HAVE_ARCH_AUDITSYSCALL ...
504 lines
12 KiB
C
504 lines
12 KiB
C
#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/compiler.h>
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#include <linux/export.h>
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <linux/security.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/mman.h>
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#include <linux/hugetlb.h>
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#include <asm/uaccess.h>
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#include "internal.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/kmem.h>
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/**
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* kstrdup - allocate space for and copy an existing string
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* @s: the string to duplicate
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* @gfp: the GFP mask used in the kmalloc() call when allocating memory
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*/
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char *kstrdup(const char *s, gfp_t gfp)
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{
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size_t len;
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char *buf;
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if (!s)
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return NULL;
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len = strlen(s) + 1;
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buf = kmalloc_track_caller(len, gfp);
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if (buf)
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memcpy(buf, s, len);
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return buf;
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}
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EXPORT_SYMBOL(kstrdup);
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/**
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* kstrndup - allocate space for and copy an existing string
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* @s: the string to duplicate
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* @max: read at most @max chars from @s
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* @gfp: the GFP mask used in the kmalloc() call when allocating memory
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*/
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char *kstrndup(const char *s, size_t max, gfp_t gfp)
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{
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size_t len;
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char *buf;
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if (!s)
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return NULL;
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len = strnlen(s, max);
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buf = kmalloc_track_caller(len+1, gfp);
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if (buf) {
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memcpy(buf, s, len);
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buf[len] = '\0';
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}
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return buf;
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}
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EXPORT_SYMBOL(kstrndup);
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/**
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* kmemdup - duplicate region of memory
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*
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* @src: memory region to duplicate
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* @len: memory region length
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* @gfp: GFP mask to use
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*/
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void *kmemdup(const void *src, size_t len, gfp_t gfp)
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{
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void *p;
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p = kmalloc_track_caller(len, gfp);
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if (p)
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memcpy(p, src, len);
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return p;
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}
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EXPORT_SYMBOL(kmemdup);
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/**
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* memdup_user - duplicate memory region from user space
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*
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* @src: source address in user space
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* @len: number of bytes to copy
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*
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* Returns an ERR_PTR() on failure.
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*/
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void *memdup_user(const void __user *src, size_t len)
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{
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void *p;
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/*
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* Always use GFP_KERNEL, since copy_from_user() can sleep and
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* cause pagefault, which makes it pointless to use GFP_NOFS
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* or GFP_ATOMIC.
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*/
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p = kmalloc_track_caller(len, GFP_KERNEL);
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if (!p)
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return ERR_PTR(-ENOMEM);
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if (copy_from_user(p, src, len)) {
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kfree(p);
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return ERR_PTR(-EFAULT);
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}
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return p;
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}
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EXPORT_SYMBOL(memdup_user);
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static __always_inline void *__do_krealloc(const void *p, size_t new_size,
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gfp_t flags)
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{
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void *ret;
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size_t ks = 0;
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if (p)
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ks = ksize(p);
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if (ks >= new_size)
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return (void *)p;
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ret = kmalloc_track_caller(new_size, flags);
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if (ret && p)
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memcpy(ret, p, ks);
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return ret;
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}
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/**
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* __krealloc - like krealloc() but don't free @p.
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* @p: object to reallocate memory for.
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* @new_size: how many bytes of memory are required.
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* @flags: the type of memory to allocate.
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*
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* This function is like krealloc() except it never frees the originally
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* allocated buffer. Use this if you don't want to free the buffer immediately
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* like, for example, with RCU.
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*/
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void *__krealloc(const void *p, size_t new_size, gfp_t flags)
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{
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if (unlikely(!new_size))
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return ZERO_SIZE_PTR;
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return __do_krealloc(p, new_size, flags);
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}
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EXPORT_SYMBOL(__krealloc);
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/**
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* krealloc - reallocate memory. The contents will remain unchanged.
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* @p: object to reallocate memory for.
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* @new_size: how many bytes of memory are required.
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* @flags: the type of memory to allocate.
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*
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* The contents of the object pointed to are preserved up to the
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* lesser of the new and old sizes. If @p is %NULL, krealloc()
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* behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
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* %NULL pointer, the object pointed to is freed.
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*/
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void *krealloc(const void *p, size_t new_size, gfp_t flags)
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{
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void *ret;
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if (unlikely(!new_size)) {
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kfree(p);
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return ZERO_SIZE_PTR;
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}
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ret = __do_krealloc(p, new_size, flags);
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if (ret && p != ret)
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kfree(p);
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return ret;
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}
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EXPORT_SYMBOL(krealloc);
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/**
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* kzfree - like kfree but zero memory
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* @p: object to free memory of
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*
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* The memory of the object @p points to is zeroed before freed.
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* If @p is %NULL, kzfree() does nothing.
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*
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* Note: this function zeroes the whole allocated buffer which can be a good
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* deal bigger than the requested buffer size passed to kmalloc(). So be
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* careful when using this function in performance sensitive code.
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*/
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void kzfree(const void *p)
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{
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size_t ks;
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void *mem = (void *)p;
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if (unlikely(ZERO_OR_NULL_PTR(mem)))
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return;
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ks = ksize(mem);
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memset(mem, 0, ks);
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kfree(mem);
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}
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EXPORT_SYMBOL(kzfree);
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/*
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* strndup_user - duplicate an existing string from user space
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* @s: The string to duplicate
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* @n: Maximum number of bytes to copy, including the trailing NUL.
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*/
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char *strndup_user(const char __user *s, long n)
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{
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char *p;
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long length;
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length = strnlen_user(s, n);
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if (!length)
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return ERR_PTR(-EFAULT);
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if (length > n)
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return ERR_PTR(-EINVAL);
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p = memdup_user(s, length);
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if (IS_ERR(p))
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return p;
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p[length - 1] = '\0';
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return p;
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}
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EXPORT_SYMBOL(strndup_user);
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void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
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struct vm_area_struct *prev, struct rb_node *rb_parent)
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{
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struct vm_area_struct *next;
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vma->vm_prev = prev;
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if (prev) {
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next = prev->vm_next;
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prev->vm_next = vma;
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} else {
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mm->mmap = vma;
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if (rb_parent)
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next = rb_entry(rb_parent,
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struct vm_area_struct, vm_rb);
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else
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next = NULL;
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}
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vma->vm_next = next;
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if (next)
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next->vm_prev = vma;
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}
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/* Check if the vma is being used as a stack by this task */
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static int vm_is_stack_for_task(struct task_struct *t,
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struct vm_area_struct *vma)
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{
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return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t));
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}
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/*
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* Check if the vma is being used as a stack.
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* If is_group is non-zero, check in the entire thread group or else
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* just check in the current task. Returns the pid of the task that
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* the vma is stack for.
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*/
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pid_t vm_is_stack(struct task_struct *task,
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struct vm_area_struct *vma, int in_group)
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{
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pid_t ret = 0;
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if (vm_is_stack_for_task(task, vma))
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return task->pid;
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if (in_group) {
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struct task_struct *t;
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rcu_read_lock();
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if (!pid_alive(task))
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goto done;
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t = task;
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do {
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if (vm_is_stack_for_task(t, vma)) {
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ret = t->pid;
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goto done;
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}
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} while_each_thread(task, t);
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done:
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rcu_read_unlock();
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}
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return ret;
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}
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#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT)
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void arch_pick_mmap_layout(struct mm_struct *mm)
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{
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mm->mmap_base = TASK_UNMAPPED_BASE;
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mm->get_unmapped_area = arch_get_unmapped_area;
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}
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#endif
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/*
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* Like get_user_pages_fast() except its IRQ-safe in that it won't fall
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* back to the regular GUP.
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* If the architecture not support this function, simply return with no
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* page pinned
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*/
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int __weak __get_user_pages_fast(unsigned long start,
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int nr_pages, int write, struct page **pages)
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{
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return 0;
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}
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EXPORT_SYMBOL_GPL(__get_user_pages_fast);
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/**
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* get_user_pages_fast() - pin user pages in memory
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* @start: starting user address
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* @nr_pages: number of pages from start to pin
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* @write: whether pages will be written to
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* @pages: array that receives pointers to the pages pinned.
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* Should be at least nr_pages long.
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*
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* Returns number of pages pinned. This may be fewer than the number
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* requested. If nr_pages is 0 or negative, returns 0. If no pages
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* were pinned, returns -errno.
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*
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* get_user_pages_fast provides equivalent functionality to get_user_pages,
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* operating on current and current->mm, with force=0 and vma=NULL. However
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* unlike get_user_pages, it must be called without mmap_sem held.
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*
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* get_user_pages_fast may take mmap_sem and page table locks, so no
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* assumptions can be made about lack of locking. get_user_pages_fast is to be
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* implemented in a way that is advantageous (vs get_user_pages()) when the
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* user memory area is already faulted in and present in ptes. However if the
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* pages have to be faulted in, it may turn out to be slightly slower so
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* callers need to carefully consider what to use. On many architectures,
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* get_user_pages_fast simply falls back to get_user_pages.
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*/
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int __weak get_user_pages_fast(unsigned long start,
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int nr_pages, int write, struct page **pages)
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{
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struct mm_struct *mm = current->mm;
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int ret;
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down_read(&mm->mmap_sem);
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ret = get_user_pages(current, mm, start, nr_pages,
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write, 0, pages, NULL);
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up_read(&mm->mmap_sem);
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return ret;
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}
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EXPORT_SYMBOL_GPL(get_user_pages_fast);
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unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
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unsigned long len, unsigned long prot,
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unsigned long flag, unsigned long pgoff)
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{
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unsigned long ret;
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struct mm_struct *mm = current->mm;
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unsigned long populate;
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ret = security_mmap_file(file, prot, flag);
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if (!ret) {
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down_write(&mm->mmap_sem);
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ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
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&populate);
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up_write(&mm->mmap_sem);
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if (populate)
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mm_populate(ret, populate);
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}
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return ret;
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}
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unsigned long vm_mmap(struct file *file, unsigned long addr,
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unsigned long len, unsigned long prot,
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unsigned long flag, unsigned long offset)
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{
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if (unlikely(offset + PAGE_ALIGN(len) < offset))
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return -EINVAL;
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if (unlikely(offset & ~PAGE_MASK))
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return -EINVAL;
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return vm_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
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}
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EXPORT_SYMBOL(vm_mmap);
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struct address_space *page_mapping(struct page *page)
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{
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struct address_space *mapping = page->mapping;
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/* This happens if someone calls flush_dcache_page on slab page */
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if (unlikely(PageSlab(page)))
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return NULL;
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if (unlikely(PageSwapCache(page))) {
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swp_entry_t entry;
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entry.val = page_private(page);
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mapping = swap_address_space(entry);
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} else if ((unsigned long)mapping & PAGE_MAPPING_ANON)
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mapping = NULL;
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return mapping;
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}
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int overcommit_ratio_handler(struct ctl_table *table, int write,
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void __user *buffer, size_t *lenp,
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loff_t *ppos)
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{
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int ret;
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ret = proc_dointvec(table, write, buffer, lenp, ppos);
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if (ret == 0 && write)
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sysctl_overcommit_kbytes = 0;
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return ret;
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}
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int overcommit_kbytes_handler(struct ctl_table *table, int write,
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void __user *buffer, size_t *lenp,
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loff_t *ppos)
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{
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int ret;
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ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
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if (ret == 0 && write)
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sysctl_overcommit_ratio = 0;
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return ret;
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}
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/*
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* Committed memory limit enforced when OVERCOMMIT_NEVER policy is used
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*/
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unsigned long vm_commit_limit(void)
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{
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unsigned long allowed;
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if (sysctl_overcommit_kbytes)
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allowed = sysctl_overcommit_kbytes >> (PAGE_SHIFT - 10);
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else
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allowed = ((totalram_pages - hugetlb_total_pages())
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* sysctl_overcommit_ratio / 100);
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allowed += total_swap_pages;
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return allowed;
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}
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/**
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* get_cmdline() - copy the cmdline value to a buffer.
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* @task: the task whose cmdline value to copy.
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* @buffer: the buffer to copy to.
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* @buflen: the length of the buffer. Larger cmdline values are truncated
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* to this length.
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* Returns the size of the cmdline field copied. Note that the copy does
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* not guarantee an ending NULL byte.
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*/
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int get_cmdline(struct task_struct *task, char *buffer, int buflen)
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{
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int res = 0;
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unsigned int len;
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struct mm_struct *mm = get_task_mm(task);
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if (!mm)
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goto out;
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if (!mm->arg_end)
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goto out_mm; /* Shh! No looking before we're done */
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len = mm->arg_end - mm->arg_start;
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if (len > buflen)
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len = buflen;
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res = access_process_vm(task, mm->arg_start, buffer, len, 0);
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/*
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* If the nul at the end of args has been overwritten, then
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* assume application is using setproctitle(3).
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*/
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if (res > 0 && buffer[res-1] != '\0' && len < buflen) {
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len = strnlen(buffer, res);
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if (len < res) {
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res = len;
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} else {
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len = mm->env_end - mm->env_start;
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if (len > buflen - res)
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len = buflen - res;
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res += access_process_vm(task, mm->env_start,
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buffer+res, len, 0);
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res = strnlen(buffer, res);
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}
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}
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out_mm:
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mmput(mm);
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out:
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return res;
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}
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/* Tracepoints definitions. */
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EXPORT_TRACEPOINT_SYMBOL(kmalloc);
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EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
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EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
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EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
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EXPORT_TRACEPOINT_SYMBOL(kfree);
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EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);
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