linux/drivers/char/tty_audit.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

341 lines
8.1 KiB
C

/*
* Creating audit events from TTY input.
*
* Copyright (C) 2007 Red Hat, Inc. All rights reserved. This copyrighted
* material is made available to anyone wishing to use, modify, copy, or
* redistribute it subject to the terms and conditions of the GNU General
* Public License v.2.
*
* Authors: Miloslav Trmac <mitr@redhat.com>
*/
#include <linux/audit.h>
#include <linux/slab.h>
#include <linux/tty.h>
struct tty_audit_buf {
atomic_t count;
struct mutex mutex; /* Protects all data below */
int major, minor; /* The TTY which the data is from */
unsigned icanon:1;
size_t valid;
unsigned char *data; /* Allocated size N_TTY_BUF_SIZE */
};
static struct tty_audit_buf *tty_audit_buf_alloc(int major, int minor,
int icanon)
{
struct tty_audit_buf *buf;
buf = kmalloc(sizeof(*buf), GFP_KERNEL);
if (!buf)
goto err;
buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
if (!buf->data)
goto err_buf;
atomic_set(&buf->count, 1);
mutex_init(&buf->mutex);
buf->major = major;
buf->minor = minor;
buf->icanon = icanon;
buf->valid = 0;
return buf;
err_buf:
kfree(buf);
err:
return NULL;
}
static void tty_audit_buf_free(struct tty_audit_buf *buf)
{
WARN_ON(buf->valid != 0);
kfree(buf->data);
kfree(buf);
}
static void tty_audit_buf_put(struct tty_audit_buf *buf)
{
if (atomic_dec_and_test(&buf->count))
tty_audit_buf_free(buf);
}
static void tty_audit_log(const char *description, struct task_struct *tsk,
uid_t loginuid, unsigned sessionid, int major,
int minor, unsigned char *data, size_t size)
{
struct audit_buffer *ab;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
if (ab) {
char name[sizeof(tsk->comm)];
uid_t uid = task_uid(tsk);
audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u "
"major=%d minor=%d comm=", description,
tsk->pid, uid, loginuid, sessionid,
major, minor);
get_task_comm(name, tsk);
audit_log_untrustedstring(ab, name);
audit_log_format(ab, " data=");
audit_log_n_hex(ab, data, size);
audit_log_end(ab);
}
}
/**
* tty_audit_buf_push - Push buffered data out
*
* Generate an audit message from the contents of @buf, which is owned by
* @tsk with @loginuid. @buf->mutex must be locked.
*/
static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid,
unsigned int sessionid,
struct tty_audit_buf *buf)
{
if (buf->valid == 0)
return;
if (audit_enabled == 0)
return;
tty_audit_log("tty", tsk, loginuid, sessionid, buf->major, buf->minor,
buf->data, buf->valid);
buf->valid = 0;
}
/**
* tty_audit_buf_push_current - Push buffered data out
*
* Generate an audit message from the contents of @buf, which is owned by
* the current task. @buf->mutex must be locked.
*/
static void tty_audit_buf_push_current(struct tty_audit_buf *buf)
{
uid_t auid = audit_get_loginuid(current);
unsigned int sessionid = audit_get_sessionid(current);
tty_audit_buf_push(current, auid, sessionid, buf);
}
/**
* tty_audit_exit - Handle a task exit
*
* Make sure all buffered data is written out and deallocate the buffer.
* Only needs to be called if current->signal->tty_audit_buf != %NULL.
*/
void tty_audit_exit(void)
{
struct tty_audit_buf *buf;
spin_lock_irq(&current->sighand->siglock);
buf = current->signal->tty_audit_buf;
current->signal->tty_audit_buf = NULL;
spin_unlock_irq(&current->sighand->siglock);
if (!buf)
return;
mutex_lock(&buf->mutex);
tty_audit_buf_push_current(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
/**
* tty_audit_fork - Copy TTY audit state for a new task
*
* Set up TTY audit state in @sig from current. @sig needs no locking.
*/
void tty_audit_fork(struct signal_struct *sig)
{
spin_lock_irq(&current->sighand->siglock);
sig->audit_tty = current->signal->audit_tty;
spin_unlock_irq(&current->sighand->siglock);
}
/**
* tty_audit_tiocsti - Log TIOCSTI
*/
void tty_audit_tiocsti(struct tty_struct *tty, char ch)
{
struct tty_audit_buf *buf;
int major, minor, should_audit;
spin_lock_irq(&current->sighand->siglock);
should_audit = current->signal->audit_tty;
buf = current->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
spin_unlock_irq(&current->sighand->siglock);
major = tty->driver->major;
minor = tty->driver->minor_start + tty->index;
if (buf) {
mutex_lock(&buf->mutex);
if (buf->major == major && buf->minor == minor)
tty_audit_buf_push_current(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
if (should_audit && audit_enabled) {
uid_t auid;
unsigned int sessionid;
auid = audit_get_loginuid(current);
sessionid = audit_get_sessionid(current);
tty_audit_log("ioctl=TIOCSTI", current, auid, sessionid, major,
minor, &ch, 1);
}
}
/**
* tty_audit_push_task - Flush task's pending audit data
*/
void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
{
struct tty_audit_buf *buf;
spin_lock_irq(&tsk->sighand->siglock);
buf = tsk->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
spin_unlock_irq(&tsk->sighand->siglock);
if (!buf)
return;
mutex_lock(&buf->mutex);
tty_audit_buf_push(tsk, loginuid, sessionid, buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
/**
* tty_audit_buf_get - Get an audit buffer.
*
* Get an audit buffer for @tty, allocate it if necessary. Return %NULL
* if TTY auditing is disabled or out of memory. Otherwise, return a new
* reference to the buffer.
*/
static struct tty_audit_buf *tty_audit_buf_get(struct tty_struct *tty)
{
struct tty_audit_buf *buf, *buf2;
buf = NULL;
buf2 = NULL;
spin_lock_irq(&current->sighand->siglock);
if (likely(!current->signal->audit_tty))
goto out;
buf = current->signal->tty_audit_buf;
if (buf) {
atomic_inc(&buf->count);
goto out;
}
spin_unlock_irq(&current->sighand->siglock);
buf2 = tty_audit_buf_alloc(tty->driver->major,
tty->driver->minor_start + tty->index,
tty->icanon);
if (buf2 == NULL) {
audit_log_lost("out of memory in TTY auditing");
return NULL;
}
spin_lock_irq(&current->sighand->siglock);
if (!current->signal->audit_tty)
goto out;
buf = current->signal->tty_audit_buf;
if (!buf) {
current->signal->tty_audit_buf = buf2;
buf = buf2;
buf2 = NULL;
}
atomic_inc(&buf->count);
/* Fall through */
out:
spin_unlock_irq(&current->sighand->siglock);
if (buf2)
tty_audit_buf_free(buf2);
return buf;
}
/**
* tty_audit_add_data - Add data for TTY auditing.
*
* Audit @data of @size from @tty, if necessary.
*/
void tty_audit_add_data(struct tty_struct *tty, unsigned char *data,
size_t size)
{
struct tty_audit_buf *buf;
int major, minor;
if (unlikely(size == 0))
return;
if (tty->driver->type == TTY_DRIVER_TYPE_PTY
&& tty->driver->subtype == PTY_TYPE_MASTER)
return;
buf = tty_audit_buf_get(tty);
if (!buf)
return;
mutex_lock(&buf->mutex);
major = tty->driver->major;
minor = tty->driver->minor_start + tty->index;
if (buf->major != major || buf->minor != minor
|| buf->icanon != tty->icanon) {
tty_audit_buf_push_current(buf);
buf->major = major;
buf->minor = minor;
buf->icanon = tty->icanon;
}
do {
size_t run;
run = N_TTY_BUF_SIZE - buf->valid;
if (run > size)
run = size;
memcpy(buf->data + buf->valid, data, run);
buf->valid += run;
data += run;
size -= run;
if (buf->valid == N_TTY_BUF_SIZE)
tty_audit_buf_push_current(buf);
} while (size != 0);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
/**
* tty_audit_push - Push buffered data out
*
* Make sure no audit data is pending for @tty on the current process.
*/
void tty_audit_push(struct tty_struct *tty)
{
struct tty_audit_buf *buf;
spin_lock_irq(&current->sighand->siglock);
if (likely(!current->signal->audit_tty)) {
spin_unlock_irq(&current->sighand->siglock);
return;
}
buf = current->signal->tty_audit_buf;
if (buf)
atomic_inc(&buf->count);
spin_unlock_irq(&current->sighand->siglock);
if (buf) {
int major, minor;
major = tty->driver->major;
minor = tty->driver->minor_start + tty->index;
mutex_lock(&buf->mutex);
if (buf->major == major && buf->minor == minor)
tty_audit_buf_push_current(buf);
mutex_unlock(&buf->mutex);
tty_audit_buf_put(buf);
}
}