2019-05-19 13:08:20 +01:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:06 -08:00
|
|
|
|
2016-01-15 16:59:09 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 14:55:56 -07:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2019-04-05 12:58:57 +11:00
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:50 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:02 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:59 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:56 -08:00
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
2016-01-15 16:58:56 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
2016-01-15 16:58:56 -08:00
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-02-16 23:07:03 +02:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
2018-06-13 19:18:40 +02:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-06-13 19:18:40 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-06-13 19:18:40 +02:00
|
|
|
|
vsprintf: Prevent crash when dereferencing invalid pointers
We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).
Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.
This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.
Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:
+ (null) when accessing data on pure pure NULL address
+ (efault) when accessing data on an invalid address
It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.
Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.
Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-17 13:53:48 +02:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
2018-06-13 19:18:40 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-06-13 19:18:40 +02:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
vsprintf: Prevent crash when dereferencing invalid pointers
We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).
Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.
This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.
Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:
+ (null) when accessing data on pure pure NULL address
+ (efault) when accessing data on an invalid address
It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.
Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.
Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-17 13:53:48 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2017-11-01 15:32:23 +11:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:09 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:09 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2019-08-09 09:24:57 +08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:09 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2019-04-17 13:53:47 +02:00
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:06 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2019-03-04 12:00:09 +02:00
|
|
|
|
2016-01-15 16:59:06 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2019-03-04 12:00:09 +02:00
|
|
|
|
2016-01-15 16:59:06 -08:00
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:59:06 -08:00
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 14:55:56 -07:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
vsprintf: Prevent crash when dereferencing invalid pointers
We already prevent crash when dereferencing some obviously broken
pointers. But the handling is not consistent. Sometimes we print "(null)"
only for pure NULL pointer, sometimes for pointers in the first
page and sometimes also for pointers in the last page (error codes).
Note that printk() call this code under logbuf_lock. Any recursive
printks are redirected to the printk_safe implementation and the messages
are stored into per-CPU buffers. These buffers might be eventually flushed
in printk_safe_flush_on_panic() but it is not guaranteed.
This patch adds a check using probe_kernel_read(). It is not a full-proof
test. But it should help to see the error message in 99% situations where
the kernel would silently crash otherwise.
Also it makes the error handling unified for "%s" and the many %p*
specifiers that need to read the data from a given address. We print:
+ (null) when accessing data on pure pure NULL address
+ (efault) when accessing data on an invalid address
It does not affect the %p* specifiers that just print the given address
in some form, namely %pF, %pf, %pS, %ps, %pB, %pK, %px, and plain %p.
Note that we print (efault) from security reasons. In fact, the real
address can be seen only by %px or eventually %pK.
Link: http://lkml.kernel.org/r/20190417115350.20479-9-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-04-17 13:53:48 +02:00
|
|
|
|
|
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2018-12-04 23:23:11 +02:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
mm, printk: introduce new format string for flags
In mm we use several kinds of flags bitfields that are sometimes printed
for debugging purposes, or exported to userspace via sysfs. To make
them easier to interpret independently on kernel version and config, we
want to dump also the symbolic flag names. So far this has been done
with repeated calls to pr_cont(), which is unreliable on SMP, and not
usable for e.g. sysfs export.
To get a more reliable and universal solution, this patch extends
printk() format string for pointers to handle the page flags (%pGp),
gfp_flags (%pGg) and vma flags (%pGv). Existing users of
dump_flag_names() are converted and simplified.
It would be possible to pass flags by value instead of pointer, but the
%p format string for pointers already has extensions for various kernel
structures, so it's a good fit, and the extra indirection in a
non-critical path is negligible.
[linux@rasmusvillemoes.dk: lots of good implementation suggestions]
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-15 14:55:56 -07:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
2019-04-05 12:58:57 +11:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
|
|
|
|
|
2019-04-05 12:58:57 +11:00
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2016-01-15 16:58:53 -08:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|
2019-04-05 12:58:57 +11:00
|
|
|
|
2015-11-06 16:30:29 -08:00
|
|
|
|
|
|
|
|
|