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2015-12-23tracing: Use seq_buf_used() in seq_buf_to_user() instead of lenJerry Snitselaar
commit 5ac48378414d ("tracing: Use trace_seq_used() and seq_buf_used() instead of len") changed the tracing code to use trace_seq_used() and seq_buf_used() instead of using the seq_buf len directly to avoid overflow issues, but missed a spot in seq_buf_to_user() that makes use of s->len. Cleaned up the code a bit as well per suggestion of Steve Rostedt. Link: http://lkml.kernel.org/r/1447703848-2951-1-git-send-email-jsnitsel@redhat.com Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-03-05seq_buf: Fix seq_buf_bprintf() truncationSteven Rostedt (Red Hat)
In seq_buf_bprintf(), bstr_printf() is used to copy the format into the buffer remaining in the seq_buf structure. The return of bstr_printf() is the amount of characters written to the buffer excluding the '\0', unless the line was truncated! If the line copied does not fit, it is truncated, and a '\0' is added to the end of the buffer. But in this case, '\0' is included in the length of the line written. To know if the buffer had overflowed, the return length will be the same or greater than the length of the buffer passed in. The check in seq_buf_bprintf() only checked if the length returned from bstr_printf() would fit in the buffer, as the seq_buf_bprintf() is only to be an all or nothing command. It either writes all the string into the seq_buf, or none of it. If the string is truncated, the pointers inside the seq_buf must be reset to what they were when the function was called. This is not the case. On overflow, it copies only part of the string. The fix is to change the overflow check to see if the length returned from bstr_printf() is less than the length remaining in the seq_buf buffer, and not if it is less than or equal to as it currently does. Then seq_buf_bprintf() will know if the write from bstr_printf() was truncated or not. Link: http://lkml.kernel.org/r/1425500481.2712.27.camel@perches.com Cc: stable@vger.kernel.org Reported-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-03-04seq_buf: Fix seq_buf_vprintf() truncationSteven Rostedt (Red Hat)
In seq_buf_vprintf(), vsnprintf() is used to copy the format into the buffer remaining in the seq_buf structure. The return of vsnprintf() is the amount of characters written to the buffer excluding the '\0', unless the line was truncated! If the line copied does not fit, it is truncated, and a '\0' is added to the end of the buffer. But in this case, '\0' is included in the length of the line written. To know if the buffer had overflowed, the return length will be the same as the length of the buffer passed in. The check in seq_buf_vprintf() only checked if the length returned from vsnprintf() would fit in the buffer, as the seq_buf_vprintf() is only to be an all or nothing command. It either writes all the string into the seq_buf, or none of it. If the string is truncated, the pointers inside the seq_buf must be reset to what they were when the function was called. This is not the case. On overflow, it copies only part of the string. The fix is to change the overflow check to see if the length returned from vsnprintf() is less than the length remaining in the seq_buf buffer, and not if it is less than or equal to as it currently does. Then seq_buf_vprintf() will know if the write from vsnpritnf() was truncated or not. Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-14bitmap, cpumask, nodemask: remove dedicated formatting functionsTejun Heo
Now that all bitmap formatting usages have been converted to '%*pb[l]', the separate formatting functions are unnecessary. The following functions are removed. * bitmap_scn[list]printf() * cpumask_scnprintf(), cpulist_scnprintf() * [__]nodemask_scnprintf(), [__]nodelist_scnprintf() * seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]() * seq_buf_bitmask() Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-20seq_buf: Move the seq_buf code to lib/Steven Rostedt (Red Hat)
The seq_buf functions are rather useful outside of tracing. Instead of having it be dependent on CONFIG_TRACING, move the code into lib/ and allow other users to have access to it even when tracing is not configured. The seq_buf utility is similar to the seq_file utility, but instead of writing sending data back up to userland, it writes it into a buffer defined at seq_buf_init(). This allows us to send a descriptor around that writes printf() formatted strings into it that can be retrieved later. It is currently used by the tracing facility for such things like trace events to convert its binary saved data in the ring buffer into an ASCII human readable context to be displayed in /sys/kernel/debug/trace. It can also be used for doing NMI prints safely from NMI context into the seq_buf and retrieved later and dumped to printk() safely. Doing printk() from an NMI context is dangerous because an NMI can preempt a current printk() and deadlock on it. Link: http://lkml.kernel.org/p/20140619213952.058255809@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>