- Fix read out of bounds bug in tracing_splice_read_pipe()
The size of the sub page being read can now be greater than a page. But
the buffer used in tracing_splice_read_pipe() only allocates a page size.
The data copied to the buffer is the amount in sub buffer which can
overflow the buffer. Use min((size_t)trace_seq_used(&iter->seq), PAGE_SIZE)
to limit the amount copied to the buffer to a max of PAGE_SIZE.
- Fix the test for NULL from "!filter_hash" to "!*filter_hash"
The add_next_hash() function checked for NULL at the wrong pointer level.
- Do not use the array in trace_adjust_address() if there are no elements
The trace_adjust_address() finds the offset of a module that was stored in
the persistent buffer when reading the previous boot buffer to see if the
address belongs to a module that was loaded in the previous boot. An array
is created that matches currently loaded modules with previously loaded
modules. The trace_adjust_address() uses that array to find the new offset
of the address that's in the previous buffer. But if no module was
loaded, it ends up reading the last element in an array that was never
allocated. Check if nr_entries is zero and exit out early if it is.
- Remove nested lock of trace_event_sem in print_event_fields()
The print_event_fields() function iterates over the ftrace_events list and
requires the trace_event_sem semaphore held for read. But this function is
always called with that semaphore held for read. Remove the taking of the
semaphore and replace it with lockdep_assert_held_read(&trace_event_sem);
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Merge tag 'trace-v6.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix read out of bounds bug in tracing_splice_read_pipe()
The size of the sub page being read can now be greater than a page.
But the buffer used in tracing_splice_read_pipe() only allocates a
page size. The data copied to the buffer is the amount in sub buffer
which can overflow the buffer.
Use min((size_t)trace_seq_used(&iter->seq), PAGE_SIZE) to limit the
amount copied to the buffer to a max of PAGE_SIZE.
- Fix the test for NULL from "!filter_hash" to "!*filter_hash"
The add_next_hash() function checked for NULL at the wrong pointer
level.
- Do not use the array in trace_adjust_address() if there are no
elements
The trace_adjust_address() finds the offset of a module that was
stored in the persistent buffer when reading the previous boot buffer
to see if the address belongs to a module that was loaded in the
previous boot. An array is created that matches currently loaded
modules with previously loaded modules. The trace_adjust_address()
uses that array to find the new offset of the address that's in the
previous buffer. But if no module was loaded, it ends up reading the
last element in an array that was never allocated.
Check if nr_entries is zero and exit out early if it is.
- Remove nested lock of trace_event_sem in print_event_fields()
The print_event_fields() function iterates over the ftrace_events
list and requires the trace_event_sem semaphore held for read. But
this function is always called with that semaphore held for read.
Remove the taking of the semaphore and replace it with
lockdep_assert_held_read(&trace_event_sem)
* tag 'trace-v6.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Do not take trace_event_sem in print_event_fields()
tracing: Fix trace_adjust_address() when there is no modules in scratch area
ftrace: Fix NULL memory allocation check
tracing: Fix oob write in trace_seq_to_buffer()
59c9ab3e8c