tracing: Fixes for v6.15

tracing updates for v6.15

- 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);

git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/fixes

Head SHA1: 0a8f11f8569e7ed16cbcedeb28c4350f6378fea6

Colin Ian King (1):
ftrace: Fix NULL memory allocation check

Jeongjun Park (1):
tracing: Fix oob write in trace_seq_to_buffer()

Steven Rostedt (2):
tracing: Fix trace_adjust_address() when there is no modules in scratch area
tracing: Do not take trace_event_sem in print_event_fields()

----

 kernel/trace/ftrace.c       | 2 +-
 kernel/trace/trace.c        | 9 ++++++---
 kernel/trace/trace_output.c | 4 ++--
 3 files changed, 9 insertions(+), 6 deletions(-)