Pull probes updates from Masami Hiramatsu:
 "BTF typecasting and variable fetch enhancements:

   - Typecast support across probe events: Extended BTF typecasting
     syntax (e.g., (STRUCT)PARAM->MEMBER) to kprobes, uprobes, and
     fprobes on function entry and return

   - Nested typecasts: Added support for chaining and nesting typecasts
     up to 3 levels, including casting registers and stack variables

   - Field specifier option: Added (STRUCT,FIELD) syntax to emulate
     container_of(), allowing retrieval of parent structures from member
     pointers

   - $current variable support: Introduced $current special variable to
     access the running task_struct via BTF dereferencing

   - Per-CPU variable access: Added this_cpu_read() and this_cpu_ptr()
     fetcharg methods to trace CPU-local data safely

   - Fetcharg bytecode dumper: Added CONFIG_PROBE_EVENTS_DUMP_FETCHARG
     to dump the compiled fetcharg bytecode instructions as comments in
     dynamic_events

   - Extended symbol name handling: Removed the MAX_COMMON_HEAD_LEN
     limit and extended MAX_ARGSTR_LEN to 256 bytes, enabling probing of
     long symbols, mangled Rust symbols and complex BTF expressions

   - eprobe variable syntax: Allowed eprobes to reference event fields
     directly without requiring a '$' prefix

   - Cleanup unused parameters, redundant codes, duplicate macros and
     pointer arithmetic

   - Use a ternary operator for simplifying fetch_type_from_btf_type()

  Expanded boot time dynamic probe support:

   - Add boot-time tracing configuration support for event probes
     (eprobes), function probes (fprobes), and tracepoint probes
     (tprobes)

   - Allow comment lines ('#') in dynamic_events file

  Optimization, robustness, and cleanups:

   - Simplify fprobe_remove_ips() by reusing graph and ftrace helpers

   - Remove __packed attribute from struct __fprobe_header to avoid
     unaligned memory access penalties on RISC architectures

   - Remove redundant memset() calls in perf event probe handlers

   - Replace legacy __ASSEMBLY__ with __ASSEMBLER__ in header files

  Selftests & refactoring:

   - Refactor parse_probe_arg() and parse_probe_vars(), and eliminate
     recursion in probe argument parsing to protect kernel stack depth

   - Add selftests for BTF typecasts and module probing without module
     prefixes

   - Force LC_ALL=C in ftracetest to prevent test failures on localized
     systems

   - Refactor btf_type_skip_modifiers() to remove ignored id parameter

   - Sort ERRORS list in trace_probe.h alphabetically

   - Fix typo in fprobe docs, and trace_fprobe function name

   - Rename FETCH_OP_DATA to FETCH_OP_IMMSTR

   - Make file offset error message probe-agnostic"

* tag 'probes-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (37 commits)
  fprobe: Simplify fprobe_remove_ips() by reusing existing helpers
  tracing/boot: Add support for eprobe, fprobe, and tprobe events
  selftests/ftrace: Force C locale in ftracetest
  tracing/probes: Treating longer symbol name on event comparation
  docs: trace: fprobe: fix 'thos' spelling
  tracing/probes: Fix extra whitespace in trace_probe_kernel.h
  tracing/kprobe: Remove redundant memset in kprobe_perf_func()
  tracing/fprobe: Remove redundant memset in fentry_perf_func()
  tracing/fprobe: Remove redundant snprintf in trace_fprobe_match_command_head()
  tracing/probes: Simplify BTF_KIND_PTR case in fetch_type_from_btf_type()
  tracing/probes: Cleanup pointer arithmetic in store_trace_entry_data()
  tracing/probes: Remove unused parameter from parse_probe_var_retval()
  tracing/probes: Remove redundant bounds check in trace_probe_compare_arg_type()
  tracing/probes: Remove redundant boolean conversion in trace_probe_has_single_file()
  tracing/probes: Remove duplicate MAX_ARRAY_LEN macro definition
  selftests/ftrace: Add test case for a symbol in a module without module name
  tracing/probes: Eliminate recursion in parse_probe_arg()
  tracing/probes: Extend max length of argument string
  tracing/probes: Sort ERRORS list in trace_probe.h alphabetically
  tracing/probes: Refactor parse_probe_arg()
  ...

Pull kselftest update from Shuah Khan:
 "Fix zram test failure in kernel_gte() when using dash and a spelling
  error in ftrace poll test comment"

* tag 'linux_kselftest-next-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/zram: fix kernel_gte() for POSIX sh
  selftests/ftrace: fix spelling error in poll test comment

Some ftracetest test cases parse command output by matching English
field names. Tools such as readelf may localize their output via
gettext, while ftracetest currently inherits the user locale from
the environment.

If a translated field name is printed, parsing can fail even though
the tested kernel behavior is unchanged. For example, add_remove_uprobe
can fail to find the ELF entry point and then write a uprobe event with
a missing offset.

Export LC_ALL=C in the top-level ftracetest runner so every test case
gets stable command output by default.

Link: https://lore.kernel.org/all/20260807081512.2974757-2-qirui.001@bytedance.com/

Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

The add_remove_uprobe test uses readelf -h to obtain the ELF entry
point (e_entry) and passes it directly as the offset to uprobe_events.
However, uprobe_events expects a file offset, not a virtual address.

For PIE binaries, the virtual address happens to equal the file offset
because the first LOAD segment has p_vaddr == p_offset, so the test
works by coincidence. But for non-PIE executables, e_entry is an
absolute virtual address that can far exceed the file size. When the
probe is enabled, uprobe_register() checks offset > i_size_read(inode)
and rejects it with -EINVAL.

Fix this by converting the virtual address to a file offset using the
ELF program headers: scan readelf -lW output for the LOAD segment
containing the entry point, then compute file_offset = e_entry -
p_vaddr + p_offset. For PIE binaries the result is unchanged; for
non-PIE binaries the offset is correctly translated.

The conversion uses only POSIX shell primitives, with no dependency on
gawk or perl.

Link: https://lore.kernel.org/all/20260807081512.2974757-3-qirui.001@bytedance.com/

Fixes: dc4b165855f2 ("selftests/ftrace: Use readelf to find entry point in uprobe test")
Cc: stable@vger.kernel.org
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

The add/remove eprobe test installs an eprobe for the openat syscall and
runs ls. It checks the filenames that were opened by ls against a
whitelist and a blacklist.

Commit 206b25c09080 ("tracing: eprobe: read the complete FILTER_PTR_STRING
pointer") fixed access to some string fields in eprobes. This triggers
test failures as the blacklist does not allow relative paths for the
openat parameters.

What makes this test unstable is the fact that the openat calls vary a
lot between different systems.

Refactor the test to make it more robust. "cd <directory>" will issue a
chdir syscall with the target directory as parameter. Set an eprobe on
the sys_enter_chdir event and filter for the exact directory name. Allow
(fault) as fallback.

Link: https://lore.kernel.org/all/20260804194705.760893-1-martin@kaiser.cx/

Fixes: 206b25c09080 ("tracing: eprobe: read the complete FILTER_PTR_STRING pointer")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202607151010.b68428e1-lkp@intel.com
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

When running instance tests, 'ftracetest' creates a new ftrace instance
and runs the tests inside it. Before starting each test, it executes
'initialize_system()' to reset the ftrace state to initial-state.

However, since 'initialize_system()' is executed in the context of the
instance directory, it only cleans up triggers and filters of that
instance.
Any triggers or dynamic events left behind in the top-level instance by
previous failed top-level tests, are left completely untouched. These
top-level leftovers can cause subsequent instance-based tests to fail
or even crash the kernel.

Fix this by executing 'initialize_system()' in the top-level tracing
directory once before entering the instance loop.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/178425671889.84440.9477850701738666404.stgit@devnote2
Fixes: b5b77be812de ("selftests: ftrace: Allow some tests to be run in a tracing instance")
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

Add a test case for probing on a symbol in a module without module name.
When probing on a symbol in a module, ftrace accepts both the syntax that
<MODNAME>:<SYMBOL> and <SYMBOL>. Current test case only checks the former
syntax. This adds a test for the latter one.

Link: https://lore.kernel.org/all/169846405196.88147.17766692778800222203.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

To avoid potential stack overflows on limited kernel stacks, convert
parse_probe_arg() from a recursive function into a loop-based
implementation with a simple local state stack.

Since recursion is eliminated using a loop with a fixed-size
stack in the context, this restricts the dereference nesting
depth. The maximum nesting depth of dereferences is now restricted
to the same limit as typecasts (TRACEPROBE_MAX_NESTED_LEVEL, which
is 8) and reports the same TOO_MANY_NESTED error. Update ftrace
selftests to reflect this restriction and simplify the checks.

Note that this change slightly alters the behavior of nested
dereferencing in fetcharg. Previously, dereferencing without BTF
allowed for up to 14 levels of nesting, whereas dereferencing
with BTF was limited to 3 levels. With this change, the nesting
depth is now limited to 8 levels in both cases.

Link: https://lore.kernel.org/all/178399141396.27810.5390060618628718661.stgit@devnote2/

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

To support BTF argument parsing (such as accessing fields within nested
structures via typecasting), the maximum argument string length needs
to be extended. Extend MAX_ARGSTR_LEN from 63 to 255.

Since MAX_ARGSTR_LEN was previously reused to format command heads in
trace_*probe_match_command_head() functions, introduce a dedicated
MAX_COMMON_HEAD_LEN (63) macro for matching command heads and switch
these functions to use the new macro.

Link: https://lore.kernel.org/all/178399140457.27810.11387684872148824707.stgit@devnote2/

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

With the introduction of container_of-style BTF typecasting and
per-CPU variable access support in trace probes, we need a way to
verify their functionality and prevent regressions.

Add a new ftrace kselftest and update the trace event sample module
to test and validate these features.

Specifically, update the trace-events-sample module to set up a
periodic timer whose callback accesses a per-CPU counter. Introduce
a new sample trace event, foo_timer_fn, to trace this callback
and log the current counter value.

Then, add a new test case, btf_probe_event.tc, which defines a
dynamic probe on the timer callback. The probe uses BTF typecasting
to recover the parent structure from the timer argument and
this_cpu_read() to fetch the per-CPU counter. The test verifies
the integrity of the implementation by ensuring the values
recorded by the dynamic probe match those from the static tracepoint.

Link: https://lore.kernel.org/all/178271368625.1176915.13502654445483530822.stgit@devnote2/

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>