x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 180 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-annotate.txt b/tools/perf/Documentation/perf-annotate.txt
new file mode 100644
index 000000000..a68873880
--- /dev/null
+++ b/tools/perf/Documentation/perf-annotate.txt
@@ -0,0 +1,180 @@
+perf-annotate(1)
+================
+
+NAME
+----
+perf-annotate - Read perf.data (created by perf record) and display annotated code
+
+SYNOPSIS
+--------
+[verse]
+'perf annotate' [-i <file> | --input=file] [symbol_name]
+
+DESCRIPTION
+-----------
+This command reads the input file and displays an annotated version of the
+code. If the object file has debug symbols then the source code will be
+displayed alongside assembly code.
+
+If there is no debug info in the object, then annotated assembly is displayed.
+
+OPTIONS
+-------
+-i::
+--input=<file>::
+        Input file name. (default: perf.data unless stdin is a fifo)
+
+-d::
+--dsos=<dso[,dso...]>::
+        Only consider symbols in these dsos.
+-s::
+--symbol=<symbol>::
+        Symbol to annotate.
+
+-f::
+--force::
+        Don't do ownership validation.
+
+-v::
+--verbose::
+        Be more verbose. (Show symbol address, etc)
+
+-q::
+--quiet::
+	Do not show any warnings or messages.  (Suppress -v)
+
+-n::
+--show-nr-samples::
+	Show the number of samples for each symbol
+
+-D::
+--dump-raw-trace::
+        Dump raw trace in ASCII.
+
+-k::
+--vmlinux=<file>::
+        vmlinux pathname.
+
+--ignore-vmlinux::
+	Ignore vmlinux files.
+
+--itrace::
+	Options for decoding instruction tracing data. The options are:
+
+include::itrace.txt[]
+
+	To disable decoding entirely, use --no-itrace.
+
+-m::
+--modules::
+        Load module symbols. WARNING: use only with -k and LIVE kernel.
+
+-l::
+--print-line::
+        Print matching source lines (may be slow).
+
+-P::
+--full-paths::
+        Don't shorten the displayed pathnames.
+
+--stdio:: Use the stdio interface.
+
+--stdio2:: Use the stdio2 interface, non-interactive, uses the TUI formatting.
+
+--stdio-color=<mode>::
+	'always', 'never' or 'auto', allowing configuring color output
+	via the command line, in addition to via "color.ui" .perfconfig.
+	Use '--stdio-color always' to generate color even when redirecting
+	to a pipe or file. Using just '--stdio-color' is equivalent to
+	using 'always'.
+
+--tui:: Use the TUI interface. Use of --tui requires a tty, if one is not
+	present, as when piping to other commands, the stdio interface is
+	used. This interfaces starts by centering on the line with more
+	samples, TAB/UNTAB cycles through the lines with more samples.
+
+--gtk:: Use the GTK interface.
+
+-C::
+--cpu=<cpu>:: Only report samples for the list of CPUs provided. Multiple CPUs can
+	be provided as a comma-separated list with no space: 0,1. Ranges of
+	CPUs are specified with -: 0-2. Default is to report samples on all
+	CPUs.
+
+--asm-raw::
+	Show raw instruction encoding of assembly instructions.
+
+--show-total-period:: Show a column with the sum of periods.
+
+--source::
+	Interleave source code with assembly code. Enabled by default,
+	disable with --no-source.
+
+--symfs=<directory[,layout]>::
+        Look for files with symbols relative to this directory. The optional
+        layout can be 'hierarchy' (default, matches full path) or 'flat'
+        (only matches base name). This is useful when debug files are stored
+        in a flat directory structure.
+
+-M::
+--disassembler-style=:: Set disassembler style for objdump.
+
+--addr2line=<path>::
+        Path to addr2line binary.
+
+--objdump=<path>::
+        Path to objdump binary.
+
+--prefix=PREFIX::
+--prefix-strip=N::
+	Remove first N entries from source file path names in executables
+	and add PREFIX. This allows to display source code compiled on systems
+	with different file system layout.
+
+--skip-missing::
+	Skip symbols that cannot be annotated.
+
+--group::
+	Show event group information together
+
+--demangle::
+	Demangle symbol names to human readable form. It's enabled by default,
+	disable with --no-demangle.
+
+--demangle-kernel::
+	Demangle kernel symbol names to human readable form (for C++ kernels).
+
+--percent-type::
+	Set annotation percent type from following choices:
+	  global-period, local-period, global-hits, local-hits
+
+	The local/global keywords set if the percentage is computed
+	in the scope of the function (local) or the whole data (global).
+	The period/hits keywords set the base the percentage is computed
+	on - the samples period or the number of samples (hits).
+
+--percent-limit::
+	Do not show functions which have an overhead under that percent on
+	stdio or stdio2 (Default: 0).  Note that this is about selection of
+	functions to display, not about lines within the function.
+
+--data-type[=TYPE_NAME]::
+	Display data type annotation instead of code.  It infers data type of
+	samples (if they are memory accessing instructions) using DWARF debug
+	information.  It can take an optional argument of data type name.  In
+	that case it'd show annotation for the type only, otherwise it'd show
+	all data types it finds.
+
+--type-stat::
+	Show stats for the data type annotation.
+
+--skip-empty::
+	Do not display empty (or dummy) events.
+
+--code-with-type::
+	Show data type info in code annotation (for memory instructions only).
+
+
+SEE ALSO
+--------
+linkperf:perf-record[1], linkperf:perf-report[1]