perf python: Port export-to-postgresql to perf module

Port export-to-postgresql.py to a standalone script in
tools/perf/python/ using the perf module and libpq via ctypes.

Improvements compared to the legacy script:
- Remove the dependency on PySide/QtSql for database creation and DDL
  execution by driving libpq directly via ctypes (PQconnectdb, PQexec,
  PQputCopyData, PQputCopyEnd) and streaming binary PostgreSQL COPY
  files in PostgresExporter, enabling export on headless servers without
  Qt installed.
- Harden database connection and SQL identifier handling by rejecting
  URI ('://') and connection-parameter ('=') injection strings in
  setup_db() and connect(), escaping single quotes and backslashes in
  connection strings, and quoting SQL identifiers (quote_ident).
- Support Intel PT and instruction trace export via
  perf.session(itrace=...) and perf.call_return callbacks, reconstructing
  relational call_paths and calls tables (including id=0 placeholder
  rows and callfk/returnfk foreign keys) and unpacking synthesized PT
  payloads (ptwrite, cbr, mwait, pwre, exstop, pwrx).
- Use a dedicated context_switch ID counter so context-switch exports
  do not advance sample database IDs out of sync with call_return
  references.

Update Documentation/db-export.txt and add a shell test
(test_export_to_postgresql_python.sh) to verify the standalone exporter.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/db-export.txt

@@ -8,7 +8,7 @@ perf tool's python scripting engine:
 supports scripts:
 
 	tools/perf/python/export-to-sqlite.py
-	tools/perf/scripts/python/export-to-postgresql.py
+	tools/perf/python/export-to-postgresql.py
 
 which export data to a SQLite3 or PostgreSQL database.
 

tools/perf/tests/shell/test_export_to_postgresql_python.sh

@@ -0,0 +1,122 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# export-to-postgresql python test (exclusive)
+
+set -e
+
+shelldir=$(dirname "$0")
+# shellcheck source=lib/setup_python.sh
+. "${shelldir}"/lib/setup_python.sh
+
+if ! "$PYTHON" -c 'import perf' > /dev/null 2>&1; then
+	echo "Skipping test, perf python module not found"
+	exit 2
+fi
+
+# If we don't have psql, we can't test
+if ! command -v psql >/dev/null 2>&1; then
+	echo "Skipping test, psql not found"
+	exit 2
+fi
+
+# Check if we can connect to postgres and create a database
+if ! psql -c "SELECT 1" postgres >/dev/null 2>&1; then
+	echo "Skipping test, cannot connect to postgres"
+	exit 2
+fi
+
+script_dir="$(dirname "$0")/../../python"
+script_path="${script_dir}/export-to-postgresql.py"
+
+if [ ! -f "$script_path" ]; then
+	echo "Skipping test, export-to-postgresql.py not found at $script_path"
+	exit 2
+fi
+
+err=0
+temp_dir=""
+temp_data=""
+temp_db=""
+
+cleanup() {
+	[ -n "${temp_dir}" ] && rm -rf "${temp_dir}"
+	psql -c "DROP DATABASE IF EXISTS ${temp_db}" postgres >/dev/null 2>&1 || true
+}
+
+trap 'cleanup' EXIT
+trap 'cleanup; exit 1' TERM INT
+
+temp_dir=$(mktemp -d /tmp/perf.pg.XXXXXX)
+temp_data="${temp_dir}/perf.data"
+temp_db="perf_test_db_$$"
+
+test_file_mode() {
+	echo "Testing export-to-postgresql.py..."
+
+	# Verify that invalid URI / key-value database names are rejected
+	if "$PYTHON" "$script_path" -i /dev/null -o "dbname=foo host=evil" >/dev/null 2>&1; then
+		echo "Connection parameter injection check failed."
+		err=1
+	fi
+
+	# Generate events with callchains and context switches
+	if ! perf record -g --switch-events -o "${temp_data}" \
+	     -- perf test -w noploop >/dev/null 2>&1 && \
+	   ! perf record -g -o "${temp_data}" -- perf test -w noploop >/dev/null 2>&1; then
+		echo "Skipping test, perf record failed"
+		exit 2
+	fi
+
+	# Ensure clean db start
+	psql -c "DROP DATABASE IF EXISTS ${temp_db}" postgres >/dev/null 2>&1 || true
+
+	# Run the script
+	if ! "$PYTHON" "$script_path" -i "${temp_data}" -o "${temp_db}" >/dev/null; then
+		echo "File mode test failed."
+		err=1
+	else
+		# Check DB
+		if ! psql -d "${temp_db}" -t -c 'SELECT COUNT(*) FROM samples WHERE id > 0;' | \
+			grep -q '[1-9]' || \
+		   ! psql -d "${temp_db}" -t -c 'SELECT COUNT(*) FROM call_paths WHERE id > 0;' | \
+			grep -q '[1-9]'; then
+			echo "PostgreSQL validation failed."
+			err=1
+		else
+			echo "File mode test passed."
+		fi
+	fi
+}
+
+test_intel_pt() {
+	echo "Testing export-to-postgresql.py with intel_pt..."
+
+	psql -c "DROP DATABASE IF EXISTS ${temp_db}" postgres >/dev/null 2>&1 || true
+	rm -f "${temp_data}"
+	# Generate some intel_pt events; use a subshell that waits for uname
+	if ! perf record -B -N --no-bpf-event -e intel_pt//u -o "${temp_data}" \
+		-- sh -c "uname; true" >/dev/null 2>&1; then
+		echo "Skipping intel_pt test, intel_pt not available."
+		return 0
+	fi
+
+	# Run the script with --itrace cr to synthesize call_returns
+	if ! "$PYTHON" "$script_path" -i "${temp_data}" -o "${temp_db}" --itrace cr >/dev/null; then
+		echo "intel_pt file mode test failed."
+		err=1
+	else
+		# Check DB for calls
+		if ! psql -d "${temp_db}" -t -c 'SELECT COUNT(*) FROM calls WHERE id > 0;' | \
+			grep -q '[1-9]'; then
+			echo "PostgreSQL intel_pt validation failed (no calls found)."
+			err=1
+		else
+			echo "intel_pt test passed (cr validated)."
+		fi
+	fi
+}
+
+test_file_mode
+test_intel_pt
+
+exit $err