Fixed issue #2234: Detect 'tsc' clock and don't enable control socket…

… by default if unavailable
derickr · Jan 29, 2024 · cb0e1c0 · cb0e1c0
1 parent 5115378
commit cb0e1c0
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Showing 9 changed files with 82 additions and 13 deletions.
diff --git a/src/base/base.c b/src/base/base.c
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2023 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -1415,6 +1415,21 @@ void xdebug_base_rinit()
 
 #ifdef __linux__
 	/* Set-up Control Socket */
+
+# if HAVE_XDEBUG_CLOCK_GETTIME
+	/* Check whether we have a broken TSC clock, and adjust if needed */
+	if (!XG_BASE(working_tsc_clock)) {
+		if (XINI_BASE(control_socket_granularity) == XDEBUG_CONTROL_SOCKET_DEFAULT) {
+			xdebug_log_ex(XLOG_CHAN_CONFIG, XLOG_WARN, "TSC-NO", "Not setting up control socket with default value due to unavailable 'tsc' clock");
+			XINI_BASE(control_socket_granularity) = XDEBUG_CONTROL_SOCKET_OFF;
+		}
+		if (XINI_BASE(control_socket_granularity) == XDEBUG_CONTROL_SOCKET_TIME) {
+			xdebug_log_ex(XLOG_CHAN_CONFIG, XLOG_WARN, "TSC-INFREQ", "Due to unavailable TSC clock, setting poll granularity to 100ms instead of 25ms");
+			XINI_BASE(control_socket_threshold_ms) = 100;
+		}
+	}
+# endif
+
 	if (XINI_BASE(control_socket_granularity) != XDEBUG_CONTROL_SOCKET_OFF) {
 		xdebug_control_socket_setup();
 	}

diff --git a/src/base/base_globals.h b/src/base/base_globals.h
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2022 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -48,6 +48,7 @@ typedef struct _xdebug_base_globals_t {
 #endif
 	xdebug_nanotime_context nanotime_context;
 	uint64_t      start_nanotime;
+	unsigned int  working_tsc_clock; /* -1 = unknown, 0 = not available, 1 = available */
 	unsigned int  prev_memory;
 	zif_handler   orig_set_time_limit_func;
 	zif_handler   orig_error_reporting_func;

diff --git a/src/base/ctrl_socket.c b/src/base/ctrl_socket.c
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2023 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -292,6 +292,7 @@ void xdebug_control_socket_dispatch(void)
 		case XDEBUG_CONTROL_SOCKET_OFF:
 			return;
 
+		case XDEBUG_CONTROL_SOCKET_DEFAULT:
 		case XDEBUG_CONTROL_SOCKET_TIME:
 			if (xdebug_get_nanotime() < (XG_BASE(control_socket_last_trigger) + (XINI_BASE(control_socket_threshold_ms) * 1000000))) {
 				return;

diff --git a/src/lib/lib.c b/src/lib/lib.c
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2023 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -214,8 +214,17 @@ int xdebug_lib_set_control_socket_granularity(char *value)
 		return 1;
 	}
 
-	XINI_BASE(control_socket_granularity) = XDEBUG_CONTROL_SOCKET_TIME;
-	XINI_BASE(control_socket_threshold_ms) = 25;
+	if (strcmp(value, "default") == 0) {
+		XINI_BASE(control_socket_granularity) = XDEBUG_CONTROL_SOCKET_DEFAULT;
+		XINI_BASE(control_socket_threshold_ms) = 25;
+		return 1;
+	}
+
+	if (strcmp(value, "time") == 0) {
+		XINI_BASE(control_socket_granularity) = XDEBUG_CONTROL_SOCKET_TIME;
+		XINI_BASE(control_socket_threshold_ms) = 25;
+		return 1;
+	}
 
 	return 0;
 }

diff --git a/src/lib/lib.h b/src/lib/lib.h
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2023 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -286,7 +286,8 @@ int xdebug_lib_get_start_upon_error(void);
 
 #if __linux__
 # define XDEBUG_CONTROL_SOCKET_OFF        1
-# define XDEBUG_CONTROL_SOCKET_TIME       4
+# define XDEBUG_CONTROL_SOCKET_DEFAULT    2
+# define XDEBUG_CONTROL_SOCKET_TIME       3
 int xdebug_lib_set_control_socket_granularity(char *value);
 #endif
 

diff --git a/src/lib/log.c b/src/lib/log.c
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2022 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -335,6 +335,7 @@ void xdebug_print_info(void)
 	php_info_print_table_row(2, "Clock Source", "clock_gettime_nsec_np");
 # elif HAVE_XDEBUG_CLOCK_GETTIME
 	php_info_print_table_row(2, "Clock Source", "clock_gettime");
+	php_info_print_table_row(2, "TSC Clock Source", XG_BASE(working_tsc_clock) ? "available" : "unavailable");
 # else
 	php_info_print_table_row(2, "Clock Source", "gettimeofday");
 # endif

diff --git a/src/lib/timing.c b/src/lib/timing.c
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2021 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -124,12 +124,43 @@ static uint64_t xdebug_get_nanotime_rel(xdebug_nanotime_context *nanotime_contex
 
 	return 0;
 }
+
+# ifdef __linux__
+bool detect_linux_working_tsc_clock(void)
+{
+	FILE *current_clocksource;
+	char contents[64];
+
+	current_clocksource = fopen("/sys/devices/system/clocksource/clocksource0/current_clocksource", "r");
+	if (!current_clocksource) {
+		/* Inconclusive, assume working clock */
+		return true;
+	}
+
+	if (!fgets(contents, sizeof(contents), current_clocksource)) {
+		/* Can't read any clock source */
+		fclose(current_clocksource);
+		return false;
+	}
+
+	if (strcmp(contents, "tsc\n") != 0) {
+		/* Current clock is not 'tsc' (+ newline) */
+		fclose(current_clocksource);
+		return false;
+	}
+
+	fclose(current_clocksource);
+	return true;
+}
+# endif
 #endif
 
 void xdebug_nanotime_init(xdebug_base_globals_t *base)
 {
 	xdebug_nanotime_context context = {0};
 
+	base->working_tsc_clock = -1;
+
 #if PHP_WIN32
 	LARGE_INTEGER tcounter;
 
@@ -156,6 +187,13 @@ void xdebug_nanotime_init(xdebug_base_globals_t *base)
 	context.last_rel = 0;
 #endif
 
+#ifdef __linux__
+# if HAVE_XDEBUG_CLOCK_GETTIME
+	/* Detect if we have a 'broken' tsc clock on Linux for clock_gettime */
+	base->working_tsc_clock = detect_linux_working_tsc_clock();
+# endif
+#endif
+
 	base->nanotime_context = context;
 }
 

diff --git a/tests/debugger/bug02123.phpt b/tests/debugger/bug02123.phpt
@@ -42,6 +42,6 @@ echo file_get_contents( $xdebugLogFileName );
 
 %A[Step Debug] WARN: Breakpoint file name does not exist: /var/www/elephpants-are-cool/does-not-exist (No such file or directory).%A
 
-[%d] Log opened at %s
+[%d] Log opened at %s%A
 [%d] [Step Debug] WARN: Breakpoint file name does not exist: /var/www/elephpants-are-cool/does-not-exist (No such file or directory).
 [%d] Log closed at %s
diff --git a/xdebug.c b/xdebug.c
@@ -2,7 +2,7 @@
    +----------------------------------------------------------------------+
    | Xdebug                                                               |
    +----------------------------------------------------------------------+
-   | Copyright (c) 2002-2023 Derick Rethans                               |
+   | Copyright (c) 2002-2024 Derick Rethans                               |
    +----------------------------------------------------------------------+
    | This source file is subject to version 1.01 of the Xdebug license,   |
    | that is bundled with this package in the file LICENSE, and is        |
@@ -241,6 +241,9 @@ ZEND_INI_DISP(display_control_socket)
 		case XDEBUG_CONTROL_SOCKET_OFF:
 			ZEND_PUTS("off");
 			break;
+		case XDEBUG_CONTROL_SOCKET_DEFAULT:
+			php_printf("time: %ldms", XINI_BASE(control_socket_threshold_ms));
+			break;
 		case XDEBUG_CONTROL_SOCKET_TIME:
 			php_printf("time: %ldms", XINI_BASE(control_socket_threshold_ms));
 			break;
@@ -310,7 +313,7 @@ PHP_INI_BEGIN()
 	STD_PHP_INI_ENTRY("xdebug.file_link_format",   "",                      PHP_INI_ALL,                   OnUpdateString, settings.library.file_link_format, zend_xdebug_globals, xdebug_globals)
 	STD_PHP_INI_ENTRY("xdebug.filename_format",    "",                      PHP_INI_ALL,                   OnUpdateString, settings.library.filename_format,  zend_xdebug_globals, xdebug_globals)
 #if __linux__
-	PHP_INI_ENTRY_EX("xdebug.control_socket",      "time",                  PHP_INI_ALL,                   OnUpdateCtrlSocket, display_control_socket)
+	PHP_INI_ENTRY_EX("xdebug.control_socket",      "default",               PHP_INI_ALL,                   OnUpdateCtrlSocket, display_control_socket)
 #endif
 
 	STD_PHP_INI_ENTRY("xdebug.log",       "",           PHP_INI_ALL, OnUpdateString, settings.library.log,       zend_xdebug_globals, xdebug_globals)