^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) S390 Debug Feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) files:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) - arch/s390/kernel/debug.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) - arch/s390/include/asm/debug.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) ------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) The goal of this feature is to provide a kernel debug logging API
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) where log records can be stored efficiently in memory, where each component
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) (e.g. device drivers) can have one separate debug log.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) One purpose of this is to inspect the debug logs after a production system crash
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) in order to analyze the reason for the crash.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) If the system still runs but only a subcomponent which uses dbf fails,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) it is possible to look at the debug logs on a live system via the Linux
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) debugfs filesystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) The debug feature may also very useful for kernel and driver development.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) Design:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) -------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) Kernel components (e.g. device drivers) can register themselves at the debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) feature with the function call :c:func:`debug_register()`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) This function initializes a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) debug log for the caller. For each debug log exists a number of debug areas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) where exactly one is active at one time. Each debug area consists of contiguous
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) pages in memory. In the debug areas there are stored debug entries (log records)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) which are written by event- and exception-calls.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) An event-call writes the specified debug entry to the active debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) area and updates the log pointer for the active area. If the end
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) of the active debug area is reached, a wrap around is done (ring buffer)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) and the next debug entry will be written at the beginning of the active
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) debug area.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) An exception-call writes the specified debug entry to the log and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) switches to the next debug area. This is done in order to be sure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) that the records which describe the origin of the exception are not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) overwritten when a wrap around for the current area occurs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) The debug areas themselves are also ordered in form of a ring buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) When an exception is thrown in the last debug area, the following debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) entries are then written again in the very first area.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) There are four versions for the event- and exception-calls: One for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) logging raw data, one for text, one for numbers (unsigned int and long),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) and one for sprintf-like formatted strings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) Each debug entry contains the following data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) - Timestamp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) - Cpu-Number of calling task
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) - Level of debug entry (0...6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) - Return Address to caller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) - Flag, if entry is an exception or not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) The debug logs can be inspected in a live system through entries in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) the debugfs-filesystem. Under the toplevel directory "``s390dbf``" there is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) a directory for each registered component, which is named like the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) corresponding component. The debugfs normally should be mounted to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) ``/sys/kernel/debug`` therefore the debug feature can be accessed under
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) ``/sys/kernel/debug/s390dbf``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) The content of the directories are files which represent different views
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) to the debug log. Each component can decide which views should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) used through registering them with the function :c:func:`debug_register_view()`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) Predefined views for hex/ascii and sprintf data are provided.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) It is also possible to define other views. The content of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) a view can be inspected simply by reading the corresponding debugfs file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) All debug logs have an actual debug level (range from 0 to 6).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) The default level is 3. Event and Exception functions have a :c:data:`level`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) parameter. Only debug entries with a level that is lower or equal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) than the actual level are written to the log. This means, when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) writing events, high priority log entries should have a low level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) value whereas low priority entries should have a high one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) The actual debug level can be changed with the help of the debugfs-filesystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) through writing a number string "x" to the ``level`` debugfs file which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) provided for every debug log. Debugging can be switched off completely
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) by using "-" on the ``level`` debugfs file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) Example::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) > echo "-" > /sys/kernel/debug/s390dbf/dasd/level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) It is also possible to deactivate the debug feature globally for every
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) debug log. You can change the behavior using 2 sysctl parameters in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) ``/proc/sys/s390dbf``:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) There are currently 2 possible triggers, which stop the debug feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) globally. The first possibility is to use the ``debug_active`` sysctl. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) set to 1 the debug feature is running. If ``debug_active`` is set to 0 the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) debug feature is turned off.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) The second trigger which stops the debug feature is a kernel oops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) That prevents the debug feature from overwriting debug information that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) happened before the oops. After an oops you can reactivate the debug feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) by piping 1 to ``/proc/sys/s390dbf/debug_active``. Nevertheless, it's not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) suggested to use an oopsed kernel in a production environment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) If you want to disallow the deactivation of the debug feature, you can use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) the ``debug_stoppable`` sysctl. If you set ``debug_stoppable`` to 0 the debug
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) feature cannot be stopped. If the debug feature is already stopped, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) will stay deactivated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) Kernel Interfaces:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) ------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) .. kernel-doc:: arch/s390/kernel/debug.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) .. kernel-doc:: arch/s390/include/asm/debug.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) Predefined views:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) extern struct debug_view debug_hex_ascii_view;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) extern struct debug_view debug_sprintf_view;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) Examples
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) --------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * hex_ascii-view Example
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) #include <asm/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) static debug_info_t *debug_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) static int init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /* register 4 debug areas with one page each and 4 byte data field */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) debug_info = debug_register("test", 1, 4, 4 );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) debug_register_view(debug_info, &debug_hex_ascii_view);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) debug_text_event(debug_info, 4 , "one ");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) debug_int_exception(debug_info, 4, 4711);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) debug_event(debug_info, 3, &debug_info, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) static void cleanup(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) debug_unregister(debug_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) module_init(init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) module_exit(cleanup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * sprintf-view Example
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) #include <asm/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) static debug_info_t *debug_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) static int init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) /* register 4 debug areas with one page each and data field for */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) /* format string pointer + 2 varargs (= 3 * sizeof(long)) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) debug_info = debug_register("test", 1, 4, sizeof(long) * 3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) debug_register_view(debug_info, &debug_sprintf_view);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) debug_sprintf_event(debug_info, 2 , "first event in %s:%i\n",__FILE__,__LINE__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) debug_sprintf_exception(debug_info, 1, "pointer to debug info: %p\n",&debug_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) static void cleanup(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) debug_unregister(debug_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) module_init(init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) module_exit(cleanup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) Debugfs Interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) Views to the debug logs can be investigated through reading the corresponding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) debugfs-files:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) Example::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) > ls /sys/kernel/debug/s390dbf/dasd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) flush hex_ascii level pages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) > cat /sys/kernel/debug/s390dbf/dasd/hex_ascii | sort -k2,2 -s
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 00 00974733272:680099 2 - 02 0006ad7e 07 ea 4a 90 | ....
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 00 00974733272:682210 2 - 02 0006ade6 46 52 45 45 | FREE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 00 00974733272:682213 2 - 02 0006adf6 07 ea 4a 90 | ....
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 00 00974733272:682281 1 * 02 0006ab08 41 4c 4c 43 | EXCP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 01 00974733272:682284 2 - 02 0006ab16 45 43 4b 44 | ECKD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 01 00974733272:682287 2 - 02 0006ab28 00 00 00 04 | ....
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 01 00974733272:682289 2 - 02 0006ab3e 00 00 00 20 | ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 01 00974733272:682297 2 - 02 0006ad7e 07 ea 4a 90 | ....
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 01 00974733272:684384 2 - 00 0006ade6 46 52 45 45 | FREE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 01 00974733272:684388 2 - 00 0006adf6 07 ea 4a 90 | ....
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) See section about predefined views for explanation of the above output!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) Changing the debug level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) ------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) Example::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) > cat /sys/kernel/debug/s390dbf/dasd/level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) > echo "5" > /sys/kernel/debug/s390dbf/dasd/level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) > cat /sys/kernel/debug/s390dbf/dasd/level
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) Flushing debug areas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) --------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) Debug areas can be flushed with piping the number of the desired
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) area (0...n) to the debugfs file "flush". When using "-" all debug areas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) are flushed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) Examples:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 1. Flush debug area 0::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) > echo "0" > /sys/kernel/debug/s390dbf/dasd/flush
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 2. Flush all debug areas::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) > echo "-" > /sys/kernel/debug/s390dbf/dasd/flush
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) Changing the size of debug areas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) ------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) It is possible the change the size of debug areas through piping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) the number of pages to the debugfs file "pages". The resize request will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) also flush the debug areas.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) Example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) Define 4 pages for the debug areas of debug feature "dasd"::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) > echo "4" > /sys/kernel/debug/s390dbf/dasd/pages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) Stopping the debug feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) --------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) Example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 1. Check if stopping is allowed::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) > cat /proc/sys/s390dbf/debug_stoppable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 2. Stop debug feature::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) > echo 0 > /proc/sys/s390dbf/debug_active
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) crash Interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) The ``crash`` tool since v5.1.0 has a built-in command
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) ``s390dbf`` to display all the debug logs or export them to the file system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) With this tool it is possible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) to investigate the debug logs on a live system and with a memory dump after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) a system crash.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) Investigating raw memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) ------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) One last possibility to investigate the debug logs at a live
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) system and after a system crash is to look at the raw memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) under VM or at the Service Element.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) It is possible to find the anchor of the debug-logs through
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) the ``debug_area_first`` symbol in the System map. Then one has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) to follow the correct pointers of the data-structures defined
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) in debug.h and find the debug-areas in memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) Normally modules which use the debug feature will also have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) a global variable with the pointer to the debug-logs. Following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) this pointer it will also be possible to find the debug logs in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) For this method it is recommended to use '16 * x + 4' byte (x = 0..n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) for the length of the data field in :c:func:`debug_register()` in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) order to see the debug entries well formatted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) Predefined Views
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) There are two predefined views: hex_ascii and sprintf.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) The hex_ascii view shows the data field in hex and ascii representation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) (e.g. ``45 43 4b 44 | ECKD``).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) The sprintf view formats the debug entries in the same way as the sprintf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) function would do. The sprintf event/exception functions write to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) debug entry a pointer to the format string (size = sizeof(long))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) and for each vararg a long value. So e.g. for a debug entry with a format
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) string plus two varargs one would need to allocate a (3 * sizeof(long))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) byte data area in the debug_register() function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) IMPORTANT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) Using "%s" in sprintf event functions is dangerous. You can only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) use "%s" in the sprintf event functions, if the memory for the passed string
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) is available as long as the debug feature exists. The reason behind this is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) that due to performance considerations only a pointer to the string is stored
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) in the debug feature. If you log a string that is freed afterwards, you will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) get an OOPS when inspecting the debug feature, because then the debug feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) will access the already freed memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) NOTE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) If using the sprintf view do NOT use other event/exception functions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) than the sprintf-event and -exception functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) The format of the hex_ascii and sprintf view is as follows:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) - Number of area
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) - Timestamp (formatted as seconds and microseconds since 00:00:00 Coordinated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) Universal Time (UTC), January 1, 1970)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) - level of debug entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) - Exception flag (* = Exception)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) - Cpu-Number of calling task
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) - Return Address to caller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) - data field
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) A typical line of the hex_ascii view will look like the following (first line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) is only for explanation and will not be displayed when 'cating' the view)::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) area time level exception cpu caller data (hex + ascii)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) --------------------------------------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 00 00964419409:440690 1 - 00 88023fe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) Defining views
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) Views are specified with the 'debug_view' structure. There are defined
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) callback functions which are used for reading and writing the debugfs files:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) struct debug_view {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) char name[DEBUG_MAX_PROCF_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) debug_prolog_proc_t* prolog_proc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) debug_header_proc_t* header_proc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) debug_format_proc_t* format_proc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) debug_input_proc_t* input_proc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) void* private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) where:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) typedef int (debug_header_proc_t) (debug_info_t* id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) struct debug_view* view,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) int area,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) debug_entry_t* entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) char* out_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) typedef int (debug_format_proc_t) (debug_info_t* id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) struct debug_view* view, char* out_buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) const char* in_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) typedef int (debug_prolog_proc_t) (debug_info_t* id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) struct debug_view* view,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) char* out_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) typedef int (debug_input_proc_t) (debug_info_t* id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) struct debug_view* view,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) struct file* file, const char* user_buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) size_t in_buf_size, loff_t* offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) The "private_data" member can be used as pointer to view specific data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) It is not used by the debug feature itself.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) The output when reading a debugfs file is structured like this::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) "prolog_proc output"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) "header_proc output 1" "format_proc output 1"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) "header_proc output 2" "format_proc output 2"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) "header_proc output 3" "format_proc output 3"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) When a view is read from the debugfs, the Debug Feature calls the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 'prolog_proc' once for writing the prolog.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) Then 'header_proc' and 'format_proc' are called for each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) existing debug entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) The input_proc can be used to implement functionality when it is written to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) the view (e.g. like with ``echo "0" > /sys/kernel/debug/s390dbf/dasd/level``).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) For header_proc there can be used the default function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) :c:func:`debug_dflt_header_fn()` which is defined in debug.h.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) and which produces the same header output as the predefined views.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) E.g::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) 00 00964419409:440761 2 - 00 88023ec
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) In order to see how to use the callback functions check the implementation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) of the default views!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) Example:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) #include <asm/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) #define UNKNOWNSTR "data: %08x"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) const char* messages[] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) {"This error...........\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) "That error...........\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) "Problem..............\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) "Something went wrong.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) "Everything ok........\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) static int debug_test_format_fn(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) debug_info_t *id, struct debug_view *view,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) char *out_buf, const char *in_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) int i, rc = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) if (id->buf_size >= 4) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) int msg_nr = *((int*)in_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (msg_nr < sizeof(messages) / sizeof(char*) - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) rc += sprintf(out_buf, "%s", messages[msg_nr]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) rc += sprintf(out_buf, UNKNOWNSTR, msg_nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) struct debug_view debug_test_view = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) "myview", /* name of view */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) NULL, /* no prolog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) &debug_dflt_header_fn, /* default header for each entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) &debug_test_format_fn, /* our own format function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) NULL, /* no input function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) NULL /* no private data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) test:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) =====
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) .. code-block:: c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) debug_info_t *debug_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) debug_info = debug_register("test", 0, 4, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) debug_register_view(debug_info, &debug_test_view);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) for (i = 0; i < 10; i ++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) debug_int_event(debug_info, 1, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) > cat /sys/kernel/debug/s390dbf/test/myview
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) 00 00964419734:611402 1 - 00 88042ca This error...........
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) 00 00964419734:611405 1 - 00 88042ca That error...........
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) 00 00964419734:611408 1 - 00 88042ca Problem..............
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) 00 00964419734:611411 1 - 00 88042ca Something went wrong.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) 00 00964419734:611414 1 - 00 88042ca Everything ok........
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) 00 00964419734:611417 1 - 00 88042ca data: 00000005
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) 00 00964419734:611419 1 - 00 88042ca data: 00000006
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) 00 00964419734:611422 1 - 00 88042ca data: 00000007
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) 00 00964419734:611425 1 - 00 88042ca data: 00000008
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) 00 00964419734:611428 1 - 00 88042ca data: 00000009
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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