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Fixes a segfault occurring when e.g. <TAB> is pressed multiple times in the ncurses tmon application. The segfault is caused by incrementing cur_thermal_record in the main function without checking if it's value reached NR_THERMAL_RECORD immediately. Since the boundary check only occurred in update_thermal_data a race condition existed, which lead to an attempted read beyond the last element of the trec array. The fix was implemented by moving the cur_thermal_record incrementation to the update_thermal_data function using a temporary variable on which the boundary condition is checked before updating cur_thread_record, so that the variable is never incremented beyond the trec array's boundary. It seems the segfault does not occur on every machine: On a HP EliteBook G4 the segfault happens, while it does not happen on a Thinkpad T540p. Signed-off-by: Frank Asseg <frank.asseg@objecthunter.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz> |
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| .. | ||
| .gitignore | ||
| Makefile | ||
| pid.c | ||
| README | ||
| sysfs.c | ||
| tmon.8 | ||
| tmon.c | ||
| tmon.h | ||
| tui.c | ||
TMON - A Monitoring and Testing Tool for Linux kernel thermal subsystem Why TMON? ========== Increasingly, Linux is running on thermally constrained devices. The simple thermal relationship between processor and fan has become past for modern computers. As hardware vendors cope with the thermal constraints on their products, more and more sensors are added, new cooling capabilities are introduced. The complexity of the thermal relationship can grow exponentially among cooling devices, zones, sensors, and trip points. They can also change dynamically. To expose such relationship to the userspace, Linux generic thermal layer introduced sysfs entry at /sys/class/thermal with a matrix of symbolic links, trip point bindings, and device instances. To traverse such matrix by hand is not a trivial task. Testing is also difficult in that thermal conditions are often exception cases that hard to reach in normal operations. TMON is conceived as a tool to help visualize, tune, and test the complex thermal subsystem. Files ===== tmon.c : main function for set up and configurations. tui.c : handles ncurses based user interface sysfs.c : access to the generic thermal sysfs pid.c : a proportional-integral-derivative (PID) controller that can be used for thermal relationship training. Requirements ============ Depends on ncurses Build ========= $ make $ sudo ./tmon -h Usage: tmon [OPTION...] -c, --control cooling device in control -d, --daemon run as daemon, no TUI -l, --log log data to /var/tmp/tmon.log -h, --help show this help message -t, --time-interval set time interval for sampling -v, --version show version -g, --debug debug message in syslog 1. For monitoring only: $ sudo ./tmon