diff options
Diffstat (limited to 'Documentation/process/debugging')
4 files changed, 32 insertions, 57 deletions
diff --git a/Documentation/process/debugging/driver_development_debugging_guide.rst b/Documentation/process/debugging/driver_development_debugging_guide.rst index 46becda8764b..aca08f457793 100644 --- a/Documentation/process/debugging/driver_development_debugging_guide.rst +++ b/Documentation/process/debugging/driver_development_debugging_guide.rst @@ -155,7 +155,7 @@ The general idea is: ``my_variable`` - Clean up the directory when removing the device - (``debugfs_remove_recursive(parent);``) + (``debugfs_remove(parent);``) For the full documentation see :doc:`/filesystems/debugfs`. diff --git a/Documentation/process/debugging/gdb-kernel-debugging.rst b/Documentation/process/debugging/gdb-kernel-debugging.rst index 895285c037c7..53e225760a4d 100644 --- a/Documentation/process/debugging/gdb-kernel-debugging.rst +++ b/Documentation/process/debugging/gdb-kernel-debugging.rst @@ -127,35 +127,31 @@ Examples of using the Linux-provided gdb helpers - Make use of the per-cpu function for the current or a specified CPU:: - (gdb) p $lx_per_cpu("runqueues").nr_running + (gdb) p $lx_per_cpu(runqueues).nr_running $3 = 1 - (gdb) p $lx_per_cpu("runqueues", 2).nr_running + (gdb) p $lx_per_cpu(runqueues, 2).nr_running $4 = 0 - Dig into hrtimers using the container_of helper:: - (gdb) set $next = $lx_per_cpu("hrtimer_bases").clock_base[0].active.next - (gdb) p *$container_of($next, "struct hrtimer", "node") + (gdb) set $leftmost = $lx_per_cpu(hrtimer_bases).clock_base[0].active.rb_root.rb_leftmost + (gdb) p *$container_of($leftmost, "struct hrtimer", "node") $5 = { node = { node = { - __rb_parent_color = 18446612133355256072, - rb_right = 0x0 <irq_stack_union>, - rb_left = 0x0 <irq_stack_union> + __rb_parent_color = 18446612686384860673, + rb_right = 0xffff888231da8b00, + rb_left = 0x0 }, - expires = { - tv64 = 1835268000000 - } + expires = 1228461000000 }, - _softexpires = { - tv64 = 1835268000000 - }, - function = 0xffffffff81078232 <tick_sched_timer>, - base = 0xffff88003fd0d6f0, - state = 1, - start_pid = 0, - start_site = 0xffffffff81055c1f <hrtimer_start_range_ns+20>, - start_comm = "swapper/2\000\000\000\000\000\000" + _softexpires = 1228461000000, + function = 0xffffffff8137ab20 <tick_nohz_handler>, + base = 0xffff888231d9b4c0, + state = 1 '\001', + is_rel = 0 '\000', + is_soft = 0 '\000', + is_hard = 1 '\001' } @@ -177,3 +173,12 @@ this is just a snapshot of the initial version:: Detailed help can be obtained via "help <command-name>" for commands and "help function <function-name>" for convenience functions. + +Debugging GDB scripts +--------------------- + +GDB does not enable a full Python backtrace which can make debugging GDB +scripts more difficult than necessary. The following will allow for printing a +full backtrace of the python environment:: + + (gdb) set python print-stack full diff --git a/Documentation/process/debugging/index.rst b/Documentation/process/debugging/index.rst index 387d33d16f5e..357243e184e1 100644 --- a/Documentation/process/debugging/index.rst +++ b/Documentation/process/debugging/index.rst @@ -15,8 +15,6 @@ general guides kgdb userspace_debugging_guide -.. only:: subproject and html - subsystem specific guides ------------------------- @@ -25,13 +23,6 @@ subsystem specific guides media_specific_debugging_guide -.. only:: subproject and html - - Indices - ======= - - * :ref:`genindex` - General debugging advice ======================== diff --git a/Documentation/process/debugging/kgdb.rst b/Documentation/process/debugging/kgdb.rst index b29b0aac2717..dd6a103073fa 100644 --- a/Documentation/process/debugging/kgdb.rst +++ b/Documentation/process/debugging/kgdb.rst @@ -380,6 +380,13 @@ virtual address where the kernel image is mapped and confuses gdb which resolves addresses of kernel symbols from the symbol table of vmlinux. +Kernel parameter: ``rodata`` +---------------------------- + +``CONFIG_STRICT_KERNEL_RWX`` is turned on by default and is not +visible to menuconfig on some architectures (arm64 for example), +you can pass ``rodata=off`` to the kernel in this case. + Using kdb ========= @@ -889,34 +896,6 @@ in the virtual console layer. On resuming kernel execution, the kernel debugger calls kgdboc_post_exp_handler() which in turn calls con_debug_leave(). -Any video driver that wants to be compatible with the kernel debugger -and the atomic kms callbacks must implement the ``mode_set_base_atomic``, -``fb_debug_enter`` and ``fb_debug_leave operations``. For the -``fb_debug_enter`` and ``fb_debug_leave`` the option exists to use the -generic drm fb helper functions or implement something custom for the -hardware. The following example shows the initialization of the -.mode_set_base_atomic operation in -drivers/gpu/drm/i915/intel_display.c:: - - - static const struct drm_crtc_helper_funcs intel_helper_funcs = { - [...] - .mode_set_base_atomic = intel_pipe_set_base_atomic, - [...] - }; - - -Here is an example of how the i915 driver initializes the -fb_debug_enter and fb_debug_leave functions to use the generic drm -helpers in ``drivers/gpu/drm/i915/intel_fb.c``:: - - - static struct fb_ops intelfb_ops = { - [...] - .fb_debug_enter = drm_fb_helper_debug_enter, - .fb_debug_leave = drm_fb_helper_debug_leave, - [...] - }; Credits |