linux/arch/arc/kernel/stacktrace.c, branch v4.5

ARC: stack unwinder to bail if PC is not kernel mode

2015-06-19T12:39:29Z

Currently, it doesn't invoke the callback but continues to unwind Also while at it - simplify the code a bit Signed-off-by: Vineet Gupta

ARC: Fix KSTK_ESP()

2015-02-27T05:18:23Z

/proc//maps currently don't annotate stack vma with "[stack]" This is because KSTK_ESP ie expected to return usermode SP of tsk while currently it returns the kernel mode SP of a sleeping tsk. While the fix is trivial, we also need to adjust the ARC kernel stack unwinder to not use KSTK_SP and friends any more. Cc: Reported-and-suggested-by: Alexey Brodkin Signed-off-by: Vineet Gupta

ARC: Make arc_unwind_core accessible externally

2015-02-27T04:45:00Z

The arc unwinder can also be used for perf callchains. Signed-off-by: Mischa Jonker Signed-off-by: Vineet Gupta

arc: export symbol for save_stack_trace() in stacktrace.c

2013-11-06T05:11:44Z

Need export its symbol just like other architectures done, or can not pass compiling with allmodconfig, the related error: MODPOST 2994 modules ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined! ERROR: "save_stack_trace" [drivers/md/persistent-data/dm-persistent-data.ko] undefined! Signed-off-by: Chen Gang Signed-off-by: Vineet Gupta

ARC: Add support for irqflags tracing and lockdep

2013-11-06T05:11:40Z

Lockdep required a small fix to stacktrace API which was incorrectly unwindign out of __switch_to for the current call frame. Signed-off-by: Vineet Gupta

ARC: pt_regs update #3: Remove unused gutter at start of callee_regs

2013-06-22T13:53:22Z

This is trickier than prev two: * context switching code saves kernel mode callee regs in the format of struct callee_regs thus needs adjustment. This also reduces the height of topmost kernel stack frame by 1 word. * Since kernel stack unwinder is sensitive to height of topmost kernel stack frame, that needs a word of adjustment too. ptrace needs a bit of updating since pt_regs now diverges from user_regs_struct. Signed-off-by: Vineet Gupta

dump_stack: consolidate dump_stack() implementations and unify their behaviors

2013-05-01T00:04:02Z

Both dump_stack() and show_stack() are currently implemented by each architecture. show_stack(NULL, NULL) dumps the backtrace for the current task as does dump_stack(). On some archs, dump_stack() prints extra information - pid, utsname and so on - in addition to the backtrace while the two are identical on other archs. The usages in arch-independent code of the two functions indicate show_stack(NULL, NULL) should print out bare backtrace while dump_stack() is used for debugging purposes when something went wrong, so it does make sense to print additional information on the task which triggered dump_stack(). There's no reason to require archs to implement two separate but mostly identical functions. It leads to unnecessary subtle information. This patch expands the dummy fallback dump_stack() implementation in lib/dump_stack.c such that it prints out debug information (taken from x86) and invokes show_stack(NULL, NULL) and drops arch-specific dump_stack() implementations in all archs except blackfin. Blackfin's dump_stack() does something wonky that I don't understand. Debug information can be printed separately by calling dump_stack_print_info() so that arch-specific dump_stack() implementation can still emit the same debug information. This is used in blackfin. This patch brings the following behavior changes. * On some archs, an extra level in backtrace for show_stack() could be printed. This is because the top frame was determined in dump_stack() on those archs while generic dump_stack() can't do that reliably. It can be compensated by inlining dump_stack() but not sure whether that'd be necessary. * Most archs didn't use to print debug info on dump_stack(). They do now. An example WARN dump follows. WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505() Hardware name: empty Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9 0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48 ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58 Call Trace: [] dump_stack+0x19/0x1b [] warn_slowpath_common+0x7f/0xc0 [] warn_slowpath_null+0x1a/0x20 [] init_workqueues+0x35/0x505 ... v2: CPU number added to the generic debug info as requested by s390 folks and dropped the s390 specific dump_stack(). This loses %ksp from the debug message which the maintainers think isn't important enough to keep the s390-specific dump_stack() implementation. dump_stack_print_info() is moved to kernel/printk.c from lib/dump_stack.c. Because linkage is per objecct file, dump_stack_print_info() living in the same lib file as generic dump_stack() means that archs which implement custom dump_stack() - at this point, only blackfin - can't use dump_stack_print_info() as that will bring in the generic version of dump_stack() too. v1 The v1 patch broke build on blackfin due to this issue. The build breakage was reported by Fengguang Wu. Signed-off-by: Tejun Heo Acked-by: David S. Miller Acked-by: Vineet Gupta Acked-by: Jesper Nilsson Acked-by: Vineet Gupta Acked-by: Martin Schwidefsky [s390 bits] Cc: Heiko Carstens Cc: Mike Frysinger Cc: Fengguang Wu Cc: Bjorn Helgaas Cc: Sam Ravnborg Acked-by: Richard Kuo [hexagon bits] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ARC: stacktracing APIs based on dw2 unwinder

2013-02-15T17:46:04Z

Signed-off-by: Vineet Gupta

ARC: Last bits (stubs) to get to a running kernel with UART

2013-02-15T17:45:57Z

This was part of port buildup strategy from Arnd to have a minimal kernel at first and then add optional features (stacktracing, ptrace, smp, kprobes, oprofile....) Signed-off-by: Vineet Gupta