Various tracing fixes:

- kbuild found missing define of MCOUNT_INSN_SIZE for various build configs
  - Initialize variable to zero as gcc thinks it is used undefined
     (it really isn't but the code is subtle enough that this doesn't hurt)
  - Convert from do_div() to div64_ull() to prevent potential divide by zero
  - Unregister a trace point on error path in sched_wakeup tracer
  - Use signed offset for archs that can have stext not be first
  - A simple indentation fix (whitespace error)
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Merge tag 'trace-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Various tracing fixes:

   - kbuild found missing define of MCOUNT_INSN_SIZE for various build
     configs

   - Initialize variable to zero as gcc thinks it is used undefined (it
     really isn't but the code is subtle enough that this doesn't hurt)

   - Convert from do_div() to div64_ull() to prevent potential divide by
     zero

   - Unregister a trace point on error path in sched_wakeup tracer

   - Use signed offset for archs that can have stext not be first

   - A simple indentation fix (whitespace error)"

* tag 'trace-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix indentation issue
  kernel/trace: Fix do not unregister tracepoints when register sched_migrate_task fail
  tracing: Change offset type to s32 in preempt/irq tracepoints
  ftrace: Avoid potential division by zero in function profiler
  tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined
  tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls
  tracing: Initialize val to zero in parse_entry of inject code
This commit is contained in:
Linus Torvalds 2020-01-06 15:38:38 -08:00
commit ae6088216c
7 changed files with 31 additions and 10 deletions

View File

@ -18,13 +18,13 @@ DECLARE_EVENT_CLASS(preemptirq_template,
TP_ARGS(ip, parent_ip),
TP_STRUCT__entry(
__field(u32, caller_offs)
__field(u32, parent_offs)
__field(s32, caller_offs)
__field(s32, parent_offs)
),
TP_fast_assign(
__entry->caller_offs = (u32)(ip - (unsigned long)_stext);
__entry->parent_offs = (u32)(parent_ip - (unsigned long)_stext);
__entry->caller_offs = (s32)(ip - (unsigned long)_stext);
__entry->parent_offs = (s32)(parent_ip - (unsigned long)_stext);
),
TP_printk("caller=%pS parent=%pS",

View File

@ -96,6 +96,20 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func,
return 0;
}
/*
* Not all archs define MCOUNT_INSN_SIZE which is used to look for direct
* functions. But those archs currently don't support direct functions
* anyway, and ftrace_find_rec_direct() is just a stub for them.
* Define MCOUNT_INSN_SIZE to keep those archs compiling.
*/
#ifndef MCOUNT_INSN_SIZE
/* Make sure this only works without direct calls */
# ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
# error MCOUNT_INSN_SIZE not defined with direct calls enabled
# endif
# define MCOUNT_INSN_SIZE 0
#endif
int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{

View File

@ -526,8 +526,7 @@ static int function_stat_show(struct seq_file *m, void *v)
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
avg = rec->time;
do_div(avg, rec->counter);
avg = div64_ul(rec->time, rec->counter);
if (tracing_thresh && (avg < tracing_thresh))
goto out;
#endif
@ -553,7 +552,8 @@ static int function_stat_show(struct seq_file *m, void *v)
* Divide only 1000 for ns^2 -> us^2 conversion.
* trace_print_graph_duration will divide 1000 again.
*/
do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
stddev = div64_ul(stddev,
rec->counter * (rec->counter - 1) * 1000);
}
trace_seq_init(&s);

View File

@ -195,7 +195,7 @@ static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
unsigned long irq_flags;
void *entry = NULL;
int entry_size;
u64 val;
u64 val = 0;
int len;
entry = trace_alloc_entry(call, &entry_size);

View File

@ -630,7 +630,7 @@ static void start_wakeup_tracer(struct trace_array *tr)
if (ret) {
pr_info("wakeup trace: Couldn't activate tracepoint"
" probe to kernel_sched_migrate_task\n");
return;
goto fail_deprobe_sched_switch;
}
wakeup_reset(tr);
@ -648,6 +648,8 @@ static void start_wakeup_tracer(struct trace_array *tr)
printk(KERN_ERR "failed to start wakeup tracer\n");
return;
fail_deprobe_sched_switch:
unregister_trace_sched_switch(probe_wakeup_sched_switch, NULL);
fail_deprobe_wake_new:
unregister_trace_sched_wakeup_new(probe_wakeup, NULL);
fail_deprobe:

View File

@ -283,6 +283,11 @@ static void check_stack(unsigned long ip, unsigned long *stack)
local_irq_restore(flags);
}
/* Some archs may not define MCOUNT_INSN_SIZE */
#ifndef MCOUNT_INSN_SIZE
# define MCOUNT_INSN_SIZE 0
#endif
static void
stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)