In arm64, the PC of the frame is matched to the last frame function, rather than the function of his frame. For the following example, the stack size of occupy_stack_init function should be 3376, rather than 176.
Wrong info: Depth Size Location (16 entries) ----- ---- -------- 0) 5400 16 __update_load_avg_se.isra.2+0x28/0x220 1) 5384 96 put_prev_entity+0x250/0x338 2) 5288 80 pick_next_task_fair+0x4c4/0x508 3) 5208 72 __schedule+0x100/0x600 4) 5136 184 preempt_schedule_common+0x28/0x48 5) 4952 32 preempt_schedule+0x28/0x30 6) 4920 16 vprintk_emit+0x170/0x1f8 7) 4904 128 vprintk_default+0x48/0x58 8) 4776 64 vprintk_func+0xf8/0x1c8 9) 4712 112 printk+0x70/0x90 10) 4600 176 occupy_stack_init+0x64/0xc0 [kernel_stack] 11) 4424 3376 do_one_initcall+0x68/0x248 12) 1048 144 do_init_module+0x60/0x1f0 13) 904 48 load_module+0x1d50/0x2340 14) 856 352 sys_finit_module+0xd0/0xe8 15) 504 504 el0_svc_naked+0x30/0x34 Correct info: Depth Size Location (18 entries) ----- ---- -------- 0) 5464 48 cgroup_rstat_updated+0x20/0x100 1) 5416 32 cgroup_base_stat_cputime_account_end.isra.0+0x30/0x60 2) 5384 32 __cgroup_account_cputime+0x3c/0x48 3) 5352 64 update_curr+0xc4/0x1d0 4) 5288 72 pick_next_task_fair+0x444/0x508 5) 5216 184 __schedule+0x100/0x600 6) 5032 32 preempt_schedule_common+0x28/0x48 7) 5000 16 preempt_schedule+0x28/0x30 8) 4984 128 vprintk_emit+0x170/0x1f8 9) 4856 64 vprintk_default+0x48/0x58 10) 4792 112 vprintk_func+0xf8/0x1c8 11) 4680 176 printk+0x70/0x90 12) 4504 80 func_test+0x7c/0xb8 [kernel_stack] 13) 4424 3376 occupy_stack_init+0x7c/0xc0 [kernel_stack] 14) 1048 144 do_one_initcall+0x68/0x248 15) 904 48 do_init_module+0x60/0x1f0 16) 856 352 load_module+0x1d50/0x2340 17) 504 504 sys_finit_module+0xd0/0xe8 Signed-off-by: Jiping Ma <jiping....@windriver.com> --- kernel/trace/trace_stack.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 5d16f73898db..ed80b95abf06 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -40,16 +40,28 @@ static void print_max_stack(void) pr_emerg(" Depth Size Location (%d entries)\n" " ----- ---- --------\n", +#ifdef CONFIG_ARM64 + stack_trace_nr_entries - 1); +#else stack_trace_nr_entries); - +#endif +#ifdef CONFIG_ARM64 + for (i = 1; i < stack_trace_nr_entries; i++) { +#else for (i = 0; i < stack_trace_nr_entries; i++) { +#endif if (i + 1 == stack_trace_nr_entries) size = stack_trace_index[i]; else size = stack_trace_index[i] - stack_trace_index[i+1]; +#ifdef CONFIG_ARM64 + pr_emerg("%3ld) %8d %5d %pS\n", i-1, stack_trace_index[i], + size, (void *)stack_dump_trace[i-1]); +#else pr_emerg("%3ld) %8d %5d %pS\n", i, stack_trace_index[i], size, (void *)stack_dump_trace[i]); +#endif } } @@ -324,8 +336,11 @@ static int t_show(struct seq_file *m, void *v) seq_printf(m, " Depth Size Location" " (%d entries)\n" " ----- ---- --------\n", +#ifdef CONFIG_ARM64 + stack_trace_nr_entries - 1); +#else stack_trace_nr_entries); - +#endif if (!stack_tracer_enabled && !stack_trace_max_size) print_disabled(m); @@ -334,6 +349,10 @@ static int t_show(struct seq_file *m, void *v) i = *(long *)v; +#ifdef CONFIG_ARM64 + if (i == 0) + return 0; +#endif if (i >= stack_trace_nr_entries) return 0; @@ -342,9 +361,14 @@ static int t_show(struct seq_file *m, void *v) else size = stack_trace_index[i] - stack_trace_index[i+1]; +#ifdef CONFIG_ARM64 + seq_printf(m, "%3ld) %8d %5d ", i-1, stack_trace_index[i], size); + trace_lookup_stack(m, i-1); +#else seq_printf(m, "%3ld) %8d %5d ", i, stack_trace_index[i], size); trace_lookup_stack(m, i); +#endif return 0; } -- 2.18.1