Re: [PATCH v2 02/13] tracing: Fix selftest config check for function graph start up test

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Hi Michael,

Le 20/12/2021 à 17:38, Christophe Leroy a écrit :
> CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is required to test
> direct tramp.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

You didn't apply this patch when you merged the series. Without it I get 
the following :

[    6.191287] Testing ftrace recursion: PASSED
[    6.473308] Testing ftrace recursion safe: PASSED
[    6.755759] Testing ftrace regs: PASSED
[    7.037994] Testing tracer nop: PASSED
[    7.042256] Testing tracer function_graph: FAILED!
[   12.216112] ------------[ cut here ]------------
[   12.220436] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1953 
run_tracer_selftest+0x138/0x1b4
[   12.229045] CPU: 0 PID: 1 Comm: swapper Not tainted 
5.17.0-rc2-s3k-dev-02096-g28b040bd2357 #1030
[   12.237735] NIP:  c00d01b4 LR: c00d01b4 CTR: c03d37fc
[   12.242724] REGS: c902bd90 TRAP: 0700   Not tainted 
(5.17.0-rc2-s3k-dev-02096-g28b040bd2357)
[   12.251157] MSR:  00029032 <EE,ME,IR,DR,RI>  CR: 28000242  XER: 00000000
[   12.257870]
[   12.257870] GPR00: c00d01b4 c902be50 c2140000 00000007 c108d224 
00000001 c11ed2e8 c108d340
[   12.257870] GPR08: 3fffbfff 00000000 c129beac 3fffc000 22000244 
00000000 c0004b78 00000000
[   12.257870] GPR16: 00000000 00000000 00000000 00000000 00000000 
00000000 00000000 c1039020
[   12.257870] GPR24: c12d0000 c1000144 c1223c48 c12b53c4 c12b55dc 
c1293118 fffffdf4 c1223c38
[   12.293843] NIP [c00d01b4] run_tracer_selftest+0x138/0x1b4
[   12.299265] LR [c00d01b4] run_tracer_selftest+0x138/0x1b4
[   12.304603] Call Trace:
[   12.307012] [c902be50] [c00d01b4] run_tracer_selftest+0x138/0x1b4 
(unreliable)
[   12.314155] [c902be70] [c100cf44] register_tracer+0x14c/0x218
[   12.319835] [c902be90] [c10011a0] do_one_initcall+0x8c/0x17c
[   12.325430] [c902bef0] [c10014c0] kernel_init_freeable+0x1a8/0x254
[   12.331540] [c902bf20] [c0004ba8] kernel_init+0x30/0x150
[   12.336789] [c902bf30] [c001222c] ret_from_kernel_thread+0x5c/0x64
[   12.342902] Instruction dump:
[   12.345828] 4bf9a135 813d0030 7fc4f378 7d2903a6 7fa3eb78 4e800421 
7c7e1b79 939f0f60
[   12.353657] 41820014 3c60c08a 3863644c 4bf9a109 <0fe00000> 387f00b0 
4bff76bd 893d0052
[   12.361659] ---[ end trace 0000000000000000 ]---


With the patch I get:

[    6.191286] Testing ftrace recursion: PASSED
[    6.473307] Testing ftrace recursion safe: PASSED
[    6.755758] Testing ftrace regs: PASSED
[    7.037993] Testing tracer nop: PASSED
[    7.042255] Testing tracer function_graph: PASSED

Is this patch going to be merged via another tree ?

Thanks
Christophe


> ---
>   kernel/trace/trace_selftest.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
> index afd937a46496..abcadbe933bb 100644
> --- a/kernel/trace/trace_selftest.c
> +++ b/kernel/trace/trace_selftest.c
> @@ -784,9 +784,7 @@ static struct fgraph_ops fgraph_ops __initdata  = {
>   	.retfunc		= &trace_graph_return,
>   };
>   
> -#if defined(CONFIG_DYNAMIC_FTRACE) && \
> -    defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS)
> -#define TEST_DIRECT_TRAMP
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
>   noinline __noclone static void trace_direct_tramp(void) { }
>   #endif
>   
> @@ -849,7 +847,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
>   		goto out;
>   	}
>   
> -#ifdef TEST_DIRECT_TRAMP
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
>   	tracing_reset_online_cpus(&tr->array_buffer);
>   	set_graph_array(tr);
>