From 4e37958d1288ce90e8b8eb526ed93d6b2ee6cf54 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Mon, 26 Mar 2018 13:31:07 -0400 Subject: [PATCH] init, tracing: Have printk come through the trace events for initcall_debug With trace events set before and after the initcall function calls, instead of having a separate routine for printing out the initcalls when initcall_debug is specified on the kernel command line, have the code register a callback to the tracepoints where the initcall trace events are. This removes the need for having a separate function to do the initcalls as the tracepoint callbacks can handle the printk. It also includes other initcalls that are not called by the do_one_initcall() which includes console and security initcalls. Signed-off-by: Steven Rostedt (VMware) --- init/main.c | 51 +++++++++++++++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 16 deletions(-) diff --git a/init/main.c b/init/main.c index 2af8f2bb5ca8..589d1226016e 100644 --- a/init/main.c +++ b/init/main.c @@ -494,6 +494,10 @@ void __init __weak thread_stack_cache_init(void) void __init __weak mem_encrypt_init(void) { } +bool initcall_debug; +core_param(initcall_debug, initcall_debug, bool, 0644); +static void __init initcall_debug_enable(void); + /* * Set up kernel memory allocators */ @@ -615,6 +619,9 @@ asmlinkage __visible void __init start_kernel(void) /* Trace events are available after this */ trace_init(); + if (initcall_debug) + initcall_debug_enable(); + context_tracking_init(); /* init some links before init_ISA_irqs() */ early_irq_init(); @@ -731,9 +738,6 @@ static void __init do_ctors(void) #endif } -bool initcall_debug; -core_param(initcall_debug, initcall_debug, bool, 0644); - #ifdef CONFIG_KALLSYMS struct blacklist_entry { struct list_head next; @@ -803,38 +807,53 @@ static bool __init_or_module initcall_blacklisted(initcall_t fn) #endif __setup("initcall_blacklist=", initcall_blacklist); -static int __init_or_module do_one_initcall_debug(initcall_t fn) +static __init_or_module void +trace_initcall_start_cb(void *data, initcall_t fn) { - ktime_t calltime, delta, rettime; - unsigned long long duration; - int ret; + ktime_t *calltime = (ktime_t *)data; printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current)); - calltime = ktime_get(); - ret = fn(); + *calltime = ktime_get(); +} + +static __init_or_module void +trace_initcall_finish_cb(void *data, initcall_t fn, int ret) +{ + ktime_t *calltime = (ktime_t *)data; + ktime_t delta, rettime; + unsigned long long duration; + rettime = ktime_get(); - delta = ktime_sub(rettime, calltime); + delta = ktime_sub(rettime, *calltime); duration = (unsigned long long) ktime_to_ns(delta) >> 10; printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn, ret, duration); +} - return ret; +static ktime_t initcall_calltime; + +static void __init initcall_debug_enable(void) +{ + int ret; + + ret = register_trace_initcall_start(trace_initcall_start_cb, + &initcall_calltime); + ret |= register_trace_initcall_finish(trace_initcall_finish_cb, + &initcall_calltime); + WARN(ret, "Failed to register initcall tracepoints\n"); } int __init_or_module do_one_initcall(initcall_t fn) { int count = preempt_count(); - int ret; char msgbuf[64]; + int ret; if (initcall_blacklisted(fn)) return -EPERM; trace_initcall_start(fn); - if (initcall_debug) - ret = do_one_initcall_debug(fn); - else - ret = fn(); + ret = fn(); trace_initcall_finish(fn, ret); msgbuf[0] = 0; -- 2.30.2