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Commit fbb789f0 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (VMware)
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sh/ftrace: Remove only user of ftrace_arch_read_dyn_info() 

I noticed that there's only one user of ftrace_arch_read_dyn_info().
That was used a while ago during the NMI updating in x86, and superh
copied it to implement its version of handling NMIs during
stop_machine().

But that is a debug feature, and this code hasn't been touched since
2009. Also, x86 no longer does the ftrace updates with stop_machine()
and instead uses breakpoints. If superh needs to modify its code, it
should implement the breakpoint conversion, and remove stop_machine().
Which also gets rid of the NMI issue.

Anyway, I want to nuke ftrace_arch_read_dyn_info() and this gets rid of
the one user, which is for an arch that shouldn't need it anymore.

Link: http://lkml.kernel.org/r/20170626181749.2ce954d1@gandalf.local.home



Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: linux-sh@vger.kernel.org
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 8c08f0d5

arch/sh/kernel/ftrace.c

+0 −18
Original line number Diff line number Diff line
@@ -96,19 +96,6 @@ static int mod_code_status; /* holds return value of text write */ 
static void *mod_code_ip;		/* holds the IP to write to */

static void *mod_code_newcode;		/* holds the text to write to the IP */



static unsigned nmi_wait_count;

static atomic_t nmi_update_count = ATOMIC_INIT(0);



int ftrace_arch_read_dyn_info(char *buf, int size)

{

	int r;



	r = snprintf(buf, size, "%u %u",

		     nmi_wait_count,

		     atomic_read(&nmi_update_count));

	return r;

}



static void clear_mod_flag(void)

{

	int old = atomic_read(&nmi_running);
@@ -144,7 +131,6 @@ void arch_ftrace_nmi_enter(void) 
	if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {

		smp_rmb();

		ftrace_mod_code();

		atomic_inc(&nmi_update_count);

	}

	/* Must have previous changes seen before executions */

	smp_mb();
@@ -165,8 +151,6 @@ static void wait_for_nmi_and_set_mod_flag(void) 
	do {

		cpu_relax();

	} while (atomic_cmpxchg(&nmi_running, 0, MOD_CODE_WRITE_FLAG));



	nmi_wait_count++;

}



static void wait_for_nmi(void)
@@ -177,8 +161,6 @@ static void wait_for_nmi(void) 
	do {

		cpu_relax();

	} while (atomic_read(&nmi_running));



	nmi_wait_count++;

}



static int