The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 552701dd0fa7c3d448142e87210590ba424694a0 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Mon, 19 Nov 2018 15:18:40 -0500
Subject: [PATCH] function_graph: Move return callback before update of
curr_ret_stack
In the past, curr_ret_stack had two functions. One was to denote the depth
of the call graph, the other is to keep track of where on the ret_stack the
data is used. Although they may be slightly related, there are two cases
where they need to be used differently.
The one case is that it keeps the ret_stack data from being corrupted by an
interrupt coming in and overwriting the data still in use. The other is just
to know where the depth of the stack currently is.
The function profiler uses the ret_stack to save a "subtime" variable that
is part of the data on the ret_stack. If curr_ret_stack is modified too
early, then this variable can be corrupted.
The "max_depth" option, when set to 1, will record the first functions going
into the kernel. To see all top functions (when dealing with timings), the
depth variable needs to be lowered before calling the return hook. But by
lowering the curr_ret_stack, it makes the data on the ret_stack still being
used by the return hook susceptible to being overwritten.
Now that there's two variables to handle both cases (curr_ret_depth), we can
move them to the locations where they can handle both cases.
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 02d4081a7f5a..4f0d72ae6362 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -261,7 +261,13 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(¤t->trace_overrun);
- trace->depth = current->curr_ret_depth;
+ trace->depth = current->curr_ret_depth--;
+ /*
+ * We still want to trace interrupts coming in if
+ * max_depth is set to 1. Make sure the decrement is
+ * seen before ftrace_graph_return.
+ */
+ barrier();
}
/*
@@ -275,9 +281,14 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
ftrace_pop_return_trace(&trace, &ret, frame_pointer);
trace.rettime = trace_clock_local();
+ ftrace_graph_return(&trace);
+ /*
+ * The ftrace_graph_return() may still access the current
+ * ret_stack structure, we need to make sure the update of
+ * curr_ret_stack is after that.
+ */
barrier();
current->curr_ret_stack--;
- current->curr_ret_depth--;
/*
* The curr_ret_stack can be less than -1 only if it was
* filtered out and it's about to return from the function.
@@ -288,13 +299,6 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
return ret;
}
- /*
- * The trace should run after decrementing the ret counter
- * in case an interrupt were to come in. We don't want to
- * lose the interrupt if max_depth is set.
- */
- ftrace_graph_return(&trace);
-
if (unlikely(!ret)) {
ftrace_graph_stop();
WARN_ON(1);
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b1b35f2e218a5b57d03bbc3b0667d5064570dc60 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Tue, 20 Nov 2018 12:51:07 -0500
Subject: [PATCH] function_graph: Have profiler use curr_ret_stack and not
depth
The profiler uses trace->depth to find its entry on the ret_stack, but the
depth may not match the actual location of where its entry is (if an
interrupt were to preempt the processing of the profiler for another
function, the depth and the curr_ret_stack will be different).
Have it use the curr_ret_stack as the index to find its ret_stack entry
instead of using the depth variable, as that is no longer guaranteed to be
the same.
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 48513954713c..77734451cb05 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -817,7 +817,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip,
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
- int index = trace->depth;
+ int index = current->curr_ret_stack;
function_profile_call(trace->func, 0, NULL, NULL);
@@ -852,7 +852,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
if (!fgraph_graph_time) {
int index;
- index = trace->depth;
+ index = current->curr_ret_stack;
/* Append this call time to the parent time to subtract */
if (index)
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 39eb456dacb543de90d3bc6a8e0ac5cf51ac475e Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Mon, 19 Nov 2018 08:07:12 -0500
Subject: [PATCH] function_graph: Use new curr_ret_depth to manage depth
instead of curr_ret_stack
Currently, the depth of the ret_stack is determined by curr_ret_stack index.
The issue is that there's a race between setting of the curr_ret_stack and
calling of the callback attached to the return of the function.
Commit 03274a3ffb44 ("tracing/fgraph: Adjust fgraph depth before calling
trace return callback") moved the calling of the callback to after the
setting of the curr_ret_stack, even stating that it was safe to do so, when
in fact, it was the reason there was a barrier() there (yes, I should have
commented that barrier()).
Not only does the curr_ret_stack keep track of the current call graph depth,
it also keeps the ret_stack content from being overwritten by new data.
The function profiler, uses the "subtime" variable of ret_stack structure
and by moving the curr_ret_stack, it allows for interrupts to use the same
structure it was using, corrupting the data, and breaking the profiler.
To fix this, there needs to be two variables to handle the call stack depth
and the pointer to where the ret_stack is being used, as they need to change
at two different locations.
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index a51c13c2b1a0..d6183a55e8eb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1116,6 +1116,7 @@ struct task_struct {
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* Index of current stored address in ret_stack: */
int curr_ret_stack;
+ int curr_ret_depth;
/* Stack of return addresses for return function tracing: */
struct ftrace_ret_stack *ret_stack;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f536f601bd46..48513954713c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6814,6 +6814,7 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
atomic_set(&t->tracing_graph_pause, 0);
atomic_set(&t->trace_overrun, 0);
t->curr_ret_stack = -1;
+ t->curr_ret_depth = -1;
/* Make sure the tasks see the -1 first: */
smp_wmb();
t->ret_stack = ret_stack_list[start++];
@@ -7038,6 +7039,7 @@ graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack)
void ftrace_graph_init_idle_task(struct task_struct *t, int cpu)
{
t->curr_ret_stack = -1;
+ t->curr_ret_depth = -1;
/*
* The idle task has no parent, it either has its own
* stack or no stack at all.
@@ -7068,6 +7070,7 @@ void ftrace_graph_init_task(struct task_struct *t)
/* Make sure we do not use the parent ret_stack */
t->ret_stack = NULL;
t->curr_ret_stack = -1;
+ t->curr_ret_depth = -1;
if (ftrace_graph_active) {
struct ftrace_ret_stack *ret_stack;
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 88ca787a1cdc..02d4081a7f5a 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -119,7 +119,7 @@ print_graph_duration(struct trace_array *tr, unsigned long long duration,
/* Add a function return address to the trace stack on thread info.*/
static int
-ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
+ftrace_push_return_trace(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
unsigned long long calltime;
@@ -177,8 +177,6 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
current->ret_stack[index].retp = retp;
#endif
- *depth = current->curr_ret_stack;
-
return 0;
}
@@ -188,14 +186,20 @@ int function_graph_enter(unsigned long ret, unsigned long func,
struct ftrace_graph_ent trace;
trace.func = func;
- trace.depth = current->curr_ret_stack + 1;
+ trace.depth = ++current->curr_ret_depth;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace))
- return -EBUSY;
+ goto out;
- return ftrace_push_return_trace(ret, func, &trace.depth,
- frame_pointer, retp);
+ if (ftrace_push_return_trace(ret, func,
+ frame_pointer, retp))
+ goto out;
+
+ return 0;
+ out:
+ current->curr_ret_depth--;
+ return -EBUSY;
}
/* Retrieve a function return address to the trace stack on thread info.*/
@@ -257,7 +261,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(¤t->trace_overrun);
- trace->depth = index;
+ trace->depth = current->curr_ret_depth;
}
/*
@@ -273,6 +277,7 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
trace.rettime = trace_clock_local();
barrier();
current->curr_ret_stack--;
+ current->curr_ret_depth--;
/*
* The curr_ret_stack can be less than -1 only if it was
* filtered out and it's about to return from the function.
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8712b27c5723c26400a2b350faf1d6d9fd7ffaad Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:25:18 -0500
Subject: [PATCH] MIPS: function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have MIPS use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Ralf Baechle <ralf(a)linux-mips.org>
Cc: Paul Burton <paul.burton(a)mips.com>
Cc: James Hogan <jhogan(a)kernel.org>
Cc: linux-mips(a)linux-mips.org
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 7f3dfdbc3657..b122cbb4aad1 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -322,7 +322,6 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
unsigned long fp)
{
unsigned long old_parent_ra;
- struct ftrace_graph_ent trace;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
int faulted, insns;
@@ -369,12 +368,6 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
if (unlikely(faulted))
goto out;
- if (ftrace_push_return_trace(old_parent_ra, self_ra, &trace.depth, fp,
- NULL) == -EBUSY) {
- *parent_ra_addr = old_parent_ra;
- return;
- }
-
/*
* Get the recorded ip of the current mcount calling site in the
* __mcount_loc section, which will be used to filter the function
@@ -382,13 +375,10 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
*/
insns = core_kernel_text(self_ra) ? 2 : MCOUNT_OFFSET_INSNS + 1;
- trace.func = self_ra - (MCOUNT_INSN_SIZE * insns);
+ self_ra -= (MCOUNT_INSN_SIZE * insns);
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace)) {
- current->curr_ret_stack--;
+ if (function_graph_enter(old_parent_ra, self_ra, fp, NULL))
*parent_ra_addr = old_parent_ra;
- }
return;
out:
ftrace_graph_stop();
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 8712b27c5723c26400a2b350faf1d6d9fd7ffaad Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:25:18 -0500
Subject: [PATCH] MIPS: function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have MIPS use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Ralf Baechle <ralf(a)linux-mips.org>
Cc: Paul Burton <paul.burton(a)mips.com>
Cc: James Hogan <jhogan(a)kernel.org>
Cc: linux-mips(a)linux-mips.org
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c
index 7f3dfdbc3657..b122cbb4aad1 100644
--- a/arch/mips/kernel/ftrace.c
+++ b/arch/mips/kernel/ftrace.c
@@ -322,7 +322,6 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
unsigned long fp)
{
unsigned long old_parent_ra;
- struct ftrace_graph_ent trace;
unsigned long return_hooker = (unsigned long)
&return_to_handler;
int faulted, insns;
@@ -369,12 +368,6 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
if (unlikely(faulted))
goto out;
- if (ftrace_push_return_trace(old_parent_ra, self_ra, &trace.depth, fp,
- NULL) == -EBUSY) {
- *parent_ra_addr = old_parent_ra;
- return;
- }
-
/*
* Get the recorded ip of the current mcount calling site in the
* __mcount_loc section, which will be used to filter the function
@@ -382,13 +375,10 @@ void prepare_ftrace_return(unsigned long *parent_ra_addr, unsigned long self_ra,
*/
insns = core_kernel_text(self_ra) ? 2 : MCOUNT_OFFSET_INSNS + 1;
- trace.func = self_ra - (MCOUNT_INSN_SIZE * insns);
+ self_ra -= (MCOUNT_INSN_SIZE * insns);
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace)) {
- current->curr_ret_stack--;
+ if (function_graph_enter(old_parent_ra, self_ra, fp, NULL))
*parent_ra_addr = old_parent_ra;
- }
return;
out:
ftrace_graph_stop();
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 01e0ab2c4ff12358f15a856fd1a7bbea0670972b Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:21:51 -0500
Subject: [PATCH] arm64: function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have arm64 use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: linux-arm-kernel(a)lists.infradead.org
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Acked-by: Will Deacon <will.deacon(a)arm.com>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index 50986e388d2b..57e962290df3 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -216,8 +216,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
{
unsigned long return_hooker = (unsigned long)&return_to_handler;
unsigned long old;
- struct ftrace_graph_ent trace;
- int err;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
return;
@@ -229,18 +227,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
*/
old = *parent;
- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace))
- return;
-
- err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, NULL);
- if (err == -EBUSY)
- return;
- else
+ if (!function_graph_enter(old, self_addr, frame_pointer, NULL))
*parent = return_hooker;
}
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 18588e1487b19e45bd90bd55ec8d3a1d44f3257f Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:33:17 -0500
Subject: [PATCH] s390/function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have s390 use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Acked-by: Martin Schwidefsky <schwidefsky(a)de.ibm.com>
Cc: Heiko Carstens <heiko.carstens(a)de.ibm.com>
Cc: Julian Wiedmann <jwi(a)linux.ibm.com>
Cc: linux-s390(a)vger.kernel.org
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 84be7f02d0c2..39b13d71a8fe 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -203,22 +203,13 @@ device_initcall(ftrace_plt_init);
*/
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
{
- struct ftrace_graph_ent trace;
-
if (unlikely(ftrace_graph_is_dead()))
goto out;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
goto out;
ip -= MCOUNT_INSN_SIZE;
- trace.func = ip;
- trace.depth = current->curr_ret_stack + 1;
- /* Only trace if the calling function expects to. */
- if (!ftrace_graph_entry(&trace))
- goto out;
- if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
- NULL) == -EBUSY)
- goto out;
- parent = (unsigned long) return_to_handler;
+ if (!function_graph_enter(parent, ip, 0, NULL))
+ parent = (unsigned long) return_to_handler;
out:
return parent;
}
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e949b6db51dc172a35c962bc4414ca148315fe21 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:31:44 -0500
Subject: [PATCH] riscv/function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have riscv use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Greentime Hu <greentime(a)andestech.com>
Cc: Alan Kao <alankao(a)andestech.com>
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Palmer Dabbelt <palmer(a)sifive.com>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 1157b6b52d25..c433f6d3dd64 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -132,7 +132,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
{
unsigned long return_hooker = (unsigned long)&return_to_handler;
unsigned long old;
- struct ftrace_graph_ent trace;
int err;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
@@ -144,17 +143,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
*/
old = *parent;
- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- if (!ftrace_graph_entry(&trace))
- return;
-
- err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, parent);
- if (err == -EBUSY)
- return;
- *parent = return_hooker;
+ if (function_graph_enter(old, self_addr, frame_pointer, parent))
+ *parent = return_hooker;
}
#ifdef CONFIG_DYNAMIC_FTRACE
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e949b6db51dc172a35c962bc4414ca148315fe21 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:31:44 -0500
Subject: [PATCH] riscv/function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have riscv use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Greentime Hu <greentime(a)andestech.com>
Cc: Alan Kao <alankao(a)andestech.com>
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Palmer Dabbelt <palmer(a)sifive.com>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 1157b6b52d25..c433f6d3dd64 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -132,7 +132,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
{
unsigned long return_hooker = (unsigned long)&return_to_handler;
unsigned long old;
- struct ftrace_graph_ent trace;
int err;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
@@ -144,17 +143,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
*/
old = *parent;
- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- if (!ftrace_graph_entry(&trace))
- return;
-
- err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, parent);
- if (err == -EBUSY)
- return;
- *parent = return_hooker;
+ if (function_graph_enter(old, self_addr, frame_pointer, parent))
+ *parent = return_hooker;
}
#ifdef CONFIG_DYNAMIC_FTRACE
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e949b6db51dc172a35c962bc4414ca148315fe21 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
Date: Sun, 18 Nov 2018 17:31:44 -0500
Subject: [PATCH] riscv/function_graph: Simplify with function_graph_enter()
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().
Have riscv use the new code, and remove the shadow stack management as well as
having to set up the trace structure.
This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.
Cc: Greentime Hu <greentime(a)andestech.com>
Cc: Alan Kao <alankao(a)andestech.com>
Cc: stable(a)kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Palmer Dabbelt <palmer(a)sifive.com>
Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 1157b6b52d25..c433f6d3dd64 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -132,7 +132,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
{
unsigned long return_hooker = (unsigned long)&return_to_handler;
unsigned long old;
- struct ftrace_graph_ent trace;
int err;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
@@ -144,17 +143,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
*/
old = *parent;
- trace.func = self_addr;
- trace.depth = current->curr_ret_stack + 1;
-
- if (!ftrace_graph_entry(&trace))
- return;
-
- err = ftrace_push_return_trace(old, self_addr, &trace.depth,
- frame_pointer, parent);
- if (err == -EBUSY)
- return;
- *parent = return_hooker;
+ if (function_graph_enter(old, self_addr, frame_pointer, parent))
+ *parent = return_hooker;
}
#ifdef CONFIG_DYNAMIC_FTRACE