* kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared; did you mean 'UCOUNT_COUNTS'?
@ 2020-01-01 18:09 kbuild test robot
2020-01-03 3:07 ` Steven Rostedt
0 siblings, 1 reply; 4+ messages in thread
From: kbuild test robot @ 2020-01-01 18:09 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: kbuild-all, linux-kernel, Steven Rostedt (VMware)
[-- Attachment #1: Type: text/plain, Size: 2605 bytes --]
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 738d2902773e30939a982c8df7a7f94293659810
commit: ff205766dbbee024a4a716638868d98ffb17748a ftrace: Fix function_graph tracer interaction with BPF trampoline
date: 3 weeks ago
config: riscv-randconfig-a001-20200102 (attached as .config)
compiler: riscv64-linux-gcc (GCC) 7.5.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout ff205766dbbee024a4a716638868d98ffb17748a
# save the attached .config to linux build tree
GCC_VERSION=7.5.0 make.cross ARCH=riscv
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
kernel//trace/fgraph.c: In function 'function_graph_enter':
>> kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared (first use in this function); did you mean 'UCOUNT_COUNTS'?
ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))
^~~~~~~~~~~~~~~~
UCOUNT_COUNTS
kernel//trace/fgraph.c:111:35: note: each undeclared identifier is reported only once for each function it appears in
vim +111 kernel//trace/fgraph.c
98
99 int function_graph_enter(unsigned long ret, unsigned long func,
100 unsigned long frame_pointer, unsigned long *retp)
101 {
102 struct ftrace_graph_ent trace;
103
104 /*
105 * Skip graph tracing if the return location is served by direct trampoline,
106 * since call sequence and return addresses is unpredicatable anymore.
107 * Ex: BPF trampoline may call original function and may skip frame
108 * depending on type of BPF programs attached.
109 */
110 if (ftrace_direct_func_count &&
> 111 ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))
112 return -EBUSY;
113 trace.func = func;
114 trace.depth = ++current->curr_ret_depth;
115
116 if (ftrace_push_return_trace(ret, func, frame_pointer, retp))
117 goto out;
118
119 /* Only trace if the calling function expects to */
120 if (!ftrace_graph_entry(&trace))
121 goto out_ret;
122
123 return 0;
124 out_ret:
125 current->curr_ret_stack--;
126 out:
127 current->curr_ret_depth--;
128 return -EBUSY;
129 }
130
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation
[-- Attachment #2: .config.gz --]
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared; did you mean 'UCOUNT_COUNTS'?
2020-01-01 18:09 kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared; did you mean 'UCOUNT_COUNTS'? kbuild test robot
@ 2020-01-03 3:07 ` Steven Rostedt
2020-01-03 3:09 ` [PATCH] tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls Steven Rostedt
2020-01-03 3:09 ` [PATCH] tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined Steven Rostedt
0 siblings, 2 replies; 4+ messages in thread
From: Steven Rostedt @ 2020-01-03 3:07 UTC (permalink / raw)
To: kbuild test robot; +Cc: Alexei Starovoitov, kbuild-all, linux-kernel
On Thu, 2 Jan 2020 02:09:22 +0800
kbuild test robot <lkp@intel.com> wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 738d2902773e30939a982c8df7a7f94293659810
> commit: ff205766dbbee024a4a716638868d98ffb17748a ftrace: Fix function_graph tracer interaction with BPF trampoline
> date: 3 weeks ago
> config: riscv-randconfig-a001-20200102 (attached as .config)
> compiler: riscv64-linux-gcc (GCC) 7.5.0
> reproduce:
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> git checkout ff205766dbbee024a4a716638868d98ffb17748a
> # save the attached .config to linux build tree
> GCC_VERSION=7.5.0 make.cross ARCH=riscv
>
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
> kernel//trace/fgraph.c: In function 'function_graph_enter':
> >> kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared (first use in this function); did you mean 'UCOUNT_COUNTS'?
> ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))
> ^~~~~~~~~~~~~~~~
> UCOUNT_COUNTS
> kernel//trace/fgraph.c:111:35: note: each undeclared identifier is reported only once for each function it appears in
>
>
The next two patches should fix this. The second patch fixes a
different location with the same problem. It appears that without
DYNAMIC_FTRACE (which x86 always has now) that this isn't defined.
-- Steve
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH] tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls
2020-01-03 3:07 ` Steven Rostedt
@ 2020-01-03 3:09 ` Steven Rostedt
2020-01-03 3:09 ` [PATCH] tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined Steven Rostedt
1 sibling, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2020-01-03 3:09 UTC (permalink / raw)
To: kbuild test robot; +Cc: Alexei Starovoitov, kbuild-all, linux-kernel
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
In order to handle direct calls along side of function graph tracer, a check
is made to see if the address being traced by the function graph tracer is a
direct call or not. To get the address used by direct callers, the return
address is subtracted by MCOUNT_INSN_SIZE.
For some archs with certain configurations, MCOUNT_INSN_SIZE is undefined
here. But these should not be using direct calls anyway. Just define
MCOUNT_INSN_SIZE to zero in this case.
Link: https://lore.kernel.org/r/202001020219.zvE3vsty%lkp@intel.com
Reported-by: kbuild test robot <lkp@intel.com>
Fixes: ff205766dbbee ("ftrace: Fix function_graph tracer interaction with BPF trampoline")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/fgraph.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index a2659735db73..1af321dec0f1 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -96,6 +96,20 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func,
return 0;
}
+/*
+ * Not all archs define MCOUNT_INSN_SIZE which is used to look for direct
+ * functions. But those archs currently don't support direct functions
+ * anyway, and ftrace_find_rec_direct() is just a stub for them.
+ * Define MCOUNT_INSN_SIZE to keep those archs compiling.
+ */
+#ifndef MCOUNT_INSN_SIZE
+/* Make sure this only works without direct calls */
+# ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+# error MCOUNT_INSN_SIZE not defined with direct calls enabled
+# endif
+# define MCOUNT_INSN_SIZE 0
+#endif
+
int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH] tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined
2020-01-03 3:07 ` Steven Rostedt
2020-01-03 3:09 ` [PATCH] tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls Steven Rostedt
@ 2020-01-03 3:09 ` Steven Rostedt
1 sibling, 0 replies; 4+ messages in thread
From: Steven Rostedt @ 2020-01-03 3:09 UTC (permalink / raw)
To: kbuild test robot; +Cc: Alexei Starovoitov, kbuild-all, linux-kernel
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
On some archs with some configurations, MCOUNT_INSN_SIZE is not defined, and
this makes the stack tracer fail to compile. Just define it to zero in this
case.
Link: https://lore.kernel.org/r/202001020219.zvE3vsty%lkp@intel.com
Cc: stable@vger.kernel.org
Fixes: 4df297129f622 ("tracing: Remove most or all of stack tracer stack size from stack_max_size")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_stack.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 4df9a209f7ca..c557f42a9397 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -283,6 +283,11 @@ static void check_stack(unsigned long ip, unsigned long *stack)
local_irq_restore(flags);
}
+/* Some archs may not define MCOUNT_INSN_SIZE */
+#ifndef MCOUNT_INSN_SIZE
+# define MCOUNT_INSN_SIZE 0
+#endif
+
static void
stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs)
--
2.20.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-01-03 3:09 UTC | newest]
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2020-01-01 18:09 kernel//trace/fgraph.c:111:35: error: 'MCOUNT_INSN_SIZE' undeclared; did you mean 'UCOUNT_COUNTS'? kbuild test robot
2020-01-03 3:07 ` Steven Rostedt
2020-01-03 3:09 ` [PATCH] tracing: Define MCOUNT_INSN_SIZE when not defined without direct calls Steven Rostedt
2020-01-03 3:09 ` [PATCH] tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined Steven Rostedt
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