* [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return'
@ 2022-03-11 1:44 kernel test robot
2022-03-11 2:04 ` Steven Rostedt
0 siblings, 1 reply; 6+ messages in thread
From: kernel test robot @ 2022-03-11 1:44 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: llvm, kbuild-all, Linux Memory Management List, Steven Rostedt (Google)
Hi Ard,
FYI, the error/warning still remains.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: 71941773e143369a73c9c4a3b62fbb60736a1182
commit: 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 [4103/11953] ARM: ftrace: enable the graph tracer with the EABI unwinder
config: arm-aspeed_g4_defconfig (https://download.01.org/0day-ci/archive/20220311/202203110903.3xDyTUVl-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install arm cross compiling tool for clang build
# apt-get install binutils-arm-linux-gnueabi
# https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=41918ec82eb6f80c8b401422f27ca76c85aa0cb7
git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git fetch --no-tags linux-next master
git checkout 41918ec82eb6f80c8b401422f27ca76c85aa0cb7
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' [-Wmissing-prototypes]
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
^
arch/arm/kernel/ftrace.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
^
static
1 warning generated.
vim +/prepare_ftrace_return +229 arch/arm/kernel/ftrace.c
376cfa8730c08c Tim Bird 2010-10-09 226
376cfa8730c08c Tim Bird 2010-10-09 227 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 228 asmlinkage
376cfa8730c08c Tim Bird 2010-10-09 @229 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 230 unsigned long frame_pointer,
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 231 unsigned long stack_pointer)
376cfa8730c08c Tim Bird 2010-10-09 232 {
376cfa8730c08c Tim Bird 2010-10-09 233 unsigned long return_hooker = (unsigned long) &return_to_handler;
376cfa8730c08c Tim Bird 2010-10-09 234 unsigned long old;
376cfa8730c08c Tim Bird 2010-10-09 235
376cfa8730c08c Tim Bird 2010-10-09 236 if (unlikely(atomic_read(¤t->tracing_graph_pause)))
376cfa8730c08c Tim Bird 2010-10-09 237 return;
376cfa8730c08c Tim Bird 2010-10-09 238
953f534a7ed6b7 Ard Biesheuvel 2022-01-25 239 if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER)) {
953f534a7ed6b7 Ard Biesheuvel 2022-01-25 240 /* FP points one word below parent's top of stack */
953f534a7ed6b7 Ard Biesheuvel 2022-01-25 241 frame_pointer += 4;
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 242 } else {
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 243 struct stackframe frame = {
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 244 .fp = frame_pointer,
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 245 .sp = stack_pointer,
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 246 .lr = self_addr,
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 247 .pc = self_addr,
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 248 };
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 249 if (unwind_frame(&frame) < 0)
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 250 return;
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 251 if (frame.lr != self_addr)
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 252 parent = frame.lr_addr;
41918ec82eb6f8 Ard Biesheuvel 2022-01-25 253 frame_pointer = frame.sp;
953f534a7ed6b7 Ard Biesheuvel 2022-01-25 254 }
953f534a7ed6b7 Ard Biesheuvel 2022-01-25 255
376cfa8730c08c Tim Bird 2010-10-09 256 old = *parent;
376cfa8730c08c Tim Bird 2010-10-09 257 *parent = return_hooker;
376cfa8730c08c Tim Bird 2010-10-09 258
f1f5b14afd7cce Steven Rostedt (VMware 2018-11-18 259) if (function_graph_enter(old, self_addr, frame_pointer, NULL))
376cfa8730c08c Tim Bird 2010-10-09 260 *parent = old;
376cfa8730c08c Tim Bird 2010-10-09 261 }
dd686eb13959e4 Rabin Vincent 2010-11-06 262
:::::: The code at line 229 was first introduced by commit
:::::: 376cfa8730c08c0394d0aa1d4a80fd8c9971f323 ARM: ftrace: function graph tracer support
:::::: TO: Tim Bird <tim.bird@am.sony.com>
:::::: CC: Rabin Vincent <rabin@rab.in>
---
0-DAY CI Kernel Test Service
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return'
2022-03-11 1:44 [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' kernel test robot
@ 2022-03-11 2:04 ` Steven Rostedt
0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2022-03-11 2:04 UTC (permalink / raw)
To: kernel test robot
Cc: Ard Biesheuvel, llvm, kbuild-all, Linux Memory Management List
On Fri, 11 Mar 2022 09:44:11 +0800
kernel test robot <lkp@intel.com> wrote:
> Hi Ard,
>
> FYI, the error/warning still remains.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head: 71941773e143369a73c9c4a3b62fbb60736a1182
> commit: 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 [4103/11953] ARM: ftrace: enable the graph tracer with the EABI unwinder
> config: arm-aspeed_g4_defconfig (https://download.01.org/0day-ci/archive/20220311/202203110903.3xDyTUVl-lkp@intel.com/config)
> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6)
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install arm cross compiling tool for clang build
> # apt-get install binutils-arm-linux-gnueabi
> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> git fetch --no-tags linux-next master
> git checkout 41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> # save the config file to linux build tree
> mkdir build_dir
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> >> arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' [-Wmissing-prototypes]
> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> ^
> arch/arm/kernel/ftrace.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> ^
> static
> 1 warning generated.
>
Hmm, this is only called from assembly code, which doesn't care about
prototypes. Is there a way to quiet this warning to say "this is called
only by assembly"?
Or do we just add a useless prototype to shut it up?
-- Steve
>
> vim +/prepare_ftrace_return +229 arch/arm/kernel/ftrace.c
>
> 376cfa8730c08c Tim Bird 2010-10-09 226
> 376cfa8730c08c Tim Bird 2010-10-09 227 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 228 asmlinkage
> 376cfa8730c08c Tim Bird 2010-10-09 @229 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 230 unsigned long frame_pointer,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 231 unsigned long stack_pointer)
> 376cfa8730c08c Tim Bird 2010-10-09 232 {
> 376cfa8730c08c Tim Bird 2010-10-09 233 unsigned long return_hooker = (unsigned long) &return_to_handler;
> 376cfa8730c08c Tim Bird 2010-10-09 234 unsigned long old;
> 376cfa8730c08c Tim Bird 2010-10-09 235
> 376cfa8730c08c Tim Bird 2010-10-09 236 if (unlikely(atomic_read(¤t->tracing_graph_pause)))
> 376cfa8730c08c Tim Bird 2010-10-09 237 return;
> 376cfa8730c08c Tim Bird 2010-10-09 238
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 239 if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER)) {
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 240 /* FP points one word below parent's top of stack */
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 241 frame_pointer += 4;
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 242 } else {
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 243 struct stackframe frame = {
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 244 .fp = frame_pointer,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 245 .sp = stack_pointer,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 246 .lr = self_addr,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 247 .pc = self_addr,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 248 };
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 249 if (unwind_frame(&frame) < 0)
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 250 return;
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 251 if (frame.lr != self_addr)
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 252 parent = frame.lr_addr;
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 253 frame_pointer = frame.sp;
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 254 }
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 255
> 376cfa8730c08c Tim Bird 2010-10-09 256 old = *parent;
> 376cfa8730c08c Tim Bird 2010-10-09 257 *parent = return_hooker;
> 376cfa8730c08c Tim Bird 2010-10-09 258
> f1f5b14afd7cce Steven Rostedt (VMware 2018-11-18 259) if (function_graph_enter(old, self_addr, frame_pointer, NULL))
> 376cfa8730c08c Tim Bird 2010-10-09 260 *parent = old;
> 376cfa8730c08c Tim Bird 2010-10-09 261 }
> dd686eb13959e4 Rabin Vincent 2010-11-06 262
>
> :::::: The code at line 229 was first introduced by commit
> :::::: 376cfa8730c08c0394d0aa1d4a80fd8c9971f323 ARM: ftrace: function graph tracer support
>
> :::::: TO: Tim Bird <tim.bird@am.sony.com>
> :::::: CC: Rabin Vincent <rabin@rab.in>
>
> ---
> 0-DAY CI Kernel Test Service
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return'
@ 2022-03-11 2:04 ` Steven Rostedt
0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2022-03-11 2:04 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 5898 bytes --]
On Fri, 11 Mar 2022 09:44:11 +0800
kernel test robot <lkp@intel.com> wrote:
> Hi Ard,
>
> FYI, the error/warning still remains.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head: 71941773e143369a73c9c4a3b62fbb60736a1182
> commit: 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 [4103/11953] ARM: ftrace: enable the graph tracer with the EABI unwinder
> config: arm-aspeed_g4_defconfig (https://download.01.org/0day-ci/archive/20220311/202203110903.3xDyTUVl-lkp(a)intel.com/config)
> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6)
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install arm cross compiling tool for clang build
> # apt-get install binutils-arm-linux-gnueabi
> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> git fetch --no-tags linux-next master
> git checkout 41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> # save the config file to linux build tree
> mkdir build_dir
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
>
> All warnings (new ones prefixed by >>):
>
> >> arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' [-Wmissing-prototypes]
> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> ^
> arch/arm/kernel/ftrace.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> ^
> static
> 1 warning generated.
>
Hmm, this is only called from assembly code, which doesn't care about
prototypes. Is there a way to quiet this warning to say "this is called
only by assembly"?
Or do we just add a useless prototype to shut it up?
-- Steve
>
> vim +/prepare_ftrace_return +229 arch/arm/kernel/ftrace.c
>
> 376cfa8730c08c Tim Bird 2010-10-09 226
> 376cfa8730c08c Tim Bird 2010-10-09 227 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 228 asmlinkage
> 376cfa8730c08c Tim Bird 2010-10-09 @229 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 230 unsigned long frame_pointer,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 231 unsigned long stack_pointer)
> 376cfa8730c08c Tim Bird 2010-10-09 232 {
> 376cfa8730c08c Tim Bird 2010-10-09 233 unsigned long return_hooker = (unsigned long) &return_to_handler;
> 376cfa8730c08c Tim Bird 2010-10-09 234 unsigned long old;
> 376cfa8730c08c Tim Bird 2010-10-09 235
> 376cfa8730c08c Tim Bird 2010-10-09 236 if (unlikely(atomic_read(¤t->tracing_graph_pause)))
> 376cfa8730c08c Tim Bird 2010-10-09 237 return;
> 376cfa8730c08c Tim Bird 2010-10-09 238
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 239 if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER)) {
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 240 /* FP points one word below parent's top of stack */
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 241 frame_pointer += 4;
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 242 } else {
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 243 struct stackframe frame = {
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 244 .fp = frame_pointer,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 245 .sp = stack_pointer,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 246 .lr = self_addr,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 247 .pc = self_addr,
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 248 };
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 249 if (unwind_frame(&frame) < 0)
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 250 return;
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 251 if (frame.lr != self_addr)
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 252 parent = frame.lr_addr;
> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 253 frame_pointer = frame.sp;
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 254 }
> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 255
> 376cfa8730c08c Tim Bird 2010-10-09 256 old = *parent;
> 376cfa8730c08c Tim Bird 2010-10-09 257 *parent = return_hooker;
> 376cfa8730c08c Tim Bird 2010-10-09 258
> f1f5b14afd7cce Steven Rostedt (VMware 2018-11-18 259) if (function_graph_enter(old, self_addr, frame_pointer, NULL))
> 376cfa8730c08c Tim Bird 2010-10-09 260 *parent = old;
> 376cfa8730c08c Tim Bird 2010-10-09 261 }
> dd686eb13959e4 Rabin Vincent 2010-11-06 262
>
> :::::: The code at line 229 was first introduced by commit
> :::::: 376cfa8730c08c0394d0aa1d4a80fd8c9971f323 ARM: ftrace: function graph tracer support
>
> :::::: TO: Tim Bird <tim.bird@am.sony.com>
> :::::: CC: Rabin Vincent <rabin@rab.in>
>
> ---
> 0-DAY CI Kernel Test Service
> https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [kbuild-all] Re: [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return'
2022-03-11 2:04 ` Steven Rostedt
(?)
@ 2022-03-18 2:24 ` Chen, Rong A
-1 siblings, 0 replies; 6+ messages in thread
From: Chen, Rong A @ 2022-03-18 2:24 UTC (permalink / raw)
To: Steven Rostedt, kernel test robot
Cc: Ard Biesheuvel, llvm, kbuild-all, Linux Memory Management List
On 3/11/2022 10:04 AM, Steven Rostedt wrote:
> On Fri, 11 Mar 2022 09:44:11 +0800
> kernel test robot <lkp@intel.com> wrote:
>
>> Hi Ard,
>>
>> FYI, the error/warning still remains.
>>
>> tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
>> head: 71941773e143369a73c9c4a3b62fbb60736a1182
>> commit: 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 [4103/11953] ARM: ftrace: enable the graph tracer with the EABI unwinder
>> config: arm-aspeed_g4_defconfig (https://download.01.org/0day-ci/archive/20220311/202203110903.3xDyTUVl-lkp@intel.com/config)
>> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6)
>> reproduce (this is a W=1 build):
>> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>> chmod +x ~/bin/make.cross
>> # install arm cross compiling tool for clang build
>> # apt-get install binutils-arm-linux-gnueabi
>> # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=41918ec82eb6f80c8b401422f27ca76c85aa0cb7
>> git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>> git fetch --no-tags linux-next master
>> git checkout 41918ec82eb6f80c8b401422f27ca76c85aa0cb7
>> # save the config file to linux build tree
>> mkdir build_dir
>> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/
>>
>> If you fix the issue, kindly add following tag as appropriate
>> Reported-by: kernel test robot <lkp@intel.com>
>>
>> All warnings (new ones prefixed by >>):
>>
>>>> arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' [-Wmissing-prototypes]
>> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
>> ^
>> arch/arm/kernel/ftrace.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
>> void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
>> ^
>> static
>> 1 warning generated.
>>
>
> Hmm, this is only called from assembly code, which doesn't care about
> prototypes. Is there a way to quiet this warning to say "this is called
> only by assembly"?
>
> Or do we just add a useless prototype to shut it up?
>
> -- Steve
Hi Steve,
Sorry for the inconvenience, it's a duplicate false positive:
https://lore.kernel.org/linux-mm/2db6ea89-846a-8d4e-a5c3-954411332029@intel.com/
please ignore the report, we are still working on it.
Best Regards,
Rong Chen
>
>
>>
>> vim +/prepare_ftrace_return +229 arch/arm/kernel/ftrace.c
>>
>> 376cfa8730c08c Tim Bird 2010-10-09 226
>> 376cfa8730c08c Tim Bird 2010-10-09 227 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 228 asmlinkage
>> 376cfa8730c08c Tim Bird 2010-10-09 @229 void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 230 unsigned long frame_pointer,
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 231 unsigned long stack_pointer)
>> 376cfa8730c08c Tim Bird 2010-10-09 232 {
>> 376cfa8730c08c Tim Bird 2010-10-09 233 unsigned long return_hooker = (unsigned long) &return_to_handler;
>> 376cfa8730c08c Tim Bird 2010-10-09 234 unsigned long old;
>> 376cfa8730c08c Tim Bird 2010-10-09 235
>> 376cfa8730c08c Tim Bird 2010-10-09 236 if (unlikely(atomic_read(¤t->tracing_graph_pause)))
>> 376cfa8730c08c Tim Bird 2010-10-09 237 return;
>> 376cfa8730c08c Tim Bird 2010-10-09 238
>> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 239 if (IS_ENABLED(CONFIG_UNWINDER_FRAME_POINTER)) {
>> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 240 /* FP points one word below parent's top of stack */
>> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 241 frame_pointer += 4;
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 242 } else {
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 243 struct stackframe frame = {
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 244 .fp = frame_pointer,
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 245 .sp = stack_pointer,
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 246 .lr = self_addr,
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 247 .pc = self_addr,
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 248 };
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 249 if (unwind_frame(&frame) < 0)
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 250 return;
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 251 if (frame.lr != self_addr)
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 252 parent = frame.lr_addr;
>> 41918ec82eb6f8 Ard Biesheuvel 2022-01-25 253 frame_pointer = frame.sp;
>> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 254 }
>> 953f534a7ed6b7 Ard Biesheuvel 2022-01-25 255
>> 376cfa8730c08c Tim Bird 2010-10-09 256 old = *parent;
>> 376cfa8730c08c Tim Bird 2010-10-09 257 *parent = return_hooker;
>> 376cfa8730c08c Tim Bird 2010-10-09 258
>> f1f5b14afd7cce Steven Rostedt (VMware 2018-11-18 259) if (function_graph_enter(old, self_addr, frame_pointer, NULL))
>> 376cfa8730c08c Tim Bird 2010-10-09 260 *parent = old;
>> 376cfa8730c08c Tim Bird 2010-10-09 261 }
>> dd686eb13959e4 Rabin Vincent 2010-11-06 262
>>
>> :::::: The code at line 229 was first introduced by commit
>> :::::: 376cfa8730c08c0394d0aa1d4a80fd8c9971f323 ARM: ftrace: function graph tracer support
>>
>> :::::: TO: Tim Bird <tim.bird@am.sony.com>
>> :::::: CC: Rabin Vincent <rabin@rab.in>
>>
>> ---
>> 0-DAY CI Kernel Test Service
>> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
> _______________________________________________
> kbuild-all mailing list -- kbuild-all@lists.01.org
> To unsubscribe send an email to kbuild-all-leave@lists.01.org
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return'
2022-03-11 2:04 ` Steven Rostedt
@ 2022-03-18 18:26 ` Nick Desaulniers
-1 siblings, 0 replies; 6+ messages in thread
From: Nick Desaulniers @ 2022-03-18 18:26 UTC (permalink / raw)
To: Steven Rostedt, Ard Biesheuvel, Marc Zyngier, Arnd Bergmann
Cc: kernel test robot, llvm, kbuild-all,
Linux Memory Management List, Linus Torvalds
, , On Thu, Mar 10, 2022 at 6:04 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Fri, 11 Mar 2022 09:44:11 +0800
> kernel test robot <lkp@intel.com> wrote:
>
> > Hi Ard,
> >
> > FYI, the error/warning still remains.
> >
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > head: 71941773e143369a73c9c4a3b62fbb60736a1182
> > commit: 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 [4103/11953] ARM: ftrace: enable the graph tracer with the EABI unwinder
> > config: arm-aspeed_g4_defconfig (https://download.01.org/0day-ci/archive/20220311/202203110903.3xDyTUVl-lkp@intel.com/config)
> > compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6)
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # install arm cross compiling tool for clang build
> > # apt-get install binutils-arm-linux-gnueabi
> > # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> > git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > git fetch --no-tags linux-next master
> > git checkout 41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> > # save the config file to linux build tree
> > mkdir build_dir
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' [-Wmissing-prototypes]
> > void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> > ^
> > arch/arm/kernel/ftrace.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> > ^
> > static
> > 1 warning generated.
> >
>
> Hmm, this is only called from assembly code, which doesn't care about
> prototypes. Is there a way to quiet this warning to say "this is called
> only by assembly"?
>
> Or do we just add a useless prototype to shut it up?
So this has come up a few times before, particularly around the usage
in the kernel of `asmlinkage`. This 0day report also only comes up for
W=1 builds, which enable -Wmissing-prototypes (see
scripts/Makefile.extrawarn).
The problem is that `asmlinkage` is not a language keyword; it's a
preprocessor define (see include/linux/linkage.h,
arch/ia64/include/asm/linkage.h, arch/x86/include/asm/linkage.h), so
the compiler has no idea that this function is only called from
assembly only. The warning is meant to catch implicit defines
(-Wimplicit-function-declaration) where the signature the caller is
expecting doesn't match the callee's actual definition (because the
callee wasn't declared in a shared header).
I think IF we had a function attribute added to the compiler that
disabled -Wmissing-prototype warnings just for that definition, then
we could do something like:
#define asmlinkage CPP_ASMLINKAGE \
__attribute__((no_wmissing_prototypes,error( \
"Called an asmlinkage function from C; remove " \
"asmlinkage or dont call this fn"))
or something. We wouldn't be able to always enable
-Wmissing-prototypes until we had such an fn attr though, due to cases
like this. I think -Wmissing-prototypes is still worthwhile, and that
Arnd previously mentioned interest in this warning.
For now, I think it's worth forward declaring the function, in the .c
file (rather than a header) with a comment that this is expected to be
called from asm only. If that ever changes, then the declaration can
be moved to a header.
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return'
@ 2022-03-18 18:26 ` Nick Desaulniers
0 siblings, 0 replies; 6+ messages in thread
From: Nick Desaulniers @ 2022-03-18 18:26 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 4157 bytes --]
, , On Thu, Mar 10, 2022 at 6:04 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Fri, 11 Mar 2022 09:44:11 +0800
> kernel test robot <lkp@intel.com> wrote:
>
> > Hi Ard,
> >
> > FYI, the error/warning still remains.
> >
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > head: 71941773e143369a73c9c4a3b62fbb60736a1182
> > commit: 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 [4103/11953] ARM: ftrace: enable the graph tracer with the EABI unwinder
> > config: arm-aspeed_g4_defconfig (https://download.01.org/0day-ci/archive/20220311/202203110903.3xDyTUVl-lkp(a)intel.com/config)
> > compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 276ca87382b8f16a65bddac700202924228982f6)
> > reproduce (this is a W=1 build):
> > wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > # install arm cross compiling tool for clang build
> > # apt-get install binutils-arm-linux-gnueabi
> > # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> > git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > git fetch --no-tags linux-next master
> > git checkout 41918ec82eb6f80c8b401422f27ca76c85aa0cb7
> > # save the config file to linux build tree
> > mkdir build_dir
> > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash arch/arm/kernel/
> >
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' [-Wmissing-prototypes]
> > void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> > ^
> > arch/arm/kernel/ftrace.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
> > ^
> > static
> > 1 warning generated.
> >
>
> Hmm, this is only called from assembly code, which doesn't care about
> prototypes. Is there a way to quiet this warning to say "this is called
> only by assembly"?
>
> Or do we just add a useless prototype to shut it up?
So this has come up a few times before, particularly around the usage
in the kernel of `asmlinkage`. This 0day report also only comes up for
W=1 builds, which enable -Wmissing-prototypes (see
scripts/Makefile.extrawarn).
The problem is that `asmlinkage` is not a language keyword; it's a
preprocessor define (see include/linux/linkage.h,
arch/ia64/include/asm/linkage.h, arch/x86/include/asm/linkage.h), so
the compiler has no idea that this function is only called from
assembly only. The warning is meant to catch implicit defines
(-Wimplicit-function-declaration) where the signature the caller is
expecting doesn't match the callee's actual definition (because the
callee wasn't declared in a shared header).
I think IF we had a function attribute added to the compiler that
disabled -Wmissing-prototype warnings just for that definition, then
we could do something like:
#define asmlinkage CPP_ASMLINKAGE \
__attribute__((no_wmissing_prototypes,error( \
"Called an asmlinkage function from C; remove " \
"asmlinkage or dont call this fn"))
or something. We wouldn't be able to always enable
-Wmissing-prototypes until we had such an fn attr though, due to cases
like this. I think -Wmissing-prototypes is still worthwhile, and that
Arnd previously mentioned interest in this warning.
For now, I think it's worth forward declaring the function, in the .c
file (rather than a header) with a comment that this is expected to be
called from asm only. If that ever changes, then the declaration can
be moved to a header.
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-03-18 18:26 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-03-11 1:44 [linux-next:master 4103/11953] arch/arm/kernel/ftrace.c:229:6: warning: no previous prototype for function 'prepare_ftrace_return' kernel test robot
2022-03-11 2:04 ` Steven Rostedt
2022-03-11 2:04 ` Steven Rostedt
2022-03-18 2:24 ` [kbuild-all] " Chen, Rong A
2022-03-18 18:26 ` Nick Desaulniers
2022-03-18 18:26 ` Nick Desaulniers
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