Re: [linux-stable-rc:linux-5.4.y 2563/9999] arch/ia64/kernel/kprobes.c:401:24: error: implicit declaration of function '__kretprobe_trampoline_handler'; did you mean 'kretprobe_trampoline'?

[Masami Hiramatsu <mhiramat@kernel.org>]

On Fri, 14 Jan 2022 08:09:44 +0100
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> On Fri, Jan 14, 2022 at 08:04:44AM +0100, Greg Kroah-Hartman wrote:
> > On Thu, Jan 13, 2022 at 06:25:33PM +0900, Masami Hiramatsu wrote:
> > > On Thu, 13 Jan 2022 04:15:43 +0800
> > > kernel test robot <lkp@intel.com> wrote:
> > > 
> > > > Hi Masami,
> > > > 
> > > > FYI, the error/warning still remains.
> > > > 
> > > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y
> > > > head:   0a4ce4977bbeea4560a1f32632650b388c834c8a
> > > > commit: 77fa5e15c933a1ec812de61ad709c00aa51e96ae [2563/9999] ia64: kprobes: Use generic kretprobe trampoline handler
> > > > config: ia64-randconfig-r002-20220112 (https://download.01.org/0day-ci/archive/20220113/202201130408.tdm9swhk-lkp@intel.com/config)
> > > > compiler: ia64-linux-gcc (GCC) 11.2.0
> > > > 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
> > > >         # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=77fa5e15c933a1ec812de61ad709c00aa51e96ae
> > > >         git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > > >         git fetch --no-tags linux-stable-rc linux-5.4.y
> > > >         git checkout 77fa5e15c933a1ec812de61ad709c00aa51e96ae
> > > >         # save the config file to linux build tree
> > > >         mkdir build_dir
> > > >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=ia64 SHELL=/bin/bash
> > > > 
> > > > If you fix the issue, kindly add following tag as appropriate
> > > > Reported-by: kernel test robot <lkp@intel.com>
> > > > 
> > > > All errors (new ones prefixed by >>):
> > > > 
> > > >    arch/ia64/kernel/kprobes.c: In function 'get_kprobe_inst':
> > > >    arch/ia64/kernel/kprobes.c:325:22: warning: variable 'template' set but not used [-Wunused-but-set-variable]
> > > >      325 |         unsigned int template;
> > > >          |                      ^~~~~~~~
> > > 
> > > OK, this is another issue, which is in the upstream master too.
> > > 
> > > >    arch/ia64/kernel/kprobes.c: At top level:
> > > >    arch/ia64/kernel/kprobes.c:399:15: warning: no previous prototype for 'trampoline_probe_handler' [-Wmissing-prototypes]> > >      399 | int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
> > > >          |               ^~~~~~~~~~~~~~~~~~~~~~~~
> > > >    arch/ia64/kernel/kprobes.c: In function 'trampoline_probe_handler':
> > > > >> arch/ia64/kernel/kprobes.c:401:24: error: implicit declaration of function '__kretprobe_trampoline_handler'; did you mean 'kretprobe_trampoline'? [-Werror=implicit-function-declaration]
> > > >      401 |         regs->cr_iip = __kretprobe_trampoline_handler(regs, kretprobe_trampoline, NULL);
> > > >          |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > >          |                        kretprobe_trampoline
> > > >    cc1: some warnings being treated as errors
> > > 
> > > This seems that the upstream commit e792ff804f49720ce003b3e4c618b5d996256a18
> > > has been picked to the stable-5.4.y tree accidentally.
> > > That is a part of lockless kretprobe series and should not be picked to
> > > the stable tree.
> > > 
> > > Greg, can you revert commit 77fa5e15c933a1ec812de61ad709c00aa51e96ae ?
> > > (Or should I send revert patch?)
> > 
> > I can revert it, thanks.
> 
> No, it does not revert cleanly, it looks like it was needed for another
> patch.  So a series of reverts if you could create them would be great.

OK, thanks for trying. Let me check what happened.

Thanks,

-- 
Masami Hiramatsu <mhiramat@kernel.org>