Re: [RFC PATCH 2/5] fprobe: rethook: Use fprobe_regs in fprobe exit handler and rethook

[kernel test robot <lkp@intel.com>]

Hi Masami,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on bpf-next/master]
[also build test WARNING on bpf/master tip/x86/core linus/master v6.5-rc4 next-20230804]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Masami-Hiramatsu-Google/fprobe-Use-fprobe_regs-in-fprobe-entry-handler/20230805-230025
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/169124749229.186149.1426658495303367593.stgit%40devnote2
patch subject: [RFC PATCH 2/5] fprobe: rethook: Use fprobe_regs in fprobe exit handler and rethook
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20230806/202308061111.cUlfueXw-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230806/202308061111.cUlfueXw-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308061111.cUlfueXw-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/kprobes.c: In function 'kretprobe_rethook_handler':
   kernel/kprobes.c:2146:32: error: implicit declaration of function 'ftrace_get_regs' [-Werror=implicit-function-declaration]
    2146 |         struct pt_regs *regs = ftrace_get_regs(fregs);
         |                                ^~~~~~~~~~~~~~~
>> kernel/kprobes.c:2146:32: warning: initialization of 'struct pt_regs *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   cc1: some warnings being treated as errors
--
   arch/x86/kernel/rethook.c: In function 'arch_rethook_fixup_return':
   arch/x86/kernel/rethook.c:111:32: error: implicit declaration of function 'ftrace_get_regs' [-Werror=implicit-function-declaration]
     111 |         struct pt_regs *regs = ftrace_get_regs(fregs);
         |                                ^~~~~~~~~~~~~~~
>> arch/x86/kernel/rethook.c:111:32: warning: initialization of 'struct pt_regs *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   arch/x86/kernel/rethook.c: In function 'arch_rethook_prepare':
   arch/x86/kernel/rethook.c:121:32: warning: initialization of 'struct pt_regs *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
     121 |         struct pt_regs *regs = ftrace_get_regs(fregs);
         |                                ^~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +2146 kernel/kprobes.c

  2140	
  2141	static void kretprobe_rethook_handler(struct rethook_node *rh, void *data,
  2142					      unsigned long ret_addr,
  2143					      struct ftrace_regs *fregs)
  2144	{
  2145		struct kretprobe *rp = (struct kretprobe *)data;
> 2146		struct pt_regs *regs = ftrace_get_regs(fregs);
  2147		struct kretprobe_instance *ri;
  2148		struct kprobe_ctlblk *kcb;
  2149	
  2150		/* This is bug because this depends on HAVE_PT_REGS_COMPAT_FTRACE_REGS */
  2151		if (WARN_ON_ONCE(!regs))
  2152			return;
  2153	
  2154		/* The data must NOT be null. This means rethook data structure is broken. */
  2155		if (WARN_ON_ONCE(!data) || !rp->handler)
  2156			return;
  2157	
  2158		__this_cpu_write(current_kprobe, &rp->kp);
  2159		kcb = get_kprobe_ctlblk();
  2160		kcb->kprobe_status = KPROBE_HIT_ACTIVE;
  2161	
  2162		ri = container_of(rh, struct kretprobe_instance, node);
  2163		rp->handler(ri, regs);
  2164	
  2165		__this_cpu_write(current_kprobe, NULL);
  2166	}
  2167	NOKPROBE_SYMBOL(kretprobe_rethook_handler);
  2168	

-- 
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https://github.com/intel/lkp-tests/wiki