Re: [PATCH v2 02/11] unwind/x86: Add HAVE_USER_UNWIND

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

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <82ef19a767cb75e76a985ecc0d47a39400b4fdf5.1726268190.git.jpoimboe@kernel.org>
References: <82ef19a767cb75e76a985ecc0d47a39400b4fdf5.1726268190.git.jpoimboe@kernel.org>
TO: Josh Poimboeuf <jpoimboe@kernel.org>

Hi Josh,

kernel test robot noticed the following build warnings:

[auto build test WARNING on perf-tools-next/perf-tools-next]
[also build test WARNING on tip/perf/core perf-tools/perf-tools linus/master acme/perf/core v6.11-rc7 next-20240913]
[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/Josh-Poimboeuf/unwind-Introduce-generic-user-space-unwinding-interface/20240914-070619
base:   https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git perf-tools-next
patch link:    https://lore.kernel.org/r/82ef19a767cb75e76a985ecc0d47a39400b4fdf5.1726268190.git.jpoimboe%40kernel.org
patch subject: [PATCH v2 02/11] unwind/x86: Add HAVE_USER_UNWIND
:::::: branch date: 25 hours ago
:::::: commit date: 25 hours ago
config: x86_64-randconfig-r072-20240914 (https://download.01.org/0day-ci/archive/20240915/202409150812.Pg1WBJPn-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)

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>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202409150812.Pg1WBJPn-lkp@intel.com/

smatch warnings:
kernel/unwind/user.c:45 user_unwind_next() error: uninitialized symbol 'ra'.

vim +/ra +45 kernel/unwind/user.c

c970b852d500d4 Josh Poimboeuf 2024-09-14  17  
c970b852d500d4 Josh Poimboeuf 2024-09-14  18  int user_unwind_next(struct user_unwind_state *state)
c970b852d500d4 Josh Poimboeuf 2024-09-14  19  {
c970b852d500d4 Josh Poimboeuf 2024-09-14  20  	struct user_unwind_frame _frame;
c970b852d500d4 Josh Poimboeuf 2024-09-14  21  	struct user_unwind_frame *frame = &_frame;
c970b852d500d4 Josh Poimboeuf 2024-09-14  22  	unsigned long cfa, fp, ra;
c970b852d500d4 Josh Poimboeuf 2024-09-14  23  	int ret = -EINVAL;
c970b852d500d4 Josh Poimboeuf 2024-09-14  24  
c970b852d500d4 Josh Poimboeuf 2024-09-14  25  	if (state->done)
c970b852d500d4 Josh Poimboeuf 2024-09-14  26  		return -EINVAL;
c970b852d500d4 Josh Poimboeuf 2024-09-14  27  
c970b852d500d4 Josh Poimboeuf 2024-09-14  28  	switch (state->type) {
c970b852d500d4 Josh Poimboeuf 2024-09-14  29  	case USER_UNWIND_TYPE_FP:
c970b852d500d4 Josh Poimboeuf 2024-09-14  30  		frame = &fp_frame;
c970b852d500d4 Josh Poimboeuf 2024-09-14  31  		break;
c970b852d500d4 Josh Poimboeuf 2024-09-14  32  	default:
c970b852d500d4 Josh Poimboeuf 2024-09-14  33  		BUG();
c970b852d500d4 Josh Poimboeuf 2024-09-14  34  	}
c970b852d500d4 Josh Poimboeuf 2024-09-14  35  
c970b852d500d4 Josh Poimboeuf 2024-09-14  36  	cfa = (frame->use_fp ? state->fp : state->sp) + frame->cfa_off;
c970b852d500d4 Josh Poimboeuf 2024-09-14  37  
c970b852d500d4 Josh Poimboeuf 2024-09-14  38  	if (frame->ra_off && get_user(ra, (unsigned long *)(cfa + frame->ra_off)))
c970b852d500d4 Josh Poimboeuf 2024-09-14  39  		goto the_end;
c970b852d500d4 Josh Poimboeuf 2024-09-14  40  
c970b852d500d4 Josh Poimboeuf 2024-09-14  41  	if (frame->fp_off && get_user(fp, (unsigned long *)(cfa + frame->fp_off)))
c970b852d500d4 Josh Poimboeuf 2024-09-14  42  		goto the_end;
c970b852d500d4 Josh Poimboeuf 2024-09-14  43  
c970b852d500d4 Josh Poimboeuf 2024-09-14  44  	state->sp = cfa;
c970b852d500d4 Josh Poimboeuf 2024-09-14 @45  	state->ip = ra;
c970b852d500d4 Josh Poimboeuf 2024-09-14  46  	if (frame->fp_off)
c970b852d500d4 Josh Poimboeuf 2024-09-14  47  		state->fp = fp;
c970b852d500d4 Josh Poimboeuf 2024-09-14  48  
c970b852d500d4 Josh Poimboeuf 2024-09-14  49  	return 0;
c970b852d500d4 Josh Poimboeuf 2024-09-14  50  
c970b852d500d4 Josh Poimboeuf 2024-09-14  51  the_end:
c970b852d500d4 Josh Poimboeuf 2024-09-14  52  	state->done = true;
c970b852d500d4 Josh Poimboeuf 2024-09-14  53  	return ret;
c970b852d500d4 Josh Poimboeuf 2024-09-14  54  }
c970b852d500d4 Josh Poimboeuf 2024-09-14  55  

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