Re: [PATCH 7/9] riscv: bpf: Avoid breaking W^X

From: kernel test robot <lkp@intel.com>
To: kbuild-all@lists.01.org
Subject: Re: [PATCH 7/9] riscv: bpf: Avoid breaking W^X
Date: Wed, 31 Mar 2021 00:39:29 +0800	[thread overview]
Message-ID: <202103310033.KbPQacrN-lkp@intel.com> (raw)
In-Reply-To: <20210330022521.2a904a8c@xhacker>

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Hi Jisheng,

I love your patch! Yet something to improve:

[auto build test ERROR on bpf-next/master]
[also build test ERROR on bpf/master linus/master v5.12-rc5]
[cannot apply to next-20210330]
[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]

url:    https://github.com/0day-ci/linux/commits/Jisheng-Zhang/riscv-improve-self-protection/20210330-023324
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
config: riscv-randconfig-r026-20210330 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 482283042f795ecc27838a3b2f76b5494991401c)
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 riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/0day-ci/linux/commit/8291e9d78fc2eb2438c93001ab65dfe1743a97f2
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jisheng-Zhang/riscv-improve-self-protection/20210330-023324
        git checkout 8291e9d78fc2eb2438c93001ab65dfe1743a97f2
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv 

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/riscv/net/bpf_jit_core.c:155:26: error: use of undeclared identifier 'header'
                   bpf_jit_binary_lock_ro(header);
                                          ^
   1 error generated.

vim +/header +155 arch/riscv/net/bpf_jit_core.c

    41	
    42	struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
    43	{
    44		bool tmp_blinded = false, extra_pass = false;
    45		struct bpf_prog *tmp, *orig_prog = prog;
    46		int pass = 0, prev_ninsns = 0, i;
    47		struct rv_jit_data *jit_data;
    48		struct rv_jit_context *ctx;
    49		unsigned int image_size = 0;
    50	
    51		if (!prog->jit_requested)
    52			return orig_prog;
    53	
    54		tmp = bpf_jit_blind_constants(prog);
    55		if (IS_ERR(tmp))
    56			return orig_prog;
    57		if (tmp != prog) {
    58			tmp_blinded = true;
    59			prog = tmp;
    60		}
    61	
    62		jit_data = prog->aux->jit_data;
    63		if (!jit_data) {
    64			jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
    65			if (!jit_data) {
    66				prog = orig_prog;
    67				goto out;
    68			}
    69			prog->aux->jit_data = jit_data;
    70		}
    71	
    72		ctx = &jit_data->ctx;
    73	
    74		if (ctx->offset) {
    75			extra_pass = true;
    76			image_size = sizeof(*ctx->insns) * ctx->ninsns;
    77			goto skip_init_ctx;
    78		}
    79	
    80		ctx->prog = prog;
    81		ctx->offset = kcalloc(prog->len, sizeof(int), GFP_KERNEL);
    82		if (!ctx->offset) {
    83			prog = orig_prog;
    84			goto out_offset;
    85		}
    86		for (i = 0; i < prog->len; i++) {
    87			prev_ninsns += 32;
    88			ctx->offset[i] = prev_ninsns;
    89		}
    90	
    91		for (i = 0; i < NR_JIT_ITERATIONS; i++) {
    92			pass++;
    93			ctx->ninsns = 0;
    94			if (build_body(ctx, extra_pass, ctx->offset)) {
    95				prog = orig_prog;
    96				goto out_offset;
    97			}
    98			bpf_jit_build_prologue(ctx);
    99			ctx->epilogue_offset = ctx->ninsns;
   100			bpf_jit_build_epilogue(ctx);
   101	
   102			if (ctx->ninsns == prev_ninsns) {
   103				if (jit_data->header)
   104					break;
   105	
   106				image_size = sizeof(*ctx->insns) * ctx->ninsns;
   107				jit_data->header =
   108					bpf_jit_binary_alloc(image_size,
   109							     &jit_data->image,
   110							     sizeof(u32),
   111							     bpf_fill_ill_insns);
   112				if (!jit_data->header) {
   113					prog = orig_prog;
   114					goto out_offset;
   115				}
   116	
   117				ctx->insns = (u16 *)jit_data->image;
   118				/*
   119				 * Now, when the image is allocated, the image can
   120				 * potentially shrink more (auipc/jalr -> jal).
   121				 */
   122			}
   123			prev_ninsns = ctx->ninsns;
   124		}
   125	
   126		if (i == NR_JIT_ITERATIONS) {
   127			pr_err("bpf-jit: image did not converge in <%d passes!\n", i);
   128			bpf_jit_binary_free(jit_data->header);
   129			prog = orig_prog;
   130			goto out_offset;
   131		}
   132	
   133	skip_init_ctx:
   134		pass++;
   135		ctx->ninsns = 0;
   136	
   137		bpf_jit_build_prologue(ctx);
   138		if (build_body(ctx, extra_pass, NULL)) {
   139			bpf_jit_binary_free(jit_data->header);
   140			prog = orig_prog;
   141			goto out_offset;
   142		}
   143		bpf_jit_build_epilogue(ctx);
   144	
   145		if (bpf_jit_enable > 1)
   146			bpf_jit_dump(prog->len, image_size, pass, ctx->insns);
   147	
   148		prog->bpf_func = (void *)ctx->insns;
   149		prog->jited = 1;
   150		prog->jited_len = image_size;
   151	
   152		bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
   153	
   154		if (!prog->is_func || extra_pass) {
 > 155			bpf_jit_binary_lock_ro(header);
   156	out_offset:
   157			kfree(ctx->offset);
   158			kfree(jit_data);
   159			prog->aux->jit_data = NULL;
   160		}
   161	out:
   162	
   163		if (tmp_blinded)
   164			bpf_jit_prog_release_other(prog, prog == orig_prog ?
   165						   tmp : orig_prog);
   166		return prog;
   167	}
   168	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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