Commit 33c24bee authored by Kees Cook's avatar Kees Cook Committed by Luis Chamberlain
Browse files

kallsyms: Add more debug output for selftest 

While debugging a recent kallsyms_selftest failure[1], I needed more
details on what specifically was failing. This adds those details for
each failure state that is checked.

[1] https://lore.kernel.org/all/202308232200.1c932a90-oliver.sang@intel.com/



Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Yonghong Song <yhs@meta.com>
Cc: "Erhard F." <erhard_f@mailbox.org>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: kernel test robot <oliver.sang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
parent a6846234

kernel/kallsyms_selftest.c

+18 −4
Original line number Diff line number Diff line
@@ -341,6 +341,7 @@ static int test_kallsyms_basic_function(void) 
		ret = lookup_symbol_name(addr, namebuf);

		if (unlikely(ret)) {

			namebuf[0] = 0;

			pr_info("%d: lookup_symbol_name(%lx) failed\n", i, addr);

			goto failed;

		}
@@ -388,8 +389,11 @@ static int test_kallsyms_basic_function(void) 
			if (stat->addr != stat2->addr ||

			    stat->real_cnt != stat2->real_cnt ||

			    memcmp(stat->addrs, stat2->addrs,

				   stat->save_cnt * sizeof(stat->addrs[0])))

				   stat->save_cnt * sizeof(stat->addrs[0]))) {

				pr_info("%s: mismatch between kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol()\n",

					namebuf);

				goto failed;

			}



			/*

			 * The average of random increments is 128, that is, one of
@@ -400,15 +404,23 @@ static int test_kallsyms_basic_function(void) 
		}



		/* Need to be found at least once */

		if (!stat->real_cnt)

		if (!stat->real_cnt) {

			pr_info("%s: Never found\n", namebuf);

			goto failed;

		}



		/*

		 * kallsyms_lookup_name() returns the address of the first

		 * symbol found and cannot be NULL.

		 */

		if (!lookup_addr || lookup_addr != stat->addrs[0])

		if (!lookup_addr) {

			pr_info("%s: NULL lookup_addr?!\n", namebuf);

			goto failed;

		}

		if (lookup_addr != stat->addrs[0]) {

			pr_info("%s: lookup_addr != stat->addrs[0]\n", namebuf);

			goto failed;

		}



		/*

		 * If the addresses of all matching symbols are recorded, the
@@ -420,10 +432,12 @@ static int test_kallsyms_basic_function(void) 
					break;

			}



			if (j == stat->save_cnt)

			if (j == stat->save_cnt) {

				pr_info("%s: j == save_cnt?!\n", namebuf);

				goto failed;

			}

		}

	}



	kfree(stat);