Messages in this thread Patch in this message |  | | From | Namhyung Kim <> | | Subject | [PATCH 5/5] perf test: Add kallsyms split test | | Date | Tue, 2 Dec 2025 00:16:45 -0800 |
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Add fake_root directory for /proc/{version,modules,kallsyms}. The kallsyms has a bad symbol in the module and it causes the main map splitted. The test ensures it only has two maps - kernel and the module and it finds the initial map after the module without creating the split maps like [kernel].0 and so on.
$ perf test -vv "split kallsyms" 69: split kallsyms: --- start --- test child forked, pid 921678 try to find fake root directory maps__set_modules_path_dir: cannot open tests/fake_root/lib/modules/X.Y.Z dir Problems setting modules path maps, continuing anyway... Failed to open tests/fake_root/proc/kcore. Note /proc/kcore requires CAP_SYS_RAWIO capability to access. Using tests/fake_root/proc/kallsyms for symbols kernel map loaded - check symbol and map ---- end(0) ---- 69: split kallsyms : Ok
Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/tests/Build | 1 + tools/perf/tests/builtin-test.c | 1 + tools/perf/tests/fake_root/proc/kallsyms | 10 ++++ tools/perf/tests/fake_root/proc/modules | 1 + tools/perf/tests/fake_root/proc/version | 1 + tools/perf/tests/kallsyms-split.c | 72 ++++++++++++++++++++++++ tools/perf/tests/tests.h | 1 + 7 files changed, 87 insertions(+) create mode 100644 tools/perf/tests/fake_root/proc/kallsyms create mode 100644 tools/perf/tests/fake_root/proc/modules create mode 100644 tools/perf/tests/fake_root/proc/version create mode 100644 tools/perf/tests/kallsyms-split.c
diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build index af67f8ef74b49c58..c2a67ce459417e0f 100644 --- a/tools/perf/tests/Build +++ b/tools/perf/tests/Build @@ -69,6 +69,7 @@ perf-test-y += util.o perf-test-y += hwmon_pmu.o perf-test-y += tool_pmu.o perf-test-y += subcmd-help.o +perf-test-y += kallsyms-split.o ifeq ($(SRCARCH),$(filter $(SRCARCH),x86 arm arm64 powerpc)) perf-test-$(CONFIG_DWARF_UNWIND) += dwarf-unwind.o diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index 9090e8238a447826..bd6ffa8e4578431a 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -140,6 +140,7 @@ static struct test_suite *generic_tests[] = { &suite__symbols, &suite__util, &suite__subcmd_help, + &suite__kallsyms_split, NULL, }; diff --git a/tools/perf/tests/fake_root/proc/kallsyms b/tools/perf/tests/fake_root/proc/kallsyms new file mode 100644 index 0000000000000000..75d65639e6889c69 --- /dev/null +++ b/tools/perf/tests/fake_root/proc/kallsyms @@ -0,0 +1,10 @@ +ffffffffab200000 T _stext +ffffffffab200010 T good_symbol +ffffffffab200020 t bad_symbol +ffffffffab200030 t main_symbol1 +ffffffffab200040 t main_symbol2 +ffffffffab200050 t main_symbol3 +ffffffffab200060 T _etext +ffffffffcd000000 T start_module [module] +ffffffffab200020 u bad_symbol [module] +ffffffffcd000040 T end_module [module] diff --git a/tools/perf/tests/fake_root/proc/modules b/tools/perf/tests/fake_root/proc/modules new file mode 100644 index 0000000000000000..608c6e2599f08d08 --- /dev/null +++ b/tools/perf/tests/fake_root/proc/modules @@ -0,0 +1 @@ +module 4096 1 - Live 0xffffffffcd000000 diff --git a/tools/perf/tests/fake_root/proc/version b/tools/perf/tests/fake_root/proc/version new file mode 100644 index 0000000000000000..9de114d87d5e940e --- /dev/null +++ b/tools/perf/tests/fake_root/proc/version @@ -0,0 +1 @@ +Linux version X.Y.Z (just for perf test) diff --git a/tools/perf/tests/kallsyms-split.c b/tools/perf/tests/kallsyms-split.c new file mode 100644 index 0000000000000000..b71a2ea6fa696895 --- /dev/null +++ b/tools/perf/tests/kallsyms-split.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/compiler.h> +#include <unistd.h> +#include "util/dso.h" +#include "util/map.h" +#include "util/symbol.h" +#include "util/debug.h" +#include "util/machine.h" +#include "tests.h" + +static int test__kallsyms_split(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct machine m; + struct map *map = NULL; + int ret = TEST_FAIL; + const char *root_dirs[] = { "tests/fake_root", "tools/perf/tests/fake_root", "fake_root" }; + unsigned int root_idx; + + /* force to use /proc/kallsyms */ + symbol_conf.ignore_vmlinux = true; + symbol_conf.ignore_vmlinux_buildid = true; + + pr_debug("try to find fake root directory\n"); + for (root_idx = 0; root_idx < ARRAY_SIZE(root_dirs); root_idx++) { + char buf[128]; + + scnprintf(buf, sizeof(buf), "%s/proc/kallsyms", root_dirs[root_idx]); + if (!access(buf, F_OK)) + break; + } + + if (root_idx == ARRAY_SIZE(root_dirs)) { + pr_debug("SKIP: cannot find the fake root directory and files\n"); + return TEST_SKIP; + } + + machine__init(&m, root_dirs[root_idx], HOST_KERNEL_ID); + if (machine__create_kernel_maps(&m) < 0) { + pr_debug("FAIL: failed to create kernel maps\n"); + goto out; + } + + if (map__load(machine__kernel_map(&m)) < 0) { + pr_debug("SKIP: failed to load kallsyms\n"); + goto out; + } + + pr_debug("kernel map loaded - check symbol and map\n"); + if (maps__nr_maps(machine__kernel_maps(&m)) != 2) { + pr_debug("FAIL: it should have the kernel and a module, but has %u maps\n", + maps__nr_maps(machine__kernel_maps(&m))); + goto out; + } + + if (machine__find_kernel_symbol_by_name(&m, "main_symbol3", &map) == NULL) { + pr_debug("FAIL: failed to find a symbol\n"); + goto out; + } + + if (!RC_CHK_EQUAL(map, machine__kernel_map(&m))) { + pr_debug("FAIL: the symbol is not in the kernel map\n"); + goto out; + } + ret = TEST_OK; + +out: + machine__exit(&m); + return ret; +} + +DEFINE_SUITE("split kallsyms", kallsyms_split); diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index f5fba95b6f3ffbd3..cb67ddbd03753531 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -178,6 +178,7 @@ DECLARE_SUITE(event_groups); DECLARE_SUITE(symbols); DECLARE_SUITE(util); DECLARE_SUITE(subcmd_help); +DECLARE_SUITE(kallsyms_split); /* * PowerPC and S390 do not support creation of instruction breakpoints using the -- 2.52.0.158.g65b55ccf14-goog
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