| Message ID | 20230201135737.800527-6-jolsa@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm/bpf/perf: Store build id in file object | expand |
On Wed, Feb 1, 2023 at 5:58 AM Jiri Olsa <jolsa@kernel.org> wrote: > > Testing iterator access to build id in vma->vm_file object > by storing each binary with buildid into map and checking > it against buildid retrieved in user space. > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > .../selftests/bpf/prog_tests/bpf_iter.c | 88 +++++++++++++++++++ > .../bpf/progs/bpf_iter_task_vma_buildid.c | 49 +++++++++++ > 2 files changed, 137 insertions(+) > create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > > diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c > index 3af6450763e9..fd3217b68c2e 100644 > --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c > +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c > @@ -33,6 +33,7 @@ > #include "bpf_iter_bpf_link.skel.h" > #include "bpf_iter_ksym.skel.h" > #include "bpf_iter_sockmap.skel.h" > +#include "bpf_iter_task_vma_buildid.skel.h" > > static int duration; > > @@ -1536,6 +1537,91 @@ static void test_task_vma_dead_task(void) > bpf_iter_task_vma__destroy(skel); > } > > +#define D_PATH_BUF_SIZE 1024 > +#define BUILD_ID_SIZE_MAX 20 > + > +struct build_id { > + u32 sz; > + char data[BUILD_ID_SIZE_MAX]; > +}; > + > +#define BUILDID_STR_SIZE (BPF_BUILD_ID_SIZE*2 + 1) > + > +static void test_task_vma_buildid(void) > +{ > + int err, iter_fd = -1, proc_maps_fd = -1; > + struct bpf_iter_task_vma_buildid *skel; > + char key[D_PATH_BUF_SIZE], *prev_key; > + char bpf_build_id[BUILDID_STR_SIZE]; > + int len, files_fd, i, cnt = 0; > + struct build_id val; > + char *build_id; > + char c; > + > + skel = bpf_iter_task_vma_buildid__open(); > + if (!ASSERT_OK_PTR(skel, "bpf_iter_task_vma_buildid__open")) > + return; > + > + err = bpf_iter_task_vma_buildid__load(skel); > + if (!ASSERT_OK(err, "bpf_iter_task_vma_buildid__load")) > + goto out; minor: you can do __open_and_load() in one step > + > + skel->links.proc_maps = bpf_program__attach_iter( > + skel->progs.proc_maps, NULL); > + > + if (!ASSERT_OK_PTR(skel->links.proc_maps, "bpf_program__attach_iter")) { > + skel->links.proc_maps = NULL; > + goto out; > + } > + > + iter_fd = bpf_iter_create(bpf_link__fd(skel->links.proc_maps)); > + if (!ASSERT_GE(iter_fd, 0, "create_iter")) > + goto out; > + > + /* trigger the iterator, there's no output, just map */ > + len = read(iter_fd, &c, 1); > + ASSERT_EQ(len, 0, "len_check"); > + > + files_fd = bpf_map__fd(skel->maps.files); > + > + prev_key = NULL; > + > + while (true) { > + err = bpf_map_get_next_key(files_fd, prev_key, &key); > + if (err) { > + if (errno == ENOENT) > + err = 0; > + break; > + } > + if (bpf_map_lookup_elem(files_fd, key, &val)) > + break; > + if (!ASSERT_LE(val.sz, BUILD_ID_SIZE_MAX, "buildid_size")) > + break; > + > + memset(bpf_build_id, 0x0, sizeof(bpf_build_id)); > + for (i = 0; i < val.sz; i++) { > + sprintf(bpf_build_id + i*2, "%02x", > + (unsigned char) val.data[i]); > + } > + > + if (!ASSERT_OK(read_buildid(key, &build_id), "read_buildid")) > + break; > + > + printf("BUILDID %s %s %s\n", bpf_build_id, build_id, key); debugging leftover or intentional? > + ASSERT_OK(strncmp(bpf_build_id, build_id, strlen(bpf_build_id)), "buildid_cmp"); > + > + free(build_id); > + prev_key = key; > + cnt++; > + } > + > + printf("checked %d files\n", cnt); ditto > +out: > + close(proc_maps_fd); > + close(iter_fd); > + bpf_iter_task_vma_buildid__destroy(skel); > +} > + > void test_bpf_sockmap_map_iter_fd(void) > { > struct bpf_iter_sockmap *skel; > @@ -1659,6 +1745,8 @@ void test_bpf_iter(void) > test_task_vma(); > if (test__start_subtest("task_vma_dead_task")) > test_task_vma_dead_task(); > + if (test__start_subtest("task_vma_buildid")) > + test_task_vma_buildid(); > if (test__start_subtest("task_btf")) > test_task_btf(); > if (test__start_subtest("tcp4")) > diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > new file mode 100644 > index 000000000000..25e2179ae5f4 > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > @@ -0,0 +1,49 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include "bpf_iter.h" > +#include <bpf/bpf_helpers.h> > +#include <string.h> > + > +char _license[] SEC("license") = "GPL"; > + > +#define VM_EXEC 0x00000004 > +#define D_PATH_BUF_SIZE 1024 > + > +struct { > + __uint(type, BPF_MAP_TYPE_HASH); > + __uint(max_entries, 10000); > + __type(key, char[D_PATH_BUF_SIZE]); > + __type(value, struct build_id); > +} files SEC(".maps"); > + > +static char tmp_key[D_PATH_BUF_SIZE]; > +static struct build_id tmp_data; > + > +SEC("iter/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx) nit: let's keep SEC() on separate line from function itself > +{ > + struct vm_area_struct *vma = ctx->vma; > + struct seq_file *seq = ctx->meta->seq; > + struct task_struct *task = ctx->task; > + unsigned long file_key; > + struct file *file; > + > + if (task == (void *)0 || vma == (void *)0) > + return 0; > + > + if (!(vma->vm_flags & VM_EXEC)) > + return 0; > + > + file = vma->vm_file; > + if (!file) > + return 0; > + > + memset(tmp_key, 0x0, D_PATH_BUF_SIZE); __builtin_memset() to not rely on compiler optimization? > + bpf_d_path(&file->f_path, (char *) &tmp_key, D_PATH_BUF_SIZE); > + > + if (bpf_map_lookup_elem(&files, &tmp_key)) > + return 0; > + > + memcpy(&tmp_data, file->f_bid, sizeof(*file->f_bid)); same about __builtin_memcpy() > + bpf_map_update_elem(&files, &tmp_key, &tmp_data, 0); > + return 0; > +} > -- > 2.39.1 >
On Wed, Feb 08, 2023 at 04:01:42PM -0800, Andrii Nakryiko wrote: SNIP > > +static void test_task_vma_buildid(void) > > +{ > > + int err, iter_fd = -1, proc_maps_fd = -1; > > + struct bpf_iter_task_vma_buildid *skel; > > + char key[D_PATH_BUF_SIZE], *prev_key; > > + char bpf_build_id[BUILDID_STR_SIZE]; > > + int len, files_fd, i, cnt = 0; > > + struct build_id val; > > + char *build_id; > > + char c; > > + > > + skel = bpf_iter_task_vma_buildid__open(); > > + if (!ASSERT_OK_PTR(skel, "bpf_iter_task_vma_buildid__open")) > > + return; > > + > > + err = bpf_iter_task_vma_buildid__load(skel); > > + if (!ASSERT_OK(err, "bpf_iter_task_vma_buildid__load")) > > + goto out; > > minor: you can do __open_and_load() in one step right, I copied that from another test, but removed all the setup in between, so we can actually call just __open_and_load SNIP > > + memset(bpf_build_id, 0x0, sizeof(bpf_build_id)); > > + for (i = 0; i < val.sz; i++) { > > + sprintf(bpf_build_id + i*2, "%02x", > > + (unsigned char) val.data[i]); > > + } > > + > > + if (!ASSERT_OK(read_buildid(key, &build_id), "read_buildid")) > > + break; > > + > > + printf("BUILDID %s %s %s\n", bpf_build_id, build_id, key); > > debugging leftover or intentional? > > > + ASSERT_OK(strncmp(bpf_build_id, build_id, strlen(bpf_build_id)), "buildid_cmp"); > > + > > + free(build_id); > > + prev_key = key; > > + cnt++; > > + } > > + > > + printf("checked %d files\n", cnt); > > ditto both intentional, first one can go out I guess, but the number of checked files seemed interesting to me ;-) SNIP > > diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > > new file mode 100644 > > index 000000000000..25e2179ae5f4 > > --- /dev/null > > +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > > @@ -0,0 +1,49 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > + > > +#include "bpf_iter.h" > > +#include <bpf/bpf_helpers.h> > > +#include <string.h> > > + > > +char _license[] SEC("license") = "GPL"; > > + > > +#define VM_EXEC 0x00000004 > > +#define D_PATH_BUF_SIZE 1024 > > + > > +struct { > > + __uint(type, BPF_MAP_TYPE_HASH); > > + __uint(max_entries, 10000); > > + __type(key, char[D_PATH_BUF_SIZE]); > > + __type(value, struct build_id); > > +} files SEC(".maps"); > > + > > +static char tmp_key[D_PATH_BUF_SIZE]; > > +static struct build_id tmp_data; > > + > > +SEC("iter/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx) > > nit: let's keep SEC() on separate line from function itself ok > > > +{ > > + struct vm_area_struct *vma = ctx->vma; > > + struct seq_file *seq = ctx->meta->seq; > > + struct task_struct *task = ctx->task; > > + unsigned long file_key; > > + struct file *file; > > + > > + if (task == (void *)0 || vma == (void *)0) > > + return 0; > > + > > + if (!(vma->vm_flags & VM_EXEC)) > > + return 0; > > + > > + file = vma->vm_file; > > + if (!file) > > + return 0; > > + > > + memset(tmp_key, 0x0, D_PATH_BUF_SIZE); > > __builtin_memset() to not rely on compiler optimization? > > > + bpf_d_path(&file->f_path, (char *) &tmp_key, D_PATH_BUF_SIZE); > > + > > + if (bpf_map_lookup_elem(&files, &tmp_key)) > > + return 0; > > + > > + memcpy(&tmp_data, file->f_bid, sizeof(*file->f_bid)); > > same about __builtin_memcpy() ah ok, did not know that, will check.. curious what could go wrong by using not '__builtin_...' version? thanks, jirka
On Thu, Feb 9, 2023 at 6:04 AM Jiri Olsa <olsajiri@gmail.com> wrote: > > On Wed, Feb 08, 2023 at 04:01:42PM -0800, Andrii Nakryiko wrote: > > SNIP > > > > +static void test_task_vma_buildid(void) > > > +{ > > > + int err, iter_fd = -1, proc_maps_fd = -1; > > > + struct bpf_iter_task_vma_buildid *skel; > > > + char key[D_PATH_BUF_SIZE], *prev_key; > > > + char bpf_build_id[BUILDID_STR_SIZE]; > > > + int len, files_fd, i, cnt = 0; > > > + struct build_id val; > > > + char *build_id; > > > + char c; > > > + > > > + skel = bpf_iter_task_vma_buildid__open(); > > > + if (!ASSERT_OK_PTR(skel, "bpf_iter_task_vma_buildid__open")) > > > + return; > > > + > > > + err = bpf_iter_task_vma_buildid__load(skel); > > > + if (!ASSERT_OK(err, "bpf_iter_task_vma_buildid__load")) > > > + goto out; > > > > minor: you can do __open_and_load() in one step > > right, I copied that from another test, but removed all the > setup in between, so we can actually call just __open_and_load > > SNIP > > > > + memset(bpf_build_id, 0x0, sizeof(bpf_build_id)); > > > + for (i = 0; i < val.sz; i++) { > > > + sprintf(bpf_build_id + i*2, "%02x", > > > + (unsigned char) val.data[i]); > > > + } > > > + > > > + if (!ASSERT_OK(read_buildid(key, &build_id), "read_buildid")) > > > + break; > > > + > > > + printf("BUILDID %s %s %s\n", bpf_build_id, build_id, key); > > > > debugging leftover or intentional? > > > > > + ASSERT_OK(strncmp(bpf_build_id, build_id, strlen(bpf_build_id)), "buildid_cmp"); > > > + > > > + free(build_id); > > > + prev_key = key; > > > + cnt++; > > > + } > > > + > > > + printf("checked %d files\n", cnt); > > > > ditto > > both intentional, first one can go out I guess, but the > number of checked files seemed interesting to me ;-) > > SNIP > > > > diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > > > new file mode 100644 > > > index 000000000000..25e2179ae5f4 > > > --- /dev/null > > > +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c > > > @@ -0,0 +1,49 @@ > > > +// SPDX-License-Identifier: GPL-2.0 > > > + > > > +#include "bpf_iter.h" > > > +#include <bpf/bpf_helpers.h> > > > +#include <string.h> > > > + > > > +char _license[] SEC("license") = "GPL"; > > > + > > > +#define VM_EXEC 0x00000004 > > > +#define D_PATH_BUF_SIZE 1024 > > > + > > > +struct { > > > + __uint(type, BPF_MAP_TYPE_HASH); > > > + __uint(max_entries, 10000); > > > + __type(key, char[D_PATH_BUF_SIZE]); > > > + __type(value, struct build_id); > > > +} files SEC(".maps"); > > > + > > > +static char tmp_key[D_PATH_BUF_SIZE]; > > > +static struct build_id tmp_data; > > > + > > > +SEC("iter/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx) > > > > nit: let's keep SEC() on separate line from function itself > > ok > > > > > > +{ > > > + struct vm_area_struct *vma = ctx->vma; > > > + struct seq_file *seq = ctx->meta->seq; > > > + struct task_struct *task = ctx->task; > > > + unsigned long file_key; > > > + struct file *file; > > > + > > > + if (task == (void *)0 || vma == (void *)0) > > > + return 0; > > > + > > > + if (!(vma->vm_flags & VM_EXEC)) > > > + return 0; > > > + > > > + file = vma->vm_file; > > > + if (!file) > > > + return 0; > > > + > > > + memset(tmp_key, 0x0, D_PATH_BUF_SIZE); > > > > __builtin_memset() to not rely on compiler optimization? > > > > > + bpf_d_path(&file->f_path, (char *) &tmp_key, D_PATH_BUF_SIZE); > > > + > > > + if (bpf_map_lookup_elem(&files, &tmp_key)) > > > + return 0; > > > + > > > + memcpy(&tmp_data, file->f_bid, sizeof(*file->f_bid)); > > > > same about __builtin_memcpy() > > ah ok, did not know that, will check.. curious what could > go wrong by using not '__builtin_...' version? if compiler doesn't optimize it into __builtin_memcpy() (which results in just explicit assembly code to copy/set data word-by-word), then BPF program will do actual call to memset(), which with C rules would be inferred as extern symbol, which would fail BPF object loading with error along the lines of "couldn't resolve memset extern". > > thanks, > jirka
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index 3af6450763e9..fd3217b68c2e 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -33,6 +33,7 @@ #include "bpf_iter_bpf_link.skel.h" #include "bpf_iter_ksym.skel.h" #include "bpf_iter_sockmap.skel.h" +#include "bpf_iter_task_vma_buildid.skel.h" static int duration; @@ -1536,6 +1537,91 @@ static void test_task_vma_dead_task(void) bpf_iter_task_vma__destroy(skel); } +#define D_PATH_BUF_SIZE 1024 +#define BUILD_ID_SIZE_MAX 20 + +struct build_id { + u32 sz; + char data[BUILD_ID_SIZE_MAX]; +}; + +#define BUILDID_STR_SIZE (BPF_BUILD_ID_SIZE*2 + 1) + +static void test_task_vma_buildid(void) +{ + int err, iter_fd = -1, proc_maps_fd = -1; + struct bpf_iter_task_vma_buildid *skel; + char key[D_PATH_BUF_SIZE], *prev_key; + char bpf_build_id[BUILDID_STR_SIZE]; + int len, files_fd, i, cnt = 0; + struct build_id val; + char *build_id; + char c; + + skel = bpf_iter_task_vma_buildid__open(); + if (!ASSERT_OK_PTR(skel, "bpf_iter_task_vma_buildid__open")) + return; + + err = bpf_iter_task_vma_buildid__load(skel); + if (!ASSERT_OK(err, "bpf_iter_task_vma_buildid__load")) + goto out; + + skel->links.proc_maps = bpf_program__attach_iter( + skel->progs.proc_maps, NULL); + + if (!ASSERT_OK_PTR(skel->links.proc_maps, "bpf_program__attach_iter")) { + skel->links.proc_maps = NULL; + goto out; + } + + iter_fd = bpf_iter_create(bpf_link__fd(skel->links.proc_maps)); + if (!ASSERT_GE(iter_fd, 0, "create_iter")) + goto out; + + /* trigger the iterator, there's no output, just map */ + len = read(iter_fd, &c, 1); + ASSERT_EQ(len, 0, "len_check"); + + files_fd = bpf_map__fd(skel->maps.files); + + prev_key = NULL; + + while (true) { + err = bpf_map_get_next_key(files_fd, prev_key, &key); + if (err) { + if (errno == ENOENT) + err = 0; + break; + } + if (bpf_map_lookup_elem(files_fd, key, &val)) + break; + if (!ASSERT_LE(val.sz, BUILD_ID_SIZE_MAX, "buildid_size")) + break; + + memset(bpf_build_id, 0x0, sizeof(bpf_build_id)); + for (i = 0; i < val.sz; i++) { + sprintf(bpf_build_id + i*2, "%02x", + (unsigned char) val.data[i]); + } + + if (!ASSERT_OK(read_buildid(key, &build_id), "read_buildid")) + break; + + printf("BUILDID %s %s %s\n", bpf_build_id, build_id, key); + ASSERT_OK(strncmp(bpf_build_id, build_id, strlen(bpf_build_id)), "buildid_cmp"); + + free(build_id); + prev_key = key; + cnt++; + } + + printf("checked %d files\n", cnt); +out: + close(proc_maps_fd); + close(iter_fd); + bpf_iter_task_vma_buildid__destroy(skel); +} + void test_bpf_sockmap_map_iter_fd(void) { struct bpf_iter_sockmap *skel; @@ -1659,6 +1745,8 @@ void test_bpf_iter(void) test_task_vma(); if (test__start_subtest("task_vma_dead_task")) test_task_vma_dead_task(); + if (test__start_subtest("task_vma_buildid")) + test_task_vma_buildid(); if (test__start_subtest("task_btf")) test_task_btf(); if (test__start_subtest("tcp4")) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c new file mode 100644 index 000000000000..25e2179ae5f4 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "bpf_iter.h" +#include <bpf/bpf_helpers.h> +#include <string.h> + +char _license[] SEC("license") = "GPL"; + +#define VM_EXEC 0x00000004 +#define D_PATH_BUF_SIZE 1024 + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 10000); + __type(key, char[D_PATH_BUF_SIZE]); + __type(value, struct build_id); +} files SEC(".maps"); + +static char tmp_key[D_PATH_BUF_SIZE]; +static struct build_id tmp_data; + +SEC("iter/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx) +{ + struct vm_area_struct *vma = ctx->vma; + struct seq_file *seq = ctx->meta->seq; + struct task_struct *task = ctx->task; + unsigned long file_key; + struct file *file; + + if (task == (void *)0 || vma == (void *)0) + return 0; + + if (!(vma->vm_flags & VM_EXEC)) + return 0; + + file = vma->vm_file; + if (!file) + return 0; + + memset(tmp_key, 0x0, D_PATH_BUF_SIZE); + bpf_d_path(&file->f_path, (char *) &tmp_key, D_PATH_BUF_SIZE); + + if (bpf_map_lookup_elem(&files, &tmp_key)) + return 0; + + memcpy(&tmp_data, file->f_bid, sizeof(*file->f_bid)); + bpf_map_update_elem(&files, &tmp_key, &tmp_data, 0); + return 0; +}
Testing iterator access to build id in vma->vm_file object by storing each binary with buildid into map and checking it against buildid retrieved in user space. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- .../selftests/bpf/prog_tests/bpf_iter.c | 88 +++++++++++++++++++ .../bpf/progs/bpf_iter_task_vma_buildid.c | 49 +++++++++++ 2 files changed, 137 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_vma_buildid.c