linux/tools/perf/tests/bpf.c

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#include <stdio.h>
#include <sys/epoll.h>
#include <util/util.h>
#include <util/bpf-loader.h>
#include <util/evlist.h>
#include <linux/bpf.h>
#include <linux/filter.h>
#include <bpf/bpf.h>
#include "tests.h"
#include "llvm.h"
#include "debug.h"
#define NR_ITERS 111
#ifdef HAVE_LIBBPF_SUPPORT
static int epoll_wait_loop(void)
{
int i;
/* Should fail NR_ITERS times */
for (i = 0; i < NR_ITERS; i++)
epoll_wait(-(i + 1), NULL, 0, 0);
return 0;
}
perf test: Test the BPF prologue adding infrastructure This patch introduces a new BPF script to test the BPF prologue adding routines. The new script probes at null_lseek, which is the function pointer used when we try to lseek on '/dev/null'. The null_lseek function is chosen because it is used by function pointers, so we don't need to consider inlining and LTO. By extracting file->f_mode, bpf-script-test-prologue.c should know whether the file is writable or readonly. According to llseek_loop() and bpf-script-test-prologue.c, one fourth of total lseeks should be collected. Committer note: Testing it: # perf test -v BPF <SNIP> Kernel build dir is set to /lib/modules/4.3.0+/build set env: KBUILD_DIR=/lib/modules/4.3.0+/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: NR_CPUS=4 set env: LINUX_VERSION_CODE=0x40300 set env: CLANG_EXEC=/usr/libexec/icecc/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.3.0+/build set env: CLANG_SOURCE=- llvm compiling command template: echo '/* * bpf-script-test-prologue.c * Test BPF prologue */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' #endif #define SEC(NAME) __attribute__((section(NAME), used)) #include <uapi/linux/fs.h> #define FMODE_READ 0x1 #define FMODE_WRITE 0x2 static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = (void *) 6; SEC("func=null_lseek file->f_mode offset orig") int bpf_func__null_lseek(void *ctx, int err, unsigned long f_mode, unsigned long offset, unsigned long orig) { if (err) return 0; if (f_mode & FMODE_WRITE) return 0; if (offset & 1) return 0; if (orig == SEEK_CUR) return 0; return 1; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - libbpf: loading object '[bpf_prologue_test]' from buffer libbpf: section .strtab, size 135, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=null_lseek file->f_mode offset orig, size 112, link 0, flags 6, type=1 libbpf: found program func=null_lseek file->f_mode offset orig libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_prologue_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_prologue_test] is 40300 libbpf: section .symtab, size 168, link 1, flags 0, type=2 bpf: config program 'func=null_lseek file->f_mode offset orig' symbol:null_lseek file:(null) line:0 offset:0 return:0 lazy:(null) parsing arg: file->f_mode into file, f_mode(1) parsing arg: offset into offset parsing arg: orig into orig bpf: config 'func=null_lseek file->f_mode offset orig' is ok Looking at the vmlinux_path (7 entries long) Using /lib/modules/4.3.0+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.3.0+/build/vmlinux Try to find probe point from debuginfo. Matched function: null_lseek Probe point found: null_lseek+0 Searching 'file' variable in context. Converting variable file into trace event. converting f_mode in file f_mode type is unsigned int. Searching 'offset' variable in context. Converting variable offset into trace event. offset type is long long int. Searching 'orig' variable in context. Converting variable orig into trace event. orig type is int. Found 1 probe_trace_events. Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: p:perf_bpf_probe/func _text+4840528 f_mode=+68(%di):u32 offset=%si:s64 orig=%dx:s32 libbpf: don't need create maps for [bpf_prologue_test] prologue: pass validation prologue: slow path prologue: fetch arg 0, base reg is %di prologue: arg 0: offset 68 prologue: fetch arg 1, base reg is %si prologue: fetch arg 2, base reg is %dx add bpf event perf_bpf_probe:func and attach bpf program 3 adding perf_bpf_probe:func adding perf_bpf_probe:func to 0x51672c0 mmap size 1052672B Opening /sys/kernel/debug/tracing//kprobe_events write=1 Opening /sys/kernel/debug/tracing//uprobe_events write=1 Parsing probe_events: p:perf_bpf_probe/func _text+4840528 f_mode=+68(%di):u32 offset=%si:s64 orig=%dx:s32 Group:perf_bpf_probe Event:func probe:p Writing event: -:perf_bpf_probe/func test child finished with 0 ---- end ---- Test BPF filter: Ok # Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1447675815-166222-13-git-send-email-wangnan0@huawei.com [ Added tools/perf/tests/llvm-src-prologue.c to .gitignore ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-16 12:10:14 +00:00
#ifdef HAVE_BPF_PROLOGUE
static int llseek_loop(void)
{
int fds[2], i;
fds[0] = open("/dev/null", O_RDONLY);
fds[1] = open("/dev/null", O_RDWR);
if (fds[0] < 0 || fds[1] < 0)
return -1;
for (i = 0; i < NR_ITERS; i++) {
lseek(fds[i % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
lseek(fds[(i + 1) % 2], i, (i / 2) % 2 ? SEEK_CUR : SEEK_SET);
}
close(fds[0]);
close(fds[1]);
return 0;
}
#endif
static struct {
enum test_llvm__testcase prog_id;
const char *desc;
const char *name;
const char *msg_compile_fail;
const char *msg_load_fail;
int (*target_func)(void);
int expect_result;
} bpf_testcase_table[] = {
{
LLVM_TESTCASE_BASE,
"Test basic BPF filtering",
"[basic_bpf_test]",
"fix 'perf test LLVM' first",
"load bpf object failed",
&epoll_wait_loop,
(NR_ITERS + 1) / 2,
},
perf test: Test the BPF prologue adding infrastructure This patch introduces a new BPF script to test the BPF prologue adding routines. The new script probes at null_lseek, which is the function pointer used when we try to lseek on '/dev/null'. The null_lseek function is chosen because it is used by function pointers, so we don't need to consider inlining and LTO. By extracting file->f_mode, bpf-script-test-prologue.c should know whether the file is writable or readonly. According to llseek_loop() and bpf-script-test-prologue.c, one fourth of total lseeks should be collected. Committer note: Testing it: # perf test -v BPF <SNIP> Kernel build dir is set to /lib/modules/4.3.0+/build set env: KBUILD_DIR=/lib/modules/4.3.0+/build unset env: KBUILD_OPTS include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: NR_CPUS=4 set env: LINUX_VERSION_CODE=0x40300 set env: CLANG_EXEC=/usr/libexec/icecc/bin/clang set env: CLANG_OPTIONS=-xc set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.9.2/include -I/home/git/linux/arch/x86/include -Iarch/x86/include/generated/uapi -Iarch/x86/include/generated -I/home/git/linux/include -Iinclude -I/home/git/linux/arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I/home/git/linux/include/uapi -Iinclude/generated/uapi -include /home/git/linux/include/linux/kconfig.h set env: WORKING_DIR=/lib/modules/4.3.0+/build set env: CLANG_SOURCE=- llvm compiling command template: echo '/* * bpf-script-test-prologue.c * Test BPF prologue */ #ifndef LINUX_VERSION_CODE # error Need LINUX_VERSION_CODE # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' #endif #define SEC(NAME) __attribute__((section(NAME), used)) #include <uapi/linux/fs.h> #define FMODE_READ 0x1 #define FMODE_WRITE 0x2 static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = (void *) 6; SEC("func=null_lseek file->f_mode offset orig") int bpf_func__null_lseek(void *ctx, int err, unsigned long f_mode, unsigned long offset, unsigned long orig) { if (err) return 0; if (f_mode & FMODE_WRITE) return 0; if (offset & 1) return 0; if (orig == SEEK_CUR) return 0; return 1; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o - libbpf: loading object '[bpf_prologue_test]' from buffer libbpf: section .strtab, size 135, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=null_lseek file->f_mode offset orig, size 112, link 0, flags 6, type=1 libbpf: found program func=null_lseek file->f_mode offset orig libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_prologue_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_prologue_test] is 40300 libbpf: section .symtab, size 168, link 1, flags 0, type=2 bpf: config program 'func=null_lseek file->f_mode offset orig' symbol:null_lseek file:(null) line:0 offset:0 return:0 lazy:(null) parsing arg: file->f_mode into file, f_mode(1) parsing arg: offset into offset parsing arg: orig into orig bpf: config 'func=null_lseek file->f_mode offset orig' is ok Looking at the vmlinux_path (7 entries long) Using /lib/modules/4.3.0+/build/vmlinux for symbols Open Debuginfo file: /lib/modules/4.3.0+/build/vmlinux Try to find probe point from debuginfo. Matched function: null_lseek Probe point found: null_lseek+0 Searching 'file' variable in context. Converting variable file into trace event. converting f_mode in file f_mode type is unsigned int. Searching 'offset' variable in context. Converting variable offset into trace event. offset type is long long int. Searching 'orig' variable in context. Converting variable orig into trace event. orig type is int. Found 1 probe_trace_events. Opening /sys/kernel/debug/tracing//kprobe_events write=1 Writing event: p:perf_bpf_probe/func _text+4840528 f_mode=+68(%di):u32 offset=%si:s64 orig=%dx:s32 libbpf: don't need create maps for [bpf_prologue_test] prologue: pass validation prologue: slow path prologue: fetch arg 0, base reg is %di prologue: arg 0: offset 68 prologue: fetch arg 1, base reg is %si prologue: fetch arg 2, base reg is %dx add bpf event perf_bpf_probe:func and attach bpf program 3 adding perf_bpf_probe:func adding perf_bpf_probe:func to 0x51672c0 mmap size 1052672B Opening /sys/kernel/debug/tracing//kprobe_events write=1 Opening /sys/kernel/debug/tracing//uprobe_events write=1 Parsing probe_events: p:perf_bpf_probe/func _text+4840528 f_mode=+68(%di):u32 offset=%si:s64 orig=%dx:s32 Group:perf_bpf_probe Event:func probe:p Writing event: -:perf_bpf_probe/func test child finished with 0 ---- end ---- Test BPF filter: Ok # Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1447675815-166222-13-git-send-email-wangnan0@huawei.com [ Added tools/perf/tests/llvm-src-prologue.c to .gitignore ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-16 12:10:14 +00:00
#ifdef HAVE_BPF_PROLOGUE
{
LLVM_TESTCASE_BPF_PROLOGUE,
"Test BPF prologue generation",
"[bpf_prologue_test]",
"fix kbuild first",
"check your vmlinux setting?",
&llseek_loop,
(NR_ITERS + 1) / 4,
},
#endif
perf test: Add libbpf relocation checker There's a bug in LLVM that it can generate unneeded relocation information. See [1] and [2]. Libbpf should check the target section of a relocation symbol. This patch adds a testcase which references a global variable (BPF doesn't support global variables). Before fixing libbpf, the new test case can be loaded into kernel, the global variable acts like the first map. It is incorrect. Result: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : FAILED! # ~/perf test -v BPF ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: relocation: insn_idx=7 Success unexpectedly: libbpf error when dealing with relocation test child finished with -1 ---- end ---- Test BPF filter subtest 2: FAILED! [1] https://llvm.org/bugs/show_bug.cgi?id=26243 [2] https://patchwork.ozlabs.org/patch/571385/ Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-25 09:55:48 +00:00
{
LLVM_TESTCASE_BPF_RELOCATION,
"Test BPF relocation checker",
"[bpf_relocation_test]",
"fix 'perf test LLVM' first",
"libbpf error when dealing with relocation",
NULL,
0,
},
};
static int do_test(struct bpf_object *obj, int (*func)(void),
int expect)
{
struct record_opts opts = {
.target = {
.uid = UINT_MAX,
.uses_mmap = true,
},
.freq = 0,
.mmap_pages = 256,
.default_interval = 1,
};
char pid[16];
char sbuf[STRERR_BUFSIZE];
struct perf_evlist *evlist;
int i, ret = TEST_FAIL, err = 0, count = 0;
struct parse_events_evlist parse_evlist;
struct parse_events_error parse_error;
bzero(&parse_error, sizeof(parse_error));
bzero(&parse_evlist, sizeof(parse_evlist));
parse_evlist.error = &parse_error;
INIT_LIST_HEAD(&parse_evlist.list);
perf tools: Apply tracepoint event definition options to BPF script Users can pass options to tracepoints defined in the BPF script. For example: # perf record -e ./test.c/no-inherit/ bash # dd if=/dev/zero of=/dev/null count=10000 # exit [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.022 MB perf.data (139 samples) ] (no-inherit works, only the sys_read issued by bash are captured, at least 10000 sys_read issued by dd are skipped.) test.c: #define SEC(NAME) __attribute__((section(NAME), used)) SEC("func=sys_read") int bpf_func__sys_read(void *ctx) { return 1; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; no-inherit is applied to the kprobe event defined in test.c. Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Cody P Schafer <dev@codyps.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1456132275-98875-10-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-22 09:10:36 +00:00
err = parse_events_load_bpf_obj(&parse_evlist, &parse_evlist.list, obj, NULL);
if (err || list_empty(&parse_evlist.list)) {
pr_debug("Failed to add events selected by BPF\n");
return TEST_FAIL;
}
snprintf(pid, sizeof(pid), "%d", getpid());
pid[sizeof(pid) - 1] = '\0';
opts.target.tid = opts.target.pid = pid;
/* Instead of perf_evlist__new_default, don't add default events */
evlist = perf_evlist__new();
if (!evlist) {
pr_debug("Not enough memory to create evlist\n");
return TEST_FAIL;
}
err = perf_evlist__create_maps(evlist, &opts.target);
if (err < 0) {
pr_debug("Not enough memory to create thread/cpu maps\n");
goto out_delete_evlist;
}
perf_evlist__splice_list_tail(evlist, &parse_evlist.list);
evlist->nr_groups = parse_evlist.nr_groups;
perf_evlist__config(evlist, &opts, NULL);
err = perf_evlist__open(evlist);
if (err < 0) {
pr_debug("perf_evlist__open: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
goto out_delete_evlist;
}
err = perf_evlist__mmap(evlist, opts.mmap_pages, false);
if (err < 0) {
pr_debug("perf_evlist__mmap: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
goto out_delete_evlist;
}
perf_evlist__enable(evlist);
(*func)();
perf_evlist__disable(evlist);
for (i = 0; i < evlist->nr_mmaps; i++) {
union perf_event *event;
while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
const u32 type = event->header.type;
if (type == PERF_RECORD_SAMPLE)
count ++;
}
}
if (count != expect) {
pr_debug("BPF filter result incorrect\n");
goto out_delete_evlist;
}
ret = TEST_OK;
out_delete_evlist:
perf_evlist__delete(evlist);
return ret;
}
static struct bpf_object *
prepare_bpf(void *obj_buf, size_t obj_buf_sz, const char *name)
{
struct bpf_object *obj;
obj = bpf__prepare_load_buffer(obj_buf, obj_buf_sz, name);
if (IS_ERR(obj)) {
pr_debug("Compile BPF program failed.\n");
return NULL;
}
return obj;
}
static int __test__bpf(int idx)
{
int ret;
void *obj_buf;
size_t obj_buf_sz;
struct bpf_object *obj;
ret = test_llvm__fetch_bpf_obj(&obj_buf, &obj_buf_sz,
bpf_testcase_table[idx].prog_id,
perf test: Add libbpf relocation checker There's a bug in LLVM that it can generate unneeded relocation information. See [1] and [2]. Libbpf should check the target section of a relocation symbol. This patch adds a testcase which references a global variable (BPF doesn't support global variables). Before fixing libbpf, the new test case can be loaded into kernel, the global variable acts like the first map. It is incorrect. Result: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : FAILED! # ~/perf test -v BPF ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: relocation: insn_idx=7 Success unexpectedly: libbpf error when dealing with relocation test child finished with -1 ---- end ---- Test BPF filter subtest 2: FAILED! [1] https://llvm.org/bugs/show_bug.cgi?id=26243 [2] https://patchwork.ozlabs.org/patch/571385/ Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-25 09:55:48 +00:00
true, NULL);
if (ret != TEST_OK || !obj_buf || !obj_buf_sz) {
pr_debug("Unable to get BPF object, %s\n",
bpf_testcase_table[idx].msg_compile_fail);
if (idx == 0)
return TEST_SKIP;
else
return TEST_FAIL;
}
obj = prepare_bpf(obj_buf, obj_buf_sz,
bpf_testcase_table[idx].name);
perf test: Add libbpf relocation checker There's a bug in LLVM that it can generate unneeded relocation information. See [1] and [2]. Libbpf should check the target section of a relocation symbol. This patch adds a testcase which references a global variable (BPF doesn't support global variables). Before fixing libbpf, the new test case can be loaded into kernel, the global variable acts like the first map. It is incorrect. Result: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : FAILED! # ~/perf test -v BPF ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: relocation: insn_idx=7 Success unexpectedly: libbpf error when dealing with relocation test child finished with -1 ---- end ---- Test BPF filter subtest 2: FAILED! [1] https://llvm.org/bugs/show_bug.cgi?id=26243 [2] https://patchwork.ozlabs.org/patch/571385/ Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-25 09:55:48 +00:00
if ((!!bpf_testcase_table[idx].target_func) != (!!obj)) {
if (!obj)
pr_debug("Fail to load BPF object: %s\n",
bpf_testcase_table[idx].msg_load_fail);
else
pr_debug("Success unexpectedly: %s\n",
bpf_testcase_table[idx].msg_load_fail);
ret = TEST_FAIL;
goto out;
}
perf test: Add libbpf relocation checker There's a bug in LLVM that it can generate unneeded relocation information. See [1] and [2]. Libbpf should check the target section of a relocation symbol. This patch adds a testcase which references a global variable (BPF doesn't support global variables). Before fixing libbpf, the new test case can be loaded into kernel, the global variable acts like the first map. It is incorrect. Result: # ~/perf test BPF 37: Test BPF filter : 37.1: Test basic BPF filtering : Ok 37.2: Test BPF prologue generation : Ok 37.3: Test BPF relocation checker : FAILED! # ~/perf test -v BPF ... libbpf: loading object '[bpf_relocation_test]' from buffer libbpf: section .strtab, size 126, link 0, flags 0, type=3 libbpf: section .text, size 0, link 0, flags 6, type=1 libbpf: section .data, size 0, link 0, flags 3, type=1 libbpf: section .bss, size 0, link 0, flags 3, type=8 libbpf: section func=sys_write, size 104, link 0, flags 6, type=1 libbpf: found program func=sys_write libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9 libbpf: section maps, size 16, link 0, flags 3, type=1 libbpf: maps in [bpf_relocation_test]: 16 bytes libbpf: section license, size 4, link 0, flags 3, type=1 libbpf: license of [bpf_relocation_test] is GPL libbpf: section version, size 4, link 0, flags 3, type=1 libbpf: kernel version of [bpf_relocation_test] is 40400 libbpf: section .symtab, size 144, link 1, flags 0, type=2 libbpf: map 0 is "my_table" libbpf: collecting relocating info for: 'func=sys_write' libbpf: relocation: insn_idx=7 Success unexpectedly: libbpf error when dealing with relocation test child finished with -1 ---- end ---- Test BPF filter subtest 2: FAILED! [1] https://llvm.org/bugs/show_bug.cgi?id=26243 [2] https://patchwork.ozlabs.org/patch/571385/ Signed-off-by: Wang Nan <wangnan0@huawei.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-25 09:55:48 +00:00
if (obj)
ret = do_test(obj,
bpf_testcase_table[idx].target_func,
bpf_testcase_table[idx].expect_result);
out:
bpf__clear();
return ret;
}
int test__bpf_subtest_get_nr(void)
{
return (int)ARRAY_SIZE(bpf_testcase_table);
}
const char *test__bpf_subtest_get_desc(int i)
{
if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
return NULL;
return bpf_testcase_table[i].desc;
}
static int check_env(void)
{
int err;
unsigned int kver_int;
char license[] = "GPL";
struct bpf_insn insns[] = {
BPF_MOV64_IMM(BPF_REG_0, 1),
BPF_EXIT_INSN(),
};
err = fetch_kernel_version(&kver_int, NULL, 0);
if (err) {
pr_debug("Unable to get kernel version\n");
return err;
}
err = bpf_load_program(BPF_PROG_TYPE_KPROBE, insns,
sizeof(insns) / sizeof(insns[0]),
license, kver_int, NULL, 0);
if (err < 0) {
pr_err("Missing basic BPF support, skip this test: %s\n",
strerror(errno));
return err;
}
close(err);
return 0;
}
int test__bpf(int i)
{
int err;
if (i < 0 || i >= (int)ARRAY_SIZE(bpf_testcase_table))
return TEST_FAIL;
if (geteuid() != 0) {
pr_debug("Only root can run BPF test\n");
return TEST_SKIP;
}
if (check_env())
return TEST_SKIP;
err = __test__bpf(i);
return err;
}
#else
int test__bpf_subtest_get_nr(void)
{
return 0;
}
const char *test__bpf_subtest_get_desc(int i __maybe_unused)
{
return NULL;
}
int test__bpf(int i __maybe_unused)
{
pr_debug("Skip BPF test because BPF support is not compiled\n");
return TEST_SKIP;
}
#endif