linux.git/tools/perf/tests/llvm.c, branch v4.9

perf tools: Remove needless includes from cache.h

2016-07-12T18:19:58+00:00

The cache.h header doesn't use any of the definitions in some of the
headers it includes, ditch them and fix the fallout, where files were
getting stuff they needed just because they were including it, sometimes
not using what it really exports at all.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-l6r2bmj8h1g3e01wr981on0n@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf config: Bring perf_default_config to the very beginning at main()

2016-02-26T22:49:16+00:00

Before this patch each subcommand calls perf_config() by themself,
reading the default configuration together with subcommand specific
options. If a subcommand doesn't have it own options, it needs to call
'perf_config(perf_default_config, NULL)' to ensure .perfconfig is
loaded.

This patch brings perf_config(perf_default_config, NULL) to the very
start of main(), so subcommands don't need to do it.

After this patch, 'llvm.clang-path' works for 'perf trace'.

Signed-off-by: Wang Nan 
Suggested-and-Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: Jiri Olsa 
Cc: Li Zefan 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1456479154-136027-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add libbpf relocation checker

2016-01-26T15:10:55+00:00

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 
Tested-by: Arnaldo Carvalho de Melo 
Cc: "David S. Miller" 
Cc: Alexei Starovoitov 
Cc: Brendan Gregg 
Cc: Daniel Borkmann 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Li Zefan 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Will Deacon 
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

perf test: Print result for each LLVM subtest

2015-11-19T16:19:16+00:00

Currently 'perf test llvm' and 'perf test BPF' have multiple sub-tests,
but the result is provided in only one line:

  # perf test LLVM
  35: Test LLVM searching and compiling                        : Ok

This patch introduces sub-tests support, allowing 'perf test' to report
result for each sub-tests:

  # perf test LLVM
  35: Test LLVM searching and compiling                        :
  35.1: Basic BPF llvm compiling test                          : Ok
  35.2: Test kbuild searching                                  : Ok
  35.3: Compile source for BPF prologue generation test        : Ok

When a failure happens:

  # cat ~/.perfconfig
  [llvm]
       clang-path = "/bin/false"
  # perf test LLVM
  35: Test LLVM searching and compiling                        :
  35.1: Basic BPF llvm compiling test                          : FAILED!
  35.2: Test kbuild searching                                  : Skip
  35.3: Compile source for BPF prologue generation test        : Skip

And:

  # rm ~/.perfconfig
  # ./perf test LLVM
  35: Test LLVM searching and compiling                        :
  35.1: Basic BPF llvm compiling test                          : Skip
  35.2: Test kbuild searching                                  : Skip
  35.3: Compile source for BPF prologue generation test        : Skip

Skip by user:

  # ./perf test -s 1,`seq -s , 3 42`
   1: vmlinux symtab matches kallsyms                          : Skip (user override)
   2: detect openat syscall event                              : Ok
  ...
  35: Test LLVM searching and compiling                        : Skip (user override)
  ...

Suggested-and-Tested-by: Arnaldo Carvalho de Melo 
Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Masami Hiramatsu 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447749170-175898-4-git-send-email-wangnan0@huawei.com
[ Changed so that func is not on an anonymous union ]
Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Pass the subtest index to each test routine

2015-11-19T16:19:15+00:00

Some tests have sub-tests we want to run, so allow passing this.

Wang tried to avoid having to touch all tests, but then, having the
test.func in an anonymous union makes the build fail on older compilers,
like the one in RHEL6, where:

  test a = {
	.func = foo,
  };

fails.

To fix it leave the func pointer in the main structure and pass the subtest
index to all tests, end result function is the same, but we have just one
function pointer, not two, with and without the subtest index as an argument.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-5genj0ficwdmelpoqlds0u4y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Test the BPF prologue adding infrastructure

2015-11-18T20:51:04+00:00

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
  
  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 

  #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 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Cc: Masami Hiramatsu 
Cc: Zefan Li 
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

perf test: Fix build of BPF and LLVM on older glibc libraries

2015-11-18T20:38:49+00:00

  $ rpm -q glibc
  glibc-2.12-1.166.el6_7.1.x86_64


    CC       /tmp/build/perf/tests/llvm.o
  cc1: warnings being treated as errors
  tests/llvm.c: In function ‘test_llvm__fetch_bpf_obj’:
  tests/llvm.c:53: error: declaration of ‘index’ shadows a global declaration
  /usr/include/string.h:489: error: shadowed declaration is here

    CC       /tmp/build/perf/tests/bpf.o
  cc1: warnings being treated as errors
  tests/bpf.c: In function ‘__test__bpf’:
  tests/bpf.c:149: error: declaration of ‘index’ shadows a global declaration
  /usr/include/string.h:489: error: shadowed declaration is here


Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: pi3orama@163.com
Cc: Wang Nan 
Cc: Zefan Li 
Fixes: b31de018a628 ("perf test: Enhance the LLVM test: update basic BPF test program")
Fixes: ba1fae431e74 ("perf test: Add 'perf test BPF'")
Link: http://lkml.kernel.org/n/tip-akpo4r750oya2phxoh9e3447@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Enhance the LLVM tests: add kbuild test

2015-11-06T20:49:50+00:00

This patch adds a kbuild testcase to check whether kernel headers can be
correctly found.

For example:
  # mv /lib/modules/4.3.0-rc5{,.bak}
  # perf test LLVM

    38: Test LLVM searching and compiling                        : Skip

  # perf test -v LLVM
  ...
  :11:10: fatal error: 'uapi/linux/fs.h' file not found
  #include 
          ^
  1 error generated.
  ERROR:	unable to compile -
  Hint:	Check error message shown above.
  Hint:	You can also pre-compile it into .o using:
     		 clang -target bpf -O2 -c -
	 with proper -I and -D options.
  Failed to compile test case: 'Test kbuild searching'
  test child finished with -2

Signed-off-by: Wang Nan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Enhance the LLVM test: update basic BPF test program

2015-11-06T20:49:24+00:00

This patch replaces the original toy BPF program with the previously
introduced bpf-script-example.c. Dynamically embeddeding it into
'llvm-src-base.c'.

The newly introduced BPF program attaches a BPF program to
'sys_epoll_pwait()'. perf itself never use that syscall, so further test
can verify their result with it. The program would generate 1 sample in
every 2 calls of epoll_pwait() system call.

Since the resulting BPF object is useful per se for further tests,
test_llvm__fetch_bpf_obj() is introduced for creating BPF objects from
source. The LLVM test was rewritten to use it.

Committer note:

Running it:

  [root@zoo wb]# perf test -v LLVM
  35: Test LLVM searching and compiling                        :
  --- start ---
  test child forked, pid 17740
  Kernel build dir is set to /lib/modules/4.3.0-rc1+/build
  set env: KBUILD_DIR=/lib/modules/4.3.0-rc1+/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-rc1+/build
  set env: CLANG_SOURCE=-
  llvm compiling command template: echo '/*
   * bpf-script-example.c
   * Test basic LLVM building
   */
  #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 BPF_ANY 0
  #define BPF_MAP_TYPE_ARRAY 2
  #define BPF_FUNC_map_lookup_elem 1
  #define BPF_FUNC_map_update_elem 2

  static void *(*bpf_map_lookup_elem)(void *map, void *key) =
	  (void *) BPF_FUNC_map_lookup_elem;
  static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
	  (void *) BPF_FUNC_map_update_elem;

  struct bpf_map_def {
	  unsigned int type;
	  unsigned int key_size;
	  unsigned int value_size;
	  unsigned int max_entries;
  };

  #define SEC(NAME) __attribute__((section(NAME), used))
  struct bpf_map_def SEC("maps") flip_table = {
	  .type = BPF_MAP_TYPE_ARRAY,
	  .key_size = sizeof(int),
	  .value_size = sizeof(int),
	  .max_entries = 1,
  };

  SEC("func=sys_epoll_pwait")
  int bpf_func__sys_epoll_pwait(void *ctx)
  {
	  int ind =0;
	  int *flag = bpf_map_lookup_elem(&flip_table, &ind);
	  int new_flag;
	  if (!flag)
		  return 0;
	  /* flip flag and store back */
	  new_flag = !*flag;
	  bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
	  return new_flag;
  }
  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 -
  test child finished with 0
  ---- end ----
  Test LLVM searching and compiling: Ok
  [root@zoo wb]#

Signed-off-by: Wang Nan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-6-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang 
Signed-off-by: Arnaldo Carvalho de Melo

bpf tools: Improve libbpf error reporting

2015-11-06T18:52:41+00:00

In this patch, a series of libbpf specific error numbers and
libbpf_strerror() are introduced to help reporting errors.

Functions are updated to pass correct the error number through the
CHECK_ERR() macro.

All users of bpf_object__open{_buffer}() and bpf_program__title() in
perf are modified accordingly. In addition, due to the error codes
changing, bpf__strerror_load() is also modified to use them.

bpf__strerror_head() is also changed accordingly so it can parse libbpf
errors. bpf_loader_strerror() is introduced for that purpose, and will
be improved by the following patch.

load_program() is improved not to dump log buffer if it is empty. log
buffer is also used to deduce whether the error was caused by an invalid
program or other problem.

v1 -> v2:

 - Using macro for error code.

 - Fetch error message based on array index, eliminate for-loop.

 - Use log buffer to detect the reason of failure. 3 new error code
   are introduced to replace LIBBPF_ERRNO__LOAD.

In v1:

  # perf record -e ./test_ill_program.o ls
  event syntax error: './test_ill_program.o'
                       \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
  SKIP

  # perf record -e ./test_kversion_nomatch_program.o ls
  event syntax error: './test_kversion_nomatch_program.o'
                       \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
  SKIP

  # perf record -e ./test_big_program.o ls
  event syntax error: './test_big_program.o'
                       \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
  SKIP

  In v2:

  # perf record -e ./test_ill_program.o ls
  event syntax error: './test_ill_program.o'
                       \___ Kernel verifier blocks program loading
  SKIP

  # perf record -e ./test_kversion_nomatch_program.o
  event syntax error: './test_kversion_nomatch_program.o'
                       \___ Incorrect kernel version
  SKIP
  (Will be further improved by following patches)

  # perf record -e ./test_big_program.o
  event syntax error: './test_big_program.o'
                       \___ Program too big
  SKIP

Signed-off-by: Wang Nan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Zefan Li 
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo