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author | Wang Nan <wangnan0@huawei.com> | 2015-11-04 11:20:05 +0000 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-11-05 12:47:50 -0300 |
commit | 4a4f66a1a7031675745812729ade94ad1caf1db6 (patch) | |
tree | 4a7d0bebe4ee5ad3caa5050820e7e1e37c950fde /tools | |
parent | 59f41af980f95cbd556a6dc2e064b412abc439cf (diff) | |
download | linux-stable-4a4f66a1a7031675745812729ade94ad1caf1db6.tar.gz linux-stable-4a4f66a1a7031675745812729ade94ad1caf1db6.tar.bz2 linux-stable-4a4f66a1a7031675745812729ade94ad1caf1db6.zip |
perf llvm: Pass LINUX_VERSION_CODE to BPF program when compiling
Arnaldo suggests to make LINUX_VERSION_CODE works like __func__ and
__FILE__ so user don't need to care setting right linux version too
much. In this patch, perf llvm transfers LINUX_VERSION_CODE macro
through clang cmdline.
[1] http://lkml.kernel.org/r/20151029223744.GK2923@kernel.org
Committer notes:
Before, forgetting to update the version:
# uname -r
4.3.0-rc1+
# cat bpf.c
__attribute__((section("fork=_do_fork"), used))
int fork(void *ctx)
{
return 1;
}
char _license[] __attribute__((section("license"), used)) = "GPL";
int _version __attribute__((section("version"), used)) = 0x40200;
#
# perf record -e bpf.c sleep 1
event syntax error: 'bpf.c'
\___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel?
(add -v to see detail)
Run 'perf list' for a list of valid events
Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]
-e, --event <event> event selector. use 'perf list' to list available events
#
After:
# grep version bpf.c
int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
# perf record -e bpf.c sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.017 MB perf.data ]
# perf evlist -v
perf_bpf_probe:fork: type: 2, size: 112, config: 0x5ee, { sample_period,
sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1,
inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all:
1, exclude_guest: 1, mmap2: 1, comm_exec: 1
#
Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446636007-239722-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/perf/util/llvm-utils.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 80eecefc604f..8ee25bea1b24 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -12,6 +12,7 @@ #define CLANG_BPF_CMD_DEFAULT_TEMPLATE \ "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\ + "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \ "$CLANG_OPTIONS $KERNEL_INC_OPTIONS " \ "-Wno-unused-value -Wno-pointer-sign " \ "-working-directory $WORKING_DIR " \ @@ -324,11 +325,33 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts) pr_debug("include option is set to %s\n", *kbuild_include_opts); } +static unsigned long +fetch_kernel_version(void) +{ + struct utsname utsname; + int version, patchlevel, sublevel, err; + + if (uname(&utsname)) + return 0; + + err = sscanf(utsname.release, "%d.%d.%d", + &version, &patchlevel, &sublevel); + + if (err != 3) { + pr_debug("Unablt to get kernel version from uname '%s'\n", + utsname.release); + return 0; + } + + return (version << 16) + (patchlevel << 8) + sublevel; +} + int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz) { int err, nr_cpus_avail; char clang_path[PATH_MAX], nr_cpus_avail_str[64]; + char linux_version_code_str[64]; const char *clang_opt = llvm_param.clang_opt; const char *template = llvm_param.clang_bpf_cmd_template; char *kbuild_dir = NULL, *kbuild_include_opts = NULL; @@ -365,7 +388,11 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d", nr_cpus_avail); + snprintf(linux_version_code_str, sizeof(linux_version_code_str), + "0x%lx", fetch_kernel_version()); + force_set_env("NR_CPUS", nr_cpus_avail_str); + force_set_env("LINUX_VERSION_CODE", linux_version_code_str); force_set_env("CLANG_EXEC", clang_path); force_set_env("CLANG_OPTIONS", clang_opt); force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts); |