[PATCH 08/37] perf bpf: Allow BPF program attach to uprobe events

[Arnaldo Carvalho de Melo]

From: Wang Nan 

This patch adds a new syntax to the BPF object section name to support
probing at uprobe event. Now we can use BPF program like this:

  SEC(
  "exec=/lib64/libc.so.6;"
  "libcwrite=__write"
  )
  int libcwrite(void *ctx)
  {
  return 1;
  }

Where, in section name of a program, before the main config string, we
can use 'key=value' style options. Now the only option key is "exec",
for uprobes.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Masami Hiramatsu 
Cc: Zefan Li 
Cc: pi3or...@163.com
Link: 
http://lkml.kernel.org/r/1447675815-166222-4-git-send-email-wangn...@huawei.com
[ Changed the separator from \n to ; ]
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/bpf-loader.c | 120 ---
 tools/perf/util/bpf-loader.h |   1 +
 2 files changed, 115 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 4c50411371db..84169d6f2585 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -110,6 +110,113 @@ bpf_prog_priv__clear(struct bpf_program *prog 
__maybe_unused,
 }
 
 static int
+config__exec(const char *value, struct perf_probe_event *pev)
+{
+   pev->uprobes = true;
+   pev->target = strdup(value);
+   if (!pev->target)
+   return -ENOMEM;
+   return 0;
+}
+
+static struct {
+   const char *key;
+   const char *usage;
+   const char *desc;
+   int (*func)(const char *, struct perf_probe_event *);
+} bpf_config_terms[] = {
+   {
+   .key= "exec",
+   .usage  = "exec=",
+   .desc   = "Set uprobe target",
+   .func   = config__exec,
+   },
+};
+
+static int
+do_config(const char *key, const char *value,
+ struct perf_probe_event *pev)
+{
+   unsigned int i;
+
+   pr_debug("config bpf program: %s=%s\n", key, value);
+   for (i = 0; i < ARRAY_SIZE(bpf_config_terms); i++)
+   if (strcmp(key, bpf_config_terms[i].key) == 0)
+   return bpf_config_terms[i].func(value, pev);
+
+   pr_debug("BPF: ERROR: invalid config option in object: %s=%s\n",
+key, value);
+
+   pr_debug("\nHint: Currently valid options are:\n");
+   for (i = 0; i < ARRAY_SIZE(bpf_config_terms); i++)
+   pr_debug("\t%s:\t%s\n", bpf_config_terms[i].usage,
+bpf_config_terms[i].desc);
+   pr_debug("\n");
+
+   return -BPF_LOADER_ERRNO__CONFIG_TERM;
+}
+
+static const char *
+parse_config_kvpair(const char *config_str, struct perf_probe_event *pev)
+{
+   char *text = strdup(config_str);
+   char *sep, *line;
+   const char *main_str = NULL;
+   int err = 0;
+
+   if (!text) {
+   pr_debug("No enough memory: dup config_str failed\n");
+   return ERR_PTR(-ENOMEM);
+   }
+
+   line = text;
+   while ((sep = strchr(line, ';'))) {
+   char *equ;
+
+   *sep = '\0';
+   equ = strchr(line, '=');
+   if (!equ) {
+   pr_warning("WARNING: invalid config in BPF object: 
%s\n",
+  line);
+   pr_warning("\tShould be 'key=value'.\n");
+   goto nextline;
+   }
+   *equ = '\0';
+
+   err = do_config(line, equ + 1, pev);
+   if (err)
+   break;
+nextline:
+   line = sep + 1;
+   }
+
+   if (!err)
+   main_str = config_str + (line - text);
+   free(text);
+
+   return err ? ERR_PTR(err) : main_str;
+}
+
+static int
+parse_config(const char *config_str, struct perf_probe_event *pev)
+{
+   int err;
+   const char *main_str = parse_config_kvpair(config_str, pev);
+
+   if (IS_ERR(main_str))
+   return PTR_ERR(main_str);
+
+   err = parse_perf_probe_command(main_str, pev);
+   if (err < 0) {
+   pr_debug("bpf: '%s' is not a valid config string\n",
+config_str);
+   /* parse failed, don't need clear pev. */
+   return -BPF_LOADER_ERRNO__CONFIG;
+   }
+   return 0;
+}
+
+static int
 config_bpf_program(struct bpf_program *prog)
 {
struct perf_probe_event *pev = NULL;
@@ -131,13 +238,9 @@ config_bpf_program(struct bpf_program *prog)
pev = >pev;
 
pr_debug("bpf: config program '%s'\n", config_str);
-   err = parse_perf_probe_command(config_str, pev);
-   if (err < 0) {
-   pr_debug("bpf: '%s' is not a valid config string\n",
-config_str);
-   err = -BPF_LOADER_ERRNO__CONFIG;
+   err = parse_config(config_str, pev);
+   if (err)
goto errout;
-   }
 
if (pev->group && strcmp(pev->group, PERF_BPF_PROBE_GROUP)) {
pr_debug("bpf: '%s': group for event is set and not '%s'.\n",

[PATCH 08/37] perf bpf: Allow BPF program attach to uprobe events

[Arnaldo Carvalho de Melo]

From: Wang Nan 

This patch adds a new syntax to the BPF object section name to support
probing at uprobe event. Now we can use BPF program like this:

  SEC(
  "exec=/lib64/libc.so.6;"
  "libcwrite=__write"
  )
  int libcwrite(void *ctx)
  {
  return 1;
  }

Where, in section name of a program, before the main config string, we
can use 'key=value' style options. Now the only option key is "exec",
for uprobes.

Signed-off-by: Wang Nan 
Cc: Alexei Starovoitov 
Cc: Masami Hiramatsu 
Cc: Zefan Li 
Cc: pi3or...@163.com
Link: 
http://lkml.kernel.org/r/1447675815-166222-4-git-send-email-wangn...@huawei.com
[ Changed the separator from \n to ; ]
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/bpf-loader.c | 120 ---
 tools/perf/util/bpf-loader.h |   1 +
 2 files changed, 115 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 4c50411371db..84169d6f2585 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -110,6 +110,113 @@ bpf_prog_priv__clear(struct bpf_program *prog 
__maybe_unused,
 }
 
 static int
+config__exec(const char *value, struct perf_probe_event *pev)
+{
+   pev->uprobes = true;
+   pev->target = strdup(value);
+   if (!pev->target)
+   return -ENOMEM;
+   return 0;
+}
+
+static struct {
+   const char *key;
+   const char *usage;
+   const char *desc;
+   int (*func)(const char *, struct perf_probe_event *);
+} bpf_config_terms[] = {
+   {
+   .key= "exec",
+   .usage  = "exec=",
+   .desc   = "Set uprobe target",
+   .func   = config__exec,
+   },
+};
+
+static int
+do_config(const char *key, const char *value,
+ struct perf_probe_event *pev)
+{
+   unsigned int i;
+
+   pr_debug("config bpf program: %s=%s\n", key, value);
+   for (i = 0; i < ARRAY_SIZE(bpf_config_terms); i++)
+   if (strcmp(key, bpf_config_terms[i].key) == 0)
+   return bpf_config_terms[i].func(value, pev);
+
+   pr_debug("BPF: ERROR: invalid config option in object: %s=%s\n",
+key, value);
+
+   pr_debug("\nHint: Currently valid options are:\n");
+   for (i = 0; i < ARRAY_SIZE(bpf_config_terms); i++)
+   pr_debug("\t%s:\t%s\n", bpf_config_terms[i].usage,
+bpf_config_terms[i].desc);
+   pr_debug("\n");
+
+   return -BPF_LOADER_ERRNO__CONFIG_TERM;
+}
+
+static const char *
+parse_config_kvpair(const char *config_str, struct perf_probe_event *pev)
+{
+   char *text = strdup(config_str);
+   char *sep, *line;
+   const char *main_str = NULL;
+   int err = 0;
+
+   if (!text) {
+   pr_debug("No enough memory: dup config_str failed\n");
+   return ERR_PTR(-ENOMEM);
+   }
+
+   line = text;
+   while ((sep = strchr(line, ';'))) {
+   char *equ;
+
+   *sep = '\0';
+   equ = strchr(line, '=');
+   if (!equ) {
+   pr_warning("WARNING: invalid config in BPF object: 
%s\n",
+  line);
+   pr_warning("\tShould be 'key=value'.\n");
+   goto nextline;
+   }
+   *equ = '\0';
+
+   err = do_config(line, equ + 1, pev);
+   if (err)
+   break;
+nextline:
+   line = sep + 1;
+   }
+
+   if (!err)
+   main_str = config_str + (line - text);
+   free(text);
+
+   return err ? ERR_PTR(err) : main_str;
+}
+
+static int
+parse_config(const char *config_str, struct perf_probe_event *pev)
+{
+   int err;
+   const char *main_str = parse_config_kvpair(config_str, pev);
+
+   if (IS_ERR(main_str))
+   return PTR_ERR(main_str);
+
+   err = parse_perf_probe_command(main_str, pev);
+   if (err < 0) {
+   pr_debug("bpf: '%s' is not a valid config string\n",
+config_str);
+   /* parse failed, don't need clear pev. */
+   return -BPF_LOADER_ERRNO__CONFIG;
+   }
+   return 0;
+}
+
+static int
 config_bpf_program(struct bpf_program *prog)
 {
struct perf_probe_event *pev = NULL;
@@ -131,13 +238,9 @@ config_bpf_program(struct bpf_program *prog)
pev = >pev;
 
pr_debug("bpf: config program '%s'\n", config_str);
-   err = parse_perf_probe_command(config_str, pev);
-   if (err < 0) {
-   pr_debug("bpf: '%s' is not a valid config string\n",
-config_str);
-   err = -BPF_LOADER_ERRNO__CONFIG;
+   err = parse_config(config_str, pev);
+   if (err)
goto errout;
-   }
 
if