perf/ebpf improvements and fixes

new file mode 100644
index 000000000000..f3a6db6ad732
@@ -0,0 +1,9 @@
+#ifndef _TOOLS_LINUX_STRING_H_
+#define _TOOLS_LINUX_STRING_H_
+
+
+#include <linux/types.h>	/* for size_t */
+
+void *memdup(const void *src, size_t len);
+
+#endif /* _LINUX_STRING_H_ */

new file mode 100644
index 000000000000..ecfd43a9b24e
@@ -0,0 +1,19 @@
+#include <stdlib.h>
+#include <string.h>
+#include <linux/string.h>
+
+/**
+ * memdup - duplicate region of memory
+ *
+ * @src: memory region to duplicate
+ * @len: memory region length
+ */
+void *memdup(const void *src, size_t len)
+{
+	void *p = malloc(len);
+
+	if (p)
+		memcpy(p, src, len);
+
+	return p;
+}

deleted file mode 100644
index 6f19c548ecc0..000000000000
@@ -1,3 +0,0 @@
-#include <string.h>
-
-void *memdup(const void *src, size_t len);

index fc8781de62db..7f7e072be746 100644
@@ -342,22 +342,6 @@ char *rtrim(char *s)
 	return s;
 }
 
-/**
- * memdup - duplicate region of memory
- * @src: memory region to duplicate
- * @len: memory region length
- */
-void *memdup(const void *src, size_t len)
-{
-	void *p;
-
-	p = malloc(len);
-	if (p)
-		memcpy(p, src, len);
-
-	return p;
-}
-
 char *asprintf_expr_inout_ints(const char *var, bool in, size_t nints, int *ints)
 {
 	/*

index f3a6db6ad732..2e2f736c039c 100644
@@ -6,4 +6,6 @@
 
 void *memdup(const void *src, size_t len);
 
+int strtobool(const char *s, bool *res);
+
 #endif /* _LINUX_STRING_H_ */

51 lines not on this page · raw message

index e176bad19bcb..e3f4c3379f14 100644
@@ -152,7 +152,11 @@ struct bpf_program {
 	} *reloc_desc;
 	int nr_reloc;
 
-	int fd;
+	struct {
+		int nr;
+		int *fds;
+	} instances;
+	bpf_program_prep_t preprocessor;
 
 	struct bpf_object *obj;
 	void *priv;

@@ -206,10 +210,25 @@ struct bpf_object {
 
 static void bpf_program__unload(struct bpf_program *prog)
 {
+	int i;
+
 	if (!prog)
 		return;
 
-	zclose(prog->fd);
+	/*
+	 * If the object is opened but the program was never loaded,
+	 * it is possible that prog->instances.nr == -1.
+	 */
+	if (prog->instances.nr > 0) {
+		for (i = 0; i < prog->instances.nr; i++)
+			zclose(prog->instances.fds[i]);
+	} else if (prog->instances.nr != -1) {
+		pr_warning("Internal error: instances.nr is %d\n",
+			   prog->instances.nr);
+	}
+
+	prog->instances.nr = -1;
+	zfree(&prog->instances.fds);
 }
 
 static void bpf_program__exit(struct bpf_program *prog)

@@ -260,7 +279,8 @@ bpf_program__init(void *data, size_t size, char *name, int idx,
 	memcpy(prog->insns, data,
 	       prog->insns_cnt * sizeof(struct bpf_insn));
 	prog->idx = idx;
-	prog->fd = -1;
+	prog->instances.fds = NULL;
+	prog->instances.nr = -1;
 
 	return 0;
 errout:

@@ -860,13 +880,73 @@ static int
 bpf_program__load(struct bpf_program *prog,
 		  char *license, u32 kern_version)
 {
-	int err, fd;
+	int err = 0, fd, i;
 
-	err = load_program(prog->insns, prog->insns_cnt,
-			   license, kern_version, &fd);
-	if (!err)
-		prog->fd = fd;
+	if (prog->instances.nr < 0 || !prog->instances.fds) {
+		if (prog->preprocessor) {
+			pr_warning("Internal error: can't load program '%s'\n",
+				   prog->section_name);
+			return -LIBBPF_ERRNO__INTERNAL;
+		}
 
+		prog->instances.fds = malloc(sizeof(int));
+		if (!prog->instances.fds) {
+			pr_warning("Not enough memory for BPF fds\n");
+			return -ENOMEM;
+		}
+		prog->instances.nr = 1;
+		prog->instances.fds[0] = -1;
+	}
+
+	if (!prog->preprocessor) {
+		if (prog->instances.nr != 1) {
+			pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
+				   prog->section_name, prog->instances.nr);
+		}
+		err = load_program(prog->insns, prog->insns_cnt,
+				   license, kern_version, &fd);
+		if (!err)
+			prog->instances.fds[0] = fd;
+		goto out;
+	}
+
+	for (i = 0; i < prog->instances.nr; i++) {
+		struct bpf_prog_prep_result result;
+		bpf_program_prep_t preprocessor = prog->preprocessor;
+
+		bzero(&result, sizeof(result));
+		err = preprocessor(prog, i, prog->insns,
+				   prog->insns_cnt, &result);
+		if (err) {
+			pr_warning("Preprocessing the %dth instance of program '%s' failed\n",
+				   i, prog->section_name);
+			goto out;
+		}
+
+		if (!result.new_insn_ptr || !result.new_insn_cnt) {
+			pr_debug("Skip loading the %dth instance of program '%s'\n",
+				 i, prog->section_name);
+			prog->instances.fds[i] = -1;
+			if (result.pfd)
+				*result.pfd = -1;
+			continue;
+		}
+
+		err = load_program(result.new_insn_ptr,
+				   result.new_insn_cnt,
+				   license, kern_version, &fd);
+
+		if (err) {
+			pr_warning("Loading the %dth instance of program '%s' failed\n",
+					i, prog->section_name);
+			goto out;
+		}
+
+		if (result.pfd)
+			*result.pfd = fd;
+		prog->instances.fds[i] = fd;
+	}
+out:
 	if (err)
 		pr_warning("failed to load program '%s'\n",
 			   prog->section_name);

@@ -1121,5 +1201,53 @@ const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
 
 int bpf_program__fd(struct bpf_program *prog)
 {
-	return prog->fd;
+	return bpf_program__nth_fd(prog, 0);
+}
+
+int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
+			  bpf_program_prep_t prep)
+{
+	int *instances_fds;
+
+	if (nr_instances <= 0 || !prep)
+		return -EINVAL;
+
+	if (prog->instances.nr > 0 || prog->instances.fds) {
+		pr_warning("Can't set pre-processor after loading\n");
+		return -EINVAL;
+	}
+
+	instances_fds = malloc(sizeof(int) * nr_instances);
+	if (!instances_fds) {
+		pr_warning("alloc memory failed for fds\n");
+		return -ENOMEM;
+	}
+
+	/* fill all fd with -1 */
+	memset(instances_fds, -1, sizeof(int) * nr_instances);
+
+	prog->instances.nr = nr_instances;
+	prog->instances.fds = instances_fds;
+	prog->preprocessor = prep;
+	return 0;
+}
+
+int bpf_program__nth_fd(struct bpf_program *prog, int n)
+{
+	int fd;
+
+	if (n >= prog->instances.nr || n < 0) {
+		pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
+			   n, prog->section_name, prog->instances.nr);
+		return -EINVAL;
+	}
+
+	fd = prog->instances.fds[n];
+	if (fd < 0) {
+		pr_warning("%dth instance of program '%s' is invalid\n",
+			   n, prog->section_name);
+		return -ENOENT;
+	}
+
+	return fd;
 }

70 lines not on this page · raw message

index 4c50411371db..84169d6f2585 100644
@@ -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=<full path of file>",
+		.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 = &priv->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",

@@ -340,6 +443,7 @@ static const char *bpf_loader_strerror_table[NR_ERRNO] = {
 	[ERRCODE_OFFSET(EVENTNAME)]	= "No event name found in config string",
 	[ERRCODE_OFFSET(INTERNAL)]	= "BPF loader internal error",
 	[ERRCODE_OFFSET(COMPILE)]	= "Error when compiling BPF scriptlet",
+	[ERRCODE_OFFSET(CONFIG_TERM)]	= "Invalid config term in config string",
 };
 
 static int

@@ -420,6 +524,10 @@ int bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
 			int err, char *buf, size_t size)
 {
 	bpf__strerror_head(err, buf, size);
+	case BPF_LOADER_ERRNO__CONFIG_TERM: {
+		scnprintf(buf, size, "%s (add -v to see detail)", emsg);
+		break;
+	}
 	bpf__strerror_entry(EEXIST, "Probe point exist. Try use 'perf probe -d \"*\"'");
 	bpf__strerror_entry(EACCES, "You need to be root");
 	bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0");

index 9caf3ae4acf3..d19f5c5d6d74 100644
@@ -20,6 +20,7 @@ enum bpf_loader_errno {
 	BPF_LOADER_ERRNO__EVENTNAME,	/* Event name is missing */
 	BPF_LOADER_ERRNO__INTERNAL,	/* BPF loader internal error */
 	BPF_LOADER_ERRNO__COMPILE,	/* Error when compiling BPF scriptlet */
+	BPF_LOADER_ERRNO__CONFIG_TERM,	/* Invalid config term in config term */
 	__BPF_LOADER_ERRNO__END,
 };
 

index 84169d6f2585..d0f02ed93804 100644
@@ -119,6 +119,16 @@ config__exec(const char *value, struct perf_probe_event *pev)
 	return 0;
 }
 
+static int
+config__module(const char *value, struct perf_probe_event *pev)
+{
+	pev->uprobes = false;
+	pev->target = strdup(value);
+	if (!pev->target)
+		return -ENOMEM;
+	return 0;
+}
+
 static struct {
 	const char *key;
 	const char *usage;

@@ -131,6 +141,12 @@ static struct {
 		.desc	= "Set uprobe target",
 		.func	= config__exec,
 	},
+	{
+		.key	= "module",
+		.usage	= "module=<module name>    ",
+		.desc	= "Set kprobe module",
+		.func	= config__module,
+	}
 };
 
 static int

index d0f02ed93804..98f2e5d1a5be 100644
@@ -7,6 +7,7 @@
 
 #include <bpf/libbpf.h>
 #include <linux/err.h>
+#include <linux/string.h>
 #include "perf.h"
 #include "debug.h"
 #include "bpf-loader.h"

@@ -129,6 +130,38 @@ config__module(const char *value, struct perf_probe_event *pev)
 	return 0;
 }
 
+static int
+config__bool(const char *value,
+	     bool *pbool, bool invert)
+{
+	int err;
+	bool bool_value;
+
+	if (!pbool)
+		return -EINVAL;
+
+	err = strtobool(value, &bool_value);
+	if (err)
+		return err;
+
+	*pbool = invert ? !bool_value : bool_value;
+	return 0;
+}
+
+static int
+config__inlines(const char *value,
+		struct perf_probe_event *pev __maybe_unused)
+{
+	return config__bool(value, &probe_conf.no_inlines, true);
+}
+
+static int
+config__force(const char *value,
+	      struct perf_probe_event *pev __maybe_unused)
+{
+	return config__bool(value, &probe_conf.force_add, false);
+}
+
 static struct {
 	const char *key;
 	const char *usage;

@@ -146,7 +179,19 @@ static struct {
 		.usage	= "module=<module name>    ",
 		.desc	= "Set kprobe module",
 		.func	= config__module,
-	}
+	},
+	{
+		.key	= "inlines",
+		.usage	= "inlines=[yes|no]        ",
+		.desc	= "Probe at inline symbol",
+		.func	= config__inlines,
+	},
+	{
+		.key	= "force",
+		.usage	= "force=[yes|no]          ",
+		.desc	= "Forcibly add events with existing name",
+		.func	= config__force,
+	},
 };
 
 static int

@@ -240,6 +285,10 @@ config_bpf_program(struct bpf_program *prog)
 	const char *config_str;
 	int err;
 
+	/* Initialize per-program probing setting */
+	probe_conf.no_inlines = false;
+	probe_conf.force_add = false;
+
 	config_str = bpf_program__title(prog, false);
 	if (IS_ERR(config_str)) {
 		pr_debug("bpf: unable to get title for program\n");

@@ -544,7 +593,7 @@ int bpf__strerror_probe(struct bpf_object *obj __maybe_unused,
 		scnprintf(buf, size, "%s (add -v to see detail)", emsg);
 		break;
 	}
-	bpf__strerror_entry(EEXIST, "Probe point exist. Try use 'perf probe -d \"*\"'");
+	bpf__strerror_entry(EEXIST, "Probe point exist. Try 'perf probe -d \"*\"' and set 'force=yes'");
 	bpf__strerror_entry(EACCES, "You need to be root");
 	bpf__strerror_entry(EPERM, "You need to be root, and /proc/sys/kernel/kptr_restrict should be 0");
 	bpf__strerror_entry(ENOENT, "You need to check probing points in BPF file");

index 03875f9154e7..93996ec4bbe3 100644
@@ -2326,8 +2326,11 @@ static int get_new_event_name(char *buf, size_t len, const char *base,
 		goto out;
 
 	if (!allow_suffix) {
-		pr_warning("Error: event \"%s\" already exists. "
-			   "(Use -f to force duplicates.)\n", buf);
+		pr_warning("Error: event \"%s\" already exists.\n"
+			   " Hint: Remove existing event by 'perf probe -d'\n"
+			   "       or force duplicates by 'perf probe -f'\n"
+			   "       or set 'force=yes' in BPF source.\n",
+			   buf);
 		ret = -EEXIST;
 		goto out;
 	}

index 98f2e5d1a5be..bd14be438cda 100644
@@ -509,6 +509,9 @@ static const char *bpf_loader_strerror_table[NR_ERRNO] = {
 	[ERRCODE_OFFSET(INTERNAL)]	= "BPF loader internal error",
 	[ERRCODE_OFFSET(COMPILE)]	= "Error when compiling BPF scriptlet",
 	[ERRCODE_OFFSET(CONFIG_TERM)]	= "Invalid config term in config string",
+	[ERRCODE_OFFSET(PROLOGUE)]	= "Failed to generate prologue",
+	[ERRCODE_OFFSET(PROLOGUE2BIG)]	= "Prologue too big for program",
+	[ERRCODE_OFFSET(PROLOGUEOOB)]	= "Offset out of bound for prologue",
 };
 
 static int

index d19f5c5d6d74..a58740b0f31e 100644
@@ -21,6 +21,9 @@ enum bpf_loader_errno {
 	BPF_LOADER_ERRNO__INTERNAL,	/* BPF loader internal error */
 	BPF_LOADER_ERRNO__COMPILE,	/* Error when compiling BPF scriptlet */
 	BPF_LOADER_ERRNO__CONFIG_TERM,	/* Invalid config term in config term */
+	BPF_LOADER_ERRNO__PROLOGUE,	/* Failed to generate prologue */
+	BPF_LOADER_ERRNO__PROLOGUE2BIG,	/* Prologue too big for program */
+	BPF_LOADER_ERRNO__PROLOGUEOOB,	/* Offset out of bound for prologue */
 	__BPF_LOADER_ERRNO__END,
 };
 

455 lines not on this page · raw message

new file mode 100644
index 000000000000..d94cbea12899
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2015, He Kuang <[email protected]>
+ * Copyright (C) 2015, Huawei Inc.
+ */
+#ifndef __BPF_PROLOGUE_H
+#define __BPF_PROLOGUE_H
+
+#include <linux/compiler.h>
+#include <linux/filter.h>
+#include "probe-event.h"
+
+#define BPF_PROLOGUE_MAX_ARGS 3
+#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
+#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2
+
+#ifdef HAVE_BPF_PROLOGUE
+int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
+		      struct bpf_insn *new_prog, size_t *new_cnt,
+		      size_t cnt_space);
+#else
+static inline int
+bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
+		  int nargs __maybe_unused,
+		  struct bpf_insn *new_prog __maybe_unused,
+		  size_t *new_cnt,
+		  size_t cnt_space __maybe_unused)
+{
+	if (!new_cnt)
+		return -EINVAL;
+	*new_cnt = 0;
+	return -ENOTSUP;
+}
+#endif
+#endif /* __BPF_PROLOGUE_H */

index bd14be438cda..190a1c7f0649 100644
@@ -5,12 +5,15 @@
  * Copyright (C) 2015 Huawei Inc.
  */
 
+#include <linux/bpf.h>
 #include <bpf/libbpf.h>
 #include <linux/err.h>
 #include <linux/string.h>
 #include "perf.h"
 #include "debug.h"
 #include "bpf-loader.h"
+#include "bpf-prologue.h"
+#include "llvm-utils.h"
 #include "probe-event.h"
 #include "probe-finder.h" // for MAX_PROBES
 #include "llvm-utils.h"

@@ -33,6 +36,8 @@ DEFINE_PRINT_FN(debug, 1)
 
 struct bpf_prog_priv {
 	struct perf_probe_event pev;
+	bool need_prologue;
+	struct bpf_insn *insns_buf;
 };
 
 static bool libbpf_initialized;

@@ -107,6 +112,7 @@ bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused,
 	struct bpf_prog_priv *priv = _priv;
 
 	cleanup_perf_probe_events(&priv->pev, 1);
+	zfree(&priv->insns_buf);
 	free(priv);
 }
 

@@ -365,6 +371,102 @@ static int bpf__prepare_probe(void)
 	return err;
 }
 
+static int
+preproc_gen_prologue(struct bpf_program *prog, int n,
+		     struct bpf_insn *orig_insns, int orig_insns_cnt,
+		     struct bpf_prog_prep_result *res)
+{
+	struct probe_trace_event *tev;
+	struct perf_probe_event *pev;
+	struct bpf_prog_priv *priv;
+	struct bpf_insn *buf;
+	size_t prologue_cnt = 0;
+	int err;
+
+	err = bpf_program__get_private(prog, (void **)&priv);
+	if (err || !priv)
+		goto errout;
+
+	pev = &priv->pev;
+
+	if (n < 0 || n >= pev->ntevs)
+		goto errout;
+
+	tev = &pev->tevs[n];
+
+	buf = priv->insns_buf;
+	err = bpf__gen_prologue(tev->args, tev->nargs,
+				buf, &prologue_cnt,
+				BPF_MAXINSNS - orig_insns_cnt);
+	if (err) {
+		const char *title;
+
+		title = bpf_program__title(prog, false);
+		if (!title)
+			title = "[unknown]";
+
+		pr_debug("Failed to generate prologue for program %s\n",
+			 title);
+		return err;
+	}
+
+	memcpy(&buf[prologue_cnt], orig_insns,
+	       sizeof(struct bpf_insn) * orig_insns_cnt);
+
+	res->new_insn_ptr = buf;
+	res->new_insn_cnt = prologue_cnt + orig_insns_cnt;
+	res->pfd = NULL;
+	return 0;
+
+errout:
+	pr_debug("Internal error in preproc_gen_prologue\n");
+	return -BPF_LOADER_ERRNO__PROLOGUE;
+}
+
+static int hook_load_preprocessor(struct bpf_program *prog)
+{
+	struct perf_probe_event *pev;
+	struct bpf_prog_priv *priv;
+	bool need_prologue = false;
+	int err, i;
+
+	err = bpf_program__get_private(prog, (void **)&priv);
+	if (err || !priv) {
+		pr_debug("Internal error when hook preprocessor\n");
+		return -BPF_LOADER_ERRNO__INTERNAL;
+	}
+
+	pev = &priv->pev;
+	for (i = 0; i < pev->ntevs; i++) {
+		struct probe_trace_event *tev = &pev->tevs[i];
+
+		if (tev->nargs > 0) {
+			need_prologue = true;
+			break;
+		}
+	}
+
+	/*
+	 * Since all tevs don't have argument, we don't need generate
+	 * prologue.
+	 */
+	if (!need_prologue) {
+		priv->need_prologue = false;
+		return 0;
+	}
+
+	priv->need_prologue = true;
+	priv->insns_buf = malloc(sizeof(struct bpf_insn) * BPF_MAXINSNS);
+	if (!priv->insns_buf) {
+		pr_debug("No enough memory: alloc insns_buf failed\n");
+		return -ENOMEM;
+	}
+
+	err = bpf_program__set_prep(prog, pev->ntevs,
+				    preproc_gen_prologue);
+	return err;
+}
+
 int bpf__probe(struct bpf_object *obj)
 {
 	int err = 0;

@@ -399,6 +501,18 @@ int bpf__probe(struct bpf_object *obj)
 			pr_debug("bpf_probe: failed to apply perf probe events");
 			goto out;
 		}
+
+		/*
+		 * After probing, let's consider prologue, which
+		 * adds program fetcher to BPF programs.
+		 *
+		 * hook_load_preprocessorr() hooks pre-processor
+		 * to bpf_program, let it generate prologue
+		 * dynamically during loading.
+		 */
+		err = hook_load_preprocessor(prog);
+		if (err)
+			goto out;
 	}
 out:
 	return err < 0 ? err : 0;

@@ -482,7 +596,11 @@ int bpf__foreach_tev(struct bpf_object *obj,
 		for (i = 0; i < pev->ntevs; i++) {
 			tev = &pev->tevs[i];
 
-			fd = bpf_program__fd(prog);
+			if (priv->need_prologue)
+				fd = bpf_program__nth_fd(prog, i);
+			else
+				fd = bpf_program__fd(prog);
+
 			if (fd < 0) {
 				pr_debug("bpf: failed to get file descriptor\n");
 				return fd;

new file mode 100644
index 000000000000..7230e62c70fc
@@ -0,0 +1,35 @@
+/*
+ * 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;

index ec16f7812c8b..c7131fa448e8 100644
@@ -19,6 +19,29 @@ static int epoll_pwait_loop(void)
 	return 0;
 }
 
+#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;

@@ -37,6 +60,17 @@ static struct {
 		&epoll_pwait_loop,
 		(NR_ITERS + 1) / 2,
 	},
+#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
 };
 
 static int do_test(struct bpf_object *obj, int (*func)(void),

index bc4cf507cde5..7f4f7f79ca2f 100644
@@ -44,6 +44,10 @@ static struct {
 		.source = test_llvm__bpf_test_kbuild_prog,
 		.desc = "Test kbuild searching",
 	},
+	[LLVM_TESTCASE_BPF_PROLOGUE] = {
+		.source = test_llvm__bpf_test_prologue_prog,
+		.desc = "Test BPF prologue generation",
+	},
 };
 
 

index d91d8f44efee..5150b4d6ef50 100644
@@ -6,10 +6,12 @@
 
 extern const char test_llvm__bpf_base_prog[];
 extern const char test_llvm__bpf_test_kbuild_prog[];
+extern const char test_llvm__bpf_test_prologue_prog[];
 
 enum test_llvm__testcase {
 	LLVM_TESTCASE_BASE,
 	LLVM_TESTCASE_KBUILD,
+	LLVM_TESTCASE_BPF_PROLOGUE,
 	__LLVM_TESTCASE_MAX,
 };
 

index c7131fa448e8..dca3998883ee 100644
@@ -102,8 +102,7 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 	err = parse_events_load_bpf_obj(&parse_evlist, &parse_evlist.list, obj);
 	if (err || list_empty(&parse_evlist.list)) {
 		pr_debug("Failed to add events selected by BPF\n");
-		if (!err)
-			return TEST_FAIL;
+		return TEST_FAIL;
 	}
 
 	snprintf(pid, sizeof(pid), "%d", getpid());

@@ -157,8 +156,10 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 		}
 	}
 
-	if (count != expect)
+	if (count != expect) {
 		pr_debug("BPF filter result incorrect\n");
+		goto out_delete_evlist;
+	}
 
 	ret = TEST_OK;
 

index 190a1c7f0649..36544e5ece43 100644
@@ -38,6 +38,8 @@ struct bpf_prog_priv {
 	struct perf_probe_event pev;
 	bool need_prologue;
 	struct bpf_insn *insns_buf;
+	int nr_types;
+	int *type_mapping;
 };
 
 static bool libbpf_initialized;

@@ -113,6 +115,7 @@ bpf_prog_priv__clear(struct bpf_program *prog __maybe_unused,
 
 	cleanup_perf_probe_events(&priv->pev, 1);
 	zfree(&priv->insns_buf);
+	zfree(&priv->type_mapping);
 	free(priv);
 }
 

@@ -381,7 +384,7 @@ preproc_gen_prologue(struct bpf_program *prog, int n,
 	struct bpf_prog_priv *priv;
 	struct bpf_insn *buf;
 	size_t prologue_cnt = 0;
-	int err;
+	int i, err;
 
 	err = bpf_program__get_private(prog, (void **)&priv);
 	if (err || !priv)

@@ -389,10 +392,21 @@ preproc_gen_prologue(struct bpf_program *prog, int n,
 
 	pev = &priv->pev;
 
-	if (n < 0 || n >= pev->ntevs)
+	if (n < 0 || n >= priv->nr_types)
 		goto errout;
 
-	tev = &pev->tevs[n];
+	/* Find a tev belongs to that type */
+	for (i = 0; i < pev->ntevs; i++) {
+		if (priv->type_mapping[i] == n)
+			break;
+	}
+
+	if (i >= pev->ntevs) {
+		pr_debug("Internal error: prologue type %d not found\n", n);
+		return -BPF_LOADER_ERRNO__PROLOGUE;
+	}
+
+	tev = &pev->tevs[i];
 
 	buf = priv->insns_buf;
 	err = bpf__gen_prologue(tev->args, tev->nargs,

@@ -423,6 +437,101 @@ errout:
 	return -BPF_LOADER_ERRNO__PROLOGUE;
 }
 
+/*
+ * compare_tev_args is reflexive, transitive and antisymmetric.
+ * I can proof it but this margin is too narrow to contain.
+ */
+static int compare_tev_args(const void *ptev1, const void *ptev2)
+{
+	int i, ret;
+	const struct probe_trace_event *tev1 =
+		*(const struct probe_trace_event **)ptev1;
+	const struct probe_trace_event *tev2 =
+		*(const struct probe_trace_event **)ptev2;
+
+	ret = tev2->nargs - tev1->nargs;
+	if (ret)
+		return ret;
+
+	for (i = 0; i < tev1->nargs; i++) {
+		struct probe_trace_arg *arg1, *arg2;
+		struct probe_trace_arg_ref *ref1, *ref2;
+
+		arg1 = &tev1->args[i];
+		arg2 = &tev2->args[i];
+
+		ret = strcmp(arg1->value, arg2->value);
+		if (ret)
+			return ret;
+
+		ref1 = arg1->ref;
+		ref2 = arg2->ref;
+
+		while (ref1 && ref2) {
+			ret = ref2->offset - ref1->offset;
+			if (ret)
+				return ret;
+
+			ref1 = ref1->next;
+			ref2 = ref2->next;
+		}
+
+		if (ref1 || ref2)
+			return ref2 ? 1 : -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Assign a type number to each tevs in a pev.
+ * mapping is an array with same slots as tevs in that pev.
+ * nr_types will be set to number of types.
+ */
+static int map_prologue(struct perf_probe_event *pev, int *mapping,
+			int *nr_types)
+{
+	int i, type = 0;
+	struct probe_trace_event **ptevs;
+
+	size_t array_sz = sizeof(*ptevs) * pev->ntevs;
+
+	ptevs = malloc(array_sz);
+	if (!ptevs) {
+		pr_debug("No ehough memory: alloc ptevs failed\n");
+		return -ENOMEM;
+	}
+
+	pr_debug("In map_prologue, ntevs=%d\n", pev->ntevs);
+	for (i = 0; i < pev->ntevs; i++)
+		ptevs[i] = &pev->tevs[i];
+
+	qsort(ptevs, pev->ntevs, sizeof(*ptevs),
+	      compare_tev_args);
+
+	for (i = 0; i < pev->ntevs; i++) {
+		int n;
+
+		n = ptevs[i] - pev->tevs;
+		if (i == 0) {
+			mapping[n] = type;
+			pr_debug("mapping[%d]=%d\n", n, type);
+			continue;
+		}
+
+		if (compare_tev_args(ptevs + i, ptevs + i - 1) == 0)
+			mapping[n] = type;
+		else
+			mapping[n] = ++type;
+
+		pr_debug("mapping[%d]=%d\n", n, mapping[n]);
+	}
+	free(ptevs);
+	*nr_types = type + 1;
+
+	return 0;
+}
+
 static int hook_load_preprocessor(struct bpf_program *prog)
 {
 	struct perf_probe_event *pev;

@@ -462,7 +571,19 @@ static int hook_load_preprocessor(struct bpf_program *prog)
 		return -ENOMEM;
 	}
 
-	err = bpf_program__set_prep(prog, pev->ntevs,
+	priv->type_mapping = malloc(sizeof(int) * pev->ntevs);
+	if (!priv->type_mapping) {
+		pr_debug("No enough memory: alloc type_mapping failed\n");
+		return -ENOMEM;
+	}
+	memset(priv->type_mapping, -1,
+	       sizeof(int) * pev->ntevs);
+
+	err = map_prologue(pev, priv->type_mapping, &priv->nr_types);
+	if (err)
+		return err;
+
+	err = bpf_program__set_prep(prog, priv->nr_types,
 				    preproc_gen_prologue);
 	return err;
 }

@@ -596,10 +717,13 @@ int bpf__foreach_tev(struct bpf_object *obj,
 		for (i = 0; i < pev->ntevs; i++) {
 			tev = &pev->tevs[i];
 
-			if (priv->need_prologue)
-				fd = bpf_program__nth_fd(prog, i);
-			else
+			if (priv->need_prologue) {
+				int type = priv->type_mapping[i];
+
+				fd = bpf_program__nth_fd(prog, type);
+			} else {
 				fd = bpf_program__fd(prog);
+			}
 
 			if (fd < 0) {
 				pr_debug("bpf: failed to get file descriptor\n");

index 80c442eab767..664c2e894b08 100644
@@ -159,7 +159,13 @@ static struct test generic_tests[] = {
 	},
 	{
 		.desc = "Test LLVM searching and compiling",
-		.func = test__llvm,
+		.need_subtests = true,
+		.subtest = {
+			.skip_if_fail	= true,
+			.get_nr		= test__llvm_subtest_get_nr,
+			.get_desc	= test__llvm_subtest_get_desc,
+			.func		= test__llvm_subtest,
+		},
 	},
 	{
 		.desc = "Test topology in session",

@@ -203,7 +209,7 @@ static bool perf_test__matches(struct test *test, int curr, int argc, const char
 	return false;
 }
 
-static int run_test(struct test *test)
+static int run_test(struct test *test, int subtest)
 {
 	int status, err = -1, child = fork();
 	char sbuf[STRERR_BUFSIZE];

@@ -216,7 +222,10 @@ static int run_test(struct test *test)
 
 	if (!child) {
 		pr_debug("test child forked, pid %d\n", getpid());
-		err = test->func();
+		if (!test->need_subtests)
+			err = test->func();
+		else
+			err = test->subtest.func(subtest);
 		exit(err);
 	}
 

@@ -234,8 +243,48 @@ static int run_test(struct test *test)
 }
 
 #define for_each_test(j, t)	 				\
-	for (j = 0; j < ARRAY_SIZE(tests); j++)	\
-		for (t = &tests[j][0]; t->func; t++)
+	for (j = 0; j < ARRAY_SIZE(tests); j++)			\
+		for (t = &tests[j][0];				\
+			(!t->need_subtests && t->func) ||	\
+			(t->need_subtests &&			\
+			 t->subtest.get_nr &&			\
+			 t->subtest.get_desc &&			\
+			 t->subtest.func);			\
+		     t++)
+
+static int test_and_print(struct test *t, bool force_skip, int subtest)
+{
+	int err;
+
+	if (!force_skip) {
+		pr_debug("\n--- start ---\n");
+		err = run_test(t, subtest);
+		pr_debug("---- end ----\n");
+	} else {
+		pr_debug("\n--- force skipped ---\n");
+		err = TEST_SKIP;
+	}
+
+	if (!t->need_subtests)
+		pr_debug("%s:", t->desc);
+	else
+		pr_debug("%s subtest %d:", t->desc, subtest);
+
+	switch (err) {
+	case TEST_OK:
+		pr_info(" Ok\n");
+		break;
+	case TEST_SKIP:
+		color_fprintf(stderr, PERF_COLOR_YELLOW, " Skip\n");
+		break;
+	case TEST_FAIL:
+	default:
+		color_fprintf(stderr, PERF_COLOR_RED, " FAILED!\n");
+		break;
+	}
+
+	return err;
+}
 
 static int __cmd_test(int argc, const char *argv[], struct intlist *skiplist)
 {

@@ -264,21 +313,43 @@ static int __cmd_test(int argc, const char *argv[], struct intlist *skiplist)
 			continue;
 		}
 
-		pr_debug("\n--- start ---\n");
-		err = run_test(t);
-		pr_debug("---- end ----\n%s:", t->desc);
-
-		switch (err) {
-		case TEST_OK:
-			pr_info(" Ok\n");
-			break;
-		case TEST_SKIP:
-			color_fprintf(stderr, PERF_COLOR_YELLOW, " Skip\n");
-			break;
-		case TEST_FAIL:
-		default:
-			color_fprintf(stderr, PERF_COLOR_RED, " FAILED!\n");
-			break;
+		if (!t->need_subtests) {
+			test_and_print(t, false, -1);
+		} else {
+			int subn = t->subtest.get_nr();
+			/*
+			 * minus 2 to align with normal testcases.
+			 * For subtest we print additional '.x' in number.
+			 * for example:
+			 *
+			 * 35: Test LLVM searching and compiling                        :
+			 * 35.1: Basic BPF llvm compiling test                          : Ok
+			 */
+			int subw = width > 2 ? width - 2 : width;
+			bool skip = false;
+			int subi;
+
+			if (subn <= 0) {
+				color_fprintf(stderr, PERF_COLOR_YELLOW,
+					      " Skip (not compiled in)\n");
+				continue;
+			}
+			pr_info("\n");
+
+			for (subi = 0; subi < subn; subi++) {
+				int len = strlen(t->subtest.get_desc(subi));
+
+				if (subw < len)
+					subw = len;
+			}
+
+			for (subi = 0; subi < subn; subi++) {
+				pr_info("%2d.%1d: %-*s:", i, subi + 1, subw,
+					t->subtest.get_desc(subi));
+				err = test_and_print(t, skip, subi);
+				if (err != TEST_OK && t->subtest.skip_if_fail)
+					skip = true;
+			}
 		}
 	}
 

81 lines not on this page · raw message

index 3c8734a3abbc..f8f9eb6eaa62 100644
@@ -1,6 +1,8 @@
 #ifndef TESTS_H
 #define TESTS_H
 
+#include <stdbool.h>
+
 #define TEST_ASSERT_VAL(text, cond)					 \
 do {									 \
 	if (!(cond)) {							 \

@@ -26,7 +28,19 @@ enum {
 
 struct test {
 	const char *desc;
-	int (*func)(void);
+
+	bool need_subtests;
+
+	union {
+		int (*func)(void);
+
+		struct {
+			bool skip_if_fail;
+			int (*get_nr)(void);
+			const char *(*get_desc)(int i);
+			int (*func)(int i);
+		} subtest;
+	};
 };
 
 /* Tests */

@@ -65,7 +79,11 @@ int test__fdarray__filter(void);
 int test__fdarray__add(void);
 int test__kmod_path__parse(void);
 int test__thread_map(void);
-int test__llvm(void);
+
+const char *test__llvm_subtest_get_desc(int i);
+int test__llvm_subtest_get_nr(void);
+int test__llvm_subtest(int i);
+
 int test__bpf(void);
 int test_session_topology(void);
 

index dca3998883ee..8c2262ddbde2 100644
@@ -215,28 +215,46 @@ out:
 	return ret;
 }
 
-int test__bpf(void)
+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;
+}
+
+int test__bpf_subtest(int i)
 {
-	unsigned 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;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(bpf_testcase_table); i++) {
-		err = __test__bpf(i);
+	err = __test__bpf(i);
+	return err;
+}
 
-		if (err != TEST_OK)
-			return err;
-	}
+#else
+int test__bpf_subtest_get_nr(void)
+{
+	return 0;
+}
 
-	return TEST_OK;
+const char *test__bpf_subtest_get_desc(int i __maybe_unused)
+{
+	return NULL;
 }
 
-#else
-int test__bpf(void)
+int test__bpf_subtest(int i __maybe_unused)
 {
 	pr_debug("Skip BPF test because BPF support is not compiled\n");
 	return TEST_SKIP;

index 664c2e894b08..2277e0ba96a9 100644
@@ -173,7 +173,13 @@ static struct test generic_tests[] = {
 	},
 	{
 		.desc = "Test BPF filter",
-		.func = test__bpf,
+		.need_subtests = true,
+		.subtest = {
+			.skip_if_fail	= true,
+			.get_nr		= test__bpf_subtest_get_nr,
+			.get_desc	= test__bpf_subtest_get_desc,
+			.func		= test__bpf_subtest,
+		},
 	},
 	{
 		.func = NULL,

index f8f9eb6eaa62..2ce66b2c48df 100644
@@ -84,7 +84,10 @@ const char *test__llvm_subtest_get_desc(int i);
 int test__llvm_subtest_get_nr(void);
 int test__llvm_subtest(int i);
 
-int test__bpf(void);
+const char *test__bpf_subtest_get_desc(int i);
+int test__bpf_subtest_get_nr(void);
+int test__bpf_subtest(int i);
+
 int test_session_topology(void);
 
 #if defined(__arm__) || defined(__aarch64__)

index 2277e0ba96a9..dd3159f53937 100644
@@ -227,7 +227,22 @@ static int run_test(struct test *test, int subtest)
 	}
 
 	if (!child) {
+		int nullfd;
+
 		pr_debug("test child forked, pid %d\n", getpid());
+
+		if (!verbose) {
+			nullfd = open("/dev/null", O_WRONLY);
+			if (nullfd >= 0) {
+				close(STDERR_FILENO);
+				close(STDOUT_FILENO);
+
+				dup2(nullfd, STDOUT_FILENO);
+				dup2(STDOUT_FILENO, STDERR_FILENO);
+				close(nullfd);
+			}
+		}
+
 		if (!test->need_subtests)
 			err = test->func();
 		else