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-rw-r--r--tools/testing/selftests/bpf/Makefile14
-rw-r--r--tools/testing/selftests/bpf/prog_tests/usdt.c313
-rw-r--r--tools/testing/selftests/bpf/progs/test_usdt.c96
-rw-r--r--tools/testing/selftests/bpf/progs/test_usdt_multispec.c34
-rw-r--r--tools/testing/selftests/bpf/sdt-config.h6
-rw-r--r--tools/testing/selftests/bpf/sdt.h513
6 files changed, 970 insertions, 6 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 3820608faf57..0f8c55dfd844 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -328,12 +328,8 @@ SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c
LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h \
linked_vars.skel.h linked_maps.skel.h \
- test_subskeleton.skel.h test_subskeleton_lib.skel.h
-
-# In the subskeleton case, we want the test_subskeleton_lib.subskel.h file
-# but that's created as a side-effect of the skel.h generation.
-test_subskeleton.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o test_subskeleton.o
-test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o
+ test_subskeleton.skel.h test_subskeleton_lib.skel.h \
+ test_usdt.skel.h
LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c \
@@ -346,6 +342,11 @@ test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
linked_funcs.skel.h-deps := linked_funcs1.o linked_funcs2.o
linked_vars.skel.h-deps := linked_vars1.o linked_vars2.o
linked_maps.skel.h-deps := linked_maps1.o linked_maps2.o
+# In the subskeleton case, we want the test_subskeleton_lib.subskel.h file
+# but that's created as a side-effect of the skel.h generation.
+test_subskeleton.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o test_subskeleton.o
+test_subskeleton_lib.skel.h-deps := test_subskeleton_lib2.o test_subskeleton_lib.o
+test_usdt.skel.h-deps := test_usdt.o test_usdt_multispec.o
LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
@@ -400,6 +401,7 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o: \
$(TRUNNER_BPF_PROGS_DIR)/*.h \
$$(INCLUDE_DIR)/vmlinux.h \
$(wildcard $(BPFDIR)/bpf_*.h) \
+ $(wildcard $(BPFDIR)/*.bpf.h) \
| $(TRUNNER_OUTPUT) $$(BPFOBJ)
$$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@, \
$(TRUNNER_BPF_CFLAGS))
diff --git a/tools/testing/selftests/bpf/prog_tests/usdt.c b/tools/testing/selftests/bpf/prog_tests/usdt.c
new file mode 100644
index 000000000000..0677c9bfd40b
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/usdt.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+#include <test_progs.h>
+
+#define _SDT_HAS_SEMAPHORES 1
+#include "../sdt.h"
+
+#include "test_usdt.skel.h"
+
+int lets_test_this(int);
+
+static volatile int idx = 2;
+static volatile __u64 bla = 0xFEDCBA9876543210ULL;
+static volatile short nums[] = {-1, -2, -3, };
+
+static volatile struct {
+ int x;
+ signed char y;
+} t1 = { 1, -127 };
+
+#define SEC(name) __attribute__((section(name), used))
+
+unsigned short test_usdt0_semaphore SEC(".probes");
+unsigned short test_usdt3_semaphore SEC(".probes");
+unsigned short test_usdt12_semaphore SEC(".probes");
+
+static void __always_inline trigger_func(int x) {
+ long y = 42;
+
+ if (test_usdt0_semaphore)
+ STAP_PROBE(test, usdt0);
+ if (test_usdt3_semaphore)
+ STAP_PROBE3(test, usdt3, x, y, &bla);
+ if (test_usdt12_semaphore) {
+ STAP_PROBE12(test, usdt12,
+ x, x + 1, y, x + y, 5,
+ y / 7, bla, &bla, -9, nums[x],
+ nums[idx], t1.y);
+ }
+}
+
+static void subtest_basic_usdt(void)
+{
+ LIBBPF_OPTS(bpf_usdt_opts, opts);
+ struct test_usdt *skel;
+ struct test_usdt__bss *bss;
+ int err;
+
+ skel = test_usdt__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ bss = skel->bss;
+ bss->my_pid = getpid();
+
+ err = test_usdt__attach(skel);
+ if (!ASSERT_OK(err, "skel_attach"))
+ goto cleanup;
+
+ /* usdt0 won't be auto-attached */
+ opts.usdt_cookie = 0xcafedeadbeeffeed;
+ skel->links.usdt0 = bpf_program__attach_usdt(skel->progs.usdt0,
+ 0 /*self*/, "/proc/self/exe",
+ "test", "usdt0", &opts);
+ if (!ASSERT_OK_PTR(skel->links.usdt0, "usdt0_link"))
+ goto cleanup;
+
+ trigger_func(1);
+
+ ASSERT_EQ(bss->usdt0_called, 1, "usdt0_called");
+ ASSERT_EQ(bss->usdt3_called, 1, "usdt3_called");
+ ASSERT_EQ(bss->usdt12_called, 1, "usdt12_called");
+
+ ASSERT_EQ(bss->usdt0_cookie, 0xcafedeadbeeffeed, "usdt0_cookie");
+ ASSERT_EQ(bss->usdt0_arg_cnt, 0, "usdt0_arg_cnt");
+ ASSERT_EQ(bss->usdt0_arg_ret, -ENOENT, "usdt0_arg_ret");
+
+ /* auto-attached usdt3 gets default zero cookie value */
+ ASSERT_EQ(bss->usdt3_cookie, 0, "usdt3_cookie");
+ ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt");
+
+ ASSERT_EQ(bss->usdt3_arg_rets[0], 0, "usdt3_arg1_ret");
+ ASSERT_EQ(bss->usdt3_arg_rets[1], 0, "usdt3_arg2_ret");
+ ASSERT_EQ(bss->usdt3_arg_rets[2], 0, "usdt3_arg3_ret");
+ ASSERT_EQ(bss->usdt3_args[0], 1, "usdt3_arg1");
+ ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2");
+ ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3");
+
+ /* auto-attached usdt12 gets default zero cookie value */
+ ASSERT_EQ(bss->usdt12_cookie, 0, "usdt12_cookie");
+ ASSERT_EQ(bss->usdt12_arg_cnt, 12, "usdt12_arg_cnt");
+
+ ASSERT_EQ(bss->usdt12_args[0], 1, "usdt12_arg1");
+ ASSERT_EQ(bss->usdt12_args[1], 1 + 1, "usdt12_arg2");
+ ASSERT_EQ(bss->usdt12_args[2], 42, "usdt12_arg3");
+ ASSERT_EQ(bss->usdt12_args[3], 42 + 1, "usdt12_arg4");
+ ASSERT_EQ(bss->usdt12_args[4], 5, "usdt12_arg5");
+ ASSERT_EQ(bss->usdt12_args[5], 42 / 7, "usdt12_arg6");
+ ASSERT_EQ(bss->usdt12_args[6], bla, "usdt12_arg7");
+ ASSERT_EQ(bss->usdt12_args[7], (uintptr_t)&bla, "usdt12_arg8");
+ ASSERT_EQ(bss->usdt12_args[8], -9, "usdt12_arg9");
+ ASSERT_EQ(bss->usdt12_args[9], nums[1], "usdt12_arg10");
+ ASSERT_EQ(bss->usdt12_args[10], nums[idx], "usdt12_arg11");
+ ASSERT_EQ(bss->usdt12_args[11], t1.y, "usdt12_arg12");
+
+ /* trigger_func() is marked __always_inline, so USDT invocations will be
+ * inlined in two different places, meaning that each USDT will have
+ * at least 2 different places to be attached to. This verifies that
+ * bpf_program__attach_usdt() handles this properly and attaches to
+ * all possible places of USDT invocation.
+ */
+ trigger_func(2);
+
+ ASSERT_EQ(bss->usdt0_called, 2, "usdt0_called");
+ ASSERT_EQ(bss->usdt3_called, 2, "usdt3_called");
+ ASSERT_EQ(bss->usdt12_called, 2, "usdt12_called");
+
+ /* only check values that depend on trigger_func()'s input value */
+ ASSERT_EQ(bss->usdt3_args[0], 2, "usdt3_arg1");
+
+ ASSERT_EQ(bss->usdt12_args[0], 2, "usdt12_arg1");
+ ASSERT_EQ(bss->usdt12_args[1], 2 + 1, "usdt12_arg2");
+ ASSERT_EQ(bss->usdt12_args[3], 42 + 2, "usdt12_arg4");
+ ASSERT_EQ(bss->usdt12_args[9], nums[2], "usdt12_arg10");
+
+ /* detach and re-attach usdt3 */
+ bpf_link__destroy(skel->links.usdt3);
+
+ opts.usdt_cookie = 0xBADC00C51E;
+ skel->links.usdt3 = bpf_program__attach_usdt(skel->progs.usdt3, -1 /* any pid */,
+ "/proc/self/exe", "test", "usdt3", &opts);
+ if (!ASSERT_OK_PTR(skel->links.usdt3, "usdt3_reattach"))
+ goto cleanup;
+
+ trigger_func(3);
+
+ ASSERT_EQ(bss->usdt3_called, 3, "usdt3_called");
+ /* this time usdt3 has custom cookie */
+ ASSERT_EQ(bss->usdt3_cookie, 0xBADC00C51E, "usdt3_cookie");
+ ASSERT_EQ(bss->usdt3_arg_cnt, 3, "usdt3_arg_cnt");
+
+ ASSERT_EQ(bss->usdt3_arg_rets[0], 0, "usdt3_arg1_ret");
+ ASSERT_EQ(bss->usdt3_arg_rets[1], 0, "usdt3_arg2_ret");
+ ASSERT_EQ(bss->usdt3_arg_rets[2], 0, "usdt3_arg3_ret");
+ ASSERT_EQ(bss->usdt3_args[0], 3, "usdt3_arg1");
+ ASSERT_EQ(bss->usdt3_args[1], 42, "usdt3_arg2");
+ ASSERT_EQ(bss->usdt3_args[2], (uintptr_t)&bla, "usdt3_arg3");
+
+cleanup:
+ test_usdt__destroy(skel);
+}
+
+unsigned short test_usdt_100_semaphore SEC(".probes");
+unsigned short test_usdt_300_semaphore SEC(".probes");
+unsigned short test_usdt_400_semaphore SEC(".probes");
+
+#define R10(F, X) F(X+0); F(X+1);F(X+2); F(X+3); F(X+4); \
+ F(X+5); F(X+6); F(X+7); F(X+8); F(X+9);
+#define R100(F, X) R10(F,X+ 0);R10(F,X+10);R10(F,X+20);R10(F,X+30);R10(F,X+40); \
+ R10(F,X+50);R10(F,X+60);R10(F,X+70);R10(F,X+80);R10(F,X+90);
+
+/* carefully control that we get exactly 100 inlines by preventing inlining */
+static void __always_inline f100(int x)
+{
+ STAP_PROBE1(test, usdt_100, x);
+}
+
+__weak void trigger_100_usdts(void)
+{
+ R100(f100, 0);
+}
+
+/* we shouldn't be able to attach to test:usdt2_300 USDT as we don't have as
+ * many slots for specs. It's important that each STAP_PROBE2() invocation
+ * (after untolling) gets different arg spec due to compiler inlining i as
+ * a constant
+ */
+static void __always_inline f300(int x)
+{
+ STAP_PROBE1(test, usdt_300, x);
+}
+
+__weak void trigger_300_usdts(void)
+{
+ R100(f300, 0);
+ R100(f300, 100);
+ R100(f300, 200);
+}
+
+static void __always_inline f400(int x __attribute__((unused)))
+{
+ static int y;
+
+ STAP_PROBE1(test, usdt_400, y++);
+}
+
+/* this time we have 400 different USDT call sites, but they have uniform
+ * argument location, so libbpf's spec string deduplication logic should keep
+ * spec count use very small and so we should be able to attach to all 400
+ * call sites
+ */
+__weak void trigger_400_usdts(void)
+{
+ R100(f400, 0);
+ R100(f400, 100);
+ R100(f400, 200);
+ R100(f400, 300);
+}
+
+static void subtest_multispec_usdt(void)
+{
+ LIBBPF_OPTS(bpf_usdt_opts, opts);
+ struct test_usdt *skel;
+ struct test_usdt__bss *bss;
+ int err, i;
+
+ skel = test_usdt__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_open"))
+ return;
+
+ bss = skel->bss;
+ bss->my_pid = getpid();
+
+ err = test_usdt__attach(skel);
+ if (!ASSERT_OK(err, "skel_attach"))
+ goto cleanup;
+
+ /* usdt_100 is auto-attached and there are 100 inlined call sites,
+ * let's validate that all of them are properly attached to and
+ * handled from BPF side
+ */
+ trigger_100_usdts();
+
+ ASSERT_EQ(bss->usdt_100_called, 100, "usdt_100_called");
+ ASSERT_EQ(bss->usdt_100_sum, 99 * 100 / 2, "usdt_100_sum");
+
+ /* Stress test free spec ID tracking. By default libbpf allows up to
+ * 256 specs to be used, so if we don't return free spec IDs back
+ * after few detachments and re-attachments we should run out of
+ * available spec IDs.
+ */
+ for (i = 0; i < 2; i++) {
+ bpf_link__destroy(skel->links.usdt_100);
+
+ skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1,
+ "/proc/self/exe",
+ "test", "usdt_100", NULL);
+ if (!ASSERT_OK_PTR(skel->links.usdt_100, "usdt_100_reattach"))
+ goto cleanup;
+
+ bss->usdt_100_sum = 0;
+ trigger_100_usdts();
+
+ ASSERT_EQ(bss->usdt_100_called, (i + 1) * 100 + 100, "usdt_100_called");
+ ASSERT_EQ(bss->usdt_100_sum, 99 * 100 / 2, "usdt_100_sum");
+ }
+
+ /* Now let's step it up and try to attach USDT that requires more than
+ * 256 attach points with different specs for each.
+ * Note that we need trigger_300_usdts() only to actually have 300
+ * USDT call sites, we are not going to actually trace them.
+ */
+ trigger_300_usdts();
+
+ /* we'll reuse usdt_100 BPF program for usdt_300 test */
+ bpf_link__destroy(skel->links.usdt_100);
+ skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1, "/proc/self/exe",
+ "test", "usdt_300", NULL);
+ err = -errno;
+ if (!ASSERT_ERR_PTR(skel->links.usdt_100, "usdt_300_bad_attach"))
+ goto cleanup;
+ ASSERT_EQ(err, -E2BIG, "usdt_300_attach_err");
+
+ /* let's check that there are no "dangling" BPF programs attached due
+ * to partial success of the above test:usdt_300 attachment
+ */
+ bss->usdt_100_called = 0;
+ bss->usdt_100_sum = 0;
+
+ f300(777); /* this is 301st instance of usdt_300 */
+
+ ASSERT_EQ(bss->usdt_100_called, 0, "usdt_301_called");
+ ASSERT_EQ(bss->usdt_100_sum, 0, "usdt_301_sum");
+
+ /* This time we have USDT with 400 inlined invocations, but arg specs
+ * should be the same across all sites, so libbpf will only need to
+ * use one spec and thus we'll be able to attach 400 uprobes
+ * successfully.
+ *
+ * Again, we are reusing usdt_100 BPF program.
+ */
+ skel->links.usdt_100 = bpf_program__attach_usdt(skel->progs.usdt_100, -1,
+ "/proc/self/exe",
+ "test", "usdt_400", NULL);
+ if (!ASSERT_OK_PTR(skel->links.usdt_100, "usdt_400_attach"))
+ goto cleanup;
+
+ trigger_400_usdts();
+
+ ASSERT_EQ(bss->usdt_100_called, 400, "usdt_400_called");
+ ASSERT_EQ(bss->usdt_100_sum, 399 * 400 / 2, "usdt_400_sum");
+
+cleanup:
+ test_usdt__destroy(skel);
+}
+
+void test_usdt(void)
+{
+ if (test__start_subtest("basic"))
+ subtest_basic_usdt();
+ if (test__start_subtest("multispec"))
+ subtest_multispec_usdt();
+}
diff --git a/tools/testing/selftests/bpf/progs/test_usdt.c b/tools/testing/selftests/bpf/progs/test_usdt.c
new file mode 100644
index 000000000000..505aab9a5234
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_usdt.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/usdt.bpf.h>
+
+int my_pid;
+
+int usdt0_called;
+u64 usdt0_cookie;
+int usdt0_arg_cnt;
+int usdt0_arg_ret;
+
+SEC("usdt")
+int usdt0(struct pt_regs *ctx)
+{
+ long tmp;
+
+ if (my_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&usdt0_called, 1);
+
+ usdt0_cookie = bpf_usdt_cookie(ctx);
+ usdt0_arg_cnt = bpf_usdt_arg_cnt(ctx);
+ /* should return -ENOENT for any arg_num */
+ usdt0_arg_ret = bpf_usdt_arg(ctx, bpf_get_prandom_u32(), &tmp);
+ return 0;
+}
+
+int usdt3_called;
+u64 usdt3_cookie;
+int usdt3_arg_cnt;
+int usdt3_arg_rets[3];
+u64 usdt3_args[3];
+
+SEC("usdt//proc/self/exe:test:usdt3")
+int usdt3(struct pt_regs *ctx)
+{
+ long tmp;
+
+ if (my_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&usdt3_called, 1);
+
+ usdt3_cookie = bpf_usdt_cookie(ctx);
+ usdt3_arg_cnt = bpf_usdt_arg_cnt(ctx);
+
+ usdt3_arg_rets[0] = bpf_usdt_arg(ctx, 0, &tmp);
+ usdt3_args[0] = (int)tmp;
+
+ usdt3_arg_rets[1] = bpf_usdt_arg(ctx, 1, &tmp);
+ usdt3_args[1] = (long)tmp;
+
+ usdt3_arg_rets[2] = bpf_usdt_arg(ctx, 2, &tmp);
+ usdt3_args[2] = (uintptr_t)tmp;
+
+ return 0;
+}
+
+int usdt12_called;
+u64 usdt12_cookie;
+int usdt12_arg_cnt;
+u64 usdt12_args[12];
+
+SEC("usdt//proc/self/exe:test:usdt12")
+int BPF_USDT(usdt12, int a1, int a2, long a3, long a4, unsigned a5,
+ long a6, __u64 a7, uintptr_t a8, int a9, short a10,
+ short a11, signed char a12)
+{
+ if (my_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&usdt12_called, 1);
+
+ usdt12_cookie = bpf_usdt_cookie(ctx);
+ usdt12_arg_cnt = bpf_usdt_arg_cnt(ctx);
+
+ usdt12_args[0] = a1;
+ usdt12_args[1] = a2;
+ usdt12_args[2] = a3;
+ usdt12_args[3] = a4;
+ usdt12_args[4] = a5;
+ usdt12_args[5] = a6;
+ usdt12_args[6] = a7;
+ usdt12_args[7] = a8;
+ usdt12_args[8] = a9;
+ usdt12_args[9] = a10;
+ usdt12_args[10] = a11;
+ usdt12_args[11] = a12;
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_usdt_multispec.c b/tools/testing/selftests/bpf/progs/test_usdt_multispec.c
new file mode 100644
index 000000000000..3a090681f981
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_usdt_multispec.c
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/usdt.bpf.h>
+
+/* this file is linked together with test_usdt.c to validate that usdt.bpf.h
+ * can be included in multiple .bpf.c files forming single final BPF object
+ * file
+ */
+
+extern int my_pid;
+
+int usdt_100_called;
+int usdt_100_sum;
+
+SEC("usdt//proc/self/exe:test:usdt_100")
+int BPF_USDT(usdt_100, int x)
+{
+ long tmp;
+
+ if (my_pid != (bpf_get_current_pid_tgid() >> 32))
+ return 0;
+
+ __sync_fetch_and_add(&usdt_100_called, 1);
+ __sync_fetch_and_add(&usdt_100_sum, x);
+
+ bpf_printk("X is %d, sum is %d", x, usdt_100_sum);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/sdt-config.h b/tools/testing/selftests/bpf/sdt-config.h
new file mode 100644
index 000000000000..733045a52771
--- /dev/null
+++ b/tools/testing/selftests/bpf/sdt-config.h
@@ -0,0 +1,6 @@
+/* includes/sys/sdt-config.h. Generated from sdt-config.h.in by configure.
+
+ This file just defines _SDT_ASM_SECTION_AUTOGROUP_SUPPORT to 0 or 1 to
+ indicate whether the assembler supports "?" in .pushsection directives. */
+
+#define _SDT_ASM_SECTION_AUTOGROUP_SUPPORT 1
diff --git a/tools/testing/selftests/bpf/sdt.h b/tools/testing/selftests/bpf/sdt.h
new file mode 100644
index 000000000000..ca0162b4dc57
--- /dev/null
+++ b/tools/testing/selftests/bpf/sdt.h
@@ -0,0 +1,513 @@
+/* <sys/sdt.h> - Systemtap static probe definition macros.
+
+ This file is dedicated to the public domain, pursuant to CC0
+ (https://creativecommons.org/publicdomain/zero/1.0/)
+*/
+
+#ifndef _SYS_SDT_H
+#define _SYS_SDT_H 1
+
+/*
+ This file defines a family of macros
+
+ STAP_PROBEn(op1, ..., opn)
+
+ that emit a nop into the instruction stream, and some data into an auxiliary
+ note section. The data in the note section describes the operands, in terms
+ of size and location. Each location is encoded as assembler operand string.
+ Consumer tools such as gdb or systemtap insert breakpoints on top of
+ the nop, and decode the location operand-strings, like an assembler,
+ to find the values being passed.
+
+ The operand strings are selected by the compiler for each operand.
+ They are constrained by gcc inline-assembler codes. The default is:
+
+ #define STAP_SDT_ARG_CONSTRAINT nor
+
+ This is a good default if the operands tend to be integral and
+ moderate in number (smaller than number of registers). In other
+ cases, the compiler may report "'asm' requires impossible reload" or
+ similar. In this case, consider simplifying the macro call (fewer
+ and simpler operands), reduce optimization, or override the default
+ constraints string via:
+
+ #define STAP_SDT_ARG_CONSTRAINT g
+ #include <sys/sdt.h>
+
+ See also:
+ https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation
+ https://gcc.gnu.org/onlinedocs/gcc/Constraints.html
+ */
+
+
+
+#ifdef __ASSEMBLER__
+# define _SDT_PROBE(provider, name, n, arglist) \
+ _SDT_ASM_BODY(provider, name, _SDT_ASM_SUBSTR_1, (_SDT_DEPAREN_##n arglist)) \
+ _SDT_ASM_BASE
+# define _SDT_ASM_1(x) x;
+# define _SDT_ASM_2(a, b) a,b;
+# define _SDT_ASM_3(a, b, c) a,b,c;
+# define _SDT_ASM_5(a, b, c, d, e) a,b,c,d,e;
+# define _SDT_ASM_STRING_1(x) .asciz #x;
+# define _SDT_ASM_SUBSTR_1(x) .ascii #x;
+# define _SDT_DEPAREN_0() /* empty */
+# define _SDT_DEPAREN_1(a) a
+# define _SDT_DEPAREN_2(a,b) a b
+# define _SDT_DEPAREN_3(a,b,c) a b c
+# define _SDT_DEPAREN_4(a,b,c,d) a b c d
+# define _SDT_DEPAREN_5(a,b,c,d,e) a b c d e
+# define _SDT_DEPAREN_6(a,b,c,d,e,f) a b c d e f
+# define _SDT_DEPAREN_7(a,b,c,d,e,f,g) a b c d e f g
+# define _SDT_DEPAREN_8(a,b,c,d,e,f,g,h) a b c d e f g h
+# define _SDT_DEPAREN_9(a,b,c,d,e,f,g,h,i) a b c d e f g h i
+# define _SDT_DEPAREN_10(a,b,c,d,e,f,g,h,i,j) a b c d e f g h i j
+# define _SDT_DEPAREN_11(a,b,c,d,e,f,g,h,i,j,k) a b c d e f g h i j k
+# define _SDT_DEPAREN_12(a,b,c,d,e,f,g,h,i,j,k,l) a b c d e f g h i j k l
+#else
+#if defined _SDT_HAS_SEMAPHORES
+#define _SDT_NOTE_SEMAPHORE_USE(provider, name) \
+ __asm__ __volatile__ ("" :: "m" (provider##_##name##_semaphore));
+#else
+#define _SDT_NOTE_SEMAPHORE_USE(provider, name)
+#endif
+
+# define _SDT_PROBE(provider, name, n, arglist) \
+ do { \
+ _SDT_NOTE_SEMAPHORE_USE(provider, name); \
+ __asm__ __volatile__ (_SDT_ASM_BODY(provider, name, _SDT_ASM_ARGS, (n)) \
+ :: _SDT_ASM_OPERANDS_##n arglist); \
+ __asm__ __volatile__ (_SDT_ASM_BASE); \
+ } while (0)
+# define _SDT_S(x) #x
+# define _SDT_ASM_1(x) _SDT_S(x) "\n"
+# define _SDT_ASM_2(a, b) _SDT_S(a) "," _SDT_S(b) "\n"
+# define _SDT_ASM_3(a, b, c) _SDT_S(a) "," _SDT_S(b) "," \
+ _SDT_S(c) "\n"
+# define _SDT_ASM_5(a, b, c, d, e) _SDT_S(a) "," _SDT_S(b) "," \
+ _SDT_S(c) "," _SDT_S(d) "," \
+ _SDT_S(e) "\n"
+# define _SDT_ASM_ARGS(n) _SDT_ASM_TEMPLATE_##n
+# define _SDT_ASM_STRING_1(x) _SDT_ASM_1(.asciz #x)
+# define _SDT_ASM_SUBSTR_1(x) _SDT_ASM_1(.ascii #x)
+
+# define _SDT_ARGFMT(no) _SDT_ASM_1(_SDT_SIGN %n[_SDT_S##no]) \
+ _SDT_ASM_1(_SDT_SIZE %n[_SDT_S##no]) \
+ _SDT_ASM_1(_SDT_TYPE %n[_SDT_S##no]) \
+ _SDT_ASM_SUBSTR(_SDT_ARGTMPL(_SDT_A##no))
+
+
+# ifndef STAP_SDT_ARG_CONSTRAINT
+# if defined __powerpc__
+# define STAP_SDT_ARG_CONSTRAINT nZr
+# elif defined __arm__
+# define STAP_SDT_ARG_CONSTRAINT g
+# else
+# define STAP_SDT_ARG_CONSTRAINT nor
+# endif
+# endif
+
+# define _SDT_STRINGIFY(x) #x
+# define _SDT_ARG_CONSTRAINT_STRING(x) _SDT_STRINGIFY(x)
+/* _SDT_S encodes the size and type as 0xSSTT which is decoded by the assembler
+ macros _SDT_SIZE and _SDT_TYPE */
+# define _SDT_ARG(n, x) \
+ [_SDT_S##n] "n" ((_SDT_ARGSIGNED (x) ? (int)-1 : 1) * (-(((int) _SDT_ARGSIZE (x)) << 8) + (-(0x7f & __builtin_classify_type (x))))), \
+ [_SDT_A##n] _SDT_ARG_CONSTRAINT_STRING (STAP_SDT_ARG_CONSTRAINT) (_SDT_ARGVAL (x))
+#endif
+#define _SDT_ASM_STRING(x) _SDT_ASM_STRING_1(x)
+#define _SDT_ASM_SUBSTR(x) _SDT_ASM_SUBSTR_1(x)
+
+#define _SDT_ARGARRAY(x) (__builtin_classify_type (x) == 14 \
+ || __builtin_classify_type (x) == 5)
+
+#ifdef __cplusplus
+# define _SDT_ARGSIGNED(x) (!_SDT_ARGARRAY (x) \
+ && __sdt_type<__typeof (x)>::__sdt_signed)
+# define _SDT_ARGSIZE(x) (_SDT_ARGARRAY (x) \
+ ? sizeof (void *) : sizeof (x))
+# define _SDT_ARGVAL(x) (x)
+
+# include <cstddef>
+
+template<typename __sdt_T>
+struct __sdt_type
+{
+ static const bool __sdt_signed = false;
+};
+
+#define __SDT_ALWAYS_SIGNED(T) \
+template<> struct __sdt_type<T> { static const bool __sdt_signed = true; };
+#define __SDT_COND_SIGNED(T,CT) \
+template<> struct __sdt_type<T> { static const bool __sdt_signed = ((CT)(-1) < 1); };
+__SDT_ALWAYS_SIGNED(signed char)
+__SDT_ALWAYS_SIGNED(short)
+__SDT_ALWAYS_SIGNED(int)
+__SDT_ALWAYS_SIGNED(long)
+__SDT_ALWAYS_SIGNED(long long)
+__SDT_ALWAYS_SIGNED(volatile signed char)
+__SDT_ALWAYS_SIGNED(volatile short)
+__SDT_ALWAYS_SIGNED(volatile int)
+__SDT_ALWAYS_SIGNED(volatile long)
+__SDT_ALWAYS_SIGNED(volatile long long)
+__SDT_ALWAYS_SIGNED(const signed char)
+__SDT_ALWAYS_SIGNED(const short)
+__SDT_ALWAYS_SIGNED(const int)
+__SDT_ALWAYS_SIGNED(const long)
+__SDT_ALWAYS_SIGNED(const long long)
+__SDT_ALWAYS_SIGNED(const volatile signed char)
+__SDT_ALWAYS_SIGNED(const volatile short)
+__SDT_ALWAYS_SIGNED(const volatile int)
+__SDT_ALWAYS_SIGNED(const volatile long)
+__SDT_ALWAYS_SIGNED(const volatile long long)
+__SDT_COND_SIGNED(char, char)
+__SDT_COND_SIGNED(wchar_t, wchar_t)
+__SDT_COND_SIGNED(volatile char, char)
+__SDT_COND_SIGNED(volatile wchar_t, wchar_t)
+__SDT_COND_SIGNED(const char, char)
+__SDT_COND_SIGNED(const wchar_t, wchar_t)
+__SDT_COND_SIGNED(const volatile char, char)
+__SDT_COND_SIGNED(const volatile wchar_t, wchar_t)
+#if defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4))
+/* __SDT_COND_SIGNED(char16_t) */
+/* __SDT_COND_SIGNED(char32_t) */
+#endif
+
+template<typename __sdt_E>
+struct __sdt_type<__sdt_E[]> : public __sdt_type<__sdt_E *> {};
+
+template<typename __sdt_E, size_t __sdt_N>
+struct __sdt_type<__sdt_E[__sdt_N]> : public __sdt_type<__sdt_E *> {};
+
+#elif !defined(__ASSEMBLER__)
+__extension__ extern unsigned long long __sdt_unsp;
+# define _SDT_ARGINTTYPE(x) \
+ __typeof (__builtin_choose_expr (((__builtin_classify_type (x) \
+ + 3) & -4) == 4, (x), 0U))
+# define _SDT_ARGSIGNED(x) \
+ (!__extension__ \
+ (__builtin_constant_p ((((unsigned long long) \
+ (_SDT_ARGINTTYPE (x)) __sdt_unsp) \
+ & ((unsigned long long)1 << (sizeof (unsigned long long) \
+ * __CHAR_BIT__ - 1))) == 0) \
+ || (_SDT_ARGINTTYPE (x)) -1 > (_SDT_ARGINTTYPE (x)) 0))
+# define _SDT_ARGSIZE(x) \
+ (_SDT_ARGARRAY (x) ? sizeof (void *) : sizeof (x))
+# define _SDT_ARGVAL(x) (x)
+#endif
+
+#if defined __powerpc__ || defined __powerpc64__
+# define _SDT_ARGTMPL(id) %I[id]%[id]
+#elif defined __i386__
+# define _SDT_ARGTMPL(id) %k[id] /* gcc.gnu.org/PR80115 sourceware.org/PR24541 */
+#else
+# define _SDT_ARGTMPL(id) %[id]
+#endif
+
+/* NB: gdb PR24541 highlighted an unspecified corner of the sdt.h
+ operand note format.
+
+ The named register may be a longer or shorter (!) alias for the
+ storage where the value in question is found. For example, on
+ i386, 64-bit value may be put in register pairs, and the register
+ name stored would identify just one of them. Previously, gcc was
+ asked to emit the %w[id] (16-bit alias of some registers holding
+ operands), even when a wider 32-bit value was used.
+
+ Bottom line: the byte-width given before the @ sign governs. If
+ there is a mismatch between that width and that of the named
+ register, then a sys/sdt.h note consumer may need to employ
+ architecture-specific heuristics to figure out where the compiler
+ has actually put the complete value.
+*/
+
+#ifdef __LP64__
+# define _SDT_ASM_ADDR .8byte
+#else
+# define _SDT_ASM_ADDR .4byte
+#endif
+
+/* The ia64 and s390 nop instructions take an argument. */
+#if defined(__ia64__) || defined(__s390__) || defined(__s390x__)
+#define _SDT_NOP nop 0
+#else
+#define _SDT_NOP nop
+#endif
+
+#define _SDT_NOTE_NAME "stapsdt"
+#define _SDT_NOTE_TYPE 3
+
+/* If the assembler supports the necessary feature, then we can play
+ nice with code in COMDAT sections, which comes up in C++ code.
+ Without that assembler support, some combinations of probe placements
+ in certain kinds of C++ code may produce link-time errors. */
+#include "sdt-config.h"
+#if _SDT_ASM_SECTION_AUTOGROUP_SUPPORT
+# define _SDT_ASM_AUTOGROUP "?"
+#else
+# define _SDT_ASM_AUTOGROUP ""
+#endif
+
+#define _SDT_DEF_MACROS \
+ _SDT_ASM_1(.altmacro) \
+ _SDT_ASM_1(.macro _SDT_SIGN x) \
+ _SDT_ASM_3(.pushsection .note.stapsdt,"","note") \
+ _SDT_ASM_1(.iflt \\x) \
+ _SDT_ASM_1(.ascii "-") \
+ _SDT_ASM_1(.endif) \
+ _SDT_ASM_1(.popsection) \
+ _SDT_ASM_1(.endm) \
+ _SDT_ASM_1(.macro _SDT_SIZE_ x) \
+ _SDT_ASM_3(.pushsection .note.stapsdt,"","note") \
+ _SDT_ASM_1(.ascii "\x") \
+ _SDT_ASM_1(.popsection) \
+ _SDT_ASM_1(.endm) \
+ _SDT_ASM_1(.macro _SDT_SIZE x) \
+ _SDT_ASM_1(_SDT_SIZE_ %%((-(-\\x*((-\\x>0)-(-\\x<0))))>>8)) \
+ _SDT_ASM_1(.endm) \
+ _SDT_ASM_1(.macro _SDT_TYPE_ x) \
+ _SDT_ASM_3(.pushsection .note.stapsdt,"","note") \
+ _SDT_ASM_2(.ifc 8,\\x) \
+ _SDT_ASM_1(.ascii "f") \
+ _SDT_ASM_1(.endif) \
+ _SDT_ASM_1(.ascii "@") \
+ _SDT_ASM_1(.popsection) \
+ _SDT_ASM_1(.endm) \
+ _SDT_ASM_1(.macro _SDT_TYPE x) \
+ _SDT_ASM_1(_SDT_TYPE_ %%((\\x)&(0xff))) \
+ _SDT_ASM_1(.endm)
+
+#define _SDT_UNDEF_MACROS \
+ _SDT_ASM_1(.purgem _SDT_SIGN) \
+ _SDT_ASM_1(.purgem _SDT_SIZE_) \
+ _SDT_ASM_1(.purgem _SDT_SIZE) \
+ _SDT_ASM_1(.purgem _SDT_TYPE_) \
+ _SDT_ASM_1(.purgem _SDT_TYPE)
+
+#define _SDT_ASM_BODY(provider, name, pack_args, args, ...) \
+ _SDT_DEF_MACROS \
+ _SDT_ASM_1(990: _SDT_NOP) \
+ _SDT_ASM_3( .pushsection .note.stapsdt,_SDT_ASM_AUTOGROUP,"note") \
+ _SDT_ASM_1( .balign 4) \
+ _SDT_ASM_3( .4byte 992f-991f, 994f-993f, _SDT_NOTE_TYPE) \
+ _SDT_ASM_1(991: .asciz _SDT_NOTE_NAME) \
+ _SDT_ASM_1(992: .balign 4) \
+ _SDT_ASM_1(993: _SDT_ASM_ADDR 990b) \
+ _SDT_ASM_1( _SDT_ASM_ADDR _.stapsdt.base) \
+ _SDT_SEMAPHORE(provider,name) \
+ _SDT_ASM_STRING(provider) \
+ _SDT_ASM_STRING(name) \
+ pack_args args \
+ _SDT_ASM_SUBSTR(\x00) \
+ _SDT_UNDEF_MACROS \
+ _SDT_ASM_1(994: .balign 4) \
+ _SDT_ASM_1( .popsection)
+
+#define _SDT_ASM_BASE \
+ _SDT_ASM_1(.ifndef _.stapsdt.base) \
+ _SDT_ASM_5( .pushsection .stapsdt.base,"aG","progbits", \
+ .stapsdt.base,comdat) \
+ _SDT_ASM_1( .weak _.stapsdt.base) \
+ _SDT_ASM_1( .hidden _.stapsdt.base) \
+ _SDT_ASM_1( _.stapsdt.base: .space 1) \
+ _SDT_ASM_2( .size _.stapsdt.base, 1) \
+ _SDT_ASM_1( .popsection) \
+ _SDT_ASM_1(.endif)
+
+#if defined _SDT_HAS_SEMAPHORES
+#define _SDT_SEMAPHORE(p,n) \
+ _SDT_ASM_1( _SDT_ASM_ADDR p##_##n##_semaphore)
+#else
+#define _SDT_SEMAPHORE(p,n) _SDT_ASM_1( _SDT_ASM_ADDR 0)
+#endif
+
+#define _SDT_ASM_BLANK _SDT_ASM_SUBSTR(\x20)
+#define _SDT_ASM_TEMPLATE_0 /* no arguments */
+#define _SDT_ASM_TEMPLATE_1 _SDT_ARGFMT(1)
+#define _SDT_ASM_TEMPLATE_2 _SDT_ASM_TEMPLATE_1 _SDT_ASM_BLANK _SDT_ARGFMT(2)
+#define _SDT_ASM_TEMPLATE_3 _SDT_ASM_TEMPLATE_2 _SDT_ASM_BLANK _SDT_ARGFMT(3)
+#define _SDT_ASM_TEMPLATE_4 _SDT_ASM_TEMPLATE_3 _SDT_ASM_BLANK _SDT_ARGFMT(4)
+#define _SDT_ASM_TEMPLATE_5 _SDT_ASM_TEMPLATE_4 _SDT_ASM_BLANK _SDT_ARGFMT(5)
+#define _SDT_ASM_TEMPLATE_6 _SDT_ASM_TEMPLATE_5 _SDT_ASM_BLANK _SDT_ARGFMT(6)
+#define _SDT_ASM_TEMPLATE_7 _SDT_ASM_TEMPLATE_6 _SDT_ASM_BLANK _SDT_ARGFMT(7)
+#define _SDT_ASM_TEMPLATE_8 _SDT_ASM_TEMPLATE_7 _SDT_ASM_BLANK _SDT_ARGFMT(8)
+#define _SDT_ASM_TEMPLATE_9 _SDT_ASM_TEMPLATE_8 _SDT_ASM_BLANK _SDT_ARGFMT(9)
+#define _SDT_ASM_TEMPLATE_10 _SDT_ASM_TEMPLATE_9 _SDT_ASM_BLANK _SDT_ARGFMT(10)
+#define _SDT_ASM_TEMPLATE_11 _SDT_ASM_TEMPLATE_10 _SDT_ASM_BLANK _SDT_ARGFMT(11)
+#define _SDT_ASM_TEMPLATE_12 _SDT_ASM_TEMPLATE_11 _SDT_ASM_BLANK _SDT_ARGFMT(12)
+#define _SDT_ASM_OPERANDS_0() [__sdt_dummy] "g" (0)
+#define _SDT_ASM_OPERANDS_1(arg1) _SDT_ARG(1, arg1)
+#define _SDT_ASM_OPERANDS_2(arg1, arg2) \
+ _SDT_ASM_OPERANDS_1(arg1), _SDT_ARG(2, arg2)
+#define _SDT_ASM_OPERANDS_3(arg1, arg2, arg3) \
+ _SDT_ASM_OPERANDS_2(arg1, arg2), _SDT_ARG(3, arg3)
+#define _SDT_ASM_OPERANDS_4(arg1, arg2, arg3, arg4) \
+ _SDT_ASM_OPERANDS_3(arg1, arg2, arg3), _SDT_ARG(4, arg4)
+#define _SDT_ASM_OPERANDS_5(arg1, arg2, arg3, arg4, arg5) \
+ _SDT_ASM_OPERANDS_4(arg1, arg2, arg3, arg4), _SDT_ARG(5, arg5)
+#define _SDT_ASM_OPERANDS_6(arg1, arg2, arg3, arg4, arg5, arg6) \
+ _SDT_ASM_OPERANDS_5(arg1, arg2, arg3, arg4, arg5), _SDT_ARG(6, arg6)
+#define _SDT_ASM_OPERANDS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
+ _SDT_ASM_OPERANDS_6(arg1, arg2, arg3, arg4, arg5, arg6), _SDT_ARG(7, arg7)
+#define _SDT_ASM_OPERANDS_8(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
+ _SDT_ASM_OPERANDS_7(arg1, arg2, arg3, arg4, arg5, arg6, arg7), \
+ _SDT_ARG(8, arg8)
+#define _SDT_ASM_OPERANDS_9(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9) \
+ _SDT_ASM_OPERANDS_8(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8), \
+ _SDT_ARG(9, arg9)
+#define _SDT_ASM_OPERANDS_10(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10) \
+ _SDT_ASM_OPERANDS_9(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9), \
+ _SDT_ARG(10, arg10)
+#define _SDT_ASM_OPERANDS_11(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11) \
+ _SDT_ASM_OPERANDS_10(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10), \
+ _SDT_ARG(11, arg11)
+#define _SDT_ASM_OPERANDS_12(arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12) \
+ _SDT_ASM_OPERANDS_11(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9, arg10, arg11), \
+ _SDT_ARG(12, arg12)
+
+/* These macros can be used in C, C++, or assembly code.
+ In assembly code the arguments should use normal assembly operand syntax. */
+
+#define STAP_PROBE(provider, name) \
+ _SDT_PROBE(provider, name, 0, ())
+#define STAP_PROBE1(provider, name, arg1) \
+ _SDT_PROBE(provider, name, 1, (arg1))
+#define STAP_PROBE2(provider, name, arg1, arg2) \
+ _SDT_PROBE(provider, name, 2, (arg1, arg2))
+#define STAP_PROBE3(provider, name, arg1, arg2, arg3) \
+ _SDT_PROBE(provider, name, 3, (arg1, arg2, arg3))
+#define STAP_PROBE4(provider, name, arg1, arg2, arg3, arg4) \
+ _SDT_PROBE(provider, name, 4, (arg1, arg2, arg3, arg4))
+#define STAP_PROBE5(provider, name, arg1, arg2, arg3, arg4, arg5) \
+ _SDT_PROBE(provider, name, 5, (arg1, arg2, arg3, arg4, arg5))
+#define STAP_PROBE6(provider, name, arg1, arg2, arg3, arg4, arg5, arg6) \
+ _SDT_PROBE(provider, name, 6, (arg1, arg2, arg3, arg4, arg5, arg6))
+#define STAP_PROBE7(provider, name, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
+ _SDT_PROBE(provider, name, 7, (arg1, arg2, arg3, arg4, arg5, arg6, arg7))
+#define STAP_PROBE8(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8) \
+ _SDT_PROBE(provider, name, 8, (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8))
+#define STAP_PROBE9(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9)\
+ _SDT_PROBE(provider, name, 9, (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9))
+#define STAP_PROBE10(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10) \
+ _SDT_PROBE(provider, name, 10, \
+ (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10))
+#define STAP_PROBE11(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11) \
+ _SDT_PROBE(provider, name, 11, \
+ (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11))
+#define STAP_PROBE12(provider,name,arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12) \
+ _SDT_PROBE(provider, name, 12, \
+ (arg1,arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9,arg10,arg11,arg12))
+
+/* This STAP_PROBEV macro can be used in variadic scenarios, where the
+ number of probe arguments is not known until compile time. Since
+ variadic macro support may vary with compiler options, you must
+ pre-#define SDT_USE_VARIADIC to enable this type of probe.
+
+ The trick to count __VA_ARGS__ was inspired by this post by
+ Laurent Deniau <laurent.deniau@cern.ch>:
+ http://groups.google.com/group/comp.std.c/msg/346fc464319b1ee5
+
+ Note that our _SDT_NARG is called with an extra 0 arg that's not
+ counted, so we don't have to worry about the behavior of macros
+ called without any arguments. */
+
+#define _SDT_NARG(...) __SDT_NARG(__VA_ARGS__, 12,11,10,9,8,7,6,5,4,3,2,1,0)
+#define __SDT_NARG(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12, N, ...) N
+#ifdef SDT_USE_VARIADIC
+#define _SDT_PROBE_N(provider, name, N, ...) \
+ _SDT_PROBE(provider, name, N, (__VA_ARGS__))
+#define STAP_PROBEV(provider, name, ...) \
+ _SDT_PROBE_N(provider, name, _SDT_NARG(0, ##__VA_ARGS__), ##__VA_ARGS__)
+#endif
+
+/* These macros are for use in asm statements. You must compile
+ with -std=gnu99 or -std=c99 to use the STAP_PROBE_ASM macro.
+
+ The STAP_PROBE_ASM macro generates a quoted string to be used in the
+ template portion of the asm statement, concatenated with strings that
+ contain the actual assembly code around the probe site.
+
+ For example:
+
+ asm ("before\n"
+ STAP_PROBE_ASM(provider, fooprobe, %eax 4(%esi))
+ "after");
+
+ emits the assembly code for "before\nafter", with a probe in between.
+ The probe arguments are the %eax register, and the value of the memory
+ word located 4 bytes past the address in the %esi register. Note that
+ because this is a simple asm, not a GNU C extended asm statement, these
+ % characters do not need to be doubled to generate literal %reg names.
+
+ In a GNU C extended asm statement, the probe arguments can be specified
+ using the macro STAP_PROBE_ASM_TEMPLATE(n) for n arguments. The paired
+ macro STAP_PROBE_ASM_OPERANDS gives the C values of these probe arguments,
+ and appears in the input operand list of the asm statement. For example:
+
+ asm ("someinsn %0,%1\n" // %0 is output operand, %1 is input operand
+ STAP_PROBE_ASM(provider, fooprobe, STAP_PROBE_ASM_TEMPLATE(3))
+ "otherinsn %[namedarg]"
+ : "r" (outvar)
+ : "g" (some_value), [namedarg] "i" (1234),
+ STAP_PROBE_ASM_OPERANDS(3, some_value, some_ptr->field, 1234));
+
+ This is just like writing:
+
+ STAP_PROBE3(provider, fooprobe, some_value, some_ptr->field, 1234));
+
+ but the probe site is right between "someinsn" and "otherinsn".
+
+ The probe arguments in STAP_PROBE_ASM can be given as assembly
+ operands instead, even inside a GNU C extended asm statement.
+ Note that these can use operand templates like %0 or %[name],
+ and likewise they must write %%reg for a literal operand of %reg. */
+
+#define _SDT_ASM_BODY_1(p,n,...) _SDT_ASM_BODY(p,n,_SDT_ASM_SUBSTR,(__VA_ARGS__))
+#define _SDT_ASM_BODY_2(p,n,...) _SDT_ASM_BODY(p,n,/*_SDT_ASM_STRING */,__VA_ARGS__)
+#define _SDT_ASM_BODY_N2(p,n,no,...) _SDT_ASM_BODY_ ## no(p,n,__VA_ARGS__)
+#define _SDT_ASM_BODY_N1(p,n,no,...) _SDT_ASM_BODY_N2(p,n,no,__VA_ARGS__)
+#define _SDT_ASM_BODY_N(p,n,...) _SDT_ASM_BODY_N1(p,n,_SDT_NARG(0, __VA_ARGS__),__VA_ARGS__)
+
+#if __STDC_VERSION__ >= 199901L
+# define STAP_PROBE_ASM(provider, name, ...) \
+ _SDT_ASM_BODY_N(provider, name, __VA_ARGS__) \
+ _SDT_ASM_BASE
+# define STAP_PROBE_ASM_OPERANDS(n, ...) _SDT_ASM_OPERANDS_##n(__VA_ARGS__)
+#else
+# define STAP_PROBE_ASM(provider, name, args) \
+ _SDT_ASM_BODY(provider, name, /* _SDT_ASM_STRING */, (args)) \
+ _SDT_ASM_BASE
+#endif
+#define STAP_PROBE_ASM_TEMPLATE(n) _SDT_ASM_TEMPLATE_##n,"use _SDT_ASM_TEMPLATE_"
+
+
+/* DTrace compatible macro names. */
+#define DTRACE_PROBE(provider,probe) \
+ STAP_PROBE(provider,probe)
+#define DTRACE_PROBE1(provider,probe,parm1) \
+ STAP_PROBE1(provider,probe,parm1)
+#define DTRACE_PROBE2(provider,probe,parm1,parm2) \
+ STAP_PROBE2(provider,probe,parm1,parm2)
+#define DTRACE_PROBE3(provider,probe,parm1,parm2,parm3) \
+ STAP_PROBE3(provider,probe,parm1,parm2,parm3)
+#define DTRACE_PROBE4(provider,probe,parm1,parm2,parm3,parm4) \
+ STAP_PROBE4(provider,probe,parm1,parm2,parm3,parm4)
+#define DTRACE_PROBE5(provider,probe,parm1,parm2,parm3,parm4,parm5) \
+ STAP_PROBE5(provider,probe,parm1,parm2,parm3,parm4,parm5)
+#define DTRACE_PROBE6(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6) \
+ STAP_PROBE6(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6)
+#define DTRACE_PROBE7(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7) \
+ STAP_PROBE7(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7)
+#define DTRACE_PROBE8(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8) \
+ STAP_PROBE8(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8)
+#define DTRACE_PROBE9(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9) \
+ STAP_PROBE9(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9)
+#define DTRACE_PROBE10(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10) \
+ STAP_PROBE10(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10)
+#define DTRACE_PROBE11(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11) \
+ STAP_PROBE11(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11)
+#define DTRACE_PROBE12(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11,parm12) \
+ STAP_PROBE12(provider,probe,parm1,parm2,parm3,parm4,parm5,parm6,parm7,parm8,parm9,parm10,parm11,parm12)
+
+
+#endif /* sys/sdt.h */