$ perf probe -x test_sdt sdt_libfoo:table_diddle
$ perf record -e sdt_libfoo:table_frob -e sdt_libfoo:table_diddle test_sdt
$ perf script
test_sdt ... 666.255678: sdt_libfoo:table_frob: (4004d7) arg0=0 arg1=0
test_sdt ... 666.255683: sdt_libfoo:table_diddle: (40051a) arg0=0 arg1=0
test_sdt ... 666.255686: sdt_libfoo:table_frob: (4004d7) arg0=1 arg1=2
test_sdt ... 666.255689: sdt_libfoo:table_diddle: (40051a) arg0=3 arg1=4
test_sdt ... 666.255692: sdt_libfoo:table_frob: (4004d7) arg0=2 arg1=4
test_sdt ... 666.255694: sdt_libfoo:table_diddle: (40051a) arg0=6 arg1=8
Signed-off-by: Alexis Berlemont <[email protected]>
---
tools/perf/arch/x86/util/perf_regs.c | 18 +++++
tools/perf/util/perf_regs.c | 4 +
tools/perf/util/perf_regs.h | 13 ++++
tools/perf/util/probe-file.c | 141 ++++++++++++++++++++++++++++++++++-
4 files changed, 172 insertions(+), 4 deletions(-)
diff --git a/tools/perf/arch/x86/util/perf_regs.c
b/tools/perf/arch/x86/util/perf_regs.c
index c5db14f..52a1e65 100644
--- a/tools/perf/arch/x86/util/perf_regs.c
+++ b/tools/perf/arch/x86/util/perf_regs.c
@@ -26,3 +26,21 @@ const struct sample_reg sample_reg_masks[] = {
#endif
SMPL_REG_END
};
+
+const struct sdt_name_reg sdt_reg_renamings[] = {
+ SDT_NAME_REG(eax, ax),
+ SDT_NAME_REG(rax, ax),
+ SDT_NAME_REG(ebx, bx),
+ SDT_NAME_REG(rbx, bx),
+ SDT_NAME_REG(ecx, cx),
+ SDT_NAME_REG(rcx, cx),
+ SDT_NAME_REG(edx, dx),
+ SDT_NAME_REG(rdx, dx),
+ SDT_NAME_REG(esi, si),
+ SDT_NAME_REG(rsi, si),
+ SDT_NAME_REG(edi, di),
+ SDT_NAME_REG(rdi, di),
+ SDT_NAME_REG(ebp, bp),
+ SDT_NAME_REG(rbp, bp),
+ SDT_NAME_REG_END,
+};
diff --git a/tools/perf/util/perf_regs.c b/tools/perf/util/perf_regs.c
index c4023f2..1c21150 100644
--- a/tools/perf/util/perf_regs.c
+++ b/tools/perf/util/perf_regs.c
@@ -6,6 +6,10 @@ const struct sample_reg __weak sample_reg_masks[] = {
SMPL_REG_END
};
+const struct sdt_name_reg __weak sdt_reg_renamings[] = {
+ SDT_NAME_REG_END,
+};
+
#ifdef HAVE_PERF_REGS_SUPPORT
int perf_reg_value(u64 *valp, struct regs_dump *regs, int id)
{
diff --git a/tools/perf/util/perf_regs.h b/tools/perf/util/perf_regs.h
index 679d6e4..41815ca 100644
--- a/tools/perf/util/perf_regs.h
+++ b/tools/perf/util/perf_regs.h
@@ -15,6 +15,19 @@ struct sample_reg {
extern const struct sample_reg sample_reg_masks[];
+struct sdt_name_reg {
+ const char *sdt_name;
+ const char *uprobe_name;
+};
+#define SDT_NAME_REG(n, m) {.sdt_name = "%" #n, .uprobe_name = "%" #m}
+#define SDT_NAME_REG_END {.sdt_name = NULL, .uprobe_name = NULL}
+
+/*
+ * The table sdt_reg_renamings is used for adjusting gcc/gas-generated
+ * registers before filling the uprobe tracer interface.
+ */
+extern const struct sdt_name_reg sdt_reg_renamings[];
+
#ifdef HAVE_PERF_REGS_SUPPORT
#include <perf_regs.h>
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 436b647..587763d 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -27,6 +27,7 @@
#include "probe-event.h"
#include "probe-file.h"
#include "session.h"
+#include "perf_regs.h"
#define MAX_CMDLEN 256
@@ -687,6 +688,137 @@ static unsigned long long sdt_note__get_addr(struct
sdt_note *note)
: (unsigned long long)note->addr.a64[0];
}
+static const char * const type_to_suffix[] = {
+ ":s64", "", "", "", ":s32", "", ":s16", ":s8",
+ "", ":u8", ":u16", "", ":u32", "", "", "", ":u64"
+};
+
+static int synthesize_sdt_probe_arg(struct strbuf *buf, int i, const char *arg)
+{
+ const struct sdt_name_reg *rnames;
+ char *tmp, *desc = strdup(arg);
+ const char *suffix = "";
+ int ret = -1;
+
+ if (desc == NULL) {
+ pr_debug4("Allocation error\n");
+ return ret;
+ }
+
+ /*
+ * The uprobe tracer format does not support all the
+ * addressing modes (notably: in x86 the scaled mode); so, we
+ * detect ',' characters, if there is just one, there is no
+ * use converting the sdt arg into a uprobe one.
+ */
+ if (strchr(desc, ',')) {
+ pr_debug4("SDT argument format not supported\n");
+ goto out;
+ }
+
+ tmp = strchr(desc, '@');
+ if (tmp) {
+ long type_idx;
+ /*
+ * Isolate the string number and convert it into a
+ * binary value; this will be an index to get suffix
+ * of the uprobe name (defining the type)
+ */
+ tmp[0] = '\0';
+ type_idx = strtol(desc, NULL, 10);
+ if (type_idx == LONG_MIN ||
+ type_idx == LONG_MAX) {
+ pr_debug4("Failed to get sdt type\n");
+ goto error;
+ }
+ suffix = type_to_suffix[type_idx + 8];
+ /* Get rid of the sdt prefix which is now useless */
+ tmp++;
+ memmove(desc, tmp, strlen(tmp) + 1);
+ }
+
+ /*
+ * The uprobe parser does not support all gas register names;
+ * so, we have to replace them (ex. for x86_64: %rax -> %ax);
+ * the loop below performs all the needed renamings if needed.
+ */
+
+ for (rnames = sdt_reg_renamings; rnames->sdt_name != NULL; rnames++) {
+ char *new_desc, *sdt_name;
+ size_t prefix_len, uprobe_len, mid_ofs, desc_len;
+
+ sdt_name = strstr(desc, rnames->sdt_name);
+ if (sdt_name == NULL)
+ continue;
+
+ new_desc = zalloc(strlen(desc) + 1 +
+ strlen(rnames->uprobe_name) -
+ strlen(rnames->sdt_name));
+ if (new_desc == NULL)
+ goto error;
+
+ prefix_len = sdt_name - desc;
+ if (prefix_len != 0)
+ memcpy(new_desc, desc, prefix_len);
+
+ uprobe_len = strlen(rnames->uprobe_name);
+ memcpy(new_desc + prefix_len, rnames->uprobe_name, uprobe_len);
+
+ mid_ofs = prefix_len + strlen(rnames->sdt_name);
+ desc_len = strlen(desc);
+ if (mid_ofs < desc_len)
+ memcpy(new_desc + prefix_len + uprobe_len,
+ desc + mid_ofs, desc_len - mid_ofs);
+
+ free(desc);
+ desc = new_desc;
+ }
+
+ if (strbuf_addf(buf, " arg%d=%s%s", i, desc, suffix) < 0)
+ goto error;
+
+out:
+ ret = 0;
+error:
+ free(desc);
+ return ret;
+}
+
+static char *synthesize_sdt_probe_command(struct sdt_note *note,
+ const char *pathname,
+ const char *sdtgrp)
+{
+ struct strbuf buf;
+ char *ret = NULL, **args;
+ int i, args_count;
+
+ if (strbuf_init(&buf, 32) < 0)
+ return NULL;
+
+ if (strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
+ sdtgrp, note->name, pathname,
+ sdt_note__get_addr(note)) < 0)
+ goto error;
+
+ if (!note->args)
+ goto out;
+
+ if (note->args) {
+ args = argv_split(note->args, &args_count);
+
+ for (i = 0; i < args_count; ++i) {
+ if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0)
+ goto error;
+ }
+ }
+
+out:
+ ret = strbuf_detach(&buf, NULL);
+error:
+ strbuf_release(&buf);
+ return ret;
+}
+
int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname)
{
struct probe_cache_entry *entry = NULL;
@@ -723,11 +855,12 @@ int probe_cache__scan_sdt(struct probe_cache *pcache,
const char *pathname)
entry->pev.group = strdup(sdtgrp);
list_add_tail(&entry->node, &pcache->entries);
}
- ret = asprintf(&buf, "p:%s/%s %s:0x%llx",
- sdtgrp, note->name, pathname,
- sdt_note__get_addr(note));
- if (ret < 0)
+ buf = synthesize_sdt_probe_command(note, pathname, sdtgrp);
+ if (!buf) {
+ ret = -ENOMEM;
break;
+ }
+
strlist__add(entry->tevlist, buf);
free(buf);
entry = NULL;
