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-rw-r--r--tools/perf/arch/x86/util/perf_regs.c83
-rw-r--r--tools/perf/util/perf_regs.c6
-rw-r--r--tools/perf/util/perf_regs.h6
-rw-r--r--tools/perf/util/probe-file.c170
4 files changed, 261 insertions, 4 deletions
diff --git a/tools/perf/arch/x86/util/perf_regs.c b/tools/perf/arch/x86/util/perf_regs.c
index c5db14f36cc7..09a7f556dc7c 100644
--- a/tools/perf/arch/x86/util/perf_regs.c
+++ b/tools/perf/arch/x86/util/perf_regs.c
@@ -1,4 +1,7 @@
+#include <string.h>
+
#include "../../perf.h"
+#include "../../util/util.h"
#include "../../util/perf_regs.h"
const struct sample_reg sample_reg_masks[] = {
@@ -26,3 +29,83 @@ const struct sample_reg sample_reg_masks[] = {
#endif
SMPL_REG_END
};
+
+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}
+
+static 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,
+};
+
+int sdt_rename_register(char **pdesc, char *old_name)
+{
+ const struct sdt_name_reg *rnames = sdt_reg_renamings;
+ char *new_desc, *old_desc = *pdesc;
+ size_t prefix_len, sdt_len, uprobe_len, old_desc_len, offset;
+ int ret = -1;
+
+ while (ret != 0 && rnames->sdt_name != NULL) {
+ sdt_len = strlen(rnames->sdt_name);
+ ret = strncmp(old_name, rnames->sdt_name, sdt_len);
+ rnames += !!ret;
+ }
+
+ if (rnames->sdt_name == NULL)
+ return 0;
+
+ sdt_len = strlen(rnames->sdt_name);
+ uprobe_len = strlen(rnames->uprobe_name);
+ old_desc_len = strlen(old_desc) + 1;
+
+ new_desc = zalloc(old_desc_len + uprobe_len - sdt_len);
+ if (new_desc == NULL)
+ return -1;
+
+ /* Copy the chars before the register name (at least '%') */
+ prefix_len = old_name - old_desc;
+ memcpy(new_desc, old_desc, prefix_len);
+
+ /* Copy the new register name */
+ memcpy(new_desc + prefix_len, rnames->uprobe_name, uprobe_len);
+
+ /* Copy the chars after the register name (if need be) */
+ offset = prefix_len + sdt_len;
+ if (offset < old_desc_len) {
+ /*
+ * The orginal register name can be suffixed by 'b',
+ * 'w' or 'd' to indicate its size; so, we need to
+ * skip this char if we met one.
+ */
+ char sfx = old_desc[offset];
+
+ if (sfx == 'b' || sfx == 'w' || sfx == 'd')
+ offset++;
+ }
+
+ if (offset < old_desc_len)
+ memcpy(new_desc + prefix_len + uprobe_len,
+ old_desc + offset, old_desc_len - offset);
+
+ free(old_desc);
+ *pdesc = new_desc;
+
+ return 0;
+}
diff --git a/tools/perf/util/perf_regs.c b/tools/perf/util/perf_regs.c
index c4023f22f287..a37e5934aa2a 100644
--- a/tools/perf/util/perf_regs.c
+++ b/tools/perf/util/perf_regs.c
@@ -6,6 +6,12 @@ const struct sample_reg __weak sample_reg_masks[] = {
SMPL_REG_END
};
+int __weak sdt_rename_register(char **pdesc __maybe_unused,
+ char *old_name __maybe_unused)
+{
+ return 0;
+}
+
#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 679d6e493962..7544a157e159 100644
--- a/tools/perf/util/perf_regs.h
+++ b/tools/perf/util/perf_regs.h
@@ -15,6 +15,12 @@ struct sample_reg {
extern const struct sample_reg sample_reg_masks[];
+/*
+ * The table sdt_reg_renamings is used for adjusting gcc/gas-generated
+ * registers before filling the uprobe tracer interface.
+ */
+int sdt_rename_register(char **pdesc, char *old_name);
+
#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 c3c287125be5..d741634cbfc0 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"
/* 4096 - 2 ('\n' + '\0') */
#define MAX_CMDLEN 4094
@@ -688,6 +689,166 @@ 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)
+{
+ char *tmp, *desc = strdup(arg);
+ const char *prefix = "", *suffix = "";
+ int ret = -1;
+
+ if (desc == NULL) {
+ pr_debug4("Allocation error\n");
+ return ret;
+ }
+
+ 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);
+ /* Check that the conversion went OK */
+ if (type_idx == LONG_MIN || type_idx == LONG_MAX) {
+ pr_debug4("Failed to parse sdt type\n");
+ goto error;
+ }
+ /* Check that the converted value is OK */
+ if (type_idx < -8 || type_idx > 8) {
+ pr_debug4("Failed to get a valid 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 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("Skipping unsupported SDT argument; %s\n", desc);
+ goto out;
+ }
+
+ /*
+ * If the argument addressing mode is indirect, we must check
+ * a few things...
+ */
+ tmp = strchr(desc, '(');
+ if (tmp) {
+ int j;
+
+ /*
+ * ...if the addressing mode is indirect with a
+ * positive offset (ex.: "1608(%ax)"), we need to add
+ * a '+' prefix so as to be compliant with uprobe
+ * format.
+ */
+ if (desc[0] != '+' && desc[0] != '-')
+ prefix = "+";
+
+ /*
+ * ...or if the addressing mode is indirect with a symbol
+ * as offset, the argument will not be supported by
+ * the uprobe tracer format; so, let's skip this one.
+ */
+ for (j = 0; j < tmp - desc; j++) {
+ if (desc[j] != '+' && desc[j] != '-' &&
+ !isdigit(desc[j])) {
+ pr_debug4("Skipping unsupported SDT argument; "
+ "%s\n", desc);
+ goto out;
+ }
+ }
+ }
+
+ /*
+ * The uprobe tracer format does not support constants; if we
+ * find one in the current argument, let's skip the argument.
+ */
+ if (strchr(desc, '$')) {
+ pr_debug4("Skipping unsupported SDT argument; %s\n", desc);
+ goto out;
+ }
+
+ /*
+ * 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 looks for the register names (starting with
+ * a '%' and tries to perform the needed renamings.
+ */
+ tmp = strchr(desc, '%');
+ while (tmp) {
+ size_t offset = tmp - desc;
+
+ ret = sdt_rename_register(&desc, desc + offset);
+ if (ret < 0)
+ goto error;
+
+ /*
+ * The desc pointer might have changed; so, let's not
+ * try to reuse tmp for next lookup
+ */
+ tmp = strchr(desc + offset + 1, '%');
+ }
+
+ if (strbuf_addf(buf, " arg%d=%s%s%s", i + 1, prefix, 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;
@@ -724,11 +885,12 @@ 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;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.