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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 09:49:56 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-30 09:49:56 -0700
commit343a9f35409b68b6de66ecd0db90a277aee90ec2 (patch)
tree8f62088c78f3eb9ee1d0dab9f4cee0cf5f3878c6 /tools
parentf4267b3604a84ff72c013a0e3e467289908603a6 (diff)
parenta2acce536921bd793bae13fa344fcea157638e72 (diff)
downloadlinux-343a9f35409b68b6de66ecd0db90a277aee90ec2.tar.bz2
Merge tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt: "The biggest change here is the updates to kprobes Back in January I posted patches to create function based events. These were the events that you suggested I make to allow developers to easily create events in code where no trace event exists. After posting those changes for review, it was suggested that we implement this instead with kprobes. The problem with kprobes is that the interface is too complex and needs to be simplified. Masami Hiramatsu posted patches in March and I've been playing with them a bit. There's been a bit of clean up in the kprobe code that was inspired by the function based event patches, and a couple of enhancements to the kprobe event interface. - If the arch supports it (we added support for x86), you can place a kprobe event at the start of a function and use $arg1, $arg2, etc to reference the arguments of a function. (Before you needed to know what register or where on the stack the argument was). - The second is a way to see array of events. For example, if you reference a mac address, you can add: echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events And this will produce: mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec} Other changes include - Exporting trace_dump_stack to modules - Have the stack tracer trace the entire stack (stop trying to remove tracing itself, as we keep removing too much). - Added support for SDT in uprobes" [ SDT - "Statically Defined Tracing" are userspace markers for tracing. Let's not use random TLA's in explanations unless they are fairly well-established as generic (at least for kernel people) - Linus ] * tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits) tracing: Have stack tracer trace full stack tracing: Export trace_dump_stack to modules tracing: probeevent: Fix uninitialized used of offset in parse args tracing/kprobes: Allow kprobe-events to record module symbol tracing/kprobes: Check the probe on unloaded module correctly tracing/uprobes: Fix to return -EFAULT if copy_from_user failed tracing: probeevent: Add $argN for accessing function args x86: ptrace: Add function argument access API tracing: probeevent: Add array type support tracing: probeevent: Add symbol type tracing: probeevent: Unify fetch_insn processing common part tracing: probeevent: Append traceprobe_ for exported function tracing: probeevent: Return consumed bytes of dynamic area tracing: probeevent: Unify fetch type tables tracing: probeevent: Introduce new argument fetching code tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions tracing: probeevent: Cleanup argument field definition tracing: probeevent: Cleanup print argument functions trace_uprobe: support reference counter in fd-based uprobe perf probe: Support SDT markers having reference counter (semaphore) ...
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/probe-event.c39
-rw-r--r--tools/perf/util/probe-event.h1
-rw-r--r--tools/perf/util/probe-file.c34
-rw-r--r--tools/perf/util/probe-file.h1
-rw-r--r--tools/perf/util/symbol-elf.c46
-rw-r--r--tools/perf/util/symbol.h7
6 files changed, 106 insertions, 22 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f119eb628dbb..e86f8be89157 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1819,6 +1819,12 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
tp->offset = strtoul(fmt2_str, NULL, 10);
}
+ if (tev->uprobes) {
+ fmt2_str = strchr(p, '(');
+ if (fmt2_str)
+ tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0);
+ }
+
tev->nargs = argc - 2;
tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs);
if (tev->args == NULL) {
@@ -2012,6 +2018,22 @@ static int synthesize_probe_trace_arg(struct probe_trace_arg *arg,
return err;
}
+static int
+synthesize_uprobe_trace_def(struct probe_trace_event *tev, struct strbuf *buf)
+{
+ struct probe_trace_point *tp = &tev->point;
+ int err;
+
+ err = strbuf_addf(buf, "%s:0x%lx", tp->module, tp->address);
+
+ if (err >= 0 && tp->ref_ctr_offset) {
+ if (!uprobe_ref_ctr_is_supported())
+ return -1;
+ err = strbuf_addf(buf, "(0x%lx)", tp->ref_ctr_offset);
+ }
+ return err >= 0 ? 0 : -1;
+}
+
char *synthesize_probe_trace_command(struct probe_trace_event *tev)
{
struct probe_trace_point *tp = &tev->point;
@@ -2041,15 +2063,17 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev)
}
/* Use the tp->address for uprobes */
- if (tev->uprobes)
- err = strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address);
- else if (!strncmp(tp->symbol, "0x", 2))
+ if (tev->uprobes) {
+ err = synthesize_uprobe_trace_def(tev, &buf);
+ } else if (!strncmp(tp->symbol, "0x", 2)) {
/* Absolute address. See try_to_find_absolute_address() */
err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "",
tp->module ? ":" : "", tp->address);
- else
+ } else {
err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "",
tp->module ? ":" : "", tp->symbol, tp->offset);
+ }
+
if (err)
goto error;
@@ -2633,6 +2657,13 @@ static void warn_uprobe_event_compat(struct probe_trace_event *tev)
{
int i;
char *buf = synthesize_probe_trace_command(tev);
+ struct probe_trace_point *tp = &tev->point;
+
+ if (tp->ref_ctr_offset && !uprobe_ref_ctr_is_supported()) {
+ pr_warning("A semaphore is associated with %s:%s and "
+ "seems your kernel doesn't support it.\n",
+ tev->group, tev->event);
+ }
/* Old uprobe event doesn't support memory dereference */
if (!tev->uprobes || tev->nargs == 0 || !buf)
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 45b14f020558..15a98c3a2a2f 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -27,6 +27,7 @@ struct probe_trace_point {
char *symbol; /* Base symbol */
char *module; /* Module name */
unsigned long offset; /* Offset from symbol */
+ unsigned long ref_ctr_offset; /* SDT reference counter offset */
unsigned long address; /* Actual address of the trace point */
bool retprobe; /* Return probe flag */
};
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index b76088fadf3d..aac7817d9e14 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -696,8 +696,16 @@ out_err:
#ifdef HAVE_GELF_GETNOTE_SUPPORT
static unsigned long long sdt_note__get_addr(struct sdt_note *note)
{
- return note->bit32 ? (unsigned long long)note->addr.a32[0]
- : (unsigned long long)note->addr.a64[0];
+ return note->bit32 ?
+ (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] :
+ (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC];
+}
+
+static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note)
+{
+ return note->bit32 ?
+ (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] :
+ (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR];
}
static const char * const type_to_suffix[] = {
@@ -775,14 +783,21 @@ static char *synthesize_sdt_probe_command(struct sdt_note *note,
{
struct strbuf buf;
char *ret = NULL, **args;
- int i, args_count;
+ int i, args_count, err;
+ unsigned long long ref_ctr_offset;
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)
+ err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx",
+ sdtgrp, note->name, pathname,
+ sdt_note__get_addr(note));
+
+ ref_ctr_offset = sdt_note__get_ref_ctr_offset(note);
+ if (ref_ctr_offset && err >= 0)
+ err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset);
+
+ if (err < 0)
goto error;
if (!note->args)
@@ -998,6 +1013,7 @@ int probe_cache__show_all_caches(struct strfilter *filter)
enum ftrace_readme {
FTRACE_README_PROBE_TYPE_X = 0,
FTRACE_README_KRETPROBE_OFFSET,
+ FTRACE_README_UPROBE_REF_CTR,
FTRACE_README_END,
};
@@ -1009,6 +1025,7 @@ static struct {
[idx] = {.pattern = pat, .avail = false}
DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
+ DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
};
static bool scan_ftrace_readme(enum ftrace_readme type)
@@ -1064,3 +1081,8 @@ bool kretprobe_offset_is_supported(void)
{
return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
}
+
+bool uprobe_ref_ctr_is_supported(void)
+{
+ return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR);
+}
diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
index 63f29b1d22c1..2a249182f2a6 100644
--- a/tools/perf/util/probe-file.h
+++ b/tools/perf/util/probe-file.h
@@ -69,6 +69,7 @@ struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache,
int probe_cache__show_all_caches(struct strfilter *filter);
bool probe_type_is_available(enum probe_type type);
bool kretprobe_offset_is_supported(void);
+bool uprobe_ref_ctr_is_supported(void);
#else /* ! HAVE_LIBELF_SUPPORT */
static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused, struct nsinfo *nsi __maybe_unused)
{
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 29770ea61768..0281d5e2cd67 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1947,6 +1947,34 @@ void kcore_extract__delete(struct kcore_extract *kce)
}
#ifdef HAVE_GELF_GETNOTE_SUPPORT
+
+static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
+{
+ if (!base_off)
+ return;
+
+ if (tmp->bit32)
+ tmp->addr.a32[SDT_NOTE_IDX_LOC] =
+ tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
+ tmp->addr.a32[SDT_NOTE_IDX_BASE];
+ else
+ tmp->addr.a64[SDT_NOTE_IDX_LOC] =
+ tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
+ tmp->addr.a64[SDT_NOTE_IDX_BASE];
+}
+
+static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
+ GElf_Addr base_off)
+{
+ if (!base_off)
+ return;
+
+ if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
+ tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
+ else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
+ tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
+}
+
/**
* populate_sdt_note : Parse raw data and identify SDT note
* @elf: elf of the opened file
@@ -1964,7 +1992,6 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len,
const char *provider, *name, *args;
struct sdt_note *tmp = NULL;
GElf_Ehdr ehdr;
- GElf_Addr base_off = 0;
GElf_Shdr shdr;
int ret = -EINVAL;
@@ -2060,17 +2087,12 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len,
* base address in the description of the SDT note. If its different,
* then accordingly, adjust the note location.
*/
- if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) {
- base_off = shdr.sh_offset;
- if (base_off) {
- if (tmp->bit32)
- tmp->addr.a32[0] = tmp->addr.a32[0] + base_off -
- tmp->addr.a32[1];
- else
- tmp->addr.a64[0] = tmp->addr.a64[0] + base_off -
- tmp->addr.a64[1];
- }
- }
+ if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
+ sdt_adjust_loc(tmp, shdr.sh_offset);
+
+ /* Adjust reference counter offset */
+ if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
+ sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
list_add_tail(&tmp->note_list, sdt_notes);
return 0;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index f25fae4b5743..20f49779116b 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -379,12 +379,19 @@ int get_sdt_note_list(struct list_head *head, const char *target);
int cleanup_sdt_note_list(struct list_head *sdt_notes);
int sdt_notes__get_count(struct list_head *start);
+#define SDT_PROBES_SCN ".probes"
#define SDT_BASE_SCN ".stapsdt.base"
#define SDT_NOTE_SCN ".note.stapsdt"
#define SDT_NOTE_TYPE 3
#define SDT_NOTE_NAME "stapsdt"
#define NR_ADDR 3
+enum {
+ SDT_NOTE_IDX_LOC = 0,
+ SDT_NOTE_IDX_BASE,
+ SDT_NOTE_IDX_REFCTR,
+};
+
struct mem_info *mem_info__new(void);
struct mem_info *mem_info__get(struct mem_info *mi);
void mem_info__put(struct mem_info *mi);