* [PATCH -perf/perf/core 0/4] Perf probe/kprobe-tracer update (support bitfield, etc)
@ 2011-02-04 12:51 Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 1/4] tracing/kprobes: Cleanup strict_strtol() using code Masami Hiramatsu
` (3 more replies)
0 siblings, 4 replies; 9+ messages in thread
From: Masami Hiramatsu @ 2011-02-04 12:51 UTC (permalink / raw
To: Arnaldo Carvalho de Melo, Ingo Molnar
Cc: Steven Rostedt, Srikar Dronamraju, linux-kernel, 2nddept-manager
Hi,
This series enhances perf-probe and kprobe-tracer to support
accessing bitfield and extending command-line buffer.
I'm not sure which tree(-tip or -perf/core) I should push into
this series ... anyway, this can be applied both of them;-)
Thank you,
---
Masami Hiramatsu (4):
perf/probe: Add bitfield member support
tracing/kprobes: Add bitfield type
tracing/kprobes: support longer(>128) command
tracing/kprobes: Cleanup strict_strtol() using code
Documentation/trace/kprobetrace.txt | 16 +++++
kernel/trace/trace_kprobe.c | 111 +++++++++++++++++++++++++++++++++--
tools/perf/util/probe-finder.c | 95 +++++++++++++++++++++---------
3 files changed, 189 insertions(+), 33 deletions(-)
--
Masami HIRAMATSU
2nd Dept. Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH -perf/perf/core 1/4] tracing/kprobes: Cleanup strict_strtol() using code
2011-02-04 12:51 [PATCH -perf/perf/core 0/4] Perf probe/kprobe-tracer update (support bitfield, etc) Masami Hiramatsu
@ 2011-02-04 12:51 ` Masami Hiramatsu
2011-02-08 15:16 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 2/4] tracing/kprobes: support longer(>128) command Masami Hiramatsu
` (2 subsequent siblings)
3 siblings, 1 reply; 9+ messages in thread
From: Masami Hiramatsu @ 2011-02-04 12:51 UTC (permalink / raw
To: Arnaldo Carvalho de Melo, Ingo Molnar
Cc: Steven Rostedt, Srikar Dronamraju, linux-kernel, 2nddept-manager,
Masami Hiramatsu, Steven Rostedt, Frederic Weisbecker,
Ingo Molnar, linux-kernel
Since strict_strtol() accepts minus digits started with '-',
it doesn' need to invert after converting.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
---
kernel/trace/trace_kprobe.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2dec9bc..2088893 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -767,16 +767,15 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
}
break;
case '+': /* deref memory */
+ arg++; /* Skip '+', because strict_strtol() rejects it. */
case '-':
tmp = strchr(arg, '(');
if (!tmp)
break;
*tmp = '\0';
- ret = strict_strtol(arg + 1, 0, &offset);
+ ret = strict_strtol(arg, 0, &offset);
if (ret)
break;
- if (arg[0] == '-')
- offset = -offset;
arg = tmp + 1;
tmp = strrchr(arg, ')');
if (tmp) {
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH -perf/perf/core 2/4] tracing/kprobes: support longer(>128) command
2011-02-04 12:51 [PATCH -perf/perf/core 0/4] Perf probe/kprobe-tracer update (support bitfield, etc) Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 1/4] tracing/kprobes: Cleanup strict_strtol() using code Masami Hiramatsu
@ 2011-02-04 12:51 ` Masami Hiramatsu
2011-02-08 15:17 ` [tip:perf/core] tracing/kprobes: Support longer (>128 bytes) command tip-bot for Masami Hiramatsu
2011-02-04 12:52 ` [PATCH -perf/perf/core 3/4] tracing/kprobes: Add bitfield type Masami Hiramatsu
2011-02-04 12:52 ` [PATCH -perf/perf/core 4/4] perf/probe: Add bitfield member support Masami Hiramatsu
3 siblings, 1 reply; 9+ messages in thread
From: Masami Hiramatsu @ 2011-02-04 12:51 UTC (permalink / raw
To: Arnaldo Carvalho de Melo, Ingo Molnar
Cc: Steven Rostedt, Srikar Dronamraju, linux-kernel, 2nddept-manager,
Masami Hiramatsu, Steven Rostedt, Frederic Weisbecker,
Ingo Molnar, linux-kernel
Expand command line buffer of kprobe-tracer to 4096 bytes.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
---
kernel/trace/trace_kprobe.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2088893..c6ed886 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1129,7 +1129,7 @@ static int command_trace_probe(const char *buf)
return ret;
}
-#define WRITE_BUFSIZE 128
+#define WRITE_BUFSIZE 4096
static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH -perf/perf/core 3/4] tracing/kprobes: Add bitfield type
2011-02-04 12:51 [PATCH -perf/perf/core 0/4] Perf probe/kprobe-tracer update (support bitfield, etc) Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 1/4] tracing/kprobes: Cleanup strict_strtol() using code Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 2/4] tracing/kprobes: support longer(>128) command Masami Hiramatsu
@ 2011-02-04 12:52 ` Masami Hiramatsu
2011-02-08 15:17 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2011-02-04 12:52 ` [PATCH -perf/perf/core 4/4] perf/probe: Add bitfield member support Masami Hiramatsu
3 siblings, 1 reply; 9+ messages in thread
From: Masami Hiramatsu @ 2011-02-04 12:52 UTC (permalink / raw
To: Arnaldo Carvalho de Melo, Ingo Molnar
Cc: Steven Rostedt, Srikar Dronamraju, linux-kernel, 2nddept-manager,
Masami Hiramatsu, Steven Rostedt, Frederic Weisbecker,
Ingo Molnar, Arnaldo Carvalho de Melo, linux-kernel
Add bitfield type for tracing arguments on kprobe-tracer.
The syntax of a bitfield type is;
b<bit-size>@<bit-offset>/<container-size>
e.g.
Accessing 2 bits-width field with 4 bits-offset in
32 bits-width data at 4 bytes offseted from the address
pointed by AX register,
+4(%ax):b2@4/32
Since the width of container data depends on the arch,
so I just added the container-size at the end.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: linux-kernel@vger.kernel.org
---
Documentation/trace/kprobetrace.txt | 16 +++++
kernel/trace/trace_kprobe.c | 104 +++++++++++++++++++++++++++++++++++
2 files changed, 118 insertions(+), 2 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index 5f77d94..52303af 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -42,11 +42,25 @@ Synopsis of kprobe_events
+|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
- (u8/u16/u32/u64/s8/s16/s32/s64) and string are supported.
+ (u8/u16/u32/u64/s8/s16/s32/s64), "string" and bitfield
+ are supported.
(*) only for return probe.
(**) this is useful for fetching a field of data structures.
+Types
+-----
+Several types are supported for fetch-args. Kprobe tracer will access memory
+by given type. Prefix 's' and 'u' means those types are singed and unsigned
+respectively. Traced arguments are shown in decimal (signed) or hex (unsigned).
+String type is a special type, which fetches a "null-terminated" string from
+kernel space. This means it will fail and store NULL if the string container
+has been paged out.
+Bitfield is another special type, which takes 3 parameters, bit-width, bit-
+offset, and container-size (usually 32). The syntax is;
+
+ b<bit-width>@<bit-offset>/<container-size>
+
Per-Probe Event Filtering
-------------------------
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c6ed886..ccdc542 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -353,6 +353,43 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
kfree(data);
}
+/* Bitfield fetch function */
+struct bitfield_fetch_param {
+ struct fetch_param orig;
+ unsigned char hi_shift;
+ unsigned char low_shift;
+};
+
+#define DEFINE_FETCH_bitfield(type) \
+static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct bitfield_fetch_param *bprm = data; \
+ type buf = 0; \
+ call_fetch(&bprm->orig, regs, &buf); \
+ if (buf) { \
+ buf <<= bprm->hi_shift; \
+ buf >>= bprm->low_shift; \
+ } \
+ *(type *)dest = buf; \
+}
+DEFINE_BASIC_FETCH_FUNCS(bitfield)
+#define fetch_bitfield_string NULL
+#define fetch_bitfield_string_size NULL
+
+static __kprobes void
+free_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+ /*
+ * Don't check the bitfield itself, because this must be the
+ * last fetch function.
+ */
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ free_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ free_symbol_cache(data->orig.data);
+ kfree(data);
+}
/* Default (unsigned long) fetch type */
#define __DEFAULT_FETCH_TYPE(t) u##t
#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -367,6 +404,7 @@ enum {
FETCH_MTD_memory,
FETCH_MTD_symbol,
FETCH_MTD_deref,
+ FETCH_MTD_bitfield,
FETCH_MTD_END,
};
@@ -387,6 +425,7 @@ ASSIGN_FETCH_FUNC(retval, ftype), \
ASSIGN_FETCH_FUNC(memory, ftype), \
ASSIGN_FETCH_FUNC(symbol, ftype), \
ASSIGN_FETCH_FUNC(deref, ftype), \
+ASSIGN_FETCH_FUNC(bitfield, ftype), \
} \
}
@@ -430,9 +469,33 @@ static const struct fetch_type *find_fetch_type(const char *type)
if (!type)
type = DEFAULT_FETCH_TYPE_STR;
+ /* Special case: bitfield */
+ if (*type == 'b') {
+ unsigned long bs;
+ type = strchr(type, '/');
+ if (!type)
+ goto fail;
+ type++;
+ if (strict_strtoul(type, 0, &bs))
+ goto fail;
+ switch (bs) {
+ case 8:
+ return find_fetch_type("u8");
+ case 16:
+ return find_fetch_type("u16");
+ case 32:
+ return find_fetch_type("u32");
+ case 64:
+ return find_fetch_type("u64");
+ default:
+ goto fail;
+ }
+ }
+
for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
if (strcmp(type, fetch_type_table[i].name) == 0)
return &fetch_type_table[i];
+fail:
return NULL;
}
@@ -586,7 +649,9 @@ error:
static void free_probe_arg(struct probe_arg *arg)
{
- if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+ if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+ free_bitfield_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
free_deref_fetch_param(arg->fetch.data);
else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
free_symbol_cache(arg->fetch.data);
@@ -806,6 +871,41 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
return ret;
}
+#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
+
+/* Bitfield type needs to be parsed into a fetch function */
+static int __parse_bitfield_probe_arg(const char *bf,
+ const struct fetch_type *t,
+ struct fetch_param *f)
+{
+ struct bitfield_fetch_param *bprm;
+ unsigned long bw, bo;
+ char *tail;
+
+ if (*bf != 'b')
+ return 0;
+
+ bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
+ if (!bprm)
+ return -ENOMEM;
+ bprm->orig = *f;
+ f->fn = t->fetch[FETCH_MTD_bitfield];
+ f->data = (void *)bprm;
+
+ bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
+ if (bw == 0 || *tail != '@')
+ return -EINVAL;
+
+ bf = tail + 1;
+ bo = simple_strtoul(bf, &tail, 0);
+ if (tail == bf || *tail != '/')
+ return -EINVAL;
+
+ bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
+ bprm->low_shift = bprm->hi_shift + bo;
+ return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
+}
+
/* String length checking wrapper */
static int parse_probe_arg(char *arg, struct trace_probe *tp,
struct probe_arg *parg, int is_return)
@@ -835,6 +935,8 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp,
parg->offset = tp->size;
tp->size += parg->type->size;
ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+ if (ret >= 0)
+ ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
if (ret >= 0) {
parg->fetch_size.fn = get_fetch_size_function(parg->type,
parg->fetch.fn);
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH -perf/perf/core 4/4] perf/probe: Add bitfield member support
2011-02-04 12:51 [PATCH -perf/perf/core 0/4] Perf probe/kprobe-tracer update (support bitfield, etc) Masami Hiramatsu
` (2 preceding siblings ...)
2011-02-04 12:52 ` [PATCH -perf/perf/core 3/4] tracing/kprobes: Add bitfield type Masami Hiramatsu
@ 2011-02-04 12:52 ` Masami Hiramatsu
2011-02-08 15:18 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
3 siblings, 1 reply; 9+ messages in thread
From: Masami Hiramatsu @ 2011-02-04 12:52 UTC (permalink / raw
To: Arnaldo Carvalho de Melo, Ingo Molnar
Cc: Steven Rostedt, Srikar Dronamraju, linux-kernel, 2nddept-manager,
Masami Hiramatsu, Peter Zijlstra, Paul Mackerras, Ingo Molnar,
linux-kernel
Add bitfield member accessing support to probe arguments.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: linux-kernel@vger.kernel.org
---
tools/perf/util/probe-finder.c | 95 +++++++++++++++++++++++++++++-----------
1 files changed, 68 insertions(+), 27 deletions(-)
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 69215bf..613e5fb 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -33,6 +33,7 @@
#include <ctype.h>
#include <dwarf-regs.h>
+#include <linux/bitops.h>
#include "event.h"
#include "debug.h"
#include "util.h"
@@ -333,13 +334,23 @@ static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
return vr_die;
}
-static bool die_is_signed_type(Dwarf_Die *tp_die)
+static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
+ Dwarf_Word *result)
{
Dwarf_Attribute attr;
+
+ if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
+ dwarf_formudata(&attr, result) != 0)
+ return -ENOENT;
+
+ return 0;
+}
+
+static bool die_is_signed_type(Dwarf_Die *tp_die)
+{
Dwarf_Word ret;
- if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
- dwarf_formudata(&attr, &ret) != 0)
+ if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
return false;
return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
@@ -348,11 +359,29 @@ static bool die_is_signed_type(Dwarf_Die *tp_die)
static int die_get_byte_size(Dwarf_Die *tp_die)
{
- Dwarf_Attribute attr;
Dwarf_Word ret;
- if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
- dwarf_formudata(&attr, &ret) != 0)
+ if (die_get_attr_udata(tp_die, DW_AT_byte_size, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+static int die_get_bit_size(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_bit_size, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+static int die_get_bit_offset(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_bit_offset, &ret))
return 0;
return (int)ret;
@@ -827,6 +856,8 @@ static_var:
return 0;
}
+#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
+
static int convert_variable_type(Dwarf_Die *vr_die,
struct probe_trace_arg *tvar,
const char *cast)
@@ -843,6 +874,14 @@ static int convert_variable_type(Dwarf_Die *vr_die,
return (tvar->type == NULL) ? -ENOMEM : 0;
}
+ if (die_get_bit_size(vr_die) != 0) {
+ /* This is a bitfield */
+ ret = snprintf(buf, 16, "b%d@%d/%lu", die_get_bit_size(vr_die),
+ die_get_bit_offset(vr_die),
+ BYTES_TO_BITS(die_get_byte_size(vr_die)));
+ goto formatted;
+ }
+
if (die_get_real_type(vr_die, &type) == NULL) {
pr_warning("Failed to get a type information of %s.\n",
dwarf_diename(vr_die));
@@ -887,29 +926,31 @@ static int convert_variable_type(Dwarf_Die *vr_die,
return (tvar->type == NULL) ? -ENOMEM : 0;
}
- ret = die_get_byte_size(&type) * 8;
- if (ret) {
- /* Check the bitwidth */
- if (ret > MAX_BASIC_TYPE_BITS) {
- pr_info("%s exceeds max-bitwidth."
- " Cut down to %d bits.\n",
- dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
- ret = MAX_BASIC_TYPE_BITS;
- }
+ ret = BYTES_TO_BITS(die_get_byte_size(&type));
+ if (!ret)
+ /* No size ... try to use default type */
+ return 0;
- ret = snprintf(buf, 16, "%c%d",
- die_is_signed_type(&type) ? 's' : 'u', ret);
- if (ret < 0 || ret >= 16) {
- if (ret >= 16)
- ret = -E2BIG;
- pr_warning("Failed to convert variable type: %s\n",
- strerror(-ret));
- return ret;
- }
- tvar->type = strdup(buf);
- if (tvar->type == NULL)
- return -ENOMEM;
+ /* Check the bitwidth */
+ if (ret > MAX_BASIC_TYPE_BITS) {
+ pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
+ dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
+ ret = MAX_BASIC_TYPE_BITS;
+ }
+ ret = snprintf(buf, 16, "%c%d",
+ die_is_signed_type(&type) ? 's' : 'u', ret);
+
+formatted:
+ if (ret < 0 || ret >= 16) {
+ if (ret >= 16)
+ ret = -E2BIG;
+ pr_warning("Failed to convert variable type: %s\n",
+ strerror(-ret));
+ return ret;
}
+ tvar->type = strdup(buf);
+ if (tvar->type == NULL)
+ return -ENOMEM;
return 0;
}
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [tip:perf/core] tracing/kprobes: Cleanup strict_strtol() using code
2011-02-04 12:51 ` [PATCH -perf/perf/core 1/4] tracing/kprobes: Cleanup strict_strtol() using code Masami Hiramatsu
@ 2011-02-08 15:16 ` tip-bot for Masami Hiramatsu
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot for Masami Hiramatsu @ 2011-02-08 15:16 UTC (permalink / raw
To: linux-tip-commits
Cc: acme, linux-kernel, hpa, mingo, masami.hiramatsu.pt, fweisbec,
rostedt, srikar, tglx, mingo
Commit-ID: 76022db323dd6d7c6958df3d595f7dedf7a14778
Gitweb: http://git.kernel.org/tip/76022db323dd6d7c6958df3d595f7dedf7a14778
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Fri, 4 Feb 2011 21:51:53 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 7 Feb 2011 09:13:36 -0200
tracing/kprobes: Cleanup strict_strtol() using code
Since strict_strtol() accepts minus digits started with '-', it doesn't
need to invert after converting.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110204125153.9507.49335.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
kernel/trace/trace_kprobe.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2dec9bc..2088893 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -767,16 +767,15 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
}
break;
case '+': /* deref memory */
+ arg++; /* Skip '+', because strict_strtol() rejects it. */
case '-':
tmp = strchr(arg, '(');
if (!tmp)
break;
*tmp = '\0';
- ret = strict_strtol(arg + 1, 0, &offset);
+ ret = strict_strtol(arg, 0, &offset);
if (ret)
break;
- if (arg[0] == '-')
- offset = -offset;
arg = tmp + 1;
tmp = strrchr(arg, ')');
if (tmp) {
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [tip:perf/core] tracing/kprobes: Support longer (>128 bytes) command
2011-02-04 12:51 ` [PATCH -perf/perf/core 2/4] tracing/kprobes: support longer(>128) command Masami Hiramatsu
@ 2011-02-08 15:17 ` tip-bot for Masami Hiramatsu
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot for Masami Hiramatsu @ 2011-02-08 15:17 UTC (permalink / raw
To: linux-tip-commits
Cc: acme, linux-kernel, hpa, mingo, acme, masami.hiramatsu.pt,
fweisbec, rostedt, srikar, tglx, mingo
Commit-ID: e3745369986ddcdaa19f70e2d24e658876b97e84
Gitweb: http://git.kernel.org/tip/e3745369986ddcdaa19f70e2d24e658876b97e84
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Fri, 4 Feb 2011 21:51:59 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 7 Feb 2011 09:15:59 -0200
tracing/kprobes: Support longer (>128 bytes) command
Expand command line buffer of kprobe-tracer to 4096 bytes.
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110204125159.9507.20895.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
kernel/trace/trace_kprobe.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 2088893..c6ed886 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1129,7 +1129,7 @@ static int command_trace_probe(const char *buf)
return ret;
}
-#define WRITE_BUFSIZE 128
+#define WRITE_BUFSIZE 4096
static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [tip:perf/core] tracing/kprobes: Add bitfield type
2011-02-04 12:52 ` [PATCH -perf/perf/core 3/4] tracing/kprobes: Add bitfield type Masami Hiramatsu
@ 2011-02-08 15:17 ` tip-bot for Masami Hiramatsu
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot for Masami Hiramatsu @ 2011-02-08 15:17 UTC (permalink / raw
To: linux-tip-commits
Cc: acme, linux-kernel, hpa, mingo, masami.hiramatsu.pt, fweisbec,
rostedt, srikar, tglx, mingo
Commit-ID: 1ff511e35ed87cc2ebade9e678e4a2fe39b6f9c5
Gitweb: http://git.kernel.org/tip/1ff511e35ed87cc2ebade9e678e4a2fe39b6f9c5
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Fri, 4 Feb 2011 21:52:05 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 7 Feb 2011 09:18:11 -0200
tracing/kprobes: Add bitfield type
Add bitfield type for tracing arguments on kprobe-tracer. The syntax of
a bitfield type is:
b<bit-size>@<bit-offset>/<container-size>
e.g.
Accessing 2 bits-width field with 4 bits-offset in 32 bits-width data at
4 bytes offseted from the address pointed by AX register:
+4(%ax):b2@4/32
Since the width of container data depends on the arch, so I just added
the container-size at the end.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110204125205.9507.11363.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
Documentation/trace/kprobetrace.txt | 16 +++++-
kernel/trace/trace_kprobe.c | 104 ++++++++++++++++++++++++++++++++++-
2 files changed, 118 insertions(+), 2 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index 5f77d94..6d27ab8 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -42,11 +42,25 @@ Synopsis of kprobe_events
+|-offs(FETCHARG) : Fetch memory at FETCHARG +|- offs address.(**)
NAME=FETCHARG : Set NAME as the argument name of FETCHARG.
FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types
- (u8/u16/u32/u64/s8/s16/s32/s64) and string are supported.
+ (u8/u16/u32/u64/s8/s16/s32/s64), "string" and bitfield
+ are supported.
(*) only for return probe.
(**) this is useful for fetching a field of data structures.
+Types
+-----
+Several types are supported for fetch-args. Kprobe tracer will access memory
+by given type. Prefix 's' and 'u' means those types are signed and unsigned
+respectively. Traced arguments are shown in decimal (signed) or hex (unsigned).
+String type is a special type, which fetches a "null-terminated" string from
+kernel space. This means it will fail and store NULL if the string container
+has been paged out.
+Bitfield is another special type, which takes 3 parameters, bit-width, bit-
+offset, and container-size (usually 32). The syntax is;
+
+ b<bit-width>@<bit-offset>/<container-size>
+
Per-Probe Event Filtering
-------------------------
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c6ed886..ccdc542 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -353,6 +353,43 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data)
kfree(data);
}
+/* Bitfield fetch function */
+struct bitfield_fetch_param {
+ struct fetch_param orig;
+ unsigned char hi_shift;
+ unsigned char low_shift;
+};
+
+#define DEFINE_FETCH_bitfield(type) \
+static __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
+ void *data, void *dest) \
+{ \
+ struct bitfield_fetch_param *bprm = data; \
+ type buf = 0; \
+ call_fetch(&bprm->orig, regs, &buf); \
+ if (buf) { \
+ buf <<= bprm->hi_shift; \
+ buf >>= bprm->low_shift; \
+ } \
+ *(type *)dest = buf; \
+}
+DEFINE_BASIC_FETCH_FUNCS(bitfield)
+#define fetch_bitfield_string NULL
+#define fetch_bitfield_string_size NULL
+
+static __kprobes void
+free_bitfield_fetch_param(struct bitfield_fetch_param *data)
+{
+ /*
+ * Don't check the bitfield itself, because this must be the
+ * last fetch function.
+ */
+ if (CHECK_FETCH_FUNCS(deref, data->orig.fn))
+ free_deref_fetch_param(data->orig.data);
+ else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn))
+ free_symbol_cache(data->orig.data);
+ kfree(data);
+}
/* Default (unsigned long) fetch type */
#define __DEFAULT_FETCH_TYPE(t) u##t
#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
@@ -367,6 +404,7 @@ enum {
FETCH_MTD_memory,
FETCH_MTD_symbol,
FETCH_MTD_deref,
+ FETCH_MTD_bitfield,
FETCH_MTD_END,
};
@@ -387,6 +425,7 @@ ASSIGN_FETCH_FUNC(retval, ftype), \
ASSIGN_FETCH_FUNC(memory, ftype), \
ASSIGN_FETCH_FUNC(symbol, ftype), \
ASSIGN_FETCH_FUNC(deref, ftype), \
+ASSIGN_FETCH_FUNC(bitfield, ftype), \
} \
}
@@ -430,9 +469,33 @@ static const struct fetch_type *find_fetch_type(const char *type)
if (!type)
type = DEFAULT_FETCH_TYPE_STR;
+ /* Special case: bitfield */
+ if (*type == 'b') {
+ unsigned long bs;
+ type = strchr(type, '/');
+ if (!type)
+ goto fail;
+ type++;
+ if (strict_strtoul(type, 0, &bs))
+ goto fail;
+ switch (bs) {
+ case 8:
+ return find_fetch_type("u8");
+ case 16:
+ return find_fetch_type("u16");
+ case 32:
+ return find_fetch_type("u32");
+ case 64:
+ return find_fetch_type("u64");
+ default:
+ goto fail;
+ }
+ }
+
for (i = 0; i < ARRAY_SIZE(fetch_type_table); i++)
if (strcmp(type, fetch_type_table[i].name) == 0)
return &fetch_type_table[i];
+fail:
return NULL;
}
@@ -586,7 +649,9 @@ error:
static void free_probe_arg(struct probe_arg *arg)
{
- if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
+ if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn))
+ free_bitfield_fetch_param(arg->fetch.data);
+ else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn))
free_deref_fetch_param(arg->fetch.data);
else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn))
free_symbol_cache(arg->fetch.data);
@@ -806,6 +871,41 @@ static int __parse_probe_arg(char *arg, const struct fetch_type *t,
return ret;
}
+#define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long))
+
+/* Bitfield type needs to be parsed into a fetch function */
+static int __parse_bitfield_probe_arg(const char *bf,
+ const struct fetch_type *t,
+ struct fetch_param *f)
+{
+ struct bitfield_fetch_param *bprm;
+ unsigned long bw, bo;
+ char *tail;
+
+ if (*bf != 'b')
+ return 0;
+
+ bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
+ if (!bprm)
+ return -ENOMEM;
+ bprm->orig = *f;
+ f->fn = t->fetch[FETCH_MTD_bitfield];
+ f->data = (void *)bprm;
+
+ bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */
+ if (bw == 0 || *tail != '@')
+ return -EINVAL;
+
+ bf = tail + 1;
+ bo = simple_strtoul(bf, &tail, 0);
+ if (tail == bf || *tail != '/')
+ return -EINVAL;
+
+ bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo);
+ bprm->low_shift = bprm->hi_shift + bo;
+ return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
+}
+
/* String length checking wrapper */
static int parse_probe_arg(char *arg, struct trace_probe *tp,
struct probe_arg *parg, int is_return)
@@ -835,6 +935,8 @@ static int parse_probe_arg(char *arg, struct trace_probe *tp,
parg->offset = tp->size;
tp->size += parg->type->size;
ret = __parse_probe_arg(arg, parg->type, &parg->fetch, is_return);
+ if (ret >= 0)
+ ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch);
if (ret >= 0) {
parg->fetch_size.fn = get_fetch_size_function(parg->type,
parg->fetch.fn);
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [tip:perf/core] perf probe: Add bitfield member support
2011-02-04 12:52 ` [PATCH -perf/perf/core 4/4] perf/probe: Add bitfield member support Masami Hiramatsu
@ 2011-02-08 15:18 ` tip-bot for Masami Hiramatsu
0 siblings, 0 replies; 9+ messages in thread
From: tip-bot for Masami Hiramatsu @ 2011-02-08 15:18 UTC (permalink / raw
To: linux-tip-commits
Cc: acme, linux-kernel, paulus, hpa, mingo, a.p.zijlstra, acme,
masami.hiramatsu.pt, rostedt, srikar, tglx, mingo
Commit-ID: 124bb83cd7de4d851af7595650233fb9e9279d5d
Gitweb: http://git.kernel.org/tip/124bb83cd7de4d851af7595650233fb9e9279d5d
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Fri, 4 Feb 2011 21:52:11 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 7 Feb 2011 12:48:48 -0200
perf probe: Add bitfield member support
Add bitfield member accessing support to probe arguments.
Suggested-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110204125211.9507.60265.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ committer note: Fixed up '%lu' use for return of BYTES_TO_BITS ('%zd') ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/probe-finder.c | 95 ++++++++++++++++++++++++++++-----------
1 files changed, 68 insertions(+), 27 deletions(-)
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 46addfb..fe461f6 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -33,6 +33,7 @@
#include <ctype.h>
#include <dwarf-regs.h>
+#include <linux/bitops.h>
#include "event.h"
#include "debug.h"
#include "util.h"
@@ -333,13 +334,23 @@ static Dwarf_Die *die_get_real_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
return vr_die;
}
-static bool die_is_signed_type(Dwarf_Die *tp_die)
+static int die_get_attr_udata(Dwarf_Die *tp_die, unsigned int attr_name,
+ Dwarf_Word *result)
{
Dwarf_Attribute attr;
+
+ if (dwarf_attr(tp_die, attr_name, &attr) == NULL ||
+ dwarf_formudata(&attr, result) != 0)
+ return -ENOENT;
+
+ return 0;
+}
+
+static bool die_is_signed_type(Dwarf_Die *tp_die)
+{
Dwarf_Word ret;
- if (dwarf_attr(tp_die, DW_AT_encoding, &attr) == NULL ||
- dwarf_formudata(&attr, &ret) != 0)
+ if (die_get_attr_udata(tp_die, DW_AT_encoding, &ret))
return false;
return (ret == DW_ATE_signed_char || ret == DW_ATE_signed ||
@@ -348,11 +359,29 @@ static bool die_is_signed_type(Dwarf_Die *tp_die)
static int die_get_byte_size(Dwarf_Die *tp_die)
{
- Dwarf_Attribute attr;
Dwarf_Word ret;
- if (dwarf_attr(tp_die, DW_AT_byte_size, &attr) == NULL ||
- dwarf_formudata(&attr, &ret) != 0)
+ if (die_get_attr_udata(tp_die, DW_AT_byte_size, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+static int die_get_bit_size(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_bit_size, &ret))
+ return 0;
+
+ return (int)ret;
+}
+
+static int die_get_bit_offset(Dwarf_Die *tp_die)
+{
+ Dwarf_Word ret;
+
+ if (die_get_attr_udata(tp_die, DW_AT_bit_offset, &ret))
return 0;
return (int)ret;
@@ -827,6 +856,8 @@ static_var:
return 0;
}
+#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long))
+
static int convert_variable_type(Dwarf_Die *vr_die,
struct probe_trace_arg *tvar,
const char *cast)
@@ -843,6 +874,14 @@ static int convert_variable_type(Dwarf_Die *vr_die,
return (tvar->type == NULL) ? -ENOMEM : 0;
}
+ if (die_get_bit_size(vr_die) != 0) {
+ /* This is a bitfield */
+ ret = snprintf(buf, 16, "b%d@%d/%zd", die_get_bit_size(vr_die),
+ die_get_bit_offset(vr_die),
+ BYTES_TO_BITS(die_get_byte_size(vr_die)));
+ goto formatted;
+ }
+
if (die_get_real_type(vr_die, &type) == NULL) {
pr_warning("Failed to get a type information of %s.\n",
dwarf_diename(vr_die));
@@ -887,29 +926,31 @@ static int convert_variable_type(Dwarf_Die *vr_die,
return (tvar->type == NULL) ? -ENOMEM : 0;
}
- ret = die_get_byte_size(&type) * 8;
- if (ret) {
- /* Check the bitwidth */
- if (ret > MAX_BASIC_TYPE_BITS) {
- pr_info("%s exceeds max-bitwidth."
- " Cut down to %d bits.\n",
- dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
- ret = MAX_BASIC_TYPE_BITS;
- }
+ ret = BYTES_TO_BITS(die_get_byte_size(&type));
+ if (!ret)
+ /* No size ... try to use default type */
+ return 0;
- ret = snprintf(buf, 16, "%c%d",
- die_is_signed_type(&type) ? 's' : 'u', ret);
- if (ret < 0 || ret >= 16) {
- if (ret >= 16)
- ret = -E2BIG;
- pr_warning("Failed to convert variable type: %s\n",
- strerror(-ret));
- return ret;
- }
- tvar->type = strdup(buf);
- if (tvar->type == NULL)
- return -ENOMEM;
+ /* Check the bitwidth */
+ if (ret > MAX_BASIC_TYPE_BITS) {
+ pr_info("%s exceeds max-bitwidth. Cut down to %d bits.\n",
+ dwarf_diename(&type), MAX_BASIC_TYPE_BITS);
+ ret = MAX_BASIC_TYPE_BITS;
+ }
+ ret = snprintf(buf, 16, "%c%d",
+ die_is_signed_type(&type) ? 's' : 'u', ret);
+
+formatted:
+ if (ret < 0 || ret >= 16) {
+ if (ret >= 16)
+ ret = -E2BIG;
+ pr_warning("Failed to convert variable type: %s\n",
+ strerror(-ret));
+ return ret;
}
+ tvar->type = strdup(buf);
+ if (tvar->type == NULL)
+ return -ENOMEM;
return 0;
}
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2011-02-08 15:19 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-02-04 12:51 [PATCH -perf/perf/core 0/4] Perf probe/kprobe-tracer update (support bitfield, etc) Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 1/4] tracing/kprobes: Cleanup strict_strtol() using code Masami Hiramatsu
2011-02-08 15:16 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2011-02-04 12:51 ` [PATCH -perf/perf/core 2/4] tracing/kprobes: support longer(>128) command Masami Hiramatsu
2011-02-08 15:17 ` [tip:perf/core] tracing/kprobes: Support longer (>128 bytes) command tip-bot for Masami Hiramatsu
2011-02-04 12:52 ` [PATCH -perf/perf/core 3/4] tracing/kprobes: Add bitfield type Masami Hiramatsu
2011-02-08 15:17 ` [tip:perf/core] " tip-bot for Masami Hiramatsu
2011-02-04 12:52 ` [PATCH -perf/perf/core 4/4] perf/probe: Add bitfield member support Masami Hiramatsu
2011-02-08 15:18 ` [tip:perf/core] perf probe: " tip-bot for Masami Hiramatsu
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