* [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
@ 2024-02-26 3:57 Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event Masami Hiramatsu (Google)
` (7 more replies)
0 siblings, 8 replies; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:57 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
Hi,
Here is version 2 series of patches to support accessing function entry data
from function *return* probes (including kretprobe and fprobe-exit event).
In this version, I added another cleanup [4/7], updated README[5/7], added
testcases[6/7] and updated document[7/7].
This allows us to access the results of some functions, which returns the
error code and its results are passed via function parameter, such as an
structure-initialization function.
For example, vfs_open() will link the file structure to the inode and update
mode. Thus we can trace that changes.
# echo 'f vfs_open mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
# echo 'f vfs_open%return mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
# echo 1 > events/fprobes/enable
# cat trace
sh-131 [006] ...1. 1945.714346: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x2 inode=0x0
sh-131 [006] ...1. 1945.714358: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4d801e inode=0xffff888008470168
cat-143 [007] ...1. 1945.717949: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
cat-143 [007] ...1. 1945.717956: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4a801d inode=0xffff888005f78d28
cat-143 [007] ...1. 1945.720616: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
cat-143 [007] ...1. 1945.728263: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0xa800d inode=0xffff888004ada8d8
So as you can see those fields are initialized at exit.
This series is based on v6.8-rc5 kernel or you can checkout from
https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/log/?h=topic/entry-data
Thank you,
---
Masami Hiramatsu (Google) (7):
tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
tracing/probes: Cleanup probe argument parser
tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
tracing: Remove redundant #else block for BTF args from README
tracing/probes: Support $argN in return probe (kprobe and fprobe)
selftests/ftrace: Add test cases for entry args at function exit
Documentation: tracing: Add entry argument access at function exit
Documentation/trace/fprobetrace.rst | 7
Documentation/trace/kprobetrace.rst | 7
kernel/trace/trace.c | 5
kernel/trace/trace_eprobe.c | 8
kernel/trace/trace_fprobe.c | 59 ++-
kernel/trace/trace_kprobe.c | 58 ++-
kernel/trace/trace_probe.c | 417 ++++++++++++++------
kernel/trace/trace_probe.h | 30 +
kernel/trace/trace_probe_tmpl.h | 10
kernel/trace/trace_uprobe.c | 14 -
.../ftrace/test.d/dynevent/fprobe_entry_arg.tc | 18 +
.../ftrace/test.d/kprobe/kretprobe_entry_arg.tc | 18 +
12 files changed, 483 insertions(+), 168 deletions(-)
create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
@ 2024-02-26 3:58 ` Masami Hiramatsu (Google)
2024-03-01 3:34 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 2/7] tracing/probes: Cleanup probe argument parser Masami Hiramatsu (Google)
` (6 subsequent siblings)
7 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:58 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Despite the fprobe event, "Kretprobe" was commented. So fix it.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_fprobe.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 7d2ddbcfa377..3ccef4d82235 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -210,7 +210,7 @@ fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
}
NOKPROBE_SYMBOL(fentry_trace_func);
-/* Kretprobe handler */
+/* function exit handler */
static nokprobe_inline void
__fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
unsigned long ret_ip, struct pt_regs *regs,
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH v2 2/7] tracing/probes: Cleanup probe argument parser
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event Masami Hiramatsu (Google)
@ 2024-02-26 3:58 ` Masami Hiramatsu (Google)
2024-03-01 3:34 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init Masami Hiramatsu (Google)
` (5 subsequent siblings)
7 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:58 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cleanup traceprobe_parse_probe_arg_body() to split out the
type parser and post-processing part of fetch_insn.
This makes no functional change.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_probe.c | 230 ++++++++++++++++++++++++++------------------
1 file changed, 137 insertions(+), 93 deletions(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 34289f9c6707..67a0b9cbb648 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1090,67 +1090,45 @@ static int __parse_bitfield_probe_arg(const char *bf,
return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0;
}
-/* String length checking wrapper */
-static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
- struct probe_arg *parg,
- struct traceprobe_parse_context *ctx)
+/* Split type part from @arg and return it. */
+static char *parse_probe_arg_type(char *arg, struct probe_arg *parg,
+ struct traceprobe_parse_context *ctx)
{
- struct fetch_insn *code, *scode, *tmp = NULL;
- char *t, *t2, *t3;
- int ret, len;
- char *arg;
+ char *t = NULL, *t2, *t3;
+ int offs;
- arg = kstrdup(argv, GFP_KERNEL);
- if (!arg)
- return -ENOMEM;
-
- ret = -EINVAL;
- len = strlen(arg);
- if (len > MAX_ARGSTR_LEN) {
- trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
- goto out;
- } else if (len == 0) {
- trace_probe_log_err(ctx->offset, NO_ARG_BODY);
- goto out;
- }
-
- ret = -ENOMEM;
- parg->comm = kstrdup(arg, GFP_KERNEL);
- if (!parg->comm)
- goto out;
-
- ret = -EINVAL;
t = strchr(arg, ':');
if (t) {
- *t = '\0';
- t2 = strchr(++t, '[');
+ *t++ = '\0';
+ t2 = strchr(t, '[');
if (t2) {
*t2++ = '\0';
t3 = strchr(t2, ']');
if (!t3) {
- int offs = t2 + strlen(t2) - arg;
+ offs = t2 + strlen(t2) - arg;
trace_probe_log_err(ctx->offset + offs,
ARRAY_NO_CLOSE);
- goto out;
+ return ERR_PTR(-EINVAL);
} else if (t3[1] != '\0') {
trace_probe_log_err(ctx->offset + t3 + 1 - arg,
BAD_ARRAY_SUFFIX);
- goto out;
+ return ERR_PTR(-EINVAL);
}
*t3 = '\0';
if (kstrtouint(t2, 0, &parg->count) || !parg->count) {
trace_probe_log_err(ctx->offset + t2 - arg,
BAD_ARRAY_NUM);
- goto out;
+ return ERR_PTR(-EINVAL);
}
if (parg->count > MAX_ARRAY_LEN) {
trace_probe_log_err(ctx->offset + t2 - arg,
ARRAY_TOO_BIG);
- goto out;
+ return ERR_PTR(-EINVAL);
}
}
}
+ offs = t ? t - arg : 0;
/*
* Since $comm and immediate string can not be dereferenced,
@@ -1161,74 +1139,52 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
strncmp(arg, "\\\"", 2) == 0)) {
/* The type of $comm must be "string", and not an array type. */
if (parg->count || (t && strcmp(t, "string"))) {
- trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
- NEED_STRING_TYPE);
- goto out;
+ trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE);
+ return ERR_PTR(-EINVAL);
}
parg->type = find_fetch_type("string", ctx->flags);
} else
parg->type = find_fetch_type(t, ctx->flags);
+
if (!parg->type) {
- trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE);
- goto out;
+ trace_probe_log_err(ctx->offset + offs, BAD_TYPE);
+ return ERR_PTR(-EINVAL);
}
- code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
- if (!code)
- goto out;
- code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
-
- ctx->last_type = NULL;
- ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
- ctx);
- if (ret)
- goto fail;
-
- /* Update storing type if BTF is available */
- if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
- ctx->last_type) {
- if (!t) {
- parg->type = find_fetch_type_from_btf_type(ctx);
- } else if (strstr(t, "string")) {
- ret = check_prepare_btf_string_fetch(t, &code, ctx);
- if (ret)
- goto fail;
- }
- }
- parg->offset = *size;
- *size += parg->type->size * (parg->count ?: 1);
+ return t;
+}
- if (parg->count) {
- len = strlen(parg->type->fmttype) + 6;
- parg->fmt = kmalloc(len, GFP_KERNEL);
- if (!parg->fmt) {
- ret = -ENOMEM;
- goto out;
- }
- snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
- parg->count);
- }
+/* After parsing, adjust the fetch_insn according to the probe_arg */
+static int finalize_fetch_insn(struct fetch_insn *code,
+ struct probe_arg *parg,
+ char *type,
+ int type_offset,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *scode;
+ int ret;
- ret = -EINVAL;
/* Store operation */
if (parg->type->is_string) {
+ /* Check bad combination of the type and the last fetch_insn. */
if (!strcmp(parg->type->name, "symstr")) {
if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK &&
code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG &&
code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) {
- trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
+ trace_probe_log_err(ctx->offset + type_offset,
BAD_SYMSTRING);
- goto fail;
+ return -EINVAL;
}
} else {
if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF &&
code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM &&
code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) {
- trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
+ trace_probe_log_err(ctx->offset + type_offset,
BAD_STRING);
- goto fail;
+ return -EINVAL;
}
}
+
if (!strcmp(parg->type->name, "symstr") ||
(code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM ||
code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG ||
@@ -1244,9 +1200,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
code++;
if (code->op != FETCH_OP_NOP) {
trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
- goto fail;
+ return -EINVAL;
}
}
+
/* If op == DEREF, replace it with STRING */
if (!strcmp(parg->type->name, "ustring") ||
code->op == FETCH_OP_UDEREF)
@@ -1267,47 +1224,134 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
code++;
if (code->op != FETCH_OP_NOP) {
trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
- goto fail;
+ return -E2BIG;
}
code->op = FETCH_OP_ST_RAW;
code->size = parg->type->size;
}
+
+ /* Save storing fetch_insn. */
scode = code;
+
/* Modify operation */
- if (t != NULL) {
- ret = __parse_bitfield_probe_arg(t, parg->type, &code);
+ if (type != NULL) {
+ /* Bitfield needs a special fetch_insn. */
+ ret = __parse_bitfield_probe_arg(type, parg->type, &code);
if (ret) {
- trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD);
- goto fail;
+ trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD);
+ return ret;
}
} else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
ctx->last_type) {
+ /* If user not specified the type, try parsing BTF bitfield. */
ret = parse_btf_bitfield(&code, ctx);
if (ret)
- goto fail;
+ return ret;
}
- ret = -EINVAL;
+
/* Loop(Array) operation */
if (parg->count) {
if (scode->op != FETCH_OP_ST_MEM &&
scode->op != FETCH_OP_ST_STRING &&
scode->op != FETCH_OP_ST_USTRING) {
- trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0),
- BAD_STRING);
- goto fail;
+ trace_probe_log_err(ctx->offset + type_offset, BAD_STRING);
+ return -EINVAL;
}
code++;
if (code->op != FETCH_OP_NOP) {
trace_probe_log_err(ctx->offset, TOO_MANY_OPS);
- goto fail;
+ return -E2BIG;
}
code->op = FETCH_OP_LP_ARRAY;
code->param = parg->count;
}
+
+ /* Finalize the fetch_insn array. */
code++;
code->op = FETCH_OP_END;
- ret = 0;
+ return 0;
+}
+
+/* String length checking wrapper */
+static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
+ struct probe_arg *parg,
+ struct traceprobe_parse_context *ctx)
+{
+ struct fetch_insn *code, *tmp = NULL;
+ char *type, *arg;
+ int ret, len;
+
+ len = strlen(argv);
+ if (len > MAX_ARGSTR_LEN) {
+ trace_probe_log_err(ctx->offset, ARG_TOO_LONG);
+ return -E2BIG;
+ } else if (len == 0) {
+ trace_probe_log_err(ctx->offset, NO_ARG_BODY);
+ return -EINVAL;
+ }
+
+ arg = kstrdup(argv, GFP_KERNEL);
+ if (!arg)
+ return -ENOMEM;
+
+ parg->comm = kstrdup(arg, GFP_KERNEL);
+ if (!parg->comm) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ type = parse_probe_arg_type(arg, parg, ctx);
+ if (IS_ERR(type)) {
+ ret = PTR_ERR(type);
+ goto out;
+ }
+
+ code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
+ if (!code) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
+
+ ctx->last_type = NULL;
+ ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
+ ctx);
+ if (ret < 0)
+ goto fail;
+
+ /* Update storing type if BTF is available */
+ if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) &&
+ ctx->last_type) {
+ if (!type) {
+ parg->type = find_fetch_type_from_btf_type(ctx);
+ } else if (strstr(type, "string")) {
+ ret = check_prepare_btf_string_fetch(type, &code, ctx);
+ if (ret)
+ goto fail;
+ }
+ }
+ parg->offset = *size;
+ *size += parg->type->size * (parg->count ?: 1);
+
+ if (parg->count) {
+ len = strlen(parg->type->fmttype) + 6;
+ parg->fmt = kmalloc(len, GFP_KERNEL);
+ if (!parg->fmt) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
+ parg->count);
+ }
+
+ ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx);
+ if (ret < 0)
+ goto fail;
+
+ for (; code < tmp + FETCH_INSN_MAX; code++)
+ if (code->op == FETCH_OP_END)
+ break;
/* Shrink down the code buffer */
parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
if (!parg->code)
@@ -1316,7 +1360,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1));
fail:
- if (ret) {
+ if (ret < 0) {
for (code = tmp; code < tmp + FETCH_INSN_MAX; code++)
if (code->op == FETCH_NOP_SYMBOL ||
code->op == FETCH_OP_DATA)
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 2/7] tracing/probes: Cleanup probe argument parser Masami Hiramatsu (Google)
@ 2024-02-26 3:58 ` Masami Hiramatsu (Google)
2024-03-01 3:37 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 4/7] tracing: Remove redundant #else block for BTF args from README Masami Hiramatsu (Google)
` (4 subsequent siblings)
7 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:58 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init().
This is a cleanup, so the behavior is not changed.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace_eprobe.c | 2 +-
kernel/trace/trace_probe.c | 10 ++++++----
kernel/trace/trace_probe.h | 2 +-
kernel/trace/trace_uprobe.c | 2 +-
4 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 03c851f57969..eb72def7410f 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -220,7 +220,7 @@ static struct trace_eprobe *alloc_event_probe(const char *group,
if (!ep->event_system)
goto error;
- ret = trace_probe_init(&ep->tp, this_event, group, false);
+ ret = trace_probe_init(&ep->tp, this_event, group, false, nargs);
if (ret < 0)
goto error;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 67a0b9cbb648..93f36f8a108e 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -1423,9 +1423,6 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
struct probe_arg *parg = &tp->args[i];
const char *body;
- /* Increment count for freeing args in error case */
- tp->nr_args++;
-
body = strchr(arg, '=');
if (body) {
if (body - arg > MAX_ARG_NAME_LEN) {
@@ -1810,7 +1807,7 @@ void trace_probe_cleanup(struct trace_probe *tp)
}
int trace_probe_init(struct trace_probe *tp, const char *event,
- const char *group, bool alloc_filter)
+ const char *group, bool alloc_filter, int nargs)
{
struct trace_event_call *call;
size_t size = sizeof(struct trace_probe_event);
@@ -1846,6 +1843,11 @@ int trace_probe_init(struct trace_probe *tp, const char *event,
goto error;
}
+ tp->nr_args = nargs;
+ /* Make sure pointers in args[] are NULL */
+ if (nargs)
+ memset(tp->args, 0, sizeof(tp->args[0]) * nargs);
+
return 0;
error:
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index c1877d018269..ed8d1052f8a7 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -338,7 +338,7 @@ static inline bool trace_probe_has_single_file(struct trace_probe *tp)
}
int trace_probe_init(struct trace_probe *tp, const char *event,
- const char *group, bool alloc_filter);
+ const char *group, bool alloc_filter, int nargs);
void trace_probe_cleanup(struct trace_probe *tp);
int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
void trace_probe_unlink(struct trace_probe *tp);
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index a84b85d8aac1..796ebcae9b38 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -337,7 +337,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
if (!tu)
return ERR_PTR(-ENOMEM);
- ret = trace_probe_init(&tu->tp, event, group, true);
+ ret = trace_probe_init(&tu->tp, event, group, true, nargs);
if (ret < 0)
goto error;
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH v2 4/7] tracing: Remove redundant #else block for BTF args from README
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
` (2 preceding siblings ...)
2024-02-26 3:58 ` [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init Masami Hiramatsu (Google)
@ 2024-02-26 3:58 ` Masami Hiramatsu (Google)
2024-03-01 3:39 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 5/7] tracing/probes: Support $argN in return probe (kprobe and fprobe) Masami Hiramatsu (Google)
` (3 subsequent siblings)
7 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:58 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Remove redundant #else block for BTF args from README message.
This is a cleanup, so no change on the message.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
kernel/trace/trace.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8198bfc54b58..516c585f5879 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5747,11 +5747,9 @@ static const char readme_msg[] =
"\t args: <name>=fetcharg[:type]\n"
"\t fetcharg: (%<register>|$<efield>), @<address>, @<symbol>[+|-<offset>],\n"
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
-#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
"\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n"
+#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
"\t <argname>[->field[->field|.field...]],\n"
-#else
- "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n"
#endif
#else
"\t $stack<index>, $stack, $retval, $comm,\n"
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH v2 5/7] tracing/probes: Support $argN in return probe (kprobe and fprobe)
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
` (3 preceding siblings ...)
2024-02-26 3:58 ` [PATCH v2 4/7] tracing: Remove redundant #else block for BTF args from README Masami Hiramatsu (Google)
@ 2024-02-26 3:58 ` Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 6/7] selftests/ftrace: Add test cases for entry args at function exit Masami Hiramatsu (Google)
` (2 subsequent siblings)
7 siblings, 0 replies; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:58 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Support accessing $argN in the return probe events. This will help users to
record entry data in function return (exit) event for simplfing the function
entry/exit information in one event, and record the result values (e.g.
allocated object/initialized object) at function exit.
For example, if we have a function `int init_foo(struct foo *obj, int param)`
sometimes we want to check how `obj` is initialized. In such case, we can
define a new return event like below;
# echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events
Thus it records the function parameter `param` and its result `obj->field1`
(the dereference will be done in the function exit timing) value at once.
This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF
is enabled, we can trace both function parameters and the return value
by following command.
# echo 'f target_function%return $arg* $retval' >> dynamic_events
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Changes in v2:
- Update README message
---
kernel/trace/trace.c | 1
kernel/trace/trace_eprobe.c | 6 +
kernel/trace/trace_fprobe.c | 57 +++++++++----
kernel/trace/trace_kprobe.c | 58 ++++++++++---
kernel/trace/trace_probe.c | 177 ++++++++++++++++++++++++++++++++++-----
kernel/trace/trace_probe.h | 28 ++++++
kernel/trace/trace_probe_tmpl.h | 10 +-
kernel/trace/trace_uprobe.c | 12 +--
8 files changed, 285 insertions(+), 64 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 516c585f5879..71a96decc276 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5755,6 +5755,7 @@ static const char readme_msg[] =
"\t $stack<index>, $stack, $retval, $comm,\n"
#endif
"\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n"
+ "\t kernel return probes support: $retval, $arg<N>, $comm\n"
"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n"
"\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n"
"\t symstr, <type>\\[<array-size>\\]\n"
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index eb72def7410f..b0e0ec85912e 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -390,8 +390,8 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec)
/* Note that we don't verify it, since the code does not come from user space */
static int
-process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
- void *base)
+process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
+ void *dest, void *base)
{
unsigned long val;
int ret;
@@ -438,7 +438,7 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec)
return;
entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
- store_trace_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &edata->ep->tp, rec, NULL, sizeof(*entry), dsize);
trace_event_buffer_commit(&fbuffer);
}
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 3ccef4d82235..4f4280815522 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -4,6 +4,7 @@
* Copyright (C) 2022 Google LLC.
*/
#define pr_fmt(fmt) "trace_fprobe: " fmt
+#include <asm/ptrace.h>
#include <linux/fprobe.h>
#include <linux/module.h>
@@ -129,8 +130,8 @@ static bool trace_fprobe_is_registered(struct trace_fprobe *tf)
* from user space.
*/
static int
-process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
- void *base)
+process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
+ void *dest, void *base)
{
struct pt_regs *regs = rec;
unsigned long val;
@@ -152,6 +153,9 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
case FETCH_OP_ARG:
val = regs_get_kernel_argument(regs, code->param);
break;
+ case FETCH_OP_EDATA:
+ val = *(unsigned long *)((unsigned long)edata + code->offset);
+ break;
#endif
case FETCH_NOP_SYMBOL: /* Ignore a place holder */
code++;
@@ -184,7 +188,7 @@ __fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
if (trace_trigger_soft_disabled(trace_file))
return;
- dsize = __get_data_size(&tf->tp, regs);
+ dsize = __get_data_size(&tf->tp, regs, NULL);
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + tf->tp.size + dsize);
@@ -194,7 +198,7 @@ __fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
fbuffer.regs = regs;
entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
entry->ip = entry_ip;
- store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tf->tp, regs, NULL, sizeof(*entry), dsize);
trace_event_buffer_commit(&fbuffer);
}
@@ -211,10 +215,23 @@ fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
NOKPROBE_SYMBOL(fentry_trace_func);
/* function exit handler */
+static int trace_fprobe_entry_handler(struct fprobe *fp, unsigned long entry_ip,
+ unsigned long ret_ip, struct pt_regs *regs,
+ void *entry_data)
+{
+ struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp);
+
+ if (tf->tp.entry_arg)
+ store_trace_entry_data(entry_data, &tf->tp, regs);
+
+ return 0;
+}
+NOKPROBE_SYMBOL(trace_fprobe_entry_handler)
+
static nokprobe_inline void
__fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
unsigned long ret_ip, struct pt_regs *regs,
- struct trace_event_file *trace_file)
+ void *entry_data, struct trace_event_file *trace_file)
{
struct fexit_trace_entry_head *entry;
struct trace_event_buffer fbuffer;
@@ -227,7 +244,7 @@ __fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
if (trace_trigger_soft_disabled(trace_file))
return;
- dsize = __get_data_size(&tf->tp, regs);
+ dsize = __get_data_size(&tf->tp, regs, entry_data);
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + tf->tp.size + dsize);
@@ -238,19 +255,19 @@ __fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
entry->func = entry_ip;
entry->ret_ip = ret_ip;
- store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tf->tp, regs, entry_data, sizeof(*entry), dsize);
trace_event_buffer_commit(&fbuffer);
}
static void
fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
- unsigned long ret_ip, struct pt_regs *regs)
+ unsigned long ret_ip, struct pt_regs *regs, void *entry_data)
{
struct event_file_link *link;
trace_probe_for_each_link_rcu(link, &tf->tp)
- __fexit_trace_func(tf, entry_ip, ret_ip, regs, link->file);
+ __fexit_trace_func(tf, entry_ip, ret_ip, regs, entry_data, link->file);
}
NOKPROBE_SYMBOL(fexit_trace_func);
@@ -269,7 +286,7 @@ static int fentry_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
if (hlist_empty(head))
return 0;
- dsize = __get_data_size(&tf->tp, regs);
+ dsize = __get_data_size(&tf->tp, regs, NULL);
__size = sizeof(*entry) + tf->tp.size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -280,7 +297,7 @@ static int fentry_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
entry->ip = entry_ip;
memset(&entry[1], 0, dsize);
- store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tf->tp, regs, NULL, sizeof(*entry), dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
return 0;
@@ -289,7 +306,8 @@ NOKPROBE_SYMBOL(fentry_perf_func);
static void
fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
- unsigned long ret_ip, struct pt_regs *regs)
+ unsigned long ret_ip, struct pt_regs *regs,
+ void *entry_data)
{
struct trace_event_call *call = trace_probe_event_call(&tf->tp);
struct fexit_trace_entry_head *entry;
@@ -301,7 +319,7 @@ fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
if (hlist_empty(head))
return;
- dsize = __get_data_size(&tf->tp, regs);
+ dsize = __get_data_size(&tf->tp, regs, entry_data);
__size = sizeof(*entry) + tf->tp.size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -312,7 +330,7 @@ fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
entry->func = entry_ip;
entry->ret_ip = ret_ip;
- store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tf->tp, regs, entry_data, sizeof(*entry), dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
}
@@ -343,10 +361,10 @@ static void fexit_dispatcher(struct fprobe *fp, unsigned long entry_ip,
struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp);
if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE))
- fexit_trace_func(tf, entry_ip, ret_ip, regs);
+ fexit_trace_func(tf, entry_ip, ret_ip, regs, entry_data);
#ifdef CONFIG_PERF_EVENTS
if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE))
- fexit_perf_func(tf, entry_ip, ret_ip, regs);
+ fexit_perf_func(tf, entry_ip, ret_ip, regs, entry_data);
#endif
}
NOKPROBE_SYMBOL(fexit_dispatcher);
@@ -389,7 +407,7 @@ static struct trace_fprobe *alloc_trace_fprobe(const char *group,
tf->tpoint = tpoint;
tf->fp.nr_maxactive = maxactive;
- ret = trace_probe_init(&tf->tp, event, group, false);
+ ret = trace_probe_init(&tf->tp, event, group, false, nargs);
if (ret < 0)
goto error;
@@ -1109,6 +1127,11 @@ static int __trace_fprobe_create(int argc, const char *argv[])
goto error; /* This can be -ENOMEM */
}
+ if (is_return && tf->tp.entry_arg) {
+ tf->fp.entry_handler = trace_fprobe_entry_handler;
+ tf->fp.entry_data_size = traceprobe_get_entry_data_size(&tf->tp);
+ }
+
ret = traceprobe_set_print_fmt(&tf->tp,
is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL);
if (ret < 0)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index c4c6e0e0068b..14099cc17fc9 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -290,7 +290,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
INIT_HLIST_NODE(&tk->rp.kp.hlist);
INIT_LIST_HEAD(&tk->rp.kp.list);
- ret = trace_probe_init(&tk->tp, event, group, false);
+ ret = trace_probe_init(&tk->tp, event, group, false, nargs);
if (ret < 0)
goto error;
@@ -740,6 +740,9 @@ static unsigned int number_of_same_symbols(char *func_name)
return ctx.count;
}
+static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
+ struct pt_regs *regs);
+
static int __trace_kprobe_create(int argc, const char *argv[])
{
/*
@@ -948,6 +951,11 @@ static int __trace_kprobe_create(int argc, const char *argv[])
if (ret)
goto error; /* This can be -ENOMEM */
}
+ /* entry handler for kretprobe */
+ if (is_return && tk->tp.entry_arg) {
+ tk->rp.entry_handler = trace_kprobe_entry_handler;
+ tk->rp.data_size = traceprobe_get_entry_data_size(&tk->tp);
+ }
ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
ret = traceprobe_set_print_fmt(&tk->tp, ptype);
@@ -1303,8 +1311,8 @@ static const struct file_operations kprobe_profile_ops = {
/* Note that we don't verify it, since the code does not come from user space */
static int
-process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
- void *base)
+process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
+ void *dest, void *base)
{
struct pt_regs *regs = rec;
unsigned long val;
@@ -1329,6 +1337,9 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
case FETCH_OP_ARG:
val = regs_get_kernel_argument(regs, code->param);
break;
+ case FETCH_OP_EDATA:
+ val = *(unsigned long *)((unsigned long)edata + code->offset);
+ break;
#endif
case FETCH_NOP_SYMBOL: /* Ignore a place holder */
code++;
@@ -1359,7 +1370,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
if (trace_trigger_soft_disabled(trace_file))
return;
- dsize = __get_data_size(&tk->tp, regs);
+ dsize = __get_data_size(&tk->tp, regs, NULL);
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + tk->tp.size + dsize);
@@ -1368,7 +1379,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
fbuffer.regs = regs;
entry->ip = (unsigned long)tk->rp.kp.addr;
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize);
trace_event_buffer_commit(&fbuffer);
}
@@ -1384,6 +1395,31 @@ kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
NOKPROBE_SYMBOL(kprobe_trace_func);
/* Kretprobe handler */
+
+static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+{
+ struct kretprobe *rp = get_kretprobe(ri);
+ struct trace_kprobe *tk;
+
+ /*
+ * There is a small chance that get_kretprobe(ri) returns NULL when
+ * the kretprobe is unregister on another CPU between kretprobe's
+ * trampoline_handler and this function.
+ */
+ if (unlikely(!rp))
+ return -ENOENT;
+
+ tk = container_of(rp, struct trace_kprobe, rp);
+
+ /* store argument values into ri->data as entry data */
+ if (tk->tp.entry_arg)
+ store_trace_entry_data(ri->data, &tk->tp, regs);
+
+ return 0;
+}
+
+
static nokprobe_inline void
__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct pt_regs *regs,
@@ -1399,7 +1435,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
if (trace_trigger_soft_disabled(trace_file))
return;
- dsize = __get_data_size(&tk->tp, regs);
+ dsize = __get_data_size(&tk->tp, regs, ri->data);
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + tk->tp.size + dsize);
@@ -1409,7 +1445,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
fbuffer.regs = regs;
entry->func = (unsigned long)tk->rp.kp.addr;
entry->ret_ip = get_kretprobe_retaddr(ri);
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize);
trace_event_buffer_commit(&fbuffer);
}
@@ -1557,7 +1593,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
if (hlist_empty(head))
return 0;
- dsize = __get_data_size(&tk->tp, regs);
+ dsize = __get_data_size(&tk->tp, regs, NULL);
__size = sizeof(*entry) + tk->tp.size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -1568,7 +1604,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
entry->ip = (unsigned long)tk->rp.kp.addr;
memset(&entry[1], 0, dsize);
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
return 0;
@@ -1593,7 +1629,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
if (hlist_empty(head))
return;
- dsize = __get_data_size(&tk->tp, regs);
+ dsize = __get_data_size(&tk->tp, regs, ri->data);
__size = sizeof(*entry) + tk->tp.size + dsize;
size = ALIGN(__size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
@@ -1604,7 +1640,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
entry->func = (unsigned long)tk->rp.kp.addr;
entry->ret_ip = get_kretprobe_retaddr(ri);
- store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
+ store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
}
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 93f36f8a108e..217169de0920 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -594,6 +594,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
return 0;
}
+static int __store_entry_arg(struct trace_probe *tp, int argnum);
+
static int parse_btf_arg(char *varname,
struct fetch_insn **pcode, struct fetch_insn *end,
struct traceprobe_parse_context *ctx)
@@ -618,11 +620,7 @@ static int parse_btf_arg(char *varname,
return -EOPNOTSUPP;
}
- if (ctx->flags & TPARG_FL_RETURN) {
- if (strcmp(varname, "$retval") != 0) {
- trace_probe_log_err(ctx->offset, NO_BTFARG);
- return -ENOENT;
- }
+ if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) {
code->op = FETCH_OP_RETVAL;
/* Check whether the function return type is not void */
if (query_btf_context(ctx) == 0) {
@@ -654,11 +652,21 @@ static int parse_btf_arg(char *varname,
const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
if (name && !strcmp(name, varname)) {
- code->op = FETCH_OP_ARG;
- if (ctx->flags & TPARG_FL_TPOINT)
- code->param = i + 1;
- else
- code->param = i;
+ if (tparg_is_function_entry(ctx->flags)) {
+ code->op = FETCH_OP_ARG;
+ if (ctx->flags & TPARG_FL_TPOINT)
+ code->param = i + 1;
+ else
+ code->param = i;
+ } else if (tparg_is_function_return(ctx->flags)) {
+ code->op = FETCH_OP_EDATA;
+ ret = __store_entry_arg(ctx->tp, i);
+ if (ret < 0) {
+ /* internal error */
+ return ret;
+ }
+ code->offset = ret;
+ }
tid = params[i].type;
goto found;
}
@@ -755,6 +763,110 @@ static int check_prepare_btf_string_fetch(char *typename,
#endif
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+
+static int __store_entry_arg(struct trace_probe *tp, int argnum)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ bool match = false;
+ int i, offset;
+
+ if (!earg) {
+ earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL);
+ if (!earg)
+ return -ENOMEM;
+ earg->size = 2 * tp->nr_args + 1;
+ earg->code = kcalloc(earg->size, sizeof(struct fetch_insn),
+ GFP_KERNEL);
+ if (!earg->code) {
+ kfree(earg);
+ return -ENOMEM;
+ }
+ /* Fill the code buffer with 'end' to simplify it */
+ for (i = 0; i < earg->size; i++)
+ earg->code[i].op = FETCH_OP_END;
+ tp->entry_arg = earg;
+ }
+
+ offset = 0;
+ for (i = 0; i < earg->size - 1; i++) {
+ switch (earg->code[i].op) {
+ case FETCH_OP_END:
+ earg->code[i].op = FETCH_OP_ARG;
+ earg->code[i].param = argnum;
+ earg->code[i + 1].op = FETCH_OP_ST_EDATA;
+ earg->code[i + 1].offset = offset;
+ return offset;
+ case FETCH_OP_ARG:
+ match = (earg->code[i].param == argnum);
+ break;
+ case FETCH_OP_ST_EDATA:
+ offset = earg->code[i].offset;
+ if (match)
+ return offset;
+ offset += sizeof(unsigned long);
+ break;
+ default:
+ break;
+ }
+ }
+ return -ENOSPC;
+}
+
+int traceprobe_get_entry_data_size(struct trace_probe *tp)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ int i, size = 0;
+
+ if (!earg)
+ return 0;
+
+ for (i = 0; i < earg->size; i++) {
+ switch (earg->code[i].op) {
+ case FETCH_OP_END:
+ goto out;
+ case FETCH_OP_ST_EDATA:
+ size = earg->code[i].offset + sizeof(unsigned long);
+ break;
+ default:
+ break;
+ }
+ }
+out:
+ return size;
+}
+
+void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs)
+{
+ struct probe_entry_arg *earg = tp->entry_arg;
+ unsigned long val;
+ int i;
+
+ if (!earg)
+ return;
+
+ for (i = 0; i < earg->size; i++) {
+ struct fetch_insn *code = &earg->code[i];
+
+ switch (code->op) {
+ case FETCH_OP_ARG:
+ val = regs_get_kernel_argument(regs, code->param);
+ break;
+ case FETCH_OP_ST_EDATA:
+ *(unsigned long *)((unsigned long)edata + code->offset) = val;
+ break;
+ case FETCH_OP_END:
+ goto end;
+ default:
+ break;
+ }
+ }
+end:
+ return;
+}
+NOKPROBE_SYMBOL(store_trace_entry_data)
+#endif
+
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
@@ -830,7 +942,7 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
len = str_has_prefix(arg, "arg");
- if (len && tparg_is_function_entry(ctx->flags)) {
+ if (len) {
ret = kstrtoul(arg + len, 10, ¶m);
if (ret)
goto inval;
@@ -839,15 +951,29 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
err = TP_ERR_BAD_ARG_NUM;
goto inval;
}
+ param--; /* argN starts from 1, but internal arg[N] starts from 0 */
- code->op = FETCH_OP_ARG;
- code->param = (unsigned int)param - 1;
- /*
- * The tracepoint probe will probe a stub function, and the
- * first parameter of the stub is a dummy and should be ignored.
- */
- if (ctx->flags & TPARG_FL_TPOINT)
- code->param++;
+ if (tparg_is_function_entry(ctx->flags)) {
+ code->op = FETCH_OP_ARG;
+ code->param = (unsigned int)param;
+ /*
+ * The tracepoint probe will probe a stub function, and the
+ * first parameter of the stub is a dummy and should be ignored.
+ */
+ if (ctx->flags & TPARG_FL_TPOINT)
+ code->param++;
+ } else if (tparg_is_function_return(ctx->flags)) {
+ /* function entry argument access from return probe */
+ ret = __store_entry_arg(ctx->tp, param);
+ if (ret < 0) /* This error should be an internal error */
+ return ret;
+
+ code->op = FETCH_OP_EDATA;
+ code->offset = ret;
+ } else {
+ err = TP_ERR_NOFENTRY_ARGS;
+ goto inval;
+ }
return 0;
}
#endif
@@ -1037,7 +1163,8 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
break;
default:
if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
- if (!tparg_is_function_entry(ctx->flags)) {
+ if (!tparg_is_function_entry(ctx->flags) &&
+ !tparg_is_function_return(ctx->flags)) {
trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
return -EINVAL;
}
@@ -1423,6 +1550,7 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
struct probe_arg *parg = &tp->args[i];
const char *body;
+ ctx->tp = tp;
body = strchr(arg, '=');
if (body) {
if (body - arg > MAX_ARG_NAME_LEN) {
@@ -1479,7 +1607,8 @@ static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
if (str_has_prefix(argv[i], "$arg")) {
trace_probe_log_set_index(i + 2);
- if (!tparg_is_function_entry(ctx->flags)) {
+ if (!tparg_is_function_entry(ctx->flags) &&
+ !tparg_is_function_return(ctx->flags)) {
trace_probe_log_err(0, NOFENTRY_ARGS);
return -EINVAL;
}
@@ -1802,6 +1931,12 @@ void trace_probe_cleanup(struct trace_probe *tp)
for (i = 0; i < tp->nr_args; i++)
traceprobe_free_probe_arg(&tp->args[i]);
+ if (tp->entry_arg) {
+ kfree(tp->entry_arg->code);
+ kfree(tp->entry_arg);
+ tp->entry_arg = NULL;
+ }
+
if (tp->event)
trace_probe_unlink(tp);
}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index ed8d1052f8a7..cef3a50628a3 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -92,6 +92,7 @@ enum fetch_op {
FETCH_OP_ARG, /* Function argument : .param */
FETCH_OP_FOFFS, /* File offset: .immediate */
FETCH_OP_DATA, /* Allocated data: .data */
+ FETCH_OP_EDATA, /* Entry data: .offset */
// Stage 2 (dereference) op
FETCH_OP_DEREF, /* Dereference: .offset */
FETCH_OP_UDEREF, /* User-space Dereference: .offset */
@@ -102,6 +103,7 @@ enum fetch_op {
FETCH_OP_ST_STRING, /* String: .offset, .size */
FETCH_OP_ST_USTRING, /* User String: .offset, .size */
FETCH_OP_ST_SYMSTR, /* Kernel Symbol String: .offset, .size */
+ FETCH_OP_ST_EDATA, /* Store Entry Data: .offset */
// Stage 4 (modify) op
FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
// Stage 5 (loop) op
@@ -232,6 +234,11 @@ struct probe_arg {
const struct fetch_type *type; /* Type of this argument */
};
+struct probe_entry_arg {
+ struct fetch_insn *code;
+ unsigned int size; /* The entry data size */
+};
+
struct trace_uprobe_filter {
rwlock_t rwlock;
int nr_systemwide;
@@ -253,6 +260,7 @@ struct trace_probe {
struct trace_probe_event *event;
ssize_t size; /* trace entry size */
unsigned int nr_args;
+ struct probe_entry_arg *entry_arg; /* This is only for return probe */
struct probe_arg args[];
};
@@ -355,6 +363,18 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char
int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
u8 *data, void *field);
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+int traceprobe_get_entry_data_size(struct trace_probe *tp);
+/* This is a runtime function to store entry data */
+void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs);
+#else /* !CONFIG_HAVE_FUNCTION_ARG_ACCESS_API */
+static inline int traceprobe_get_entry_data_size(struct trace_probe *tp)
+{
+ return 0;
+}
+#define store_trace_entry_data(edata, tp, regs) do { } while (0)
+#endif
+
#define trace_probe_for_each_link(pos, tp) \
list_for_each_entry(pos, &(tp)->event->files, list)
#define trace_probe_for_each_link_rcu(pos, tp) \
@@ -381,6 +401,11 @@ static inline bool tparg_is_function_entry(unsigned int flags)
return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_FENTRY);
}
+static inline bool tparg_is_function_return(unsigned int flags)
+{
+ return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_RETURN);
+}
+
struct traceprobe_parse_context {
struct trace_event_call *event;
/* BTF related parameters */
@@ -392,6 +417,7 @@ struct traceprobe_parse_context {
const struct btf_type *last_type; /* Saved type */
u32 last_bitoffs; /* Saved bitoffs */
u32 last_bitsize; /* Saved bitsize */
+ struct trace_probe *tp;
unsigned int flags;
int offset;
};
@@ -506,7 +532,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(NO_BTFARG, "This variable is not found at this probe point"),\
C(NO_BTF_ENTRY, "No BTF entry for this probe point"), \
C(BAD_VAR_ARGS, "$arg* must be an independent parameter without name etc."),\
- C(NOFENTRY_ARGS, "$arg* can be used only on function entry"), \
+ C(NOFENTRY_ARGS, "$arg* can be used only on function entry or exit"), \
C(DOUBLE_ARGS, "$arg* can be used only once in the parameters"), \
C(ARGS_2LONG, "$arg* failed because the argument list is too long"), \
C(ARGIDX_2BIG, "$argN index is too big"), \
diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h
index 3935b347f874..2caf0d2afb32 100644
--- a/kernel/trace/trace_probe_tmpl.h
+++ b/kernel/trace/trace_probe_tmpl.h
@@ -54,7 +54,7 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf)
* If dest is NULL, don't store result and return required dynamic data size.
*/
static int
-process_fetch_insn(struct fetch_insn *code, void *rec,
+process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
void *dest, void *base);
static nokprobe_inline int fetch_store_strlen(unsigned long addr);
static nokprobe_inline int
@@ -232,7 +232,7 @@ process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
/* Sum up total data length for dynamic arrays (strings) */
static nokprobe_inline int
-__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
+__get_data_size(struct trace_probe *tp, struct pt_regs *regs, void *edata)
{
struct probe_arg *arg;
int i, len, ret = 0;
@@ -240,7 +240,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
if (unlikely(arg->dynamic)) {
- len = process_fetch_insn(arg->code, regs, NULL, NULL);
+ len = process_fetch_insn(arg->code, regs, edata, NULL, NULL);
if (len > 0)
ret += len;
}
@@ -251,7 +251,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
/* Store the value of each argument */
static nokprobe_inline void
-store_trace_args(void *data, struct trace_probe *tp, void *rec,
+store_trace_args(void *data, struct trace_probe *tp, void *rec, void *edata,
int header_size, int maxlen)
{
struct probe_arg *arg;
@@ -266,7 +266,7 @@ store_trace_args(void *data, struct trace_probe *tp, void *rec,
/* Point the dynamic data area if needed */
if (unlikely(arg->dynamic))
*dl = make_data_loc(maxlen, dyndata - base);
- ret = process_fetch_insn(arg->code, rec, dl, base);
+ ret = process_fetch_insn(arg->code, rec, edata, dl, base);
if (arg->dynamic && likely(ret > 0)) {
dyndata += ret;
maxlen -= ret;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 796ebcae9b38..9e461362450a 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -211,8 +211,8 @@ static unsigned long translate_user_vaddr(unsigned long file_offset)
/* Note that we don't verify it, since the code does not come from user space */
static int
-process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
- void *base)
+process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
+ void *dest, void *base)
{
struct pt_regs *regs = rec;
unsigned long val;
@@ -1490,11 +1490,11 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
- dsize = __get_data_size(&tu->tp, regs);
+ dsize = __get_data_size(&tu->tp, regs, NULL);
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get();
- store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
+ store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
ret |= uprobe_trace_func(tu, regs, ucb, dsize);
@@ -1525,11 +1525,11 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
- dsize = __get_data_size(&tu->tp, regs);
+ dsize = __get_data_size(&tu->tp, regs, NULL);
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get();
- store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
+ store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
uretprobe_trace_func(tu, func, regs, ucb, dsize);
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH v2 6/7] selftests/ftrace: Add test cases for entry args at function exit
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
` (4 preceding siblings ...)
2024-02-26 3:58 ` [PATCH v2 5/7] tracing/probes: Support $argN in return probe (kprobe and fprobe) Masami Hiramatsu (Google)
@ 2024-02-26 3:58 ` Masami Hiramatsu (Google)
2024-02-26 3:59 ` [PATCH v2 7/7] Documentation: tracing: Add entry argument access " Masami Hiramatsu (Google)
2024-02-28 16:23 ` [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Jiri Olsa
7 siblings, 0 replies; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:58 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Add kretprobe and function exit probe test cases for checking whether
those can access entry arguments at function exit correctly.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
.../ftrace/test.d/dynevent/fprobe_entry_arg.tc | 18 ++++++++++++++++++
.../ftrace/test.d/kprobe/kretprobe_entry_arg.tc | 18 ++++++++++++++++++
2 files changed, 36 insertions(+)
create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc
diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc
new file mode 100644
index 000000000000..d183b8a8ecf8
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc
@@ -0,0 +1,18 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Function return probe entry argument access
+# requires: dynamic_events 'f[:[<group>/][<event>]] <func-name>':README 'kernel return probes support:':README
+
+echo 'f:tests/myevent1 vfs_open arg=$arg1' >> dynamic_events
+echo 'f:tests/myevent2 vfs_open%return arg=$arg1' >> dynamic_events
+
+echo 1 > events/tests/enable
+
+echo > trace
+cat trace > /dev/null
+
+function streq() {
+ test $1 = $2
+}
+
+streq `grep -A 1 -m 1 myevent1 trace | sed -r 's/^.*(arg=.*)/\1/' `
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc
new file mode 100644
index 000000000000..53b82f36a1d0
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc
@@ -0,0 +1,18 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Kretprobe entry argument access
+# requires: kprobe_events 'kernel return probes support:':README
+
+echo 'p:myevent1 vfs_open arg=$arg1' >> kprobe_events
+echo 'r:myevent2 vfs_open arg=$arg1' >> kprobe_events
+
+echo 1 > events/kprobes/enable
+
+echo > trace
+cat trace > /dev/null
+
+function streq() {
+ test $1 = $2
+}
+
+streq `grep -A 1 -m 1 myevent1 trace | sed -r 's/^.*(arg=.*)/\1/' `
^ permalink raw reply related [flat|nested] 20+ messages in thread
* [PATCH v2 7/7] Documentation: tracing: Add entry argument access at function exit
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
` (5 preceding siblings ...)
2024-02-26 3:58 ` [PATCH v2 6/7] selftests/ftrace: Add test cases for entry args at function exit Masami Hiramatsu (Google)
@ 2024-02-26 3:59 ` Masami Hiramatsu (Google)
2024-02-28 16:23 ` [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Jiri Olsa
7 siblings, 0 replies; 20+ messages in thread
From: Masami Hiramatsu (Google) @ 2024-02-26 3:59 UTC (permalink / raw)
To: Steven Rostedt, Jiri Olsa
Cc: linux-kernel, linux-trace-kernel, mhiramat, linux-doc, linux-kselftest
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Add a notes about the entry argument access at function exit probes for
kprobes and fprobe trace event.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Documentation/trace/fprobetrace.rst | 7 +++++++
Documentation/trace/kprobetrace.rst | 7 +++++++
2 files changed, 14 insertions(+)
diff --git a/Documentation/trace/fprobetrace.rst b/Documentation/trace/fprobetrace.rst
index e35e6b18df40..ab71ebf178cb 100644
--- a/Documentation/trace/fprobetrace.rst
+++ b/Documentation/trace/fprobetrace.rst
@@ -70,6 +70,13 @@ Synopsis of fprobe-events
For the details of TYPE, see :ref:`kprobetrace documentation <kprobetrace_types>`.
+Function arguments at exit
+--------------------------
+Function arguments can be accessed at exit probe using $arg<N> fetcharg. This
+is useful to record the function parameter and return value at once, and
+trace the difference of structure fields (for debuging a function whether it
+correctly updates the given data structure or not)
+
BTF arguments
-------------
BTF (BPF Type Format) argument allows user to trace function and tracepoint
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
index bf9cecb69fc9..35a383f95746 100644
--- a/Documentation/trace/kprobetrace.rst
+++ b/Documentation/trace/kprobetrace.rst
@@ -70,6 +70,13 @@ Synopsis of kprobe_events
(\*3) this is useful for fetching a field of data structures.
(\*4) "u" means user-space dereference. See :ref:`user_mem_access`.
+Function arguments at kretprobe
+-------------------------------
+Function arguments can be accessed at kretprobe using $arg<N> fetcharg. This
+is useful to record the function parameter and return value at once, and
+trace the difference of structure fields (for debuging a function whether it
+correctly updates the given data structure or not)
+
.. _kprobetrace_types:
Types
^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
` (6 preceding siblings ...)
2024-02-26 3:59 ` [PATCH v2 7/7] Documentation: tracing: Add entry argument access " Masami Hiramatsu (Google)
@ 2024-02-28 16:23 ` Jiri Olsa
2024-02-29 5:51 ` Masami Hiramatsu
7 siblings, 1 reply; 20+ messages in thread
From: Jiri Olsa @ 2024-02-28 16:23 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Steven Rostedt, linux-kernel, linux-trace-kernel, linux-doc,
linux-kselftest
On Mon, Feb 26, 2024 at 12:57:53PM +0900, Masami Hiramatsu (Google) wrote:
> Hi,
>
> Here is version 2 series of patches to support accessing function entry data
> from function *return* probes (including kretprobe and fprobe-exit event).
>
> In this version, I added another cleanup [4/7], updated README[5/7], added
> testcases[6/7] and updated document[7/7].
>
> This allows us to access the results of some functions, which returns the
> error code and its results are passed via function parameter, such as an
> structure-initialization function.
>
> For example, vfs_open() will link the file structure to the inode and update
> mode. Thus we can trace that changes.
>
> # echo 'f vfs_open mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
> # echo 'f vfs_open%return mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
> # echo 1 > events/fprobes/enable
> # cat trace
> sh-131 [006] ...1. 1945.714346: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x2 inode=0x0
> sh-131 [006] ...1. 1945.714358: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4d801e inode=0xffff888008470168
> cat-143 [007] ...1. 1945.717949: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
> cat-143 [007] ...1. 1945.717956: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4a801d inode=0xffff888005f78d28
> cat-143 [007] ...1. 1945.720616: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
> cat-143 [007] ...1. 1945.728263: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0xa800d inode=0xffff888004ada8d8
hi,
I hit a crash while playing with this, by runnning:
# echo 'f vfs_read%return $arg*' >> dynamic_events
# echo 1 > events/fprobes/enable
jirka
---
[ 86.805519][ T712] general protection fault, probably for non-canonical address 0xef01a20a8bd21200: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
[ 86.807259][ T712] CPU: 0 PID: 712 Comm: cat Not tainted 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
[ 86.808417][ T712] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
[ 86.809294][ T712] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.809930][ T712] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.811727][ T712] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
[ 86.812316][ T712] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
[ 86.813106][ T712] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
[ 86.813881][ T712] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
[ 86.814626][ T712] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
[ 86.815357][ T712] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
[ 86.816114][ T712] FS: 00007f22d7c1f740(0000) GS:ffff88846ce00000(0000) knlGS:0000000000000000
[ 86.816885][ T712] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.817455][ T712] CR2: 00007f22d7b9c000 CR3: 0000000176918001 CR4: 0000000000770ef0
[ 86.818221][ T712] PKRU: 55555554
[ 86.818579][ T712] Call Trace:
[ 86.818900][ T712] <TASK>
[ 86.819194][ T712] ? die_addr+0x32/0x80
[ 86.819583][ T712] ? exc_general_protection+0x276/0x4d0
[ 86.820079][ T712] ? asm_exc_general_protection+0x22/0x30
[ 86.820600][ T712] ? ksys_read+0x69/0xf0
[ 86.821022][ T712] ? ksys_read+0x69/0xf0
[ 86.821422][ T712] ? rethook_trampoline_handler+0x8e/0x200
[ 86.821984][ T712] ? rethook_trampoline_handler+0x91/0x200
[ 86.822539][ T712] arch_rethook_trampoline_callback+0x36/0x50
[ 86.823097][ T712] arch_rethook_trampoline+0x2c/0x60
[ 86.823584][ T712] ? ksys_read+0x69/0xf0
[ 86.823962][ T712] osnoise_arch_unregister+0x210/0x210
[ 86.824463][ T712] do_syscall_64+0x87/0x1b0
[ 86.824910][ T712] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 86.825418][ T712] RIP: 0033:0x7f22d7d230b1
[ 86.825859][ T712] Code: d5 fe ff ff 55 48 8d 3d 25 47 0a 00 48 89 e5 e8 b5 18 02 00 0f 1f 44 00 00 f3 0f 1e fa 80 3d 2d b5 0d 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec
[ 86.827635][ T712] RSP: 002b:00007fffdaaef668 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 86.828355][ T712] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f22d7d230b1
[ 86.829017][ T712] RDX: 0000000000020000 RSI: 00007f22d7b9c000 RDI: 0000000000000003
[ 86.829710][ T712] RBP: 00007fffdaaef690 R08: 00000000ffffffff R09: 0000000000000000
[ 86.831165][ T712] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000
[ 86.831910][ T712] R13: 00007f22d7b9c000 R14: 0000000000000003 R15: 0000000000000000
[ 86.832691][ T712] </TASK>
[ 86.833016][ T712] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
[ 86.835078][ T634] general protection fault, probably for non-canonical address 0x440038d965baf00: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
[ 86.835196][ T712] ---[ end trace 0000000000000000 ]---
[ 86.835943][ T634] CPU: 3 PID: 634 Comm: sshd Tainted: G D 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
[ 86.835946][ T634] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
[ 86.835947][ T634] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.835952][ T634] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.836363][ T712] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.837090][ T634] RSP: 0018:ffffc90001d3bdf8 EFLAGS: 00010206
[ 86.837776][ T712] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.838205][ T634]
[ 86.839488][ T712] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
[ 86.839890][ T634] RAX: ffffc90001d3bef0 RBX: ffff888176cbbaa0 RCX: ffffc90001d3be40
[ 86.840239][ T712]
[ 86.840240][ T712] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
[ 86.841309][ T634] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888176cbba90
[ 86.841311][ T634] RBP: ffff888176cbbaa0 R08: 0000000000000001 R09: 0000000000000000
[ 86.841312][ T634] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff81545129
[ 86.841313][ T634] R13: 0440038d965baf00 R14: ffffc90001d3bee8 R15: ffffc90001d3be40
[ 86.841314][ T634] FS: 00007f1ddf838940(0000) GS:ffff88846da00000(0000) knlGS:0000000000000000
[ 86.841316][ T634] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.841477][ T712] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
[ 86.841800][ T634] CR2: 0000559fb5f9f000 CR3: 0000000176e2e004 CR4: 0000000000770ef0
[ 86.842308][ T712] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
[ 86.842456][ T634] PKRU: 55555554
[ 86.842458][ T634] Call Trace:
[ 86.842459][ T634] <TASK>
[ 86.842462][ T634] ? die_addr+0x32/0x80
[ 86.842978][ T712] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
[ 86.843508][ T634] ? exc_general_protection+0x276/0x4d0
[ 86.843516][ T634] ? asm_exc_general_protection+0x22/0x30
[ 86.844002][ T712] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
[ 86.844004][ T712] FS: 00007f22d7c1f740(0000) GS:ffff88846ce00000(0000) knlGS:0000000000000000
[ 86.844503][ T634] ? ksys_read+0x69/0xf0
[ 86.844507][ T634] ? ksys_read+0x69/0xf0
[ 86.844510][ T634] ? rethook_trampoline_handler+0x8e/0x200
[ 86.845033][ T712] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.845677][ T634] ? rethook_trampoline_handler+0x91/0x200
[ 86.845680][ T634] arch_rethook_trampoline_callback+0x36/0x50
[ 86.845684][ T634] arch_rethook_trampoline+0x2c/0x60
[ 86.846111][ T712] CR2: 00007f22d7b9c000 CR3: 0000000176918001 CR4: 0000000000770ef0
[ 86.846674][ T634] ? ksys_read+0x69/0xf0
[ 86.846679][ T634] osnoise_arch_unregister+0x210/0x210
[ 86.847213][ T712] PKRU: 55555554
[ 86.847648][ T634] do_syscall_64+0x87/0x1b0
[ 86.847653][ T634] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 86.847868][ T712] note: cat[712] exited with preempt_count 1
[ 86.848096][ T634] RIP: 0033:0x7f1ddfc4a0b1
[ 86.869351][ T634] Code: d5 fe ff ff 55 48 8d 3d 25 47 0a 00 48 89 e5 e8 b5 18 02 00 0f 1f 44 00 00 f3 0f 1e fa 80 3d 2d b5 0d 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec
[ 86.871186][ T634] RSP: 002b:00007fffdd061ae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 86.871995][ T634] RAX: ffffffffffffffda RBX: 0000000000008000 RCX: 00007f1ddfc4a0b1
[ 86.872785][ T634] RDX: 0000000000008000 RSI: 000055bbb41e37b0 RDI: 000000000000000c
[ 86.873553][ T634] RBP: 00007fffdd061b50 R08: 0000000000000000 R09: 0000000000000000
[ 86.874320][ T634] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
[ 86.874960][ T634] R13: 0000000000000000 R14: 000055bbb4172840 R15: 000000000000000c
[ 86.875670][ T634] </TASK>
[ 86.875964][ T634] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
[ 86.877814][ T634] ---[ end trace 0000000000000000 ]---
[ 86.877991][ T450] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
[ 86.878210][ T634] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.878217][ T634] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.878219][ T634] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
[ 86.878221][ T634] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
[ 86.878222][ T634] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
[ 86.878224][ T634] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
[ 86.878225][ T634] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
[ 86.878226][ T634] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
[ 86.878227][ T634] FS: 00007f1ddf838940(0000) GS:ffff88846da00000(0000) knlGS:0000000000000000
[ 86.878228][ T634] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.878230][ T634] CR2: 0000559fb5f9f000 CR3: 0000000176e2e004 CR4: 0000000000770ef0
[ 86.878233][ T634] PKRU: 55555554
[ 86.878235][ T634] note: sshd[634] exited with preempt_count 1
[ 86.888492][ T450] BUG: unable to handle page fault for address: ffffc90001cdff58
[ 86.889266][ T450] #PF: supervisor instruction fetch in kernel mode
[ 86.889914][ T450] #PF: error_code(0x0011) - permissions violation
[ 86.891248][ T450] PGD 100000067 P4D 100000067 PUD 102a49067 PMD 10b3ee067 PTE 8000000109295163
[ 86.892032][ T450] Oops: 0011 [#3] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
[ 86.892560][ T450] CPU: 1 PID: 450 Comm: systemd-journal Tainted: G D 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
[ 86.893758][ T450] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
[ 86.894542][ T450] RIP: 0010:0xffffc90001cdff58
[ 86.894964][ T450] Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 e6 00 60 82 ff ff ff ff <00> 00 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 86.896519][ T450] RSP: 0018:ffffc90000b13df0 EFLAGS: 00010282
[ 86.897004][ T450] RAX: ffffc90001cdfef0 RBX: ffff88817759a8a0 RCX: ffffc90000b13e40
[ 86.897672][ T450] RDX: ffffffff81545129 RSI: ffffffffffffffff RDI: ffff88817759a890
[ 86.898341][ T450] RBP: ffff88817759a8a0 R08: 0000000000000001 R09: ffff888102b2c470
[ 86.899143][ T450] R10: ffffc90000b13e58 R11: ffffffff83976548 R12: ffffffff81545129
[ 86.899871][ T450] R13: ffffc90001cdff58 R14: ffffc90000b13ee8 R15: ffffc90000b13e40
[ 86.900547][ T450] FS: 00007f20a7635940(0000) GS:ffff88846d200000(0000) knlGS:0000000000000000
[ 86.901259][ T450] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.901773][ T450] CR2: ffffc90001cdff58 CR3: 0000000176a7a003 CR4: 0000000000770ef0
[ 86.902411][ T450] PKRU: 55555554
[ 86.902722][ T450] Call Trace:
[ 86.903009][ T450] <TASK>
[ 86.903271][ T450] ? __die+0x1f/0x70
[ 86.903613][ T450] ? page_fault_oops+0x176/0x4d0
[ 86.904126][ T450] ? exc_page_fault+0x16c/0x250
[ 86.904614][ T450] ? asm_exc_page_fault+0x22/0x30
[ 86.905140][ T450] ? ksys_read+0x69/0xf0
[ 86.905615][ T450] ? ksys_read+0x69/0xf0
[ 86.906053][ T450] ? rethook_trampoline_handler+0x91/0x200
[ 86.906643][ T450] ? arch_rethook_trampoline_callback+0x36/0x50
[ 86.907271][ T450] ? arch_rethook_trampoline+0x2c/0x60
[ 86.907845][ T450] ? ksys_read+0x69/0xf0
[ 86.908300][ T450] ? osnoise_arch_unregister+0x210/0x210
[ 86.908781][ T450] ? do_syscall_64+0x87/0x1b0
[ 86.909186][ T450] ? entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 86.909681][ T450] </TASK>
[ 86.909959][ T450] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
[ 86.911681][ T450] CR2: ffffc90001cdff58
[ 86.912108][ T450] ---[ end trace 0000000000000000 ]---
[ 86.912674][ T450] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.913232][ T450] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.914702][ T450] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
[ 86.915196][ T450] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
[ 86.915853][ T450] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
[ 86.916644][ T450] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
[ 86.917449][ T450] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
[ 86.918238][ T450] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
[ 86.919043][ T450] FS: 00007f20a7635940(0000) GS:ffff88846d200000(0000) knlGS:0000000000000000
[ 86.919906][ T450] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.921265][ T450] CR2: ffffc90001cdff58 CR3: 0000000176a7a003 CR4: 0000000000770ef0
[ 86.921972][ T450] PKRU: 55555554
[ 86.922365][ T450] note: systemd-journal[450] exited with irqs disabled
[ 86.923076][ T450] note: systemd-journal[450] exited with preempt_count 1
[ 86.927597][ T47] audit: type=1106 audit(1709132147.391:266): pid=619 uid=0 auid=1000 ses=1 subj=system_u:system_r:sshd_t:s0-s0:c0.c1023 msg='op=PAM:session_close grantors=pam_selinux,pam_loginuid,pam_selinux,pam_namespace,pam_keyinit,pam_keyinit,pam_limits,pam_systemd,pam_unix,pam_umask,pam_lastlog acct="jolsa" exe="/usr/sbin/sshd" hostname=192.168.122.1 addr=192.168.122.1 terminal=ssh res=success'
[ 86.928777][ T450] systemd-journal (450) used greatest stack depth: 11424 bytes left
[ 86.929578][ T1] general protection fault, probably for non-canonical address 0xd4f06e07d9d64800: 0000 [#4] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
[ 86.929582][ T1] CPU: 2 PID: 1 Comm: systemd Tainted: G D 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
[ 86.929584][ T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
[ 86.929586][ T1] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.929591][ T1] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.929592][ T1] RSP: 0018:ffffc90000013df8 EFLAGS: 00010286
[ 86.929594][ T1] RAX: ffffc90000013ef0 RBX: ffff888177598aa0 RCX: ffffc90000013e40
[ 86.929595][ T1] RDX: ffffffff81545129 RSI: 0000000000000010 RDI: ffff888177598a90
[ 86.929596][ T1] RBP: ffff888177598aa0 R08: 0000000000000010 R09: ffff888175005750
[ 86.929597][ T1] R10: 0000000000000000 R11: ffffc90000013dd8 R12: ffffffff81545129
[ 86.929598][ T1] R13: d4f06e07d9d64800 R14: ffffc90000013ee8 R15: ffffc90000013e40
[ 86.929599][ T1] FS: 00007f0ec5012940(0000) GS:ffff88846d600000(0000) knlGS:0000000000000000
[ 86.929600][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.929601][ T1] CR2: 00005595e83bf5b0 CR3: 000000010805e001 CR4: 0000000000770ef0
[ 86.929604][ T1] PKRU: 55555554
[ 86.929605][ T1] Call Trace:
[ 86.929606][ T1] <TASK>
[ 86.929606][ T1] ? die_addr+0x32/0x80
[ 86.929610][ T1] ? exc_general_protection+0x276/0x4d0
[ 86.929616][ T1] ? asm_exc_general_protection+0x22/0x30
[ 86.929621][ T1] ? ksys_read+0x69/0xf0
[ 86.929624][ T1] ? ksys_read+0x69/0xf0
[ 86.929627][ T1] ? rethook_trampoline_handler+0x8e/0x200
[ 86.929629][ T1] ? rethook_trampoline_handler+0x91/0x200
[ 86.929631][ T1] arch_rethook_trampoline_callback+0x36/0x50
[ 86.929635][ T1] arch_rethook_trampoline+0x2c/0x60
[ 86.929639][ T1] ? ksys_read+0x69/0xf0
[ 86.929640][ T1] osnoise_arch_unregister+0x210/0x210
[ 86.929643][ T1] do_syscall_64+0x87/0x1b0
[ 86.929645][ T1] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 86.929647][ T1] RIP: 0033:0x7f0ec49230ea
[ 86.929653][ T1] Code: 55 48 89 e5 48 83 ec 20 48 89 55 e8 48 89 75 f0 89 7d f8 e8 e8 79 f8 ff 48 8b 55 e8 48 8b 75 f0 41 89 c0 8b 7d f8 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 2e 44 89 c7 48 89 45 f8 e8 42 7a f8 ff 48 8b
[ 86.929655][ T1] RSP: 002b:00007ffead1dc7a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 86.929656][ T1] RAX: ffffffffffffffda RBX: 00005625bff4efe0 RCX: 00007f0ec49230ea
[ 86.929657][ T1] RDX: 0000000000000400 RSI: 00005625bfeda010 RDI: 0000000000000019
[ 86.929658][ T1] RBP: 00007ffead1dc7c0 R08: 0000000000000000 R09: 0000000000000001
[ 86.929659][ T1] R10: 0000000000001000 R11: 0000000000000246 R12: 00007f0ec49f3660
[ 86.929659][ T1] R13: 00007f0ec50127d0 R14: 0000000000000a68 R15: 00007f0ec49f2d60
[ 86.929663][ T1] </TASK>
[ 86.929663][ T1] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
[ 86.929676][ T1] ---[ end trace 0000000000000000 ]---
[ 86.929677][ T1] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
[ 86.929679][ T1] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
[ 86.929680][ T1] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
[ 86.929681][ T1] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
[ 86.929682][ T1] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
[ 86.929683][ T1] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
[ 86.929684][ T1] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
[ 86.929685][ T1] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
[ 86.929686][ T1] FS: 00007f0ec5012940(0000) GS:ffff88846d600000(0000) knlGS:0000000000000000
[ 86.929687][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 86.929688][ T1] CR2: 00005595e83bf5b0 CR3: 000000010805e001 CR4: 0000000000770ef0
[ 86.929688][ T1] PKRU: 55555554
[ 86.929689][ T1] note: systemd[1] exited with preempt_count 1
[ 86.929692][ T1] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[ 86.929992][ T1] Kernel Offset: disabled
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-02-28 16:23 ` [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Jiri Olsa
@ 2024-02-29 5:51 ` Masami Hiramatsu
2024-02-29 6:38 ` Masami Hiramatsu
0 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu @ 2024-02-29 5:51 UTC (permalink / raw)
To: Jiri Olsa
Cc: Steven Rostedt, linux-kernel, linux-trace-kernel, linux-doc,
linux-kselftest
On Wed, 28 Feb 2024 17:23:34 +0100
Jiri Olsa <olsajiri@gmail.com> wrote:
> On Mon, Feb 26, 2024 at 12:57:53PM +0900, Masami Hiramatsu (Google) wrote:
> > Hi,
> >
> > Here is version 2 series of patches to support accessing function entry data
> > from function *return* probes (including kretprobe and fprobe-exit event).
> >
> > In this version, I added another cleanup [4/7], updated README[5/7], added
> > testcases[6/7] and updated document[7/7].
> >
> > This allows us to access the results of some functions, which returns the
> > error code and its results are passed via function parameter, such as an
> > structure-initialization function.
> >
> > For example, vfs_open() will link the file structure to the inode and update
> > mode. Thus we can trace that changes.
> >
> > # echo 'f vfs_open mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
> > # echo 'f vfs_open%return mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
> > # echo 1 > events/fprobes/enable
> > # cat trace
> > sh-131 [006] ...1. 1945.714346: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x2 inode=0x0
> > sh-131 [006] ...1. 1945.714358: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4d801e inode=0xffff888008470168
> > cat-143 [007] ...1. 1945.717949: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
> > cat-143 [007] ...1. 1945.717956: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4a801d inode=0xffff888005f78d28
> > cat-143 [007] ...1. 1945.720616: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
> > cat-143 [007] ...1. 1945.728263: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0xa800d inode=0xffff888004ada8d8
>
> hi,
> I hit a crash while playing with this, by runnning:
>
> # echo 'f vfs_read%return $arg*' >> dynamic_events
> # echo 1 > events/fprobes/enable
Thanks for reporting! But I can not reproduce it.
Can you share your kconfig?
>
> jirka
>
>
> ---
> [ 86.805519][ T712] general protection fault, probably for non-canonical address 0xef01a20a8bd21200: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
> [ 86.807259][ T712] CPU: 0 PID: 712 Comm: cat Not tainted 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
> [ 86.808417][ T712] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
> [ 86.809294][ T712] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.809930][ T712] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.811727][ T712] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
> [ 86.812316][ T712] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
> [ 86.813106][ T712] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
> [ 86.813881][ T712] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
> [ 86.814626][ T712] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
> [ 86.815357][ T712] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
> [ 86.816114][ T712] FS: 00007f22d7c1f740(0000) GS:ffff88846ce00000(0000) knlGS:0000000000000000
> [ 86.816885][ T712] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.817455][ T712] CR2: 00007f22d7b9c000 CR3: 0000000176918001 CR4: 0000000000770ef0
> [ 86.818221][ T712] PKRU: 55555554
> [ 86.818579][ T712] Call Trace:
> [ 86.818900][ T712] <TASK>
> [ 86.819194][ T712] ? die_addr+0x32/0x80
> [ 86.819583][ T712] ? exc_general_protection+0x276/0x4d0
> [ 86.820079][ T712] ? asm_exc_general_protection+0x22/0x30
> [ 86.820600][ T712] ? ksys_read+0x69/0xf0
> [ 86.821022][ T712] ? ksys_read+0x69/0xf0
> [ 86.821422][ T712] ? rethook_trampoline_handler+0x8e/0x200
> [ 86.821984][ T712] ? rethook_trampoline_handler+0x91/0x200
> [ 86.822539][ T712] arch_rethook_trampoline_callback+0x36/0x50
> [ 86.823097][ T712] arch_rethook_trampoline+0x2c/0x60
> [ 86.823584][ T712] ? ksys_read+0x69/0xf0
> [ 86.823962][ T712] osnoise_arch_unregister+0x210/0x210
> [ 86.824463][ T712] do_syscall_64+0x87/0x1b0
> [ 86.824910][ T712] entry_SYSCALL_64_after_hwframe+0x6e/0x76
> [ 86.825418][ T712] RIP: 0033:0x7f22d7d230b1
> [ 86.825859][ T712] Code: d5 fe ff ff 55 48 8d 3d 25 47 0a 00 48 89 e5 e8 b5 18 02 00 0f 1f 44 00 00 f3 0f 1e fa 80 3d 2d b5 0d 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec
> [ 86.827635][ T712] RSP: 002b:00007fffdaaef668 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> [ 86.828355][ T712] RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f22d7d230b1
> [ 86.829017][ T712] RDX: 0000000000020000 RSI: 00007f22d7b9c000 RDI: 0000000000000003
> [ 86.829710][ T712] RBP: 00007fffdaaef690 R08: 00000000ffffffff R09: 0000000000000000
> [ 86.831165][ T712] R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020000
> [ 86.831910][ T712] R13: 00007f22d7b9c000 R14: 0000000000000003 R15: 0000000000000000
> [ 86.832691][ T712] </TASK>
> [ 86.833016][ T712] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
> [ 86.835078][ T634] general protection fault, probably for non-canonical address 0x440038d965baf00: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
> [ 86.835196][ T712] ---[ end trace 0000000000000000 ]---
> [ 86.835943][ T634] CPU: 3 PID: 634 Comm: sshd Tainted: G D 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
> [ 86.835946][ T634] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
> [ 86.835947][ T634] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.835952][ T634] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.836363][ T712] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.837090][ T634] RSP: 0018:ffffc90001d3bdf8 EFLAGS: 00010206
> [ 86.837776][ T712] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.838205][ T634]
> [ 86.839488][ T712] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
> [ 86.839890][ T634] RAX: ffffc90001d3bef0 RBX: ffff888176cbbaa0 RCX: ffffc90001d3be40
> [ 86.840239][ T712]
> [ 86.840240][ T712] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
> [ 86.841309][ T634] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888176cbba90
> [ 86.841311][ T634] RBP: ffff888176cbbaa0 R08: 0000000000000001 R09: 0000000000000000
> [ 86.841312][ T634] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff81545129
> [ 86.841313][ T634] R13: 0440038d965baf00 R14: ffffc90001d3bee8 R15: ffffc90001d3be40
> [ 86.841314][ T634] FS: 00007f1ddf838940(0000) GS:ffff88846da00000(0000) knlGS:0000000000000000
> [ 86.841316][ T634] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.841477][ T712] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
> [ 86.841800][ T634] CR2: 0000559fb5f9f000 CR3: 0000000176e2e004 CR4: 0000000000770ef0
> [ 86.842308][ T712] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
> [ 86.842456][ T634] PKRU: 55555554
> [ 86.842458][ T634] Call Trace:
> [ 86.842459][ T634] <TASK>
> [ 86.842462][ T634] ? die_addr+0x32/0x80
> [ 86.842978][ T712] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
> [ 86.843508][ T634] ? exc_general_protection+0x276/0x4d0
> [ 86.843516][ T634] ? asm_exc_general_protection+0x22/0x30
> [ 86.844002][ T712] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
> [ 86.844004][ T712] FS: 00007f22d7c1f740(0000) GS:ffff88846ce00000(0000) knlGS:0000000000000000
> [ 86.844503][ T634] ? ksys_read+0x69/0xf0
> [ 86.844507][ T634] ? ksys_read+0x69/0xf0
> [ 86.844510][ T634] ? rethook_trampoline_handler+0x8e/0x200
> [ 86.845033][ T712] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.845677][ T634] ? rethook_trampoline_handler+0x91/0x200
> [ 86.845680][ T634] arch_rethook_trampoline_callback+0x36/0x50
> [ 86.845684][ T634] arch_rethook_trampoline+0x2c/0x60
> [ 86.846111][ T712] CR2: 00007f22d7b9c000 CR3: 0000000176918001 CR4: 0000000000770ef0
> [ 86.846674][ T634] ? ksys_read+0x69/0xf0
> [ 86.846679][ T634] osnoise_arch_unregister+0x210/0x210
> [ 86.847213][ T712] PKRU: 55555554
> [ 86.847648][ T634] do_syscall_64+0x87/0x1b0
> [ 86.847653][ T634] entry_SYSCALL_64_after_hwframe+0x6e/0x76
> [ 86.847868][ T712] note: cat[712] exited with preempt_count 1
> [ 86.848096][ T634] RIP: 0033:0x7f1ddfc4a0b1
> [ 86.869351][ T634] Code: d5 fe ff ff 55 48 8d 3d 25 47 0a 00 48 89 e5 e8 b5 18 02 00 0f 1f 44 00 00 f3 0f 1e fa 80 3d 2d b5 0d 00 00 74 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 4f c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec
> [ 86.871186][ T634] RSP: 002b:00007fffdd061ae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> [ 86.871995][ T634] RAX: ffffffffffffffda RBX: 0000000000008000 RCX: 00007f1ddfc4a0b1
> [ 86.872785][ T634] RDX: 0000000000008000 RSI: 000055bbb41e37b0 RDI: 000000000000000c
> [ 86.873553][ T634] RBP: 00007fffdd061b50 R08: 0000000000000000 R09: 0000000000000000
> [ 86.874320][ T634] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
> [ 86.874960][ T634] R13: 0000000000000000 R14: 000055bbb4172840 R15: 000000000000000c
> [ 86.875670][ T634] </TASK>
> [ 86.875964][ T634] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
> [ 86.877814][ T634] ---[ end trace 0000000000000000 ]---
> [ 86.877991][ T450] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
> [ 86.878210][ T634] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.878217][ T634] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.878219][ T634] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
> [ 86.878221][ T634] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
> [ 86.878222][ T634] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
> [ 86.878224][ T634] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
> [ 86.878225][ T634] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
> [ 86.878226][ T634] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
> [ 86.878227][ T634] FS: 00007f1ddf838940(0000) GS:ffff88846da00000(0000) knlGS:0000000000000000
> [ 86.878228][ T634] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.878230][ T634] CR2: 0000559fb5f9f000 CR3: 0000000176e2e004 CR4: 0000000000770ef0
> [ 86.878233][ T634] PKRU: 55555554
> [ 86.878235][ T634] note: sshd[634] exited with preempt_count 1
> [ 86.888492][ T450] BUG: unable to handle page fault for address: ffffc90001cdff58
> [ 86.889266][ T450] #PF: supervisor instruction fetch in kernel mode
> [ 86.889914][ T450] #PF: error_code(0x0011) - permissions violation
> [ 86.891248][ T450] PGD 100000067 P4D 100000067 PUD 102a49067 PMD 10b3ee067 PTE 8000000109295163
> [ 86.892032][ T450] Oops: 0011 [#3] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
> [ 86.892560][ T450] CPU: 1 PID: 450 Comm: systemd-journal Tainted: G D 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
> [ 86.893758][ T450] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
> [ 86.894542][ T450] RIP: 0010:0xffffc90001cdff58
> [ 86.894964][ T450] Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 e6 00 60 82 ff ff ff ff <00> 00 00 00 00 00 00 00 03 00 00 00 00 00 00 00 00 00 00 00 00 00
> [ 86.896519][ T450] RSP: 0018:ffffc90000b13df0 EFLAGS: 00010282
> [ 86.897004][ T450] RAX: ffffc90001cdfef0 RBX: ffff88817759a8a0 RCX: ffffc90000b13e40
> [ 86.897672][ T450] RDX: ffffffff81545129 RSI: ffffffffffffffff RDI: ffff88817759a890
> [ 86.898341][ T450] RBP: ffff88817759a8a0 R08: 0000000000000001 R09: ffff888102b2c470
> [ 86.899143][ T450] R10: ffffc90000b13e58 R11: ffffffff83976548 R12: ffffffff81545129
> [ 86.899871][ T450] R13: ffffc90001cdff58 R14: ffffc90000b13ee8 R15: ffffc90000b13e40
> [ 86.900547][ T450] FS: 00007f20a7635940(0000) GS:ffff88846d200000(0000) knlGS:0000000000000000
> [ 86.901259][ T450] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.901773][ T450] CR2: ffffc90001cdff58 CR3: 0000000176a7a003 CR4: 0000000000770ef0
> [ 86.902411][ T450] PKRU: 55555554
> [ 86.902722][ T450] Call Trace:
> [ 86.903009][ T450] <TASK>
> [ 86.903271][ T450] ? __die+0x1f/0x70
> [ 86.903613][ T450] ? page_fault_oops+0x176/0x4d0
> [ 86.904126][ T450] ? exc_page_fault+0x16c/0x250
> [ 86.904614][ T450] ? asm_exc_page_fault+0x22/0x30
> [ 86.905140][ T450] ? ksys_read+0x69/0xf0
> [ 86.905615][ T450] ? ksys_read+0x69/0xf0
> [ 86.906053][ T450] ? rethook_trampoline_handler+0x91/0x200
> [ 86.906643][ T450] ? arch_rethook_trampoline_callback+0x36/0x50
> [ 86.907271][ T450] ? arch_rethook_trampoline+0x2c/0x60
> [ 86.907845][ T450] ? ksys_read+0x69/0xf0
> [ 86.908300][ T450] ? osnoise_arch_unregister+0x210/0x210
> [ 86.908781][ T450] ? do_syscall_64+0x87/0x1b0
> [ 86.909186][ T450] ? entry_SYSCALL_64_after_hwframe+0x6e/0x76
> [ 86.909681][ T450] </TASK>
> [ 86.909959][ T450] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
> [ 86.911681][ T450] CR2: ffffc90001cdff58
> [ 86.912108][ T450] ---[ end trace 0000000000000000 ]---
> [ 86.912674][ T450] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.913232][ T450] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.914702][ T450] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
> [ 86.915196][ T450] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
> [ 86.915853][ T450] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
> [ 86.916644][ T450] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
> [ 86.917449][ T450] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
> [ 86.918238][ T450] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
> [ 86.919043][ T450] FS: 00007f20a7635940(0000) GS:ffff88846d200000(0000) knlGS:0000000000000000
> [ 86.919906][ T450] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.921265][ T450] CR2: ffffc90001cdff58 CR3: 0000000176a7a003 CR4: 0000000000770ef0
> [ 86.921972][ T450] PKRU: 55555554
> [ 86.922365][ T450] note: systemd-journal[450] exited with irqs disabled
> [ 86.923076][ T450] note: systemd-journal[450] exited with preempt_count 1
> [ 86.927597][ T47] audit: type=1106 audit(1709132147.391:266): pid=619 uid=0 auid=1000 ses=1 subj=system_u:system_r:sshd_t:s0-s0:c0.c1023 msg='op=PAM:session_close grantors=pam_selinux,pam_loginuid,pam_selinux,pam_namespace,pam_keyinit,pam_keyinit,pam_limits,pam_systemd,pam_unix,pam_umask,pam_lastlog acct="jolsa" exe="/usr/sbin/sshd" hostname=192.168.122.1 addr=192.168.122.1 terminal=ssh res=success'
> [ 86.928777][ T450] systemd-journal (450) used greatest stack depth: 11424 bytes left
> [ 86.929578][ T1] general protection fault, probably for non-canonical address 0xd4f06e07d9d64800: 0000 [#4] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
> [ 86.929582][ T1] CPU: 2 PID: 1 Comm: systemd Tainted: G D 6.8.0-rc5+ #432 b8184d32457f2dd20b7178757a1fce97b3f847e2
> [ 86.929584][ T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014
> [ 86.929586][ T1] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.929591][ T1] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.929592][ T1] RSP: 0018:ffffc90000013df8 EFLAGS: 00010286
> [ 86.929594][ T1] RAX: ffffc90000013ef0 RBX: ffff888177598aa0 RCX: ffffc90000013e40
> [ 86.929595][ T1] RDX: ffffffff81545129 RSI: 0000000000000010 RDI: ffff888177598a90
> [ 86.929596][ T1] RBP: ffff888177598aa0 R08: 0000000000000010 R09: ffff888175005750
> [ 86.929597][ T1] R10: 0000000000000000 R11: ffffc90000013dd8 R12: ffffffff81545129
> [ 86.929598][ T1] R13: d4f06e07d9d64800 R14: ffffc90000013ee8 R15: ffffc90000013e40
> [ 86.929599][ T1] FS: 00007f0ec5012940(0000) GS:ffff88846d600000(0000) knlGS:0000000000000000
> [ 86.929600][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.929601][ T1] CR2: 00005595e83bf5b0 CR3: 000000010805e001 CR4: 0000000000770ef0
> [ 86.929604][ T1] PKRU: 55555554
> [ 86.929605][ T1] Call Trace:
> [ 86.929606][ T1] <TASK>
> [ 86.929606][ T1] ? die_addr+0x32/0x80
> [ 86.929610][ T1] ? exc_general_protection+0x276/0x4d0
> [ 86.929616][ T1] ? asm_exc_general_protection+0x22/0x30
> [ 86.929621][ T1] ? ksys_read+0x69/0xf0
> [ 86.929624][ T1] ? ksys_read+0x69/0xf0
> [ 86.929627][ T1] ? rethook_trampoline_handler+0x8e/0x200
> [ 86.929629][ T1] ? rethook_trampoline_handler+0x91/0x200
> [ 86.929631][ T1] arch_rethook_trampoline_callback+0x36/0x50
> [ 86.929635][ T1] arch_rethook_trampoline+0x2c/0x60
> [ 86.929639][ T1] ? ksys_read+0x69/0xf0
> [ 86.929640][ T1] osnoise_arch_unregister+0x210/0x210
> [ 86.929643][ T1] do_syscall_64+0x87/0x1b0
> [ 86.929645][ T1] entry_SYSCALL_64_after_hwframe+0x6e/0x76
> [ 86.929647][ T1] RIP: 0033:0x7f0ec49230ea
> [ 86.929653][ T1] Code: 55 48 89 e5 48 83 ec 20 48 89 55 e8 48 89 75 f0 89 7d f8 e8 e8 79 f8 ff 48 8b 55 e8 48 8b 75 f0 41 89 c0 8b 7d f8 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 2e 44 89 c7 48 89 45 f8 e8 42 7a f8 ff 48 8b
> [ 86.929655][ T1] RSP: 002b:00007ffead1dc7a0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> [ 86.929656][ T1] RAX: ffffffffffffffda RBX: 00005625bff4efe0 RCX: 00007f0ec49230ea
> [ 86.929657][ T1] RDX: 0000000000000400 RSI: 00005625bfeda010 RDI: 0000000000000019
> [ 86.929658][ T1] RBP: 00007ffead1dc7c0 R08: 0000000000000000 R09: 0000000000000001
> [ 86.929659][ T1] R10: 0000000000001000 R11: 0000000000000246 R12: 00007f0ec49f3660
> [ 86.929659][ T1] R13: 00007f0ec50127d0 R14: 0000000000000a68 R15: 00007f0ec49f2d60
> [ 86.929663][ T1] </TASK>
> [ 86.929663][ T1] Modules linked in: intel_rapl_msr intel_rapl_common crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel kvm_intel rapl iTCO_wdt iTCO_vendor_support i2c_i801 i2c_smbus lpc_ich drm loop drm_panel_orientation_quirks zram
> [ 86.929676][ T1] ---[ end trace 0000000000000000 ]---
> [ 86.929677][ T1] RIP: 0010:rethook_trampoline_handler+0x8e/0x200
> [ 86.929679][ T1] Code: 5e 20 00 48 8b a8 c8 2a 00 00 48 85 ed 75 2f e9 8b 00 00 00 4d 85 ed 74 17 48 8b 45 08 48 8d 7d f0 4c 89 f9 4c 89 e2 48 8b 30 <41> ff d5 0f 1f 00 48 39 dd 74 6a 48 8b 6d 00 48 85 ed 74 61 4c 39
> [ 86.929680][ T1] RSP: 0018:ffffc90001e0bdf8 EFLAGS: 00010286
> [ 86.929681][ T1] RAX: ffffc90001e0bef0 RBX: ffff8881775999a0 RCX: ffffc90001e0be40
> [ 86.929682][ T1] RDX: ffffffff81545129 RSI: 0000000000000000 RDI: ffff888177599990
> [ 86.929683][ T1] RBP: ffff8881775999a0 R08: 0000000000000000 R09: ffff88810246af00
> [ 86.929684][ T1] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81545129
> [ 86.929685][ T1] R13: ef01a20a8bd21200 R14: ffffc90001e0bee8 R15: ffffc90001e0be40
> [ 86.929686][ T1] FS: 00007f0ec5012940(0000) GS:ffff88846d600000(0000) knlGS:0000000000000000
> [ 86.929687][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 86.929688][ T1] CR2: 00005595e83bf5b0 CR3: 000000010805e001 CR4: 0000000000770ef0
> [ 86.929688][ T1] PKRU: 55555554
> [ 86.929689][ T1] note: systemd[1] exited with preempt_count 1
> [ 86.929692][ T1] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> [ 86.929992][ T1] Kernel Offset: disabled
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-02-29 5:51 ` Masami Hiramatsu
@ 2024-02-29 6:38 ` Masami Hiramatsu
2024-02-29 7:13 ` Masami Hiramatsu
0 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu @ 2024-02-29 6:38 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Jiri Olsa, Steven Rostedt, linux-kernel, linux-trace-kernel,
linux-doc, linux-kselftest
On Thu, 29 Feb 2024 14:51:39 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> On Wed, 28 Feb 2024 17:23:34 +0100
> Jiri Olsa <olsajiri@gmail.com> wrote:
>
> > On Mon, Feb 26, 2024 at 12:57:53PM +0900, Masami Hiramatsu (Google) wrote:
> > > Hi,
> > >
> > > Here is version 2 series of patches to support accessing function entry data
> > > from function *return* probes (including kretprobe and fprobe-exit event).
> > >
> > > In this version, I added another cleanup [4/7], updated README[5/7], added
> > > testcases[6/7] and updated document[7/7].
> > >
> > > This allows us to access the results of some functions, which returns the
> > > error code and its results are passed via function parameter, such as an
> > > structure-initialization function.
> > >
> > > For example, vfs_open() will link the file structure to the inode and update
> > > mode. Thus we can trace that changes.
> > >
> > > # echo 'f vfs_open mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
> > > # echo 'f vfs_open%return mode=file->f_mode:x32 inode=file->f_inode:x64' >> dynamic_events
> > > # echo 1 > events/fprobes/enable
> > > # cat trace
> > > sh-131 [006] ...1. 1945.714346: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x2 inode=0x0
> > > sh-131 [006] ...1. 1945.714358: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4d801e inode=0xffff888008470168
> > > cat-143 [007] ...1. 1945.717949: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
> > > cat-143 [007] ...1. 1945.717956: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0x4a801d inode=0xffff888005f78d28
> > > cat-143 [007] ...1. 1945.720616: vfs_open__entry: (vfs_open+0x4/0x40) mode=0x1 inode=0x0
> > > cat-143 [007] ...1. 1945.728263: vfs_open__exit: (do_open+0x274/0x3d0 <- vfs_open) mode=0xa800d inode=0xffff888004ada8d8
> >
> > hi,
> > I hit a crash while playing with this, by runnning:
> >
> > # echo 'f vfs_read%return $arg*' >> dynamic_events
> > # echo 1 > events/fprobes/enable
>
> Thanks for reporting! But I can not reproduce it.
> Can you share your kconfig?
No problem, I could reproduce it.
/sys/kernel/tracing # echo 'f vfs_read%return $arg* $retval' >> dynamic_events
/sys/kernel/tracing # echo 1 > events/fprobes/enable
/sys/kernel/tracing #
/sys/kernel/tracing # [ 67.709725] general protection fault, maybe for address 0xffffc9000047bef8: 0000 [#1] PREEMPT SMP PTI
[ 67.714672] CPU: 5 PID: 132 Comm: sh Tainted: G N 6.8.0-rc5-00007-gd5e41e4cee7e #149
[ 67.716491] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[ 67.718036] RIP: 0010:__x86_indirect_thunk_r13+0xa/0x20
[ 67.719087] Code: e8 01 00 00 00 cc 4c 89 24 24 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 0f 1f 44 00 00 e8 01 00 00 00 cc 4c 89 2c 24 <c3> cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 0f 1f 44 00 00
[ 67.722314] RSP: 0018:ffffc9000047bdf0 EFLAGS: 00010286
[ 67.723251] RAX: ffffc9000047bef8 RBX: ffff8880073258e0 RCX: ffffc9000047be48
[ 67.724704] RDX: ffffffff813aba09 RSI: 0000000000000000 RDI: ffff8880073258d0
[ 67.725840] RBP: ffff8880073258e0 R08: 0000000000000000 R09: ffff888005053648
[ 67.727017] R10: ffff888008452388 R11: 0000000000000001 R12: ffffffff813aba09
[ 67.728107] R13: 9c73d7ba3660c600 R14: ffffc9000047bef0 R15: ffffc9000047be48
[ 67.729630] FS: 000000000115d8c0(0000) GS:ffff88807d940000(0000) knlGS:0000000000000000
[ 67.731231] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 67.732285] CR2: 00000000005a2319 CR3: 0000000005ad6000 CR4: 00000000000006b0
[ 67.733502] Call Trace:
[ 67.734013] <TASK>
[ 67.734504] ? die_addr+0x37/0x90
[ 67.735307] ? exc_general_protection+0x1ac/0x3f0
[ 67.736158] ? asm_exc_general_protection+0x26/0x30
[ 67.736984] ? ksys_read+0x69/0xf0
[ 67.737559] ? ksys_read+0x69/0xf0
[ 67.738142] ? __x86_indirect_thunk_r13+0xa/0x20
[ 67.739160] ? rethook_trampoline_handler+0x95/0x200
[ 67.739919] ? arch_rethook_trampoline_callback+0x3a/0x50
[ 67.740665] ? arch_rethook_trampoline+0x2c/0x60
[ 67.741362] ? ksys_read+0x69/0xf0
[ 67.741980] ? trace_clock_x86_tsc+0x20/0x20
[ 67.742662] ? do_syscall_64+0xcc/0x1e0
[ 67.743289] ? entry_SYSCALL_64_after_hwframe+0x6f/0x77
[ 67.744620] </TASK>
[ 67.745044] Modules linked in:
[ 67.745559] ---[ end trace 0000000000000000 ]---
[ 67.746221] RIP: 0010:__x86_indirect_thunk_r13+0xa/0x20
[ 67.746927] Code: e8 01 00 00 00 cc 4c 89 24 24 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 0f 1f 44 00 00 e8 01 00 00 00 cc 4c 89 2c 24 <c3> cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 0f 1f 44 00 00
[ 67.749176] RSP: 0018:ffffc9000047bdf0 EFLAGS: 00010286
[ 67.749835] RAX: ffffc9000047bef8 RBX: ffff8880073258e0 RCX: ffffc9000047be48
[ 67.750687] RDX: ffffffff813aba09 RSI: 0000000000000000 RDI: ffff8880073258d0
[ 67.751880] RBP: ffff8880073258e0 R08: 0000000000000000 R09: ffff888005053648
[ 67.752810] R10: ffff888008452388 R11: 0000000000000001 R12: ffffffff813aba09
[ 67.753721] R13: 9c73d7ba3660c600 R14: ffffc9000047bef0 R15: ffffc9000047be48
[ 67.754554] FS: 000000000115d8c0(0000) GS:ffff88807d940000(0000) knlGS:0000000000000000
[ 67.755568] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 67.756278] CR2: 00000000005a2319 CR3: 0000000005ad6000 CR4: 00000000000006b0
[ 67.757089] Kernel panic - not syncing: Fatal exception
[ 67.757917] Kernel Offset: disabled
[ 67.758404] ---[ end Kernel panic - not syncing: Fatal exception ]---
Hmm, this seems arch_rethook_trampoline caused the issue.
And curiously, it depends on the number of stored data.
OK:
/sys/kernel/tracing # echo 'f vfs_read%return $arg1 $arg2 $arg3' >> dynamic_events
/sys/kernel/tracing # echo 1 > events/fprobes/enable
NG:
/sys/kernel/tracing # echo 'f vfs_read%return $arg1 $arg2 $arg3 $arg4' >> dynamic_events
/sys/kernel/tracing # echo 1 > events/fprobes/enable
I also confirmed that on 'vfs_write' caused the same result. 3 arguments(24 bytes) is OK,
but 4 arguments (32bytes) is NG.
Thank you,
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-02-29 6:38 ` Masami Hiramatsu
@ 2024-02-29 7:13 ` Masami Hiramatsu
2024-02-29 8:52 ` Masami Hiramatsu
0 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu @ 2024-02-29 7:13 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Jiri Olsa, Steven Rostedt, linux-kernel, linux-trace-kernel,
linux-doc, linux-kselftest
On Thu, 29 Feb 2024 15:38:55 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> Hmm, this seems arch_rethook_trampoline caused the issue.
>
> And curiously, it depends on the number of stored data.
>
> OK:
> /sys/kernel/tracing # echo 'f vfs_read%return $arg1 $arg2 $arg3' >> dynamic_events
> /sys/kernel/tracing # echo 1 > events/fprobes/enable
>
> NG:
> /sys/kernel/tracing # echo 'f vfs_read%return $arg1 $arg2 $arg3 $arg4' >> dynamic_events
> /sys/kernel/tracing # echo 1 > events/fprobes/enable
>
> I also confirmed that on 'vfs_write' caused the same result. 3 arguments(24 bytes) is OK,
> but 4 arguments (32bytes) is NG.
And this may be the fprobe bug. kretprobe events doesn't show this issue.
OK:
/sys/kernel/tracing # echo 'r vfs_read $arg*' >> kprobe_events
/sys/kernel/tracing # echo 1 > events/kprobes/enable
But this is strange because both uses same rethook...
Thank you,
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-02-29 7:13 ` Masami Hiramatsu
@ 2024-02-29 8:52 ` Masami Hiramatsu
2024-03-01 3:41 ` Steven Rostedt
0 siblings, 1 reply; 20+ messages in thread
From: Masami Hiramatsu @ 2024-02-29 8:52 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: Jiri Olsa, Steven Rostedt, linux-kernel, linux-trace-kernel,
linux-doc, linux-kselftest
On Thu, 29 Feb 2024 16:13:20 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> On Thu, 29 Feb 2024 15:38:55 +0900
> Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
>
> > Hmm, this seems arch_rethook_trampoline caused the issue.
> >
> > And curiously, it depends on the number of stored data.
> >
> > OK:
> > /sys/kernel/tracing # echo 'f vfs_read%return $arg1 $arg2 $arg3' >> dynamic_events
> > /sys/kernel/tracing # echo 1 > events/fprobes/enable
> >
> > NG:
> > /sys/kernel/tracing # echo 'f vfs_read%return $arg1 $arg2 $arg3 $arg4' >> dynamic_events
> > /sys/kernel/tracing # echo 1 > events/fprobes/enable
> >
> > I also confirmed that on 'vfs_write' caused the same result. 3 arguments(24 bytes) is OK,
> > but 4 arguments (32bytes) is NG.
>
> And this may be the fprobe bug. kretprobe events doesn't show this issue.
>
> OK:
> /sys/kernel/tracing # echo 'r vfs_read $arg*' >> kprobe_events
> /sys/kernel/tracing # echo 1 > events/kprobes/enable
>
> But this is strange because both uses same rethook...
Lol, I haven't allocate the entry data size when initialize rethook.
That's a bug.
Please try below.
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 6cd2a4e3afb8..9ff018245840 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -189,9 +189,6 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
{
int size;
- if (num <= 0)
- return -EINVAL;
-
if (!fp->exit_handler) {
fp->rethook = NULL;
return 0;
@@ -199,15 +196,16 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
/* Initialize rethook if needed */
if (fp->nr_maxactive)
- size = fp->nr_maxactive;
+ num = fp->nr_maxactive;
else
- size = num * num_possible_cpus() * 2;
- if (size <= 0)
+ num *= num_possible_cpus() * 2;
+ if (num <= 0)
return -EINVAL;
+ size = sizeof(struct fprobe_rethook_node) + fp->entry_data_size;
+
/* Initialize rethook */
- fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler,
- sizeof(struct fprobe_rethook_node), size);
+ fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler, size, num);
if (IS_ERR(fp->rethook))
return PTR_ERR(fp->rethook);
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply related [flat|nested] 20+ messages in thread
* Re: [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
2024-02-26 3:58 ` [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event Masami Hiramatsu (Google)
@ 2024-03-01 3:34 ` Steven Rostedt
0 siblings, 0 replies; 20+ messages in thread
From: Steven Rostedt @ 2024-03-01 3:34 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Mon, 26 Feb 2024 12:58:03 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Despite the fprobe event, "Kretprobe" was commented. So fix it.
>
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
> ---
> kernel/trace/trace_fprobe.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
> index 7d2ddbcfa377..3ccef4d82235 100644
> --- a/kernel/trace/trace_fprobe.c
> +++ b/kernel/trace/trace_fprobe.c
> @@ -210,7 +210,7 @@ fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
> }
> NOKPROBE_SYMBOL(fentry_trace_func);
>
> -/* Kretprobe handler */
> +/* function exit handler */
> static nokprobe_inline void
> __fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
> unsigned long ret_ip, struct pt_regs *regs,
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 2/7] tracing/probes: Cleanup probe argument parser
2024-02-26 3:58 ` [PATCH v2 2/7] tracing/probes: Cleanup probe argument parser Masami Hiramatsu (Google)
@ 2024-03-01 3:34 ` Steven Rostedt
0 siblings, 0 replies; 20+ messages in thread
From: Steven Rostedt @ 2024-03-01 3:34 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Mon, 26 Feb 2024 12:58:13 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Cleanup traceprobe_parse_probe_arg_body() to split out the
> type parser and post-processing part of fetch_insn.
> This makes no functional change.
>
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
> ---
> kernel/trace/trace_probe.c | 230 ++++++++++++++++++++++++++------------------
> 1 file changed, 137 insertions(+), 93 deletions(-)
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
2024-02-26 3:58 ` [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init Masami Hiramatsu (Google)
@ 2024-03-01 3:37 ` Steven Rostedt
2024-03-03 15:48 ` Masami Hiramatsu
0 siblings, 1 reply; 20+ messages in thread
From: Steven Rostedt @ 2024-03-01 3:37 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Mon, 26 Feb 2024 12:58:23 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init().
> This is a cleanup, so the behavior is not changed.
The change is fine, but the change log does not say why this was done.
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
>
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 4/7] tracing: Remove redundant #else block for BTF args from README
2024-02-26 3:58 ` [PATCH v2 4/7] tracing: Remove redundant #else block for BTF args from README Masami Hiramatsu (Google)
@ 2024-03-01 3:39 ` Steven Rostedt
0 siblings, 0 replies; 20+ messages in thread
From: Steven Rostedt @ 2024-03-01 3:39 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Mon, 26 Feb 2024 12:58:33 +0900
"Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Remove redundant #else block for BTF args from README message.
> This is a cleanup, so no change on the message.
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
>
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> ---
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-02-29 8:52 ` Masami Hiramatsu
@ 2024-03-01 3:41 ` Steven Rostedt
2024-03-03 15:22 ` Masami Hiramatsu
0 siblings, 1 reply; 20+ messages in thread
From: Steven Rostedt @ 2024-03-01 3:41 UTC (permalink / raw)
To: Masami Hiramatsu (Google)
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Thu, 29 Feb 2024 17:52:16 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> Lol, I haven't allocate the entry data size when initialize rethook.
> That's a bug.
> Please try below.
I'll wait to review patches 5,6,7 as I'm guessing this will have a v3?
-- Steve
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe
2024-03-01 3:41 ` Steven Rostedt
@ 2024-03-03 15:22 ` Masami Hiramatsu
0 siblings, 0 replies; 20+ messages in thread
From: Masami Hiramatsu @ 2024-03-03 15:22 UTC (permalink / raw)
To: Steven Rostedt
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Thu, 29 Feb 2024 22:41:34 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Thu, 29 Feb 2024 17:52:16 +0900
> Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
>
> > Lol, I haven't allocate the entry data size when initialize rethook.
> > That's a bug.
> > Please try below.
>
> I'll wait to review patches 5,6,7 as I'm guessing this will have a v3?
Ah, actually I pushed this fix separately because it is an actual
bug and may silently cause an issue in the selftest. I pushed it
in probes-fixes-v6.8-rc5.
Anyway, let me send v3 it with that fix.
Thank you,
>
> -- Steve
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
2024-03-01 3:37 ` Steven Rostedt
@ 2024-03-03 15:48 ` Masami Hiramatsu
0 siblings, 0 replies; 20+ messages in thread
From: Masami Hiramatsu @ 2024-03-03 15:48 UTC (permalink / raw)
To: Steven Rostedt
Cc: Jiri Olsa, linux-kernel, linux-trace-kernel, linux-doc, linux-kselftest
On Thu, 29 Feb 2024 22:37:53 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 26 Feb 2024 12:58:23 +0900
> "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
>
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> >
> > Instead of incrementing the trace_probe::nr_args, init it at trace_probe_init().
> > This is a cleanup, so the behavior is not changed.
>
> The change is fine, but the change log does not say why this was done.
This change is to get the number of trace_probe arguments while parsing
the argument strings.
Thank you,
>
> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
>
> -- Steve
>
>
> >
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > ---
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 20+ messages in thread
end of thread, other threads:[~2024-03-03 15:48 UTC | newest]
Thread overview: 20+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-02-26 3:57 [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 1/7] tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event Masami Hiramatsu (Google)
2024-03-01 3:34 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 2/7] tracing/probes: Cleanup probe argument parser Masami Hiramatsu (Google)
2024-03-01 3:34 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 3/7] tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init Masami Hiramatsu (Google)
2024-03-01 3:37 ` Steven Rostedt
2024-03-03 15:48 ` Masami Hiramatsu
2024-02-26 3:58 ` [PATCH v2 4/7] tracing: Remove redundant #else block for BTF args from README Masami Hiramatsu (Google)
2024-03-01 3:39 ` Steven Rostedt
2024-02-26 3:58 ` [PATCH v2 5/7] tracing/probes: Support $argN in return probe (kprobe and fprobe) Masami Hiramatsu (Google)
2024-02-26 3:58 ` [PATCH v2 6/7] selftests/ftrace: Add test cases for entry args at function exit Masami Hiramatsu (Google)
2024-02-26 3:59 ` [PATCH v2 7/7] Documentation: tracing: Add entry argument access " Masami Hiramatsu (Google)
2024-02-28 16:23 ` [PATCH v2 0/7] tracing/probes: Support function parameter access from return probe Jiri Olsa
2024-02-29 5:51 ` Masami Hiramatsu
2024-02-29 6:38 ` Masami Hiramatsu
2024-02-29 7:13 ` Masami Hiramatsu
2024-02-29 8:52 ` Masami Hiramatsu
2024-03-01 3:41 ` Steven Rostedt
2024-03-03 15:22 ` Masami Hiramatsu
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