From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Florent Revest <revest@chromium.org>,
Will Deacon <will@kernel.org>
Subject: [for-next][PATCH 01/25] fprobe: Pass entry_data to handlers
Date: Wed, 29 Mar 2023 15:45:17 -0400 [thread overview]
Message-ID: <20230329194549.186982647@goodmis.org> (raw)
In-Reply-To: <20230329194516.146147554@goodmis.org>
From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Pass the private entry_data to the entry and exit handlers so that
they can share the context data, something like saved function
arguments etc.
User must specify the private entry_data size by @entry_data_size
field before registering the fprobe.
Link: https://lkml.kernel.org/r/167526696173.433354.17408372048319432574.stgit@mhiramat.roam.corp.google.com
Cc: Florent Revest <revest@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
include/linux/fprobe.h | 8 ++++++--
kernel/trace/bpf_trace.c | 2 +-
kernel/trace/fprobe.c | 21 ++++++++++++++-------
lib/test_fprobe.c | 6 ++++--
samples/fprobe/fprobe_example.c | 6 ++++--
5 files changed, 29 insertions(+), 14 deletions(-)
diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h
index 1c2bde0ead73..e0d4e6136249 100644
--- a/include/linux/fprobe.h
+++ b/include/linux/fprobe.h
@@ -13,6 +13,7 @@
* @nmissed: The counter for missing events.
* @flags: The status flag.
* @rethook: The rethook data structure. (internal data)
+ * @entry_data_size: The private data storage size.
* @entry_handler: The callback function for function entry.
* @exit_handler: The callback function for function exit.
*/
@@ -29,9 +30,12 @@ struct fprobe {
unsigned long nmissed;
unsigned int flags;
struct rethook *rethook;
+ size_t entry_data_size;
- void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs);
- void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs);
+ void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip,
+ struct pt_regs *regs, void *entry_data);
+ void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip,
+ struct pt_regs *regs, void *entry_data);
};
/* This fprobe is soft-disabled. */
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e8da032bb6fc..fa403c323501 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2646,7 +2646,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
static void
kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
- struct pt_regs *regs)
+ struct pt_regs *regs, void *data)
{
struct bpf_kprobe_multi_link *link;
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index e8143e368074..fa25d09c9d57 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -17,14 +17,16 @@
struct fprobe_rethook_node {
struct rethook_node node;
unsigned long entry_ip;
+ char data[];
};
static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct ftrace_regs *fregs)
{
struct fprobe_rethook_node *fpr;
- struct rethook_node *rh;
+ struct rethook_node *rh = NULL;
struct fprobe *fp;
+ void *entry_data = NULL;
int bit;
fp = container_of(ops, struct fprobe, ops);
@@ -37,9 +39,6 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
return;
}
- if (fp->entry_handler)
- fp->entry_handler(fp, ip, ftrace_get_regs(fregs));
-
if (fp->exit_handler) {
rh = rethook_try_get(fp->rethook);
if (!rh) {
@@ -48,9 +47,16 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
}
fpr = container_of(rh, struct fprobe_rethook_node, node);
fpr->entry_ip = ip;
- rethook_hook(rh, ftrace_get_regs(fregs), true);
+ if (fp->entry_data_size)
+ entry_data = fpr->data;
}
+ if (fp->entry_handler)
+ fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data);
+
+ if (rh)
+ rethook_hook(rh, ftrace_get_regs(fregs), true);
+
out:
ftrace_test_recursion_unlock(bit);
}
@@ -81,7 +87,8 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data,
fpr = container_of(rh, struct fprobe_rethook_node, node);
- fp->exit_handler(fp, fpr->entry_ip, regs);
+ fp->exit_handler(fp, fpr->entry_ip, regs,
+ fp->entry_data_size ? (void *)fpr->data : NULL);
}
NOKPROBE_SYMBOL(fprobe_exit_handler);
@@ -146,7 +153,7 @@ static int fprobe_init_rethook(struct fprobe *fp, int num)
for (i = 0; i < size; i++) {
struct fprobe_rethook_node *node;
- node = kzalloc(sizeof(*node), GFP_KERNEL);
+ node = kzalloc(sizeof(*node) + fp->entry_data_size, GFP_KERNEL);
if (!node) {
rethook_free(fp->rethook);
fp->rethook = NULL;
diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
index 1fb56cf5e5ce..e4f65d114ed2 100644
--- a/lib/test_fprobe.c
+++ b/lib/test_fprobe.c
@@ -30,7 +30,8 @@ static noinline u32 fprobe_selftest_target2(u32 value)
return (value / div_factor) + 1;
}
-static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs)
+static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip,
+ struct pt_regs *regs, void *data)
{
KUNIT_EXPECT_FALSE(current_test, preemptible());
/* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
@@ -39,7 +40,8 @@ static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, struct
entry_val = (rand1 / div_factor);
}
-static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs)
+static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
+ struct pt_regs *regs, void *data)
{
unsigned long ret = regs_return_value(regs);
diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c
index e22da8573116..dd794990ad7e 100644
--- a/samples/fprobe/fprobe_example.c
+++ b/samples/fprobe/fprobe_example.c
@@ -48,7 +48,8 @@ static void show_backtrace(void)
stack_trace_print(stacks, len, 24);
}
-static void sample_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs)
+static void sample_entry_handler(struct fprobe *fp, unsigned long ip,
+ struct pt_regs *regs, void *data)
{
if (use_trace)
/*
@@ -63,7 +64,8 @@ static void sample_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_
show_backtrace();
}
-static void sample_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs)
+static void sample_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs,
+ void *data)
{
unsigned long rip = instruction_pointer(regs);
--
2.39.1
next prev parent reply other threads:[~2023-03-29 19:46 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-29 19:45 [for-next][PATCH 00/25] tracing: Updates for 6.4 Steven Rostedt
2023-03-29 19:45 ` Steven Rostedt [this message]
2023-03-29 19:45 ` [for-next][PATCH 02/25] lib/test_fprobe: Add private entry_data testcases Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 03/25] fprobe: Add nr_maxactive to specify rethook_node pool size Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 04/25] lib/test_fprobe: Add a test case for nr_maxactive Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 05/25] fprobe: Skip exit_handler if entry_handler returns !0 Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 06/25] lib/test_fprobe: Add a testcase for skipping exit_handler Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 07/25] docs: tracing: Update fprobe documentation Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 08/25] selftests: use canonical ftrace path Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 09/25] leaking_addresses: also skip " Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 10/25] tools/kvm_stat: use " Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 11/25] tracing: Add "fields" option to show raw trace event fields Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 12/25] tracing/user_events: Split header into uapi and kernel Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 13/25] tracing/user_events: Track fork/exec/exit for mm lifetime Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 14/25] tracing/user_events: Use remote writes for event enablement Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 15/25] tracing/user_events: Fixup enable faults asyncly Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 16/25] tracing/user_events: Add ioctl for disabling addresses Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 17/25] tracing/user_events: Update self-tests to write ABI Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 18/25] tracing/user_events: Add ABI self-test Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 19/25] tracing/user_events: Use write ABI in example Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 20/25] tracing/user_events: Update documentation for ABI Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 21/25] tracing/user_events: Charge event allocs to cgroups Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 22/25] tracing/user_events: Limit global user_event count Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 23/25] tracing/user_events: Align structs with tabs for readability Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 24/25] tracing/user_events: Use print_format_fields() for trace output Steven Rostedt
2023-03-29 19:45 ` [for-next][PATCH 25/25] tracing: Unbreak user events Steven Rostedt
2023-03-29 20:29 ` Steven Rostedt
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