diff mbox series

[bpf-next,v4,07/27] ftrace: Add multi direct modify interface

Message ID 20210826193922.66204-8-jolsa@kernel.org (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series x86/ftrace/bpf: Add batch support for direct/tracing attach | expand

Checks

Context Check Description
bpf/vmtest fail Kernel LATEST + selftests
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count fail Series longer than 15 patches
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/cc_maintainers warning 3 maintainers not CCed: kpsingh@kernel.org mingo@redhat.com andrii@kernel.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit fail Errors and warnings before: 6780 this patch: 6781
netdev/kdoc success Errors and warnings before: 37 this patch: 37
netdev/verify_fixes success Link
netdev/checkpatch warning CHECK: Please use a blank line after function/struct/union/enum declarations WARNING: From:/Signed-off-by: email address mismatch: 'From: Jiri Olsa <jolsa@redhat.com>' != 'Signed-off-by: Jiri Olsa <jolsa@kernel.org>'
netdev/build_allmodconfig_warn fail Errors and warnings before: 5832 this patch: 5833
netdev/header_inline success Link
bpf/vmtest-bpf-next fail Kernel LATEST + selftests

Commit Message

Jiri Olsa Aug. 26, 2021, 7:39 p.m. UTC
Adding interface to modify registered direct function
for ftrace_ops. Adding following function:

   modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)

The function changes the currently registered direct
function for all attached functions.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 include/linux/ftrace.h |  6 ++++++
 kernel/trace/ftrace.c  | 43 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 93d8f12e70b3..63ca0a424947 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -318,6 +318,8 @@  int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
 unsigned long ftrace_find_rec_direct(unsigned long ip);
 int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
 int unregister_ftrace_direct_multi(struct ftrace_ops *ops);
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr);
+
 #else
 # define ftrace_direct_func_count 0
 static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
@@ -356,6 +358,10 @@  int unregister_ftrace_direct_multi(struct ftrace_ops *ops)
 {
 	return -ENODEV;
 }
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
 
 #ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7243769493c9..59940a6a907c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5518,6 +5518,49 @@  int unregister_ftrace_direct_multi(struct ftrace_ops *ops)
 	return err;
 }
 EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi);
+
+int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
+{
+	struct ftrace_hash *hash = ops->func_hash->filter_hash;
+	struct ftrace_func_entry *entry, *iter;
+	int i, size;
+	int err;
+
+	if (check_direct_multi(ops))
+		return -EINVAL;
+	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
+		return -EINVAL;
+
+	mutex_lock(&direct_mutex);
+	mutex_lock(&ftrace_lock);
+
+	/*
+	 * Shutdown the ops, change 'direct' pointer for each
+	 * ops entry in direct_functions hash and startup the
+	 * ops back again.
+	 */
+	err = ftrace_shutdown(ops, 0);
+	if (err)
+		goto out_unlock;
+
+	size = 1 << hash->size_bits;
+	for (i = 0; i < size; i++) {
+		hlist_for_each_entry(iter, &hash->buckets[i], hlist) {
+			entry = __ftrace_lookup_ip(direct_functions, iter->ip);
+			if (!entry)
+				continue;
+			entry->direct = addr;
+		}
+	}
+
+	err = ftrace_startup(ops, 0);
+
+ out_unlock:
+	mutex_unlock(&ftrace_lock);
+	mutex_unlock(&direct_mutex);
+	return err;
+}
+EXPORT_SYMBOL_GPL(modify_ftrace_direct_multi);
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
 
 /**