This is a note to let you know that I've just added the patch titled
tracing/kprobes: Fix symbol counting logic by looking at modules as well
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-kprobes-fix-symbol-counting-logic-by-looking-at-modules-as-well.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 926fe783c8a64b33997fec405cf1af3e61aed441 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@xxxxxxxxxx>
Date: Fri, 27 Oct 2023 16:31:26 -0700
Subject: tracing/kprobes: Fix symbol counting logic by looking at modules as well
From: Andrii Nakryiko <andrii@xxxxxxxxxx>
commit 926fe783c8a64b33997fec405cf1af3e61aed441 upstream.
Recent changes to count number of matching symbols when creating
a kprobe event failed to take into account kernel modules. As such, it
breaks kprobes on kernel module symbols, by assuming there is no match.
Fix this my calling module_kallsyms_on_each_symbol() in addition to
kallsyms_on_each_match_symbol() to perform a proper counting.
Link: https://lore.kernel.org/all/20231027233126.2073148-1-andrii@xxxxxxxxxx/
Cc: Francis Laniel <flaniel@xxxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Fixes: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 95c5b0668cb7..e834f149695b 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -714,14 +714,30 @@ static int count_symbols(void *data, unsigned long unused)
return 0;
}
+struct sym_count_ctx {
+ unsigned int count;
+ const char *name;
+};
+
+static int count_mod_symbols(void *data, const char *name, unsigned long unused)
+{
+ struct sym_count_ctx *ctx = data;
+
+ if (strcmp(name, ctx->name) == 0)
+ ctx->count++;
+
+ return 0;
+}
+
static unsigned int number_of_same_symbols(char *func_name)
{
- unsigned int count;
+ struct sym_count_ctx ctx = { .count = 0, .name = func_name };
+
+ kallsyms_on_each_match_symbol(count_symbols, func_name, &ctx.count);
- count = 0;
- kallsyms_on_each_match_symbol(count_symbols, func_name, &count);
+ module_kallsyms_on_each_symbol(NULL, count_mod_symbols, &ctx);
- return count;
+ return ctx.count;
}
static int __trace_kprobe_create(int argc, const char *argv[])
--
2.42.0
Patches currently in stable-queue which might be from andrii@xxxxxxxxxx are
queue-6.1/tracing-kprobes-fix-symbol-counting-logic-by-looking-at-modules-as-well.patch
