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: Hao Wei Tee <angelsl@xxxxxxx> --- Fixed for 6.1. Please cherry-pick 73feb8d5fa3b755bb51077c0aabfb6aa556fd498 too. Sorry for the bad patch originally. I had a mixup.. kernel/trace/trace_kprobe.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index a34a4fcdab7b..e3993d19687d 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -714,14 +714,31 @@ 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, + struct module *module, 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(count_mod_symbols, &ctx); - return count; + return ctx.count; } static int __trace_kprobe_create(int argc, const char *argv[]) -- 2.43.0
