Commit 00f13e28 authored by Ian Rogers's avatar Ian Rogers Committed by Steven Rostedt (Google)
Browse files

tracing: Avoid possible signed 64-bit truncation 

64-bit truncation to 32-bit can result in the sign of the truncated
value changing. The cmp_mod_entry is used in bsearch and so the
truncation could result in an invalid search order. This would only
happen were the addresses more than 2GB apart and so unlikely, but
let's fix the potentially broken compare anyway.

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260108002625.333331-1-irogers@google.com


Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 90f9f5d6

kernel/trace/trace.c

+4 −4
Original line number Diff line number Diff line
@@ -6115,10 +6115,10 @@ static int cmp_mod_entry(const void *key, const void *pivot) 
	unsigned long addr = (unsigned long)key;

	const struct trace_mod_entry *ent = pivot;



	if (addr >= ent[0].mod_addr && addr < ent[1].mod_addr)

		return 0;

	else

		return addr - ent->mod_addr;

	if (addr < ent[0].mod_addr)

		return -1;



	return addr >= ent[1].mod_addr;

}



/**