Commit 9161a864 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)

tracing/kprobes: Fix to check notrace function with correct range

Fix within_notrace_func() to check notrace function correctly.

Since the ftrace_location_range(start, end) function checks
the range inclusively (start <= ftrace-loc <= end), the end
address must not include the entry address of next function.

However, within_notrace_func() uses kallsyms_lookup_size_offset()
to get the function size and calculate the end address from
adding the size to the entry address. This means the end address
is the entry address of the next function.

In the result, within_notrace_func() fails to find notrace
function if the next function of the target function is
ftraced.

Let's subtract 1 from the end address so that ftrace_location_range()
can check it correctly.

Link: http://lkml.kernel.org/r/153485669706.16611.17726752296213785504.stgit@devbox

Fixes: commit 45408c4f ("tracing: kprobes: Prohibit probing on notrace function")
Reported-by: default avatarMichael Rodin <michael@rodin.online>
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 6b7dca40
...@@ -513,7 +513,14 @@ static bool within_notrace_func(struct trace_kprobe *tk) ...@@ -513,7 +513,14 @@ static bool within_notrace_func(struct trace_kprobe *tk)
if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
return false; return false;
return !ftrace_location_range(addr - offset, addr - offset + size); /* Get the entry address of the target function */
addr -= offset;
/*
* Since ftrace_location_range() does inclusive range check, we need
* to subtract 1 byte from the end address.
*/
return !ftrace_location_range(addr, addr + size - 1);
} }
#else #else
#define within_notrace_func(tk) (false) #define within_notrace_func(tk) (false)
......
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