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authorMasami Hiramatsu <mhiramat@kernel.org>2019-10-29 09:31:44 +0100
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-11-14 19:15:12 +0100
commitc7411a1a126f649be71526a36d4afac9e5aefa13 (patch)
tree4e9c314806469e2fb762189b535fd6410cba134b /kernel/trace/trace_kprobe.c
parenttracing: use kvcalloc for tgid_map array allocation (diff)
downloadlinux-c7411a1a126f649be71526a36d4afac9e5aefa13.tar.xz
linux-c7411a1a126f649be71526a36d4afac9e5aefa13.zip
tracing/kprobe: Check whether the non-suffixed symbol is notrace
Check whether the non-suffixed symbol is notrace, since suffixed symbols are generated by the compilers for optimization. Based on these suffixed symbols, notrace check might not work because some of them are just a partial code of the original function. (e.g. cold-cache (unlikely) code is separated from original function as FUNCTION.cold.XX) For example, without this fix, # echo p device_add.cold.67 > /sys/kernel/debug/tracing/kprobe_events sh: write error: Invalid argument # cat /sys/kernel/debug/tracing/error_log [ 135.491035] trace_kprobe: error: Failed to register probe event Command: p device_add.cold.67 ^ # dmesg | tail -n 1 [ 135.488599] trace_kprobe: Could not probe notrace function device_add.cold.67 With this, # echo p device_add.cold.66 > /sys/kernel/debug/tracing/kprobe_events # cat /sys/kernel/debug/kprobes/list ffffffff81599de9 k device_add.cold.66+0x0 [DISABLED] Actually, kprobe blacklist already did similar thing, see within_kprobe_blacklist(). Link: http://lkml.kernel.org/r/157233790394.6706.18243942030937189679.stgit@devnote2 Fixes: 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function") Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c27
1 files changed, 24 insertions, 3 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1552a95c743b..7f890262c8a3 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -435,11 +435,10 @@ static int disable_trace_kprobe(struct trace_event_call *call,
#if defined(CONFIG_KPROBES_ON_FTRACE) && \
!defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE)
-static bool within_notrace_func(struct trace_kprobe *tk)
+static bool __within_notrace_func(unsigned long addr)
{
- unsigned long offset, size, addr;
+ unsigned long offset, size;
- addr = trace_kprobe_address(tk);
if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset))
return false;
@@ -452,6 +451,28 @@ static bool within_notrace_func(struct trace_kprobe *tk)
*/
return !ftrace_location_range(addr, addr + size - 1);
}
+
+static bool within_notrace_func(struct trace_kprobe *tk)
+{
+ unsigned long addr = addr = trace_kprobe_address(tk);
+ char symname[KSYM_NAME_LEN], *p;
+
+ if (!__within_notrace_func(addr))
+ return false;
+
+ /* Check if the address is on a suffixed-symbol */
+ if (!lookup_symbol_name(addr, symname)) {
+ p = strchr(symname, '.');
+ if (!p)
+ return true;
+ *p = '\0';
+ addr = (unsigned long)kprobe_lookup_name(symname, 0);
+ if (addr)
+ return __within_notrace_func(addr);
+ }
+
+ return true;
+}
#else
#define within_notrace_func(tk) (false)
#endif