From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
peterz@infradead.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrea Righi <righi.andrea@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
stable@vger.kernel.org
Subject: [PATCH 5/9] kprobes: Search non-suffixed symbol in blacklist
Date: Thu, 10 Jan 2019 11:56:24 +0900 [thread overview]
Message-ID: <154708898461.6325.17046972809561067053.stgit@devbox> (raw)
In-Reply-To: <154708884117.6325.4454464467156828009.stgit@devbox>
Newer gcc can generate some different instances of a function
with suffixed symbols if the function is optimized and only
has a part of that. (e.g. .constprop, .part etc.)
In this case, it is not enough to check the entry of kprobe
blacklist because it only records non-suffixed symbol address.
To fix this issue, search non-suffixed symbol in blacklist if
given address is within a symbol which has a suffix.
Note that this can cause false positive cases if a kprobe-safe
function is optimized to suffixed instance and has same name
symbol which is blacklisted.
But I would like to chose a fail-safe design for this issue.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/kprobes.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index e8c76164f541..faa519f07aad 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1396,7 +1396,7 @@ bool __weak arch_within_kprobe_blacklist(unsigned long addr)
addr < (unsigned long)__kprobes_text_end;
}
-bool within_kprobe_blacklist(unsigned long addr)
+static bool __within_kprobe_blacklist(unsigned long addr)
{
struct kprobe_blacklist_entry *ent;
@@ -1410,7 +1410,26 @@ bool within_kprobe_blacklist(unsigned long addr)
if (addr >= ent->start_addr && addr < ent->end_addr)
return true;
}
+ return false;
+}
+bool within_kprobe_blacklist(unsigned long addr)
+{
+ char symname[KSYM_NAME_LEN], *p;
+
+ if (__within_kprobe_blacklist(addr))
+ return true;
+
+ /* Check if the address is on a suffixed-symbol */
+ if (!lookup_symbol_name(addr, symname)) {
+ p = strchr(symname, '.');
+ if (!p)
+ return false;
+ *p = '\0';
+ addr = (unsigned long)kprobe_lookup_name(symname, 0);
+ if (addr)
+ return __within_kprobe_blacklist(addr);
+ }
return false;
}
next prev parent reply other threads:[~2019-01-10 2:56 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-10 2:54 [PATCH 0/9] kprobes: Fix and improve blacklist symbols Masami Hiramatsu
2019-01-10 2:54 ` [PATCH 1/9] x86/kprobes: Prohibit probing on optprobe template code Masami Hiramatsu
2019-01-10 6:07 ` Greg KH
2019-01-10 14:57 ` Masami Hiramatsu
2019-01-10 17:10 ` Steven Rostedt
2019-01-11 0:52 ` Masami Hiramatsu
2019-01-10 2:54 ` [PATCH 2/9] x86/kprobes: Move trampoline code into RODATA Masami Hiramatsu
2019-01-10 2:55 ` [PATCH 3/9] x86/kprobes: Prohibit probing on functions before kprobe_int3_handler() Masami Hiramatsu
2019-01-10 2:55 ` [PATCH 4/9] x86/kprobes: Prohibit probing on IRQ handlers directly Masami Hiramatsu
2019-01-10 2:56 ` Masami Hiramatsu [this message]
2019-01-10 2:56 ` [PATCH 6/9] kprobes: Prohibit probing on hardirq tracers Masami Hiramatsu
2019-01-10 17:12 ` Steven Rostedt
2019-01-11 14:21 ` Masami Hiramatsu
2019-01-10 2:57 ` [PATCH 7/9] kprobes: Prohibit probing on preempt_check debug functions Masami Hiramatsu
2019-01-10 2:57 ` [PATCH 8/9] kprobes: Prohibit probing on RCU debug routine Masami Hiramatsu
2019-01-10 2:58 ` [PATCH 9/9] kprobes: Prohibit probing on lockdep functions Masami Hiramatsu
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