linux-kernel - [PATCH] kernel/extable.c: mark core_kernel

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 21 Jun 2017 09:03:26 +0200
From:   Marcin Nowakowski <marcin.nowakowski@...tec.com>
To:     Andrew Morton <akpm@...ux-foundation.org>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Thomas Meyer <thomas@...3r.de>, Ingo Molnar <mingo@...nel.org>,
        "Steven Rostedt (VMware)" <rostedt@...dmis.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Paul Gortmaker <paul.gortmaker@...driver.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        <linux-kernel@...r.kernel.org>
CC:     <linux-mips@...ux-mips.org>,
        Marcin Nowakowski <marcin.nowakowski@...tec.com>
Subject: [PATCH] kernel/extable.c: mark core_kernel_text notrace

core_kernel_text is used by MIPS in its function graph trace processing,
so having this method traced leads to an infinite set of recursive calls
such as:

[    2.972075] Call Trace:
[    2.972111]
[    2.976731] [<80506584>] ftrace_return_to_handler+0x50/0x128
[    2.983379] [<8045478c>] core_kernel_text+0x10/0x1b8
[    2.989146] [<804119b8>] prepare_ftrace_return+0x6c/0x114
[    2.995402] [<80411b2c>] ftrace_graph_caller+0x20/0x44
[    3.001362] [<80411b60>] return_to_handler+0x10/0x30
[    3.007159] [<80411b50>] return_to_handler+0x0/0x30
[    3.012827] [<80411b50>] return_to_handler+0x0/0x30
[    3.018621] [<804e589c>] ftrace_ops_no_ops+0x114/0x1bc
[    3.024602] [<8045478c>] core_kernel_text+0x10/0x1b8
[    3.030377] [<8045478c>] core_kernel_text+0x10/0x1b8
[    3.036140] [<8045478c>] core_kernel_text+0x10/0x1b8
[    3.041915] [<804e589c>] ftrace_ops_no_ops+0x114/0x1bc
[    3.047923] [<8045478c>] core_kernel_text+0x10/0x1b8
[    3.053682] [<804119b8>] prepare_ftrace_return+0x6c/0x114
[    3.059938] [<80411b2c>] ftrace_graph_caller+0x20/0x44
(...)

Mark the function notrace to avoid it being traced.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@...tec.com>
---
 kernel/extable.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/extable.c b/kernel/extable.c
index 2676d7f..4efaf26 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -70,7 +70,7 @@ static inline int init_kernel_text(unsigned long addr)
 	return 0;
 }
 
-int core_kernel_text(unsigned long addr)
+int notrace core_kernel_text(unsigned long addr)
 {
 	if (addr >= (unsigned long)_stext &&
 	    addr < (unsigned long)_etext)
-- 
2.7.4