| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 046/116] ftrace/x86: Anotate text_mutex split between ftrace_arch_code_modify_post_process() and ftrace_arch_code_modify_prepare() | Date | Wed, 1 Apr 2020 18:17:02 +0200 |
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From: Jiri Kosina <jkosina@suse.cz>
commit 074376ac0e1d1fcd4fafebca86ee6158e7c20680 upstream.
ftrace_arch_code_modify_prepare() is acquiring text_mutex, while the corresponding release is happening in ftrace_arch_code_modify_post_process().
This has already been documented in the code, but let's also make the fact that this is intentional clear to the semantic analysis tools such as sparse.
Link: http://lkml.kernel.org/r/nycvar.YFH.7.76.1906292321170.27227@cbobk.fhfr.pm
Fixes: 39611265edc1a ("ftrace/x86: Add a comment to why we take text_mutex in ftrace_arch_code_modify_prepare()") Fixes: d5b844a2cf507 ("ftrace/x86: Remove possible deadlock between register_kprobe() and ftrace_run_update_code()") Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kernel/ftrace.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -35,6 +35,7 @@ #ifdef CONFIG_DYNAMIC_FTRACE int ftrace_arch_code_modify_prepare(void) + __acquires(&text_mutex) { mutex_lock(&text_mutex); set_kernel_text_rw(); @@ -43,6 +44,7 @@ int ftrace_arch_code_modify_prepare(void } int ftrace_arch_code_modify_post_process(void) + __releases(&text_mutex) { set_all_modules_text_ro(); set_kernel_text_ro();
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