Messages in this thread Patch in this message | | | From | Zong Li <> | Subject | [PATCH 8/8] riscv: add two hook functions of ftrace | Date | Mon, 17 Feb 2020 16:32:23 +0800 |
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After the text section be mask as non-writable, the ftrace have to change the permission of text for dynamic patching the intructions. Add ftrace_arch_code_modify_prepare and ftrace_arch_code_modify_post_process to change permission.
Signed-off-by: Zong Li <zong.li@sifive.com> --- arch/riscv/kernel/ftrace.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c index c40fdcdeb950..576df0807200 100644 --- a/arch/riscv/kernel/ftrace.c +++ b/arch/riscv/kernel/ftrace.c @@ -7,9 +7,27 @@ #include <linux/ftrace.h> #include <linux/uaccess.h> +#include <linux/memory.h> +#include <asm/set_memory.h> #include <asm/cacheflush.h> #ifdef CONFIG_DYNAMIC_FTRACE +int ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex) +{ + mutex_lock(&text_mutex); + set_kernel_text_rw(); + set_all_modules_text_rw(); + return 0; +} + +int ftrace_arch_code_modify_post_process(void) __releases(&text_mutex) +{ + set_all_modules_text_ro(); + set_kernel_text_ro(); + mutex_unlock(&text_mutex); + return 0; +} + static int ftrace_check_current_call(unsigned long hook_pos, unsigned int *expected) { -- 2.25.0
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