diff options
Diffstat (limited to 'arch/x86/kernel/ftrace.c')
-rw-r--r-- | arch/x86/kernel/ftrace.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 0927bb158ffc..024c3053dbba 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -22,6 +22,7 @@ #include <linux/init.h> #include <linux/list.h> #include <linux/module.h> +#include <linux/memory.h> #include <trace/syscall.h> @@ -34,16 +35,25 @@ #ifdef CONFIG_DYNAMIC_FTRACE int ftrace_arch_code_modify_prepare(void) + __acquires(&text_mutex) { + /* + * Need to grab text_mutex to prevent a race from module loading + * and live kernel patching from changing the text permissions while + * ftrace has it set to "read/write". + */ + 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; } @@ -300,7 +310,6 @@ int ftrace_int3_handler(struct pt_regs *regs) ip = regs->ip - INT3_INSN_SIZE; -#ifdef CONFIG_X86_64 if (ftrace_location(ip)) { int3_emulate_call(regs, (unsigned long)ftrace_regs_caller); return 1; @@ -312,12 +321,6 @@ int ftrace_int3_handler(struct pt_regs *regs) int3_emulate_call(regs, ftrace_update_func_call); return 1; } -#else - if (ftrace_location(ip) || is_ftrace_caller(ip)) { - int3_emulate_jmp(regs, ip + CALL_INSN_SIZE); - return 1; - } -#endif return 0; } @@ -370,7 +373,7 @@ static int add_brk_on_nop(struct dyn_ftrace *rec) return add_break(rec->ip, old); } -static int add_breakpoints(struct dyn_ftrace *rec, int enable) +static int add_breakpoints(struct dyn_ftrace *rec, bool enable) { unsigned long ftrace_addr; int ret; @@ -478,7 +481,7 @@ static int add_update_nop(struct dyn_ftrace *rec) return add_update_code(ip, new); } -static int add_update(struct dyn_ftrace *rec, int enable) +static int add_update(struct dyn_ftrace *rec, bool enable) { unsigned long ftrace_addr; int ret; @@ -524,7 +527,7 @@ static int finish_update_nop(struct dyn_ftrace *rec) return ftrace_write(ip, new, 1); } -static int finish_update(struct dyn_ftrace *rec, int enable) +static int finish_update(struct dyn_ftrace *rec, bool enable) { unsigned long ftrace_addr; int ret; |