diff options
Diffstat (limited to 'arch/arm64/kernel/ftrace.c')
| -rw-r--r-- | arch/arm64/kernel/ftrace.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 9669b331a23b..8f7005bc35bd 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -29,12 +29,11 @@ static int ftrace_modify_code(unsigned long pc, u32 old, u32 new, /* * Note: - * Due to modules and __init, code can disappear and change, - * we need to protect against faulting as well as code changing. - * We do this by aarch64_insn_*() which use the probe_kernel_*(). - * - * No lock is held here because all the modifications are run - * through stop_machine(). + * We are paranoid about modifying text, as if a bug were to happen, it + * could cause us to read or write to someplace that could cause harm. + * Carefully read and modify the code with aarch64_insn_*() which uses + * probe_kernel_*(), and make sure what we read is what we expected it + * to be before modifying it. */ if (validate) { if (aarch64_insn_read((void *)pc, &replaced)) |