diff options
Diffstat (limited to 'arch/powerpc/kernel/ftrace.c')
| -rw-r--r-- | arch/powerpc/kernel/ftrace.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index cc52d9795f88..5c9f50c1aa99 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -47,13 +47,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) unsigned int replaced; /* - * 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 using the - * probe_kernel_* functions. - * - * No real locking needed, this code is run through - * kstop_machine, or before SMP starts. + * Note: + * We are paranoid about modifying text, as if a bug was to happen, it + * could cause us to read or write to someplace that could cause harm. + * Carefully read and modify the code with probe_kernel_*(), and make + * sure what we read is what we expected it to be before modifying it. */ /* read the text we want to modify */ @@ -593,7 +591,8 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip) if (!ftrace_graph_entry(&trace)) goto out; - if (ftrace_push_return_trace(parent, ip, &trace.depth, 0) == -EBUSY) + if (ftrace_push_return_trace(parent, ip, &trace.depth, 0, + NULL) == -EBUSY) goto out; parent = return_hooker; |
