powerpc64/ftrace: Add a field in paca to disable ftrace in unsafe code paths
We have some C code that we call into from real mode where we cannot take any exceptions. Though the C functions themselves are mostly safe, if these functions are traced, there is a possibility that we may take an exception. For instance, in certain conditions, the ftrace code uses WARN(), which uses a 'trap' to do its job. For such scenarios, introduce a new field in paca 'ftrace_enabled', which is checked on ftrace entry before continuing. This field can then be set to zero to disable/pause ftrace, and set to a non-zero value to resume ftrace. Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Showing
想要评论请 注册 或 登录