On Wed, 19 Nov 2014 19:29:25 +0100 (CET) Thomas Gleixner <[email protected]> wrote:
> On Wed, 19 Nov 2014, Steven Rostedt wrote: > > From: "Steven Rostedt (Red Hat)" <[email protected]> > > Date: Tue, 18 Nov 2014 21:14:11 -0500 > > Subject: [PATCH] ftrace/x86/extable: Add is_ftrace_trampoline() function > > > > Stack traces that happen from function tracing check if the address > > on the stack is a __kernel_text_address(). That is, is the address > > kernel code. This calls core_kernel_text() which returns true > > if the address is part of the builtin kernel code. It also calls > > is_module_text_address() which returns true if the address belongs > > to module code. > > > > But what is missing is ftrace dynamically allocated trampolines. > > These trampolines are allocated for individual ftrace_ops that > > call the ftrace_ops callback functions directly. But if they do a > > stack trace, the code checking the stack wont detect them as they > > are neither core kernel code nor module address space. > > > > Adding another field to ftrace_ops that also stores the size of > > the trampoline assigned to it we can create a new function called > > is_ftrace_trampoline() that returns true if the address is a > > dynamically allocate ftrace trampoline. Note, it ignores trampolines > > that are not dynamically allocated as they will return true with > > the core_kernel_text() function. > > > > Link: http://lkml.kernel.org/r/[email protected] > > > > Cc: Thomas Gleixner <[email protected]> > > Cc: Ingo Molnar <[email protected]> > > Cc: "H. Peter Anvin" <[email protected]> > > Signed-off-by: Steven Rostedt <[email protected]> > > Acked-by: Thomas Gleixner <[email protected]> Thanks! -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
