On Fri, 9 Aug 2019 10:17:19 +0800 Jiping Ma <[email protected]> wrote:
> On 2019年08月09日 01:24, Steven Rostedt wrote: > > On Thu, 8 Aug 2019 18:11:53 +0100 > > Will Deacon <[email protected]> wrote: > > > >>> We could make it more descriptive of what it will do and not the reason > >>> for why it is done... > >>> > >>> > >>> ARCH_FTRACE_SHIFT_STACK_TRACER > >> Acked-by: Will Deacon <[email protected]> > > Thanks Will! > > > > Here's the official patch. > > > > From: "Steven Rostedt (VMware)" <[email protected]> > > > > Most archs (well at least x86) store the function call return address on the > > stack before storing the local variables for the function. The max stack > > tracer depends on this in its algorithm to display the stack size of each > > function it finds in the back trace. > > > > Some archs (arm64), may store the return address (from its link register) > > just before calling a nested function. There's no reason to save the link > > register on leaf functions, as it wont be updated. This breaks the algorithm > > of the max stack tracer. > > > > Add a new define ARCH_RET_ADDR_AFTER_LOCAL_VARS that an architecture may > > set > > ARCH_FTRACE_SHIFT_STACK_TRACER is used in the code. Ah, I did a s/x/y/ to the diff of the patch, but not the change log. Thanks for pointing that out. I also need to update the comment in 2/2. -- Steve > > Jiping > >
