On Wed, Dec 11, 2024 at 7:53 PM Steven Rostedt <[email protected]> wrote:
> From: Steven Rostedt <[email protected]> > > A bug was discovered where the idle shadow stacks were not initialized > for offline CPUs when starting function graph tracer, and when they came > online they were not traced due to the missing shadow stack. To fix > this, the idle task shadow stack initialization was moved to using the > CPU hotplug callbacks. But it removed the initialization when the > function graph was enabled. The problem here is that the hotplug > callbacks are called when the CPUs come online, but the idle shadow > stack initialization only happens if function graph is currently > active. This caused the online CPUs to not get their shadow stack > initialized. > > The idle shadow stack initialization still needs to be done when the > function graph is registered, as they will not be allocated if function > graph is not registered. > > Cc: [email protected] > Fixes: 2c02f7375e65 ("fgraph: Use CPU hotplug mechanism to initialize idle > shadow stacks") > Reported-by: Linus Walleij <[email protected]> > Closes: > https://lore.kernel.org/all/CACRpkdaTBrHwRbbrphVy-=sedz6mssxhtkypotlrtq+dgga...@mail.gmail.com/ > Signed-off-by: Steven Rostedt (Google) <[email protected]> Yep that solves my issue and I can go on debugging my boot! Tested-by: Linus Walleij <[email protected]> Thanks for patching this up so quickly Stephen, you're the best. Yours, Linus Walleij
