On Tue, Jan 06, 2026 at 12:21:47PM +0000, Mark Rutland wrote: > On Tue, Jan 06, 2026 at 02:16:35AM -0800, Breno Leitao wrote: > > The arm64 kernel doesn't boot with annotated branches > > (PROFILE_ANNOTATED_BRANCHES) enabled and CONFIG_DEBUG_VIRTUAL together. > > > > Bisecting it, I found that disabling branch profiling in arch/arm64/mm > > solved the problem. Narrowing down a bit further, I found that > > physaddr.c is the file that needs to have branch profiling disabled to > > get the machine to boot. > > > > I suspect that it might invoke some ftrace helper very early in the boot > > process and ftrace is still not enabled(!?). > > > > Rather than playing whack-a-mole with individual files, disable branch > > profiling for the entire arch/arm64 tree, similar to what x86 already > > does in arch/x86/Kbuild. > > > > Cc: [email protected] > > Fixes: ec6d06efb0bac ("arm64: Add support for CONFIG_DEBUG_VIRTUAL") > > Signed-off-by: Breno Leitao <[email protected]> > > I don't think ec6d06efb0bac is to blame here, and CONFIG_DEBUG_VIRTUAL > is unsound in a number of places, so I'd prefer to remove that Fixes tag > and backport this for all stable trees. > > Regardless, I'm in favour of disabling CONFIG_DEBUG_VIRTUAL widely, so: > > Acked-by: Mark Rutland <[email protected]>
Whoops; s/CONFIG_DEBUG_VIRTUAL/PROFILE_ANNOTATED_BRANCHES/ in both places in my reply. Mark.
