diff options
| author | Breno Leitao | 2026-01-06 02:16:35 -0800 |
|---|---|---|
| committer | Sasha Levin | 2026-03-04 07:21:39 -0500 |
| commit | 43a19467d3f31a0b80e9e74cb4ae96aba40399e0 (patch) | |
| tree | b3004dc58cc6bf16b4c635bad1aa2c8ce86eab80 /arch | |
| parent | ce904c8a5bbe697eae0f7e34b07095bd7a6dee19 (diff) | |
arm64: Disable branch profiling for all arm64 code
[ Upstream commit f22c81bebf8bda6e54dc132df0ed54f6bf8756f9 ]
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: stable@vger.kernel.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/Kbuild | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild index 5bfbf7d79c99..d876bc0e5421 100644 --- a/arch/arm64/Kbuild +++ b/arch/arm64/Kbuild @@ -1,4 +1,8 @@ # SPDX-License-Identifier: GPL-2.0-only + +# Branch profiling isn't noinstr-safe +subdir-ccflags-$(CONFIG_TRACE_BRANCH_PROFILING) += -DDISABLE_BRANCH_PROFILING + obj-y += kernel/ mm/ net/ obj-$(CONFIG_KVM) += kvm/ obj-$(CONFIG_XEN) += xen/ |