diff options
| -rw-r--r-- | arch/x86/kernel/Makefile | 14 | ||||
| -rw-r--r-- | arch/x86/mm/Makefile | 2 |
2 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index e9aeeeafad17..47a32f583930 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -44,6 +44,20 @@ KCOV_INSTRUMENT_unwind_orc.o := n KCOV_INSTRUMENT_unwind_frame.o := n KCOV_INSTRUMENT_unwind_guess.o := n +# Disable KCOV to prevent crashes during kexec: load_segments() invalidates +# the GS base, which KCOV relies on for per-CPU data. +# +# As KCOV and KEXEC compatibility should be preserved (e.g. syzkaller is +# using it to collect crash dumps during kernel fuzzing), disabling +# KCOV for KEXEC kernels is not an option. Selectively disabling KCOV +# instrumentation for individual affected functions can be fragile, while +# adding more checks to KCOV would slow it down. +# +# As a compromise solution, disable KCOV instrumentation for the whole +# source code file. If its coverage is ever needed, other approaches +# should be considered. +KCOV_INSTRUMENT_machine_kexec_64.o := n + CFLAGS_head32.o := -fno-stack-protector CFLAGS_head64.o := -fno-stack-protector CFLAGS_irq.o := -I $(src)/../include/asm/trace diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 5b9908f13dcf..3a5364853eab 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -4,6 +4,8 @@ KCOV_INSTRUMENT_tlb.o := n KCOV_INSTRUMENT_mem_encrypt.o := n KCOV_INSTRUMENT_mem_encrypt_amd.o := n KCOV_INSTRUMENT_pgprot.o := n +# See the "Disable KCOV" comment in arch/x86/kernel/Makefile. +KCOV_INSTRUMENT_physaddr.o := n KASAN_SANITIZE_mem_encrypt.o := n KASAN_SANITIZE_mem_encrypt_amd.o := n |