On 23/03/26 11:41, Mahesh J Salgaonkar wrote:
On 2026-03-21 11:01:17 Sat, Sourabh Jain wrote:KASAN instrumentation is intended to be disabled for the kexec core code, but the existing Makefile entry misses the object suffix. As a result, the flag is not applied correctly to core_$(BITS).o. So when KASAN is enabled, kexec_copy_flush and copy_segments in kexec/core_64.c are instrumented, which can result in accesses to shadow memory via normal address translation paths. Since these run with the MMU disabled, such accesses may trigger page faults (bad_page_fault) that cannot be handled in the kdump path, ultimately causing a hang and preventing the kdump kernel from booting. The same is true for kexec as well, since the same functions are used there. Update the entry to include the “.o” suffix so that KASAN instrumentation is properly disabled for this object file. Fixes: 2ab2d5794f14 ("powerpc/kasan: Disable address sanitization in kexec paths") Reported-by: Venkat Rao Bagalkote <[email protected]> Closes: https://lore.kernel.org/all/[email protected]/ Cc: Aboorva Devarajan <[email protected]> Cc: Aditya Gupta <[email protected]> Cc: Daniel Axtens <[email protected]> Cc: Hari Bathini <[email protected]> Cc: Madhavan Srinivasan <[email protected]> Cc: Mahesh Salgaonkar <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Ritesh Harjani (IBM) <[email protected]> Cc: Shivang Upadhyay <[email protected]> Signed-off-by: Sourabh Jain <[email protected]> --- arch/powerpc/kexec/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile index 470eb0453e17..ec7a0eed75dc 100644 --- a/arch/powerpc/kexec/Makefile +++ b/arch/powerpc/kexec/Makefile @@ -16,4 +16,4 @@ GCOV_PROFILE_core_$(BITS).o := n KCOV_INSTRUMENT_core_$(BITS).o := n UBSAN_SANITIZE_core_$(BITS).o := n KASAN_SANITIZE_core.o := n -KASAN_SANITIZE_core_$(BITS) := n +KASAN_SANITIZE_core_$(BITS).o := nNice catch. Thakns for fixing. Acked-by: Mahesh Salgaonkar <[email protected]>
Thanks for the Ack Mahesh. - Sourabh Jain
