On Tue, 2020-12-22 at 10:53 -0800, Lakshmi Ramasubramanian wrote: > On 12/22/20 6:26 AM, Mimi Zohar wrote: > > Hi Mimi, > > > > > On Sat, 2020-12-19 at 09:57 -0800, Lakshmi Ramasubramanian wrote: > >> > >> diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile > >> index 4aff6846c772..b6c52608cb49 100644 > >> --- a/arch/powerpc/kexec/Makefile > >> +++ b/arch/powerpc/kexec/Makefile > >> @@ -9,13 +9,6 @@ obj-$(CONFIG_PPC32) += relocate_32.o > >> > >> obj-$(CONFIG_KEXEC_FILE) += file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o > >> > >> -ifdef CONFIG_HAVE_IMA_KEXEC > >> -ifdef CONFIG_IMA > >> -obj-y += ima.o > >> -endif > >> -endif > > > > Notice how "kexec/ima.o" is only included if the architecture supports > > it and IMA is configured. In addition only if CONFIG_IMA_KEXEC is > > configured, is the IMA measurement list carried across kexec. After > > moving the rest of ima.c to drivers/of/kexec.c, this changes. Notice > > how drivers/of/Kconfig includes kexec.o: > > > > obj-$(CONFIG_KEXEC_FILE) += kexec.o > > > > It is not dependent on CONFIG_HAVE_IMA_KEXEC. Shouldn't all of the > > functions defined in ima.c being moved to kexec.o be defined within a > > CONFIG_HAVE_IMA_KEXEC ifdef? > > > > Thanks for reviewing the changes. > > In "drivers/of/kexec.c" the function remove_ima_buffer() is defined > under "#ifdef CONFIG_HAVE_IMA_KEXEC" > > setup_ima_buffer() is defined under "#ifdef CONFIG_IMA_KEXEC" - the same > way it was defined in "arch/powerpc/kexec/ima.c". > > As you know, CONFIG_IMA_KEXEC depends on CONFIG_HAVE_IMA_KEXEC (as > defined in "security/integrity/ima/Kconfig"). > > ima_get_kexec_buffer() and ima_free_kexec_buffer() are unconditionally > defined in "drivers/of/kexec.c" even though they are called only when > CONFIG_HAVE_IMA_KEXEC is enabled. I will update these two functions to > be moved under "#ifdef CONFIG_HAVE_IMA_KEXEC" The issue is the reverse. CONFIG_HAVE_IMA_KEXEC may be enabled without CONFIG_IMA_KEXEC being enabled. This allows the architecture to support carrying the measurement list across kexec, but requires enabling it at build time. Only if CONFIG_HAVE_IMA_KEXEC is enabled should any of these functions be compiled at build. This allows restoring the previous IMA measurement list, even if CONFIG_IMA_KEXEC is not enabled. Only if CONFIG_IMA_KEXEC is enabled, should carrying the measurement list across kexec be enabled. See how arch_ima_add_kexec_buffer, write_number, setup_ima_buffer are ifdef'ed in arch/powerpc/kexec/ima.c. Mimi
