Commit 2ab2d579 authored by Daniel Axtens's avatar Daniel Axtens Committed by Michael Ellerman
Browse files

powerpc/kasan: Disable address sanitization in kexec paths 



The kexec code paths involve code that necessarily run in real mode, as
CPUs are disabled and control is transferred to the new kernel. Disable
address sanitization for the kexec code and the functions called in real
mode on CPUs being disabled.

[paulus@ozlabs.org: combined a few work-in-progress commits of
 Daniel's and wrote the commit message.]

Signed-off-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
[mpe: Move pseries_machine_kexec() into kexec.c so setup.c can be instrumented]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/YoTFSQ2TUSEaDdVC@cleo
parent 5352090a

arch/powerpc/kexec/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -13,3 +13,5 @@ obj-$(CONFIG_KEXEC_FILE) += file_load.o ranges.o file_load_$(BITS).o elf_$(BITS) 
GCOV_PROFILE_core_$(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

arch/powerpc/platforms/pseries/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -33,3 +33,5 @@ obj-$(CONFIG_SUSPEND) += suspend.o 
obj-$(CONFIG_PPC_VAS)		+= vas.o vas-sysfs.o



obj-$(CONFIG_ARCH_HAS_CC_PLATFORM)	+= cc_platform.o



KASAN_SANITIZE_kexec.o := n

arch/powerpc/platforms/pseries/kexec.c

+8 −0
Original line number Diff line number Diff line
@@ -61,3 +61,11 @@ void pseries_kexec_cpu_down(int crash_shutdown, int secondary) 
	} else

		xics_kexec_teardown_cpu(secondary);

}



void pseries_machine_kexec(struct kimage *image)

{

	if (firmware_has_feature(FW_FEATURE_SET_MODE))

		pseries_disable_reloc_on_exc();



	default_machine_kexec(image);

}

arch/powerpc/platforms/pseries/pseries.h

+1 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ static inline void smp_init_pseries(void) { } 
#endif



extern void pseries_kexec_cpu_down(int crash_shutdown, int secondary);

void pseries_machine_kexec(struct kimage *image);



extern void pSeries_final_fixup(void);

arch/powerpc/platforms/pseries/setup.c

+1 −11
Original line number Diff line number Diff line
@@ -421,16 +421,6 @@ void pseries_disable_reloc_on_exc(void) 
}

EXPORT_SYMBOL(pseries_disable_reloc_on_exc);



#ifdef CONFIG_KEXEC_CORE

static void pSeries_machine_kexec(struct kimage *image)

{

	if (firmware_has_feature(FW_FEATURE_SET_MODE))

		pseries_disable_reloc_on_exc();



	default_machine_kexec(image);

}

#endif



#ifdef __LITTLE_ENDIAN__

void pseries_big_endian_exceptions(void)

{
@@ -1099,7 +1089,7 @@ define_machine(pseries) { 
	.machine_check_exception = pSeries_machine_check_exception,

	.machine_check_log_err	= pSeries_machine_check_log_err,

#ifdef CONFIG_KEXEC_CORE

	.machine_kexec          = pSeries_machine_kexec,

	.machine_kexec          = pseries_machine_kexec,

	.kexec_cpu_down         = pseries_kexec_cpu_down,

#endif

#ifdef CONFIG_MEMORY_HOTPLUG