Commit ed0192bc authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Vasily Gorbik
Browse files

s390/maccess: rework absolute lowcore accessors 



Macro mem_assign_absolute() is able to access the whole memory, but
is only used and makes sense when updating the absolute lowcore.
Instead, introduce get_abs_lowcore() and put_abs_lowcore() macros
that limit access to absolute lowcore addresses only.

Suggested-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 9097fc79

arch/s390/include/asm/processor.h

+12 −5
Original line number Diff line number Diff line
@@ -319,11 +319,18 @@ extern void (*s390_base_pgm_handler_fn)(struct pt_regs *regs); 
extern int memcpy_real(void *, unsigned long, size_t);

extern void memcpy_absolute(void *, void *, size_t);



#define mem_assign_absolute(dest, val) do {			\

	__typeof__(dest) __tmp = (val);				\

#define put_abs_lowcore(member, x) do {					\

	unsigned long __abs_address = offsetof(struct lowcore, member);	\

	__typeof__(((struct lowcore *)0)->member) __tmp = (x);		\

									\

	BUILD_BUG_ON(sizeof(__tmp) != sizeof(val));		\

	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\

	memcpy_absolute(__va(__abs_address), &__tmp, sizeof(__tmp));	\

} while (0)



#define get_abs_lowcore(x, member) do {					\

	unsigned long __abs_address = offsetof(struct lowcore, member);	\

	__typeof__(((struct lowcore *)0)->member) *__ptr = &(x);	\

									\

	memcpy_absolute(__ptr, __va(__abs_address), sizeof(*__ptr));	\

} while (0)



extern int s390_isolate_bp(void);

arch/s390/kernel/ipl.c

+2 −2
Original line number Diff line number Diff line
@@ -1646,8 +1646,8 @@ static void dump_reipl_run(struct shutdown_trigger *trigger) 


	csum = (__force unsigned int)

	       csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);

	mem_assign_absolute(S390_lowcore.ipib, ipib);

	mem_assign_absolute(S390_lowcore.ipib_checksum, csum);

	put_abs_lowcore(ipib, ipib);

	put_abs_lowcore(ipib_checksum, csum);

	dump_run(trigger);

}

arch/s390/kernel/machine_kexec.c

+1 −1
Original line number Diff line number Diff line
@@ -226,7 +226,7 @@ void arch_crash_save_vmcoreinfo(void) 
	vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);

	vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);

	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());

	mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());

	put_abs_lowcore(vmcore_info, paddr_vmcoreinfo_note());

}



void machine_shutdown(void)

arch/s390/kernel/os_info.c

+1 −1
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ void __init os_info_init(void) 
	os_info.version_minor = OS_INFO_VERSION_MINOR;

	os_info.magic = OS_INFO_MAGIC;

	os_info.csum = os_info_csum(&os_info);

	mem_assign_absolute(S390_lowcore.os_info, __pa(ptr));

	put_abs_lowcore(os_info, __pa(ptr));

}



#ifdef CONFIG_CRASH_DUMP

arch/s390/kernel/setup.c

+10 −9
Original line number Diff line number Diff line
@@ -481,11 +481,11 @@ static void __init setup_lowcore_dat_off(void) 
	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;



	/* Setup absolute zero lowcore */

	mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);

	mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);

	mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);

	mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);

	mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);

	put_abs_lowcore(restart_stack, lc->restart_stack);

	put_abs_lowcore(restart_fn, lc->restart_fn);

	put_abs_lowcore(restart_data, lc->restart_data);

	put_abs_lowcore(restart_source, lc->restart_source);

	put_abs_lowcore(restart_psw, lc->restart_psw);



	lc->spinlock_lockval = arch_spin_lockval(0);

	lc->spinlock_index = 0;
@@ -501,6 +501,7 @@ static void __init setup_lowcore_dat_off(void) 
static void __init setup_lowcore_dat_on(void)

{

	struct lowcore *lc = lowcore_ptr[0];

	int cr;



	__ctl_clear_bit(0, 28);

	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
@@ -509,10 +510,10 @@ static void __init setup_lowcore_dat_on(void) 
	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;

	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);

	__ctl_set_bit(0, 28);

	mem_assign_absolute(S390_lowcore.restart_flags, RESTART_FLAG_CTLREGS);

	mem_assign_absolute(S390_lowcore.program_new_psw, lc->program_new_psw);

	memcpy_absolute(&S390_lowcore.cregs_save_area, lc->cregs_save_area,

			sizeof(S390_lowcore.cregs_save_area));

	put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS);

	put_abs_lowcore(program_new_psw, lc->program_new_psw);

	for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)

		put_abs_lowcore(cregs_save_area[cr], lc->cregs_save_area[cr]);

}



static struct resource code_resource = {