From 70caac180f14e996ffd90776b75546485ac33a0c Mon Sep 17 00:00:00 2001 From: Alexander Gordeev Date: Thu, 17 Mar 2022 15:03:03 +0100 Subject: [PATCH] s390/maccess: rework absolute lowcore accessors [ Upstream commit ed0192bc644f3553d64a5cb461bdd0b1fbae3fdf ] 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: Heiko Carstens Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/include/asm/processor.h | 17 ++++++++++++----- arch/s390/kernel/ipl.c | 4 ++-- arch/s390/kernel/machine_kexec.c | 2 +- arch/s390/kernel/os_info.c | 2 +- arch/s390/kernel/setup.c | 19 ++++++++++--------- arch/s390/kernel/smp.c | 12 ++++++------ 6 files changed, 32 insertions(+), 24 deletions(-) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index e9db8ef..d7ca76b 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -321,11 +321,18 @@ extern void (*s390_base_pgm_handler_fn)(void); 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); \ - \ - BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \ - memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \ +#define put_abs_lowcore(member, x) do { \ + unsigned long __abs_address = offsetof(struct lowcore, member); \ + __typeof__(((struct lowcore *)0)->member) __tmp = (x); \ + \ + 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); diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c index 5ad1dde..ba29887 100644 --- a/arch/s390/kernel/ipl.c +++ b/arch/s390/kernel/ipl.c @@ -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); } diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c index 0505e55..4b95684 100644 --- a/arch/s390/kernel/machine_kexec.c +++ b/arch/s390/kernel/machine_kexec.c @@ -227,7 +227,7 @@ 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) diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c index 6b5b64e..1acc2e0 100644 --- a/arch/s390/kernel/os_info.c +++ b/arch/s390/kernel/os_info.c @@ -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 diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 36c1f31..6b1a869 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -479,11 +479,11 @@ 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; @@ -500,6 +500,7 @@ 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; @@ -508,10 +509,10 @@ 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 = { diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 7bbcb5b..35af70e 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -334,10 +334,10 @@ static void pcpu_delegate(struct pcpu *pcpu, lc->restart_data = (unsigned long)data; lc->restart_source = source_cpu; } else { - mem_assign_absolute(lc->restart_stack, stack); - mem_assign_absolute(lc->restart_fn, (unsigned long)func); - mem_assign_absolute(lc->restart_data, (unsigned long)data); - mem_assign_absolute(lc->restart_source, source_cpu); + put_abs_lowcore(restart_stack, stack); + put_abs_lowcore(restart_fn, (unsigned long)func); + put_abs_lowcore(restart_data, (unsigned long)data); + put_abs_lowcore(restart_source, source_cpu); } __bpon(); asm volatile( @@ -593,9 +593,9 @@ void smp_ctl_set_clear_bit(int cr, int bit, bool set) parms.andval = ~(1UL << bit); } spin_lock(&ctl_lock); - memcpy_absolute(&ctlreg, &S390_lowcore.cregs_save_area[cr], sizeof(ctlreg)); + get_abs_lowcore(ctlreg, cregs_save_area[cr]); ctlreg = (ctlreg & parms.andval) | parms.orval; - memcpy_absolute(&S390_lowcore.cregs_save_area[cr], &ctlreg, sizeof(ctlreg)); + put_abs_lowcore(cregs_save_area[cr], ctlreg); spin_unlock(&ctl_lock); on_each_cpu(smp_ctl_bit_callback, &parms, 1); } -- 2.7.4