From ce3dc447493ff4186b192b38d723ab5e8c1eb52f Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 12 Sep 2017 16:37:33 +0200 Subject: s390: add support for virtually mapped kernel stacks With virtually mapped kernel stacks the kernel stack overflow detection is now fault based, every stack has a guard page in the vmalloc space. The panic_stack is renamed to nodat_stack and is used for all function that need to run without DAT, e.g. memcpy_real or do_start_kdump. The main effect is a reduction in the kernel image size as with vmap stacks the old style overflow checking that adds two instructions per function is not needed anymore. Result from bloat-o-meter: add/remove: 20/1 grow/shrink: 13/26854 up/down: 2198/-216240 (-214042) In regard to performance the micro-benchmark for fork has a hit of a few microseconds, allocating 4 pages in vmalloc space is more expensive compare to an order-2 page allocation. But with real workload I could not find a noticeable difference. Acked-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/Kconfig | 2 + arch/s390/include/asm/lowcore.h | 4 +- arch/s390/include/asm/processor.h | 8 ++++ arch/s390/include/asm/thread_info.h | 3 -- arch/s390/kernel/asm-offsets.c | 2 +- arch/s390/kernel/base.S | 2 +- arch/s390/kernel/dumpstack.c | 6 +-- arch/s390/kernel/entry.S | 53 +++++++++++++++------- arch/s390/kernel/entry.h | 3 ++ arch/s390/kernel/head64.S | 4 +- arch/s390/kernel/irq.c | 2 +- arch/s390/kernel/machine_kexec.c | 17 +++++-- arch/s390/kernel/setup.c | 89 +++++++++++++++++++++++++++++++++---- arch/s390/kernel/smp.c | 86 ++++++++++++++++++++--------------- arch/s390/kernel/swsusp.S | 7 +-- arch/s390/mm/maccess.c | 25 ++++++++--- 16 files changed, 225 insertions(+), 88 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 9a9c7a6fe925..6061dd7578fe 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -125,6 +125,7 @@ config S390 select HAVE_ARCH_SOFT_DIRTY select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE + select HAVE_ARCH_VMAP_STACK select HAVE_EBPF_JIT if PACK_STACK && HAVE_MARCH_Z196_FEATURES select HAVE_CMPXCHG_DOUBLE select HAVE_CMPXCHG_LOCAL @@ -649,6 +650,7 @@ config PACK_STACK config CHECK_STACK def_bool y + depends on !VMAP_STACK prompt "Detect kernel stack overflow" help This option enables the compiler option -mstack-guard and diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h index 406d940173ab..cc0947e08b6f 100644 --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -102,9 +102,9 @@ struct lowcore { __u64 current_task; /* 0x0338 */ __u64 kernel_stack; /* 0x0340 */ - /* Interrupt, panic and restart stack. */ + /* Interrupt, DAT-off and restartstack. */ __u64 async_stack; /* 0x0348 */ - __u64 panic_stack; /* 0x0350 */ + __u64 nodat_stack; /* 0x0350 */ __u64 restart_stack; /* 0x0358 */ /* Restart function and parameter. */ diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 43494a014d5b..3c1e723a143a 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -162,6 +162,14 @@ struct thread_struct { typedef struct thread_struct thread_struct; +/* + * General size of a stack + */ +#define STACK_ORDER 2 +#define STACK_SIZE (PAGE_SIZE << STACK_ORDER) +#define STACK_INIT_OFFSET \ + (STACK_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs)) + /* * Stack layout of a C stack frame. */ diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index 3c883c368eb0..3fa2fea0ba23 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -14,10 +14,7 @@ * Size of kernel stack for each process */ #define THREAD_SIZE_ORDER 2 -#define ASYNC_ORDER 2 - #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) -#define ASYNC_SIZE (PAGE_SIZE << ASYNC_ORDER) #ifndef __ASSEMBLY__ #include diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index 66e830f1c7bf..164bec175628 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -159,7 +159,7 @@ int main(void) OFFSET(__LC_CURRENT, lowcore, current_task); OFFSET(__LC_KERNEL_STACK, lowcore, kernel_stack); OFFSET(__LC_ASYNC_STACK, lowcore, async_stack); - OFFSET(__LC_PANIC_STACK, lowcore, panic_stack); + OFFSET(__LC_NODAT_STACK, lowcore, nodat_stack); OFFSET(__LC_RESTART_STACK, lowcore, restart_stack); OFFSET(__LC_RESTART_FN, lowcore, restart_fn); OFFSET(__LC_RESTART_DATA, lowcore, restart_data); diff --git a/arch/s390/kernel/base.S b/arch/s390/kernel/base.S index b65874b0b412..f268fca67e82 100644 --- a/arch/s390/kernel/base.S +++ b/arch/s390/kernel/base.S @@ -18,7 +18,7 @@ ENTRY(s390_base_mcck_handler) basr %r13,0 -0: lg %r15,__LC_PANIC_STACK # load panic stack +0: lg %r15,__LC_NODAT_STACK # load panic stack aghi %r15,-STACK_FRAME_OVERHEAD larl %r1,s390_base_mcck_handler_fn lg %r9,0(%r1) diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index 5b23c4f6e50c..301b945de77b 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -77,11 +77,11 @@ void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task, frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); #ifdef CONFIG_CHECK_STACK sp = __dump_trace(func, data, sp, - S390_lowcore.panic_stack + frame_size - PAGE_SIZE, - S390_lowcore.panic_stack + frame_size); + S390_lowcore.nodat_stack + frame_size - STACK_SIZE, + S390_lowcore.nodat_stack + frame_size); #endif sp = __dump_trace(func, data, sp, - S390_lowcore.async_stack + frame_size - ASYNC_SIZE, + S390_lowcore.async_stack + frame_size - STACK_SIZE, S390_lowcore.async_stack + frame_size); task = task ?: current; __dump_trace(func, data, sp, diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 150130c897c3..724fba4d09d2 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -85,14 +85,34 @@ _LPP_OFFSET = __LC_LPP #endif .endm - .macro CHECK_STACK stacksize,savearea + .macro CHECK_STACK savearea #ifdef CONFIG_CHECK_STACK - tml %r15,\stacksize - CONFIG_STACK_GUARD + tml %r15,STACK_SIZE - CONFIG_STACK_GUARD lghi %r14,\savearea jz stack_overflow #endif .endm + .macro CHECK_VMAP_STACK savearea,oklabel +#ifdef CONFIG_VMAP_STACK + lgr %r14,%r15 + nill %r14,0x10000 - STACK_SIZE + oill %r14,STACK_INIT + clg %r14,__LC_KERNEL_STACK + je \oklabel + clg %r14,__LC_ASYNC_STACK + je \oklabel + clg %r14,__LC_NODAT_STACK + je \oklabel + clg %r14,__LC_RESTART_STACK + je \oklabel + lghi %r14,\savearea + j stack_overflow +#else + j \oklabel +#endif + .endm + .macro SWITCH_ASYNC savearea,timer tmhh %r8,0x0001 # interrupting from user ? jnz 1f @@ -104,11 +124,11 @@ _LPP_OFFSET = __LC_LPP brasl %r14,cleanup_critical tmhh %r8,0x0001 # retest problem state after cleanup jnz 1f -0: lg %r14,__LC_ASYNC_STACK # are we already on the async stack? +0: lg %r14,__LC_ASYNC_STACK # are we already on the target stack? slgr %r14,%r15 srag %r14,%r14,STACK_SHIFT jnz 2f - CHECK_STACK 1< enabled, can't be a double fault tm __LC_PGM_ILC+3,0x80 # check for per exception jnz .Lpgm_svcper # -> single stepped svc -1: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC +1: CHECK_STACK __LC_SAVE_AREA_SYNC aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) - j 4f + # CHECK_VMAP_STACK branches to stack_overflow or 4f + CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,4f 2: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP lg %r15,__LC_KERNEL_STACK @@ -1136,7 +1157,8 @@ ENTRY(mcck_int_handler) jnz 4f TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID jno .Lmcck_panic -4: SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER +4: ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off + SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER .Lmcck_skip: lghi %r14,__LC_GPREGS_SAVE_AREA+64 stmg %r0,%r7,__PT_R0(%r11) @@ -1163,7 +1185,6 @@ ENTRY(mcck_int_handler) xc __SF_BACKCHAIN(8,%r1),__SF_BACKCHAIN(%r1) la %r11,STACK_FRAME_OVERHEAD(%r1) lgr %r15,%r1 - ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off TSTMSK __LC_CPU_FLAGS,_CIF_MCCK_PENDING jno .Lmcck_return TRACE_IRQS_OFF @@ -1182,7 +1203,7 @@ ENTRY(mcck_int_handler) lpswe __LC_RETURN_MCCK_PSW .Lmcck_panic: - lg %r15,__LC_PANIC_STACK + lg %r15,__LC_NODAT_STACK la %r11,STACK_FRAME_OVERHEAD(%r15) j .Lmcck_skip @@ -1193,12 +1214,10 @@ ENTRY(restart_int_handler) ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40 stg %r15,__LC_SAVE_AREA_RESTART lg %r15,__LC_RESTART_STACK - aghi %r15,-__PT_SIZE # create pt_regs on stack - xc 0(__PT_SIZE,%r15),0(%r15) - stmg %r0,%r14,__PT_R0(%r15) - mvc __PT_R15(8,%r15),__LC_SAVE_AREA_RESTART - mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw - aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack + xc STACK_FRAME_OVERHEAD(__PT_SIZE,%r15),STACK_FRAME_OVERHEAD(%r15) + stmg %r0,%r14,STACK_FRAME_OVERHEAD+__PT_R0(%r15) + mvc STACK_FRAME_OVERHEAD+__PT_R15(8,%r15),__LC_SAVE_AREA_RESTART + mvc STACK_FRAME_OVERHEAD+__PT_PSW(16,%r15),__LC_RST_OLD_PSW xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) lg %r1,__LC_RESTART_FN # load fn, parm & source cpu lg %r2,__LC_RESTART_DATA @@ -1216,14 +1235,14 @@ ENTRY(restart_int_handler) .section .kprobes.text, "ax" -#ifdef CONFIG_CHECK_STACK +#if defined(CONFIG_CHECK_STACK) || defined(CONFIG_VMAP_STACK) /* * The synchronous or the asynchronous stack overflowed. We are dead. * No need to properly save the registers, we are going to panic anyway. * Setup a pt_regs so that show_trace can provide a good call trace. */ stack_overflow: - lg %r15,__LC_PANIC_STACK # change to panic stack + lg %r15,__LC_NODAT_STACK # change to panic stack la %r11,STACK_FRAME_OVERHEAD(%r15) stmg %r0,%r7,__PT_R0(%r11) stmg %r8,%r9,__PT_PSW(%r11) diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h index 472fa2f1a4a5..c3816ae108b0 100644 --- a/arch/s390/kernel/entry.h +++ b/arch/s390/kernel/entry.h @@ -86,4 +86,7 @@ DECLARE_PER_CPU(u64, mt_cycles[8]); void gs_load_bc_cb(struct pt_regs *regs); void set_fs_fixup(void); +unsigned long stack_alloc(void); +void stack_free(unsigned long stack); + #endif /* _ENTRY_H */ diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S index b31dfb102700..57bba24b1c27 100644 --- a/arch/s390/kernel/head64.S +++ b/arch/s390/kernel/head64.S @@ -36,9 +36,7 @@ ENTRY(startup_continue) # larl %r14,init_task stg %r14,__LC_CURRENT - larl %r15,init_thread_union+THREAD_SIZE - stg %r15,__LC_KERNEL_STACK # set end of kernel stack - aghi %r15,-STACK_FRAME_OVERHEAD + larl %r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD # # Early setup functions that may not rely on an initialized bss section, # like moving the initrd. Returns with an initialized bss section. diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 0e8d68bac82c..b2bc0eb1ca7a 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -171,7 +171,7 @@ void do_softirq_own_stack(void) old = current_stack_pointer(); /* Check against async. stack address range. */ new = S390_lowcore.async_stack; - if (((new - old) >> (PAGE_SHIFT + THREAD_SIZE_ORDER)) != 0) { + if (((new - old) >> (PAGE_SHIFT + STACK_ORDER)) != 0) { CALL_ON_STACK(__do_softirq, new, 0); } else { /* We are already on the async stack. */ diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c index b7020e721ae3..cb582649aba6 100644 --- a/arch/s390/kernel/machine_kexec.c +++ b/arch/s390/kernel/machine_kexec.c @@ -142,18 +142,27 @@ static noinline void __machine_kdump(void *image) } #endif +static unsigned long do_start_kdump(unsigned long addr) +{ + struct kimage *image = (struct kimage *) addr; + int (*start_kdump)(int) = (void *)image->start; + int rc; + + __arch_local_irq_stnsm(0xfb); /* disable DAT */ + rc = start_kdump(0); + __arch_local_irq_stosm(0x04); /* enable DAT */ + return rc; +} + /* * Check if kdump checksums are valid: We call purgatory with parameter "0" */ static bool kdump_csum_valid(struct kimage *image) { #ifdef CONFIG_CRASH_DUMP - int (*start_kdump)(int) = (void *)image->start; int rc; - __arch_local_irq_stnsm(0xfb); /* disable DAT */ - rc = start_kdump(0); - __arch_local_irq_stosm(0x04); /* enable DAT */ + rc = CALL_ON_STACK(do_start_kdump, S390_lowcore.nodat_stack, 1, image); return rc == 0; #else return false; diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index c637c12f9e37..eca51c485d09 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include @@ -303,6 +304,78 @@ early_param("vmalloc", parse_vmalloc); void *restart_stack __section(.data); +unsigned long stack_alloc(void) +{ +#ifdef CONFIG_VMAP_STACK + return (unsigned long) + __vmalloc_node_range(STACK_SIZE, STACK_SIZE, + VMALLOC_START, VMALLOC_END, + THREADINFO_GFP, + PAGE_KERNEL, 0, NUMA_NO_NODE, + __builtin_return_address(0)); +#else + return __get_free_pages(GFP_KERNEL, STACK_ORDER); +#endif +} + +void stack_free(unsigned long stack) +{ +#ifdef CONFIG_VMAP_STACK + vfree((void *) stack); +#else + free_pages(stack, STACK_ORDER); +#endif +} + +int __init arch_early_irq_init(void) +{ + unsigned long stack; + + stack = __get_free_pages(GFP_KERNEL, STACK_ORDER); + if (!stack) + panic("Couldn't allocate async stack"); + S390_lowcore.async_stack = stack + STACK_INIT_OFFSET; + return 0; +} + +static int __init async_stack_realloc(void) +{ + unsigned long old, new; + + old = S390_lowcore.async_stack - STACK_INIT_OFFSET; + new = stack_alloc(); + if (!new) + panic("Couldn't allocate async stack"); + S390_lowcore.async_stack = new + STACK_INIT_OFFSET; + free_pages(old, STACK_ORDER); + return 0; +} +early_initcall(async_stack_realloc); + +void __init arch_call_rest_init(void) +{ + struct stack_frame *frame; + unsigned long stack; + + stack = stack_alloc(); + if (!stack) + panic("Couldn't allocate kernel stack"); + current->stack = (void *) stack; +#ifdef CONFIG_VMAP_STACK + current->stack_vm_area = (void *) stack; +#endif + set_task_stack_end_magic(current); + stack += STACK_INIT_OFFSET; + S390_lowcore.kernel_stack = stack; + frame = (struct stack_frame *) stack; + memset(frame, 0, sizeof(*frame)); + /* Branch to rest_init on the new stack, never returns */ + asm volatile( + " la 15,0(%[_frame])\n" + " jg rest_init\n" + : : [_frame] "a" (frame)); +} + static void __init setup_lowcore(void) { struct lowcore *lc; @@ -329,14 +402,8 @@ static void __init setup_lowcore(void) PSW_MASK_DAT | PSW_MASK_MCHECK; lc->io_new_psw.addr = (unsigned long) io_int_handler; lc->clock_comparator = clock_comparator_max; - lc->kernel_stack = ((unsigned long) &init_thread_union) + lc->nodat_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); - lc->async_stack = (unsigned long) - memblock_virt_alloc(ASYNC_SIZE, ASYNC_SIZE) - + ASYNC_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); - lc->panic_stack = (unsigned long) - memblock_virt_alloc(PAGE_SIZE, PAGE_SIZE) - + PAGE_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs); lc->current_task = (unsigned long)&init_task; lc->lpp = LPP_MAGIC; lc->machine_flags = S390_lowcore.machine_flags; @@ -357,8 +424,12 @@ static void __init setup_lowcore(void) lc->last_update_timer = S390_lowcore.last_update_timer; lc->last_update_clock = S390_lowcore.last_update_clock; - restart_stack = memblock_virt_alloc(ASYNC_SIZE, ASYNC_SIZE); - restart_stack += ASYNC_SIZE; + /* + * Allocate the global restart stack which is the same for + * all CPUs in cast *one* of them does a PSW restart. + */ + restart_stack = memblock_virt_alloc(STACK_SIZE, STACK_SIZE); + restart_stack += STACK_INIT_OFFSET; /* * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 2f8f7d7dd9a8..fccdb96a04cb 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -186,36 +186,34 @@ static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit) pcpu_sigp_retry(pcpu, order, 0); } -#define ASYNC_FRAME_OFFSET (ASYNC_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) -#define PANIC_FRAME_OFFSET (PAGE_SIZE - STACK_FRAME_OVERHEAD - __PT_SIZE) - static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) { - unsigned long async_stack, panic_stack; + unsigned long async_stack, nodat_stack; struct lowcore *lc; if (pcpu != &pcpu_devices[0]) { pcpu->lowcore = (struct lowcore *) __get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER); - async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER); - panic_stack = __get_free_page(GFP_KERNEL); - if (!pcpu->lowcore || !panic_stack || !async_stack) + nodat_stack = __get_free_pages(GFP_KERNEL, STACK_ORDER); + if (!pcpu->lowcore || !nodat_stack) goto out; } else { - async_stack = pcpu->lowcore->async_stack - ASYNC_FRAME_OFFSET; - panic_stack = pcpu->lowcore->panic_stack - PANIC_FRAME_OFFSET; + nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET; } + async_stack = stack_alloc(); + if (!async_stack) + goto out; lc = pcpu->lowcore; memcpy(lc, &S390_lowcore, 512); memset((char *) lc + 512, 0, sizeof(*lc) - 512); - lc->async_stack = async_stack + ASYNC_FRAME_OFFSET; - lc->panic_stack = panic_stack + PANIC_FRAME_OFFSET; + lc->async_stack = async_stack + STACK_INIT_OFFSET; + lc->nodat_stack = nodat_stack + STACK_INIT_OFFSET; lc->cpu_nr = cpu; lc->spinlock_lockval = arch_spin_lockval(cpu); lc->spinlock_index = 0; lc->br_r1_trampoline = 0x07f1; /* br %r1 */ if (nmi_alloc_per_cpu(lc)) - goto out; + goto out_async; if (vdso_alloc_per_cpu(lc)) goto out_mcesa; lowcore_ptr[cpu] = lc; @@ -224,10 +222,11 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu) out_mcesa: nmi_free_per_cpu(lc); +out_async: + stack_free(async_stack); out: if (pcpu != &pcpu_devices[0]) { - free_page(panic_stack); - free_pages(async_stack, ASYNC_ORDER); + free_pages(nodat_stack, STACK_ORDER); free_pages((unsigned long) pcpu->lowcore, LC_ORDER); } return -ENOMEM; @@ -237,15 +236,21 @@ out: static void pcpu_free_lowcore(struct pcpu *pcpu) { + unsigned long async_stack, nodat_stack, lowcore; + + nodat_stack = pcpu->lowcore->nodat_stack - STACK_INIT_OFFSET; + async_stack = pcpu->lowcore->async_stack - STACK_INIT_OFFSET; + lowcore = (unsigned long) pcpu->lowcore; + pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0); lowcore_ptr[pcpu - pcpu_devices] = NULL; vdso_free_per_cpu(pcpu->lowcore); nmi_free_per_cpu(pcpu->lowcore); + stack_free(async_stack); if (pcpu == &pcpu_devices[0]) return; - free_page(pcpu->lowcore->panic_stack-PANIC_FRAME_OFFSET); - free_pages(pcpu->lowcore->async_stack-ASYNC_FRAME_OFFSET, ASYNC_ORDER); - free_pages((unsigned long) pcpu->lowcore, LC_ORDER); + free_pages(nodat_stack, STACK_ORDER); + free_pages(lowcore, LC_ORDER); } #endif /* CONFIG_HOTPLUG_CPU */ @@ -293,7 +298,7 @@ static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) { struct lowcore *lc = pcpu->lowcore; - lc->restart_stack = lc->kernel_stack; + lc->restart_stack = lc->nodat_stack; lc->restart_fn = (unsigned long) func; lc->restart_data = (unsigned long) data; lc->restart_source = -1UL; @@ -303,15 +308,20 @@ static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data) /* * Call function via PSW restart on pcpu and stop the current cpu. */ +static void __pcpu_delegate(void (*func)(void*), void *data) +{ + func(data); /* should not return */ +} + static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), void *data, unsigned long stack) { struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; unsigned long source_cpu = stap(); - __load_psw_mask(PSW_KERNEL_BITS); + __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); if (pcpu->address == source_cpu) - func(data); /* should not return */ + CALL_ON_STACK(__pcpu_delegate, stack, 2, func, data); /* Stop target cpu (if func returns this stops the current cpu). */ pcpu_sigp_retry(pcpu, SIGP_STOP, 0); /* Restart func on the target cpu and stop the current cpu. */ @@ -372,8 +382,7 @@ void smp_call_online_cpu(void (*func)(void *), void *data) void smp_call_ipl_cpu(void (*func)(void *), void *data) { pcpu_delegate(&pcpu_devices[0], func, data, - pcpu_devices->lowcore->panic_stack - - PANIC_FRAME_OFFSET + PAGE_SIZE); + pcpu_devices->lowcore->nodat_stack); } int smp_find_processor_id(u16 address) @@ -791,37 +800,42 @@ void __init smp_detect_cpus(void) memblock_free_early((unsigned long)info, sizeof(*info)); } -/* - * Activate a secondary processor. - */ -static void smp_start_secondary(void *cpuvoid) +static void smp_init_secondary(void) { int cpu = smp_processor_id(); - S390_lowcore.last_update_clock = get_tod_clock(); - S390_lowcore.restart_stack = (unsigned long) restart_stack; - S390_lowcore.restart_fn = (unsigned long) do_restart; - S390_lowcore.restart_data = 0; - S390_lowcore.restart_source = -1UL; - restore_access_regs(S390_lowcore.access_regs_save_area); - __ctl_load(S390_lowcore.cregs_save_area, 0, 15); - __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); cpu_init(); preempt_disable(); init_cpu_timer(); vtime_init(); pfault_init(); - notify_cpu_starting(cpu); + notify_cpu_starting(smp_processor_id()); if (topology_cpu_dedicated(cpu)) set_cpu_flag(CIF_DEDICATED_CPU); else clear_cpu_flag(CIF_DEDICATED_CPU); - set_cpu_online(cpu, true); + set_cpu_online(smp_processor_id(), true); inc_irq_stat(CPU_RST); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } +/* + * Activate a secondary processor. + */ +static void smp_start_secondary(void *cpuvoid) +{ + S390_lowcore.last_update_clock = get_tod_clock(); + S390_lowcore.restart_stack = (unsigned long) restart_stack; + S390_lowcore.restart_fn = (unsigned long) do_restart; + S390_lowcore.restart_data = 0; + S390_lowcore.restart_source = -1UL; + restore_access_regs(S390_lowcore.access_regs_save_area); + __ctl_load(S390_lowcore.cregs_save_area, 0, 15); + __load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT); + CALL_ON_STACK(smp_init_secondary, S390_lowcore.kernel_stack, 0); +} + /* Upping and downing of CPUs */ int __cpu_up(unsigned int cpu, struct task_struct *tidle) { diff --git a/arch/s390/kernel/swsusp.S b/arch/s390/kernel/swsusp.S index 34b014b5cf03..537f97fde37f 100644 --- a/arch/s390/kernel/swsusp.S +++ b/arch/s390/kernel/swsusp.S @@ -29,10 +29,11 @@ .section .text ENTRY(swsusp_arch_suspend) - stmg %r6,%r15,__SF_GPRS(%r15) + lg %r1,__LC_NODAT_STACK + aghi %r1,-STACK_FRAME_OVERHEAD + stmg %r6,%r15,__SF_GPRS(%r1) + stg %r15,__SF_BACKCHAIN(%r1) lgr %r1,%r15 - aghi %r15,-STACK_FRAME_OVERHEAD - stg %r1,__SF_BACKCHAIN(%r15) /* Store FPU registers */ brasl %r14,save_fpu_regs diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c index 7be06475809b..97b3ee53852b 100644 --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -89,10 +89,8 @@ static int __memcpy_real(void *dest, void *src, size_t count) return rc; } -/* - * Copy memory in real mode (kernel to kernel) - */ -int memcpy_real(void *dest, void *src, size_t count) +static unsigned long _memcpy_real(unsigned long dest, unsigned long src, + unsigned long count) { int irqs_disabled, rc; unsigned long flags; @@ -103,13 +101,30 @@ int memcpy_real(void *dest, void *src, size_t count) irqs_disabled = arch_irqs_disabled_flags(flags); if (!irqs_disabled) trace_hardirqs_off(); - rc = __memcpy_real(dest, src, count); + rc = __memcpy_real((void *) dest, (void *) src, (size_t) count); if (!irqs_disabled) trace_hardirqs_on(); __arch_local_irq_ssm(flags); return rc; } +/* + * Copy memory in real mode (kernel to kernel) + */ +int memcpy_real(void *dest, void *src, size_t count) +{ + if (S390_lowcore.nodat_stack != 0) + return CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack, + 3, dest, src, count); + /* + * This is a really early memcpy_real call, the stacks are + * not set up yet. Just call _memcpy_real on the early boot + * stack + */ + return _memcpy_real((unsigned long) dest,(unsigned long) src, + (unsigned long) count); +} + /* * Copy memory in absolute mode (kernel to kernel) */ -- cgit v1.2.3-59-g8ed1b