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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
s390/smp: make absolute lowcore / cpu restart parameter accesses more robust
Setting the cpu restart parameters is done in three different fashions: - directly setting the four parameters individually - copying the four parameters with memcpy (using 4 * sizeof(long)) - copying the four parameters using a private structure In addition code in entry*.S relies on a certain order of the restart members of struct _lowcore. Make all of this more robust to future changes by adding a mem_absolute_assign(dest, val) define, which assigns val to dest using absolute addressing mode. Also the load multiple instructions in entry*.S have been split into separate load instruction so the order of the struct _lowcore members doesn't matter anymore. In addition move the prototypes of memcpy_real/absolute from uaccess.h to processor.h. These memcpy* variants are not related to uaccess at all. string.h doesn't seem to match as well, so lets use processor.h. Also replace the eight byte array in struct _lowcore which represents a misaliged u64 with a u64. The compiler will always create code that handles the misaligned u64 correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
72f6e3a8bc
commit
fbe765680d
10 changed files with 38 additions and 35 deletions
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@ -302,12 +302,7 @@ struct _lowcore {
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*/
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__u64 ipib; /* 0x0e00 */
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__u32 ipib_checksum; /* 0x0e08 */
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/*
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* Because the vmcore_info pointer is not 8 byte aligned it never
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* should not be accessed directly. For accessing the pointer, first
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* copy it to a local pointer variable.
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*/
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__u8 vmcore_info[8]; /* 0x0e0c */
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__u64 vmcore_info; /* 0x0e0c */
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__u8 pad_0x0e14[0x0e18-0x0e14]; /* 0x0e14 */
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__u64 os_info; /* 0x0e18 */
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__u8 pad_0x0e20[0x0f00-0x0e20]; /* 0x0e20 */
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@ -348,4 +348,14 @@ extern void (*s390_base_ext_handler_fn)(void);
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".previous\n"
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#endif
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extern int memcpy_real(void *, void *, size_t);
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extern void memcpy_absolute(void *, void *, size_t);
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#define mem_assign_absolute(dest, val) { \
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__typeof__(dest) __tmp = (val); \
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\
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BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \
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memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \
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}
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#endif /* __ASM_S390_PROCESSOR_H */
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@ -381,8 +381,6 @@ clear_user(void __user *to, unsigned long n)
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return n;
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}
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extern int memcpy_real(void *, void *, size_t);
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extern void memcpy_absolute(void *, void *, size_t);
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extern int copy_to_user_real(void __user *dest, void *src, size_t count);
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extern int copy_from_user_real(void *dest, void __user *src, size_t count);
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@ -131,6 +131,8 @@ int main(void)
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DEFINE(__LC_PANIC_STACK, offsetof(struct _lowcore, panic_stack));
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DEFINE(__LC_RESTART_STACK, offsetof(struct _lowcore, restart_stack));
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DEFINE(__LC_RESTART_FN, offsetof(struct _lowcore, restart_fn));
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DEFINE(__LC_RESTART_DATA, offsetof(struct _lowcore, restart_data));
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DEFINE(__LC_RESTART_SOURCE, offsetof(struct _lowcore, restart_source));
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DEFINE(__LC_USER_ASCE, offsetof(struct _lowcore, user_asce));
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DEFINE(__LC_INT_CLOCK, offsetof(struct _lowcore, int_clock));
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DEFINE(__LC_MCCK_CLOCK, offsetof(struct _lowcore, mcck_clock));
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@ -724,7 +724,9 @@ ENTRY(restart_int_handler)
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mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw
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ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
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xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
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lm %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu
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l %r1,__LC_RESTART_FN # load fn, parm & source cpu
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l %r2,__LC_RESTART_DATA
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l %r3,__LC_RESTART_SOURCE
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ltr %r3,%r3 # test source cpu address
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jm 1f # negative -> skip source stop
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0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
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@ -751,7 +751,9 @@ ENTRY(restart_int_handler)
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mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw
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aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack
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xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15)
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lmg %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu
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lg %r1,__LC_RESTART_FN # load fn, parm & source cpu
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lg %r2,__LC_RESTART_DATA
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lg %r3,__LC_RESTART_SOURCE
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ltgr %r3,%r3 # test source cpu address
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jm 1f # negative -> skip source stop
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0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu
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@ -1528,15 +1528,12 @@ static struct shutdown_action __refdata dump_action = {
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static void dump_reipl_run(struct shutdown_trigger *trigger)
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{
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struct {
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void *addr;
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__u32 csum;
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} __packed ipib;
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unsigned long ipib = (unsigned long) &reipl_block_actual;
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unsigned int csum;
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ipib.csum = csum_partial(reipl_block_actual,
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reipl_block_actual->hdr.len, 0);
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ipib.addr = reipl_block_actual;
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memcpy_absolute(&S390_lowcore.ipib, &ipib, sizeof(ipib));
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csum = csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);
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mem_assign_absolute(S390_lowcore.ipib, ipib);
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mem_assign_absolute(S390_lowcore.ipib_checksum, csum);
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dump_run(trigger);
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}
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@ -60,7 +60,7 @@ void __init os_info_init(void)
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os_info.version_minor = OS_INFO_VERSION_MINOR;
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os_info.magic = OS_INFO_MAGIC;
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os_info.csum = os_info_csum(&os_info);
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memcpy_absolute(&S390_lowcore.os_info, &ptr, sizeof(ptr));
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mem_assign_absolute(S390_lowcore.os_info, (unsigned long) ptr);
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}
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#ifdef CONFIG_CRASH_DUMP
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@ -430,10 +430,11 @@ static void __init setup_lowcore(void)
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lc->restart_source = -1UL;
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/* Setup absolute zero lowcore */
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memcpy_absolute(&S390_lowcore.restart_stack, &lc->restart_stack,
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4 * sizeof(unsigned long));
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memcpy_absolute(&S390_lowcore.restart_psw, &lc->restart_psw,
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sizeof(lc->restart_psw));
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mem_assign_absolute(S390_lowcore.restart_stack, lc->restart_stack);
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mem_assign_absolute(S390_lowcore.restart_fn, lc->restart_fn);
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mem_assign_absolute(S390_lowcore.restart_data, lc->restart_data);
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mem_assign_absolute(S390_lowcore.restart_source, lc->restart_source);
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mem_assign_absolute(S390_lowcore.restart_psw, lc->restart_psw);
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set_prefix((u32)(unsigned long) lc);
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lowcore_ptr[0] = lc;
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@ -598,9 +599,7 @@ static void __init setup_memory_end(void)
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static void __init setup_vmcoreinfo(void)
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{
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#ifdef CONFIG_KEXEC
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unsigned long ptr = paddr_vmcoreinfo_note();
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memcpy_absolute(&S390_lowcore.vmcore_info, &ptr, sizeof(ptr));
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mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note());
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#endif
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}
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@ -273,26 +273,24 @@ static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
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void *data, unsigned long stack)
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{
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struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
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struct {
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unsigned long stack;
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void *func;
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void *data;
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unsigned long source;
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} restart = { stack, func, data, stap() };
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unsigned long source_cpu = stap();
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__load_psw_mask(psw_kernel_bits);
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if (pcpu->address == restart.source)
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if (pcpu->address == source_cpu)
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func(data); /* should not return */
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/* Stop target cpu (if func returns this stops the current cpu). */
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pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
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/* Restart func on the target cpu and stop the current cpu. */
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memcpy_absolute(&lc->restart_stack, &restart, sizeof(restart));
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mem_assign_absolute(lc->restart_stack, stack);
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mem_assign_absolute(lc->restart_fn, (unsigned long) func);
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mem_assign_absolute(lc->restart_data, (unsigned long) data);
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mem_assign_absolute(lc->restart_source, source_cpu);
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asm volatile(
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"0: sigp 0,%0,%2 # sigp restart to target cpu\n"
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" brc 2,0b # busy, try again\n"
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"1: sigp 0,%1,%3 # sigp stop to current cpu\n"
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" brc 2,1b # busy, try again\n"
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: : "d" (pcpu->address), "d" (restart.source),
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: : "d" (pcpu->address), "d" (source_cpu),
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"K" (SIGP_RESTART), "K" (SIGP_STOP)
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: "0", "1", "cc");
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for (;;) ;
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