From: Heiko Carstens Date: Tue, 5 Jun 2012 07:59:52 +0000 (+0200) Subject: s390/smp: make absolute lowcore / cpu restart parameter accesses more robust X-Git-Tag: v3.6-rc1~126^2~11 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=fbe765680d1fe9d08187ea4dad5041a7955a2c3a;p=~emulex%2Finfiniband.git 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 Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h index 47853debb3b..a47c6e221a9 100644 --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -302,12 +302,7 @@ struct _lowcore { */ __u64 ipib; /* 0x0e00 */ __u32 ipib_checksum; /* 0x0e08 */ - /* - * Because the vmcore_info pointer is not 8 byte aligned it never - * should not be accessed directly. For accessing the pointer, first - * copy it to a local pointer variable. - */ - __u8 vmcore_info[8]; /* 0x0e0c */ + __u64 vmcore_info; /* 0x0e0c */ __u8 pad_0x0e14[0x0e18-0x0e14]; /* 0x0e14 */ __u64 os_info; /* 0x0e18 */ __u8 pad_0x0e20[0x0f00-0x0e20]; /* 0x0e20 */ diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 20d0585cf90..f1700c5c888 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -348,4 +348,14 @@ extern void (*s390_base_ext_handler_fn)(void); ".previous\n" #endif +extern int memcpy_real(void *, void *, size_t); +extern void memcpy_absolute(void *, void *, size_t); + +#define mem_assign_absolute(dest, val) { \ + __typeof__(dest) __tmp = (val); \ + \ + BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \ + memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \ +} + #endif /* __ASM_S390_PROCESSOR_H */ diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index 1f3a79bcd26..7e7285179aa 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -381,8 +381,6 @@ clear_user(void __user *to, unsigned long n) return n; } -extern int memcpy_real(void *, void *, size_t); -extern void memcpy_absolute(void *, void *, size_t); extern int copy_to_user_real(void __user *dest, void *src, size_t count); extern int copy_from_user_real(void *dest, void __user *src, size_t count); diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index 83e6edf5cf1..0e974ddd156 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -131,6 +131,8 @@ int main(void) DEFINE(__LC_PANIC_STACK, offsetof(struct _lowcore, panic_stack)); DEFINE(__LC_RESTART_STACK, offsetof(struct _lowcore, restart_stack)); DEFINE(__LC_RESTART_FN, offsetof(struct _lowcore, restart_fn)); + DEFINE(__LC_RESTART_DATA, offsetof(struct _lowcore, restart_data)); + DEFINE(__LC_RESTART_SOURCE, offsetof(struct _lowcore, restart_source)); DEFINE(__LC_USER_ASCE, offsetof(struct _lowcore, user_asce)); DEFINE(__LC_INT_CLOCK, offsetof(struct _lowcore, int_clock)); DEFINE(__LC_MCCK_CLOCK, offsetof(struct _lowcore, mcck_clock)); diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 3787f9e6907..4ea53cd7c8c 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -724,7 +724,9 @@ ENTRY(restart_int_handler) mvc __PT_PSW(8,%r15),__LC_RST_OLD_PSW # store restart old psw ahi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) - lm %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu + l %r1,__LC_RESTART_FN # load fn, parm & source cpu + l %r2,__LC_RESTART_DATA + l %r3,__LC_RESTART_SOURCE ltr %r3,%r3 # test source cpu address jm 1f # negative -> skip source stop 0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index d5f02e480e5..2813e831ba3 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -751,7 +751,9 @@ ENTRY(restart_int_handler) mvc __PT_PSW(16,%r15),__LC_RST_OLD_PSW # store restart old psw aghi %r15,-STACK_FRAME_OVERHEAD # create stack frame on stack xc 0(STACK_FRAME_OVERHEAD,%r15),0(%r15) - lmg %r1,%r3,__LC_RESTART_FN # load fn, parm & source cpu + lg %r1,__LC_RESTART_FN # load fn, parm & source cpu + lg %r2,__LC_RESTART_DATA + lg %r3,__LC_RESTART_SOURCE ltgr %r3,%r3 # test source cpu address jm 1f # negative -> skip source stop 0: sigp %r4,%r3,SIGP_SENSE # sigp sense to source cpu diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c index 2f6cfd460cb..25241cd8ddd 100644 --- a/arch/s390/kernel/ipl.c +++ b/arch/s390/kernel/ipl.c @@ -1528,15 +1528,12 @@ static struct shutdown_action __refdata dump_action = { static void dump_reipl_run(struct shutdown_trigger *trigger) { - struct { - void *addr; - __u32 csum; - } __packed ipib; - - ipib.csum = csum_partial(reipl_block_actual, - reipl_block_actual->hdr.len, 0); - ipib.addr = reipl_block_actual; - memcpy_absolute(&S390_lowcore.ipib, &ipib, sizeof(ipib)); + unsigned long ipib = (unsigned long) &reipl_block_actual; + unsigned int csum; + + csum = 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); dump_run(trigger); } diff --git a/arch/s390/kernel/os_info.c b/arch/s390/kernel/os_info.c index 95fa5ac6c4c..46480d81df0 100644 --- a/arch/s390/kernel/os_info.c +++ b/arch/s390/kernel/os_info.c @@ -60,7 +60,7 @@ 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); - memcpy_absolute(&S390_lowcore.os_info, &ptr, sizeof(ptr)); + mem_assign_absolute(S390_lowcore.os_info, (unsigned long) ptr); } #ifdef CONFIG_CRASH_DUMP diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index 489d1d8d96b..49158cb1927 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -430,10 +430,11 @@ static void __init setup_lowcore(void) lc->restart_source = -1UL; /* Setup absolute zero lowcore */ - memcpy_absolute(&S390_lowcore.restart_stack, &lc->restart_stack, - 4 * sizeof(unsigned long)); - memcpy_absolute(&S390_lowcore.restart_psw, &lc->restart_psw, - sizeof(lc->restart_psw)); + 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); set_prefix((u32)(unsigned long) lc); lowcore_ptr[0] = lc; @@ -598,9 +599,7 @@ static void __init setup_memory_end(void) static void __init setup_vmcoreinfo(void) { #ifdef CONFIG_KEXEC - unsigned long ptr = paddr_vmcoreinfo_note(); - - memcpy_absolute(&S390_lowcore.vmcore_info, &ptr, sizeof(ptr)); + mem_assign_absolute(S390_lowcore.vmcore_info, paddr_vmcoreinfo_note()); #endif } diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index e01408429ad..dc602a61233 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -273,26 +273,24 @@ static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *), void *data, unsigned long stack) { struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices]; - struct { - unsigned long stack; - void *func; - void *data; - unsigned long source; - } restart = { stack, func, data, stap() }; + unsigned long source_cpu = stap(); __load_psw_mask(psw_kernel_bits); - if (pcpu->address == restart.source) + if (pcpu->address == source_cpu) func(data); /* should not return */ /* 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. */ - memcpy_absolute(&lc->restart_stack, &restart, sizeof(restart)); + 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); asm volatile( "0: sigp 0,%0,%2 # sigp restart to target cpu\n" " brc 2,0b # busy, try again\n" "1: sigp 0,%1,%3 # sigp stop to current cpu\n" " brc 2,1b # busy, try again\n" - : : "d" (pcpu->address), "d" (restart.source), + : : "d" (pcpu->address), "d" (source_cpu), "K" (SIGP_RESTART), "K" (SIGP_STOP) : "0", "1", "cc"); for (;;) ;