From af0ebc40a81c694ad25f034383c13a233c4a2f55 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 7 Oct 2013 16:15:29 +0200 Subject: s390/mm,kvm: fix software dirty bits vs. kvm for old machines For machines without enhanced supression on protection the software dirty bit code forces the pte dirty bit and clears the page protection bit in pgste_set_pte. This is done for all pte types, the check for present ptes is missing. As a result swap ptes and other not-present ptes can get corrupted. Add a check for the _PAGE_PRESENT bit to pgste_set_pte before modifying the pte value. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 9b60a36c348..2204400d0bd 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -748,7 +748,9 @@ static inline void pgste_set_key(pte_t *ptep, pgste_t pgste, pte_t entry) static inline void pgste_set_pte(pte_t *ptep, pte_t entry) { - if (!MACHINE_HAS_ESOP && (pte_val(entry) & _PAGE_WRITE)) { + if (!MACHINE_HAS_ESOP && + (pte_val(entry) & _PAGE_PRESENT) && + (pte_val(entry) & _PAGE_WRITE)) { /* * Without enhanced suppression-on-protection force * the dirty bit on for all writable ptes. -- cgit v1.2.3-18-g5258 From 0ebfd313fd4baf3fa1bd02d5f106e377595d4987 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 14 Oct 2013 12:09:37 +0200 Subject: s390/compat,signal: fix return value of copy_siginfo_(to|from)_user32() The return value of copy_siginfo_(to|from)_user32() gets passed to user space, however we do not convert a positive return value from copy_(to|from)_user to -EFAULT. Therefore these functions (and the calling system calls) my incorrectly return a positive number (bytes not copied) instead of -EFAULT. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/compat_signal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c index 1389b637dae..adaa9e9478d 100644 --- a/arch/s390/kernel/compat_signal.c +++ b/arch/s390/kernel/compat_signal.c @@ -99,7 +99,7 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from) break; } } - return err; + return err ? -EFAULT : 0; } int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) @@ -148,7 +148,7 @@ int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from) break; } } - return err; + return err ? -EFAULT : 0; } static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs) -- cgit v1.2.3-18-g5258 From 8c071b0f19dfa230335d22ce56a8fab5bd20cedc Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 17 Oct 2013 12:38:17 +0200 Subject: s390/time: correct use of store clock fast The result of the store-clock-fast (STCKF) instruction is a bit fuzzy. It can happen that the value stored on one CPU is smaller than the value stored on another CPU, although the order of the stores is the other way around. This can cause deltas of get_tod_clock() values to become negative when they should not be. We need to be more careful with store-clock-fast, this patch partially reverts git commit e4b7b4238e666682555461fa52eecd74652f36bb "time: always use stckf instead of stck if available". The get_tod_clock() function now uses the store-clock-extended (STCKE) instruction. get_tod_clock_fast() can be used if the fuzziness of store-clock-fast is acceptable e.g. for wait loops local to a CPU. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/timex.h | 28 ++++++++++++++-------------- arch/s390/kernel/debug.c | 2 +- arch/s390/kvm/interrupt.c | 6 +++--- arch/s390/lib/delay.c | 14 +++++++------- 4 files changed, 25 insertions(+), 25 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h index 8ad8af91503..819b94d2272 100644 --- a/arch/s390/include/asm/timex.h +++ b/arch/s390/include/asm/timex.h @@ -71,30 +71,30 @@ static inline void local_tick_enable(unsigned long long comp) typedef unsigned long long cycles_t; -static inline unsigned long long get_tod_clock(void) -{ - unsigned long long clk; - -#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES - asm volatile(".insn s,0xb27c0000,%0" : "=Q" (clk) : : "cc"); -#else - asm volatile("stck %0" : "=Q" (clk) : : "cc"); -#endif - return clk; -} - static inline void get_tod_clock_ext(char *clk) { asm volatile("stcke %0" : "=Q" (*clk) : : "cc"); } -static inline unsigned long long get_tod_clock_xt(void) +static inline unsigned long long get_tod_clock(void) { unsigned char clk[16]; get_tod_clock_ext(clk); return *((unsigned long long *)&clk[1]); } +static inline unsigned long long get_tod_clock_fast(void) +{ +#ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES + unsigned long long clk; + + asm volatile("stckf %0" : "=Q" (clk) : : "cc"); + return clk; +#else + return get_tod_clock(); +#endif +} + static inline cycles_t get_cycles(void) { return (cycles_t) get_tod_clock() >> 2; @@ -125,7 +125,7 @@ extern u64 sched_clock_base_cc; */ static inline unsigned long long get_tod_clock_monotonic(void) { - return get_tod_clock_xt() - sched_clock_base_cc; + return get_tod_clock() - sched_clock_base_cc; } /** diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c index f1279dc2e1b..17d62fe5d7b 100644 --- a/arch/s390/kernel/debug.c +++ b/arch/s390/kernel/debug.c @@ -867,7 +867,7 @@ static inline void debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level, int exception) { - active->id.stck = get_tod_clock(); + active->id.stck = get_tod_clock_fast(); active->id.fields.cpuid = smp_processor_id(); active->caller = __builtin_return_address(0); active->id.fields.exception = exception; diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 7f35cb33e51..7f1f7ac5cf7 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -385,7 +385,7 @@ static int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) } if ((!rc) && (vcpu->arch.sie_block->ckc < - get_tod_clock() + vcpu->arch.sie_block->epoch)) { + get_tod_clock_fast() + vcpu->arch.sie_block->epoch)) { if ((!psw_extint_disabled(vcpu)) && (vcpu->arch.sie_block->gcr[0] & 0x800ul)) rc = 1; @@ -425,7 +425,7 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu) goto no_timer; } - now = get_tod_clock() + vcpu->arch.sie_block->epoch; + now = get_tod_clock_fast() + vcpu->arch.sie_block->epoch; if (vcpu->arch.sie_block->ckc < now) { __unset_cpu_idle(vcpu); return 0; @@ -515,7 +515,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu) } if ((vcpu->arch.sie_block->ckc < - get_tod_clock() + vcpu->arch.sie_block->epoch)) + get_tod_clock_fast() + vcpu->arch.sie_block->epoch)) __try_deliver_ckc_interrupt(vcpu); if (atomic_read(&fi->active)) { diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c index 57c87d7d7ed..a9f3d0042d5 100644 --- a/arch/s390/lib/delay.c +++ b/arch/s390/lib/delay.c @@ -44,7 +44,7 @@ static void __udelay_disabled(unsigned long long usecs) do { set_clock_comparator(end); vtime_stop_cpu(); - } while (get_tod_clock() < end); + } while (get_tod_clock_fast() < end); lockdep_on(); __ctl_load(cr0, 0, 0); __ctl_load(cr6, 6, 6); @@ -55,7 +55,7 @@ static void __udelay_enabled(unsigned long long usecs) { u64 clock_saved, end; - end = get_tod_clock() + (usecs << 12); + end = get_tod_clock_fast() + (usecs << 12); do { clock_saved = 0; if (end < S390_lowcore.clock_comparator) { @@ -65,7 +65,7 @@ static void __udelay_enabled(unsigned long long usecs) vtime_stop_cpu(); if (clock_saved) local_tick_enable(clock_saved); - } while (get_tod_clock() < end); + } while (get_tod_clock_fast() < end); } /* @@ -109,8 +109,8 @@ void udelay_simple(unsigned long long usecs) { u64 end; - end = get_tod_clock() + (usecs << 12); - while (get_tod_clock() < end) + end = get_tod_clock_fast() + (usecs << 12); + while (get_tod_clock_fast() < end) cpu_relax(); } @@ -120,10 +120,10 @@ void __ndelay(unsigned long long nsecs) nsecs <<= 9; do_div(nsecs, 125); - end = get_tod_clock() + nsecs; + end = get_tod_clock_fast() + nsecs; if (nsecs & ~0xfffUL) __udelay(nsecs >> 12); - while (get_tod_clock() < end) + while (get_tod_clock_fast() < end) barrier(); } EXPORT_SYMBOL(__ndelay); -- cgit v1.2.3-18-g5258