diff options
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/fpu/api.h | 34 | ||||
| -rw-r--r-- | arch/s390/kernel/compat_signal.c | 4 | ||||
| -rw-r--r-- | arch/s390/kernel/fpu.c | 4 | ||||
| -rw-r--r-- | arch/s390/kernel/ptrace.c | 13 | ||||
| -rw-r--r-- | arch/s390/kernel/signal.c | 4 | ||||
| -rw-r--r-- | arch/s390/kernel/vmlinux.lds.S | 1 | ||||
| -rw-r--r-- | arch/s390/kvm/kvm-s390.c | 5 |
7 files changed, 29 insertions, 36 deletions
diff --git a/arch/s390/include/asm/fpu/api.h b/arch/s390/include/asm/fpu/api.h index b714ed0ef688..dc34de234ed7 100644 --- a/arch/s390/include/asm/fpu/api.h +++ b/arch/s390/include/asm/fpu/api.h @@ -51,21 +51,27 @@ void save_fpu_regs(void); void load_fpu_regs(void); void __load_fpu_regs(void); -static inline int test_fp_ctl(u32 fpc) +/** + * sfpc_safe - Set floating point control register safely. + * @fpc: new value for floating point control register + * + * Set floating point control register. This may lead to an exception, + * since a saved value may have been modified by user space (ptrace, + * signal return, kvm registers) to an invalid value. In such a case + * set the floating point control register to zero. + */ +static inline void sfpc_safe(u32 fpc) { - u32 orig_fpc; - int rc; - - asm volatile( - " efpc %1\n" - " sfpc %2\n" - "0: sfpc %1\n" - " la %0,0\n" - "1:\n" - EX_TABLE(0b,1b) - : "=d" (rc), "=&d" (orig_fpc) - : "d" (fpc), "0" (-EINVAL)); - return rc; + asm volatile("\n" + "0: sfpc %[fpc]\n" + "1: nopr %%r7\n" + ".pushsection .fixup, \"ax\"\n" + "2: lghi %[fpc],0\n" + " jg 0b\n" + ".popsection\n" + EX_TABLE(1b, 2b) + : [fpc] "+d" (fpc) + : : "memory"); } #define KERNEL_FPC 1 diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c index cecedd01d4ec..8b90bf89b62c 100644 --- a/arch/s390/kernel/compat_signal.c +++ b/arch/s390/kernel/compat_signal.c @@ -98,10 +98,6 @@ static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs) if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI)) return -EINVAL; - /* Test the floating-point-control word. */ - if (test_fp_ctl(user_sregs.fpregs.fpc)) - return -EINVAL; - /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */ regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) | (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 | diff --git a/arch/s390/kernel/fpu.c b/arch/s390/kernel/fpu.c index 4666b29ac8a1..35aaf99bab16 100644 --- a/arch/s390/kernel/fpu.c +++ b/arch/s390/kernel/fpu.c @@ -177,10 +177,10 @@ EXPORT_SYMBOL(__kernel_fpu_end); void __load_fpu_regs(void) { - struct fpu *state = ¤t->thread.fpu; unsigned long *regs = current->thread.fpu.regs; + struct fpu *state = ¤t->thread.fpu; - asm volatile("lfpc %0" : : "Q" (state->fpc)); + sfpc_safe(state->fpc); if (likely(MACHINE_HAS_VX)) { asm volatile("lgr 1,%0\n" "VLM 0,15,0,1\n" diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index c7ed302a6b59..df2ee1b88024 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -392,9 +392,7 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data) /* * floating point control reg. is in the thread structure */ - save_fpu_regs(); - if ((unsigned int) data != 0 || - test_fp_ctl(data >> (BITS_PER_LONG - 32))) + if ((unsigned int)data != 0) return -EINVAL; child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32); @@ -749,9 +747,6 @@ static int __poke_user_compat(struct task_struct *child, /* * floating point control reg. is in the thread structure */ - save_fpu_regs(); - if (test_fp_ctl(tmp)) - return -EINVAL; child->thread.fpu.fpc = data; } else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) { @@ -913,7 +908,9 @@ static int s390_fpregs_set(struct task_struct *target, int rc = 0; freg_t fprs[__NUM_FPRS]; - save_fpu_regs(); + if (target == current) + save_fpu_regs(); + if (MACHINE_HAS_VX) convert_vx_to_fp(fprs, target->thread.fpu.vxrs); else @@ -926,7 +923,7 @@ static int s390_fpregs_set(struct task_struct *target, 0, offsetof(s390_fp_regs, fprs)); if (rc) return rc; - if (ufpc[1] != 0 || test_fp_ctl(ufpc[0])) + if (ufpc[1] != 0) return -EINVAL; target->thread.fpu.fpc = ufpc[0]; } diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c index d63557d3868c..0e926e896808 100644 --- a/arch/s390/kernel/signal.c +++ b/arch/s390/kernel/signal.c @@ -149,10 +149,6 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs) if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW_MASK_RI)) return -EINVAL; - /* Test the floating-point-control word. */ - if (test_fp_ctl(user_sregs.fpregs.fpc)) - return -EINVAL; - /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */ regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) | (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI)); diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S index 2ae201ebf90b..e32ef446f451 100644 --- a/arch/s390/kernel/vmlinux.lds.S +++ b/arch/s390/kernel/vmlinux.lds.S @@ -52,6 +52,7 @@ SECTIONS SOFTIRQENTRY_TEXT FTRACE_HOTPATCH_TRAMPOLINES_TEXT *(.text.*_indirect_*) + *(.fixup) *(.gnu.warning) . = ALIGN(PAGE_SIZE); _etext = .; /* End of text section */ diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 1a1af4db5afc..432688acc523 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -4962,10 +4962,7 @@ static void sync_regs(struct kvm_vcpu *vcpu) current->thread.fpu.regs = vcpu->run->s.regs.vrs; else current->thread.fpu.regs = vcpu->run->s.regs.fprs; - current->thread.fpu.fpc = READ_ONCE(vcpu->run->s.regs.fpc); - if (test_fp_ctl(current->thread.fpu.fpc)) - /* User space provided an invalid FPC, let's clear it */ - current->thread.fpu.fpc = 0; + current->thread.fpu.fpc = vcpu->run->s.regs.fpc; /* Sync fmt2 only data */ if (likely(!kvm_s390_pv_cpu_is_protected(vcpu))) { |