diff options
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 68 |
1 files changed, 65 insertions, 3 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index bb65a68b4b49..223b223f713f 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -671,7 +671,7 @@ void set_personality_64bit(void) task_pt_regs(current)->orig_ax = __NR_execve; current_thread_info()->status &= ~TS_COMPAT; if (current->mm) - current->mm->context.flags = MM_CONTEXT_HAS_VSYSCALL; + __set_bit(MM_CONTEXT_HAS_VSYSCALL, ¤t->mm->context.flags); /* TBD: overwrites user setup. Should have two bits. But 64bit processes have always behaved this way, @@ -708,7 +708,7 @@ static void __set_personality_ia32(void) * uprobes applied to this MM need to know this and * cannot use user_64bit_mode() at that time. */ - current->mm->context.flags = MM_CONTEXT_UPROBE_IA32; + __set_bit(MM_CONTEXT_UPROBE_IA32, ¤t->mm->context.flags); } current->personality |= force_personality32; @@ -743,6 +743,52 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr) } #endif +#ifdef CONFIG_ADDRESS_MASKING + +#define LAM_U57_BITS 6 + +static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits) +{ + if (!cpu_feature_enabled(X86_FEATURE_LAM)) + return -ENODEV; + + /* PTRACE_ARCH_PRCTL */ + if (current->mm != mm) + return -EINVAL; + + if (mm_valid_pasid(mm) && + !test_bit(MM_CONTEXT_FORCE_TAGGED_SVA, &mm->context.flags)) + return -EINVAL; + + if (mmap_write_lock_killable(mm)) + return -EINTR; + + if (test_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags)) { + mmap_write_unlock(mm); + return -EBUSY; + } + + if (!nr_bits) { + mmap_write_unlock(mm); + return -EINVAL; + } else if (nr_bits <= LAM_U57_BITS) { + mm->context.lam_cr3_mask = X86_CR3_LAM_U57; + mm->context.untag_mask = ~GENMASK(62, 57); + } else { + mmap_write_unlock(mm); + return -EINVAL; + } + + write_cr3(__read_cr3() | mm->context.lam_cr3_mask); + set_tlbstate_lam_mode(mm); + set_bit(MM_CONTEXT_LOCK_LAM, &mm->context.flags); + + mmap_write_unlock(mm); + + return 0; +} +#endif + long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2) { int ret = 0; @@ -830,7 +876,23 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2) case ARCH_MAP_VDSO_64: return prctl_map_vdso(&vdso_image_64, arg2); #endif - +#ifdef CONFIG_ADDRESS_MASKING + case ARCH_GET_UNTAG_MASK: + return put_user(task->mm->context.untag_mask, + (unsigned long __user *)arg2); + case ARCH_ENABLE_TAGGED_ADDR: + return prctl_enable_tagged_addr(task->mm, arg2); + case ARCH_FORCE_TAGGED_SVA: + if (current != task) + return -EINVAL; + set_bit(MM_CONTEXT_FORCE_TAGGED_SVA, &task->mm->context.flags); + return 0; + case ARCH_GET_MAX_TAG_BITS: + if (!cpu_feature_enabled(X86_FEATURE_LAM)) + return put_user(0, (unsigned long __user *)arg2); + else + return put_user(LAM_U57_BITS, (unsigned long __user *)arg2); +#endif default: ret = -EINVAL; break; |