diff options
Diffstat (limited to 'arch/x86/lib/insn-eval.c')
| -rw-r--r-- | arch/x86/lib/insn-eval.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 98631c0e7a11..4e385cbfd444 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -13,6 +13,7 @@ #include <asm/insn.h> #include <asm/insn-eval.h> #include <asm/ldt.h> +#include <asm/msr.h> #include <asm/vm86.h> #undef pr_fmt @@ -631,14 +632,21 @@ static bool get_desc(struct desc_struct *out, unsigned short sel) /* Bits [15:3] contain the index of the desired entry. */ sel >>= 3; - mutex_lock(¤t->active_mm->context.lock); - ldt = current->active_mm->context.ldt; + /* + * If we're not in a valid context with a real (not just lazy) + * user mm, then don't even try. + */ + if (!nmi_uaccess_okay()) + return false; + + mutex_lock(¤t->mm->context.lock); + ldt = current->mm->context.ldt; if (ldt && sel < ldt->nr_entries) { *out = ldt->entries[sel]; success = true; } - mutex_unlock(¤t->active_mm->context.lock); + mutex_unlock(¤t->mm->context.lock); return success; } @@ -702,16 +710,16 @@ unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx) unsigned long base; if (seg_reg_idx == INAT_SEG_REG_FS) { - rdmsrl(MSR_FS_BASE, base); + rdmsrq(MSR_FS_BASE, base); } else if (seg_reg_idx == INAT_SEG_REG_GS) { /* * swapgs was called at the kernel entry point. Thus, * MSR_KERNEL_GS_BASE will have the user-space GS base. */ if (user_mode(regs)) - rdmsrl(MSR_KERNEL_GS_BASE, base); + rdmsrq(MSR_KERNEL_GS_BASE, base); else - rdmsrl(MSR_GS_BASE, base); + rdmsrq(MSR_GS_BASE, base); } else { base = 0; } |