diff options
| -rw-r--r-- | arch/x86/mm/fault.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 6dea040cc3a..e7fa28bf326 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1022,11 +1022,11 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs) * routines. */ static void __kprobes -__do_page_fault(struct pt_regs *regs, unsigned long error_code) +__do_page_fault(struct pt_regs *regs, unsigned long error_code, + unsigned long address) { struct vm_area_struct *vma; struct task_struct *tsk; - unsigned long address; struct mm_struct *mm; int fault; unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; @@ -1034,9 +1034,6 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code) tsk = current; mm = tsk->mm; - /* Get the faulting address: */ - address = read_cr2(); - /* * Detect and handle instructions that would cause a page fault for * both a tracked kernel page and a userspace page. @@ -1252,9 +1249,11 @@ dotraplinkage void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) { enum ctx_state prev_state; + /* Get the faulting address: */ + unsigned long address = read_cr2(); prev_state = exception_enter(); - __do_page_fault(regs, error_code); + __do_page_fault(regs, error_code, address); exception_exit(prev_state); } @@ -1271,9 +1270,16 @@ dotraplinkage void __kprobes trace_do_page_fault(struct pt_regs *regs, unsigned long error_code) { enum ctx_state prev_state; + /* + * The exception_enter and tracepoint processing could + * trigger another page faults (user space callchain + * reading) and destroy the original cr2 value, so read + * the faulting address now. + */ + unsigned long address = read_cr2(); prev_state = exception_enter(); trace_page_fault_entries(regs, error_code); - __do_page_fault(regs, error_code); + __do_page_fault(regs, error_code, address); exception_exit(prev_state); } |