There are totally 7 bad_area[_nosemaphore] error branch in do_user_addr_fault().
Consolidate all these handling to the end to make the code a little neat. BTW, after doing so, function bad_area is not used any more. Remove it. Signed-off-by: Wei Yang <[email protected]> --- arch/x86/mm/fault.c | 44 ++++++++++++++++---------------------------- 1 file changed, 16 insertions(+), 28 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 9ceacd1156db..9d18b73b5f77 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -933,12 +933,6 @@ __bad_area(struct pt_regs *regs, unsigned long error_code, __bad_area_nosemaphore(regs, error_code, address, pkey, si_code); } -static noinline void -bad_area(struct pt_regs *regs, unsigned long error_code, unsigned long address) -{ - __bad_area(regs, error_code, address, 0, SEGV_MAPERR); -} - static inline bool bad_area_access_from_pkeys(unsigned long error_code, struct vm_area_struct *vma) { @@ -1313,19 +1307,14 @@ void do_user_addr_fault(struct pt_regs *regs, if (unlikely(cpu_feature_enabled(X86_FEATURE_SMAP) && !(hw_error_code & X86_PF_USER) && !(regs->flags & X86_EFLAGS_AC))) - { - bad_area_nosemaphore(regs, hw_error_code, address); - return; - } + goto bad_area_nosem; /* * If we're in an interrupt, have no user context or are running * in a region with pagefaults disabled then we must not take the fault */ - if (unlikely(faulthandler_disabled() || !mm)) { - bad_area_nosemaphore(regs, hw_error_code, address); - return; - } + if (unlikely(faulthandler_disabled() || !mm)) + goto bad_area_nosem; /* * It's safe to allow irq's after cr2 has been saved and the @@ -1385,8 +1374,7 @@ void do_user_addr_fault(struct pt_regs *regs, * Fault from code in kernel from * which we do not expect faults. */ - bad_area_nosemaphore(regs, hw_error_code, address); - return; + goto bad_area_nosem; } retry: down_read(&mm->mmap_sem); @@ -1400,20 +1388,14 @@ void do_user_addr_fault(struct pt_regs *regs, } vma = find_vma(mm, address); - if (unlikely(!vma)) { - bad_area(regs, hw_error_code, address); - return; - } + if (unlikely(!vma)) + goto bad_area; if (likely(vma->vm_start <= address)) goto good_area; - if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { - bad_area(regs, hw_error_code, address); - return; - } - if (unlikely(expand_stack(vma, address))) { - bad_area(regs, hw_error_code, address); - return; - } + if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) + goto bad_area; + if (unlikely(expand_stack(vma, address))) + goto bad_area; /* * Ok, we have a good vm_area for this memory access, so @@ -1483,6 +1465,12 @@ void do_user_addr_fault(struct pt_regs *regs, } check_v8086_mode(regs, address, tsk); + return; + +bad_area: + up_read(&mm->mmap_sem); +bad_area_nosem: + bad_area_nosemaphore(regs, hw_error_code, address); } NOKPROBE_SYMBOL(do_user_addr_fault); -- 2.17.1
