[PATCH] x86_64: Remove CONFIG_CHECKING and add command line option for pagefault...

[firefly-linux-kernel-4.4.55.git] / arch / x86_64 / mm / fault.c

diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index 816732d8858c3195c7b6d78419b2b0b537de3f10..3a63707a698ba34d954770d5a5a7b3016ac53c03 100644 (file)
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -221,12 +221,13 @@ int unhandled_signal(struct task_struct *tsk, int sig)
 static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
                                 unsigned long error_code)
 {
-       oops_begin();
+       unsigned long flags = oops_begin();
+
        printk(KERN_ALERT "%s: Corrupted page table at address %lx\n",
               current->comm, address);
        dump_pagetable(address);
        __die("Bad pagetable", regs, error_code);
-       oops_end();
+       oops_end(flags);
        do_exit(SIGKILL);
 }
 
@@ -304,20 +305,9 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
        unsigned long address;
        const struct exception_table_entry *fixup;
        int write;
+       unsigned long flags;
        siginfo_t info;
 
-#ifdef CONFIG_CHECKING
-       { 
-               unsigned long gs; 
-               struct x8664_pda *pda = cpu_pda + stack_smp_processor_id(); 
-               rdmsrl(MSR_GS_BASE, gs); 
-               if (gs != (unsigned long)pda) { 
-                       wrmsrl(MSR_GS_BASE, pda); 
-                       printk("page_fault: wrong gs %lx expected %p\n", gs, pda);
-               }
-       }
-#endif
-
        /* get the address */
        __asm__("movq %%cr2,%0":"=r" (address));
        if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
@@ -521,7 +511,7 @@ no_context:
  * terminate things with extreme prejudice.
  */
 
-       oops_begin(); 
+       flags = oops_begin();
 
        if (address < PAGE_SIZE)
                printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
@@ -534,7 +524,7 @@ no_context:
        __die("Oops", regs, error_code);
        /* Executive summary in case the body of the oops scrolled away */
        printk(KERN_EMERG "CR2: %016lx\n", address);
-       oops_end(); 
+       oops_end(flags);
        do_exit(SIGKILL);
 
 /*
@@ -569,3 +559,10 @@ do_sigbus:
        force_sig_info(SIGBUS, &info, tsk);
        return;
 }
+
+static int __init enable_pagefaulttrace(char *str)
+{
+       page_fault_trace = 1;
+       return 0;
+}
+__setup("pagefaulttrace", enable_pagefaulttrace);