import PULS_20160108

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / mm / fault.c

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 5dbf13f954f6f493aaae525d4f3b93282ac88f75..ce5f1130a13cae607d166c630003e4f4f1e67dd0 100644 (file)
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -19,6 +19,7 @@
 #include <linux/sched.h>
 #include <linux/highmem.h>
 #include <linux/perf_event.h>
+#include <linux/aee.h>
 
 #include <asm/exception.h>
 #include <asm/pgtable.h>
@@ -276,10 +277,10 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
                local_irq_enable();
 
        /*
-        * If we're in an interrupt or have no user
+        * If we're in an interrupt, or have no irqs, or have no user
         * context, we must not take the fault..
         */
-       if (in_atomic() || !mm)
+       if (in_atomic() || irqs_disabled() || !mm)
                goto no_context;
 
        /*
@@ -521,7 +522,7 @@ struct fsr_info {
 #include "fsr-2level.c"
 #endif
 
-void __init
+void 
 hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),
                int sig, int code, const char *name)
 {
@@ -533,6 +534,7 @@ hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *)
        fsr_info[nr].code = code;
        fsr_info[nr].name = name;
 }
+EXPORT_SYMBOL(hook_fault_code);
 
 /*
  * Dispatch a data abort to the relevant handler.
@@ -540,11 +542,37 @@ hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *)
 asmlinkage void __exception
 do_DataAbort(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
+       struct thread_info *thread = current_thread_info();
+       int ret;
        const struct fsr_info *inf = fsr_info + fsr_fs(fsr);
        struct siginfo info;
 
-       if (!inf->fn(addr, fsr & ~FSR_LNX_PF, regs))
+       if (!user_mode(regs)) {
+               thread->cpu_excp++;
+               if (thread->cpu_excp == 1) {
+                       thread->regs_on_excp = (void *)regs;
+                       aee_excp_regs = (void*)regs;
+               }
+               /*
+                * NoteXXX: The data abort exception may happen twice
+                *          when calling probe_kernel_address() in which.
+                *          __copy_from_user_inatomic() is used and the
+                *          fixup table lookup may be performed.
+                *          Check if the nested panic happens via 
+                *          (cpu_excp >= 3).
+                */
+               if (thread->cpu_excp >= 3) {
+                       aee_stop_nested_panic(regs);
+               }
+       }
+
+       ret = inf->fn(addr, fsr & ~FSR_LNX_PF, regs);
+       if (!ret) {
+               if (!user_mode(regs)) {
+                       thread->cpu_excp--;
+               }
                return;
+       }
 
        printk(KERN_ALERT "Unhandled fault: %s (0x%03x) at 0x%08lx\n",
                inf->name, fsr, addr);
@@ -572,11 +600,36 @@ hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *
 asmlinkage void __exception
 do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
 {
+       struct thread_info *thread = current_thread_info();
+       int ret;  
        const struct fsr_info *inf = ifsr_info + fsr_fs(ifsr);
        struct siginfo info;
 
-       if (!inf->fn(addr, ifsr | FSR_LNX_PF, regs))
+       if (!user_mode(regs)) {
+               thread->cpu_excp++;
+               if (thread->cpu_excp == 1) {
+                       thread->regs_on_excp = (void *)regs;
+               }
+               /*
+                * NoteXXX: The data abort exception may happen twice
+                *          when calling probe_kernel_address() in which.
+                *          __copy_from_user_inatomic() is used and the
+                *          fixup table lookup may be performed.
+                *          Check if the nested panic happens via 
+                *          (cpu_excp >= 3).
+                */
+               if (thread->cpu_excp >= 3) {
+                       aee_stop_nested_panic(regs);
+               }
+       }
+
+       ret = inf->fn(addr, ifsr | FSR_LNX_PF, regs);
+       if (!ret) {
+               if (!user_mode(regs)) {
+                       thread->cpu_excp--;
+               }
                return;
+       }
 
        printk(KERN_ALERT "Unhandled prefetch abort: %s (0x%03x) at 0x%08lx\n",
                inf->name, ifsr, addr);